An outline of the palaeogeographic evolution of the Australasian region since the beginning of the Neoproterozoic

An outline of the palaeogeographic evolution of the Australasian region since the beginning of the Neoproterozoic

Earth-Science Reviews 53 Ž2001. 237–277 www.elsevier.comrlocaterearscirev An outline of the palaeogeographic evolution of the Australasian region sin...

3MB Sizes 2 Downloads 30 Views

Earth-Science Reviews 53 Ž2001. 237–277 www.elsevier.comrlocaterearscirev

An outline of the palaeogeographic evolution of the Australasian region since the beginning of the Neoproterozoic Z.X. Li ) , C.McA. Powell Tectonics Special Research Centre, Department of Geology and Geophysics, The UniÕersity of Western Australia, Nedlands, Perth, WA 6907, Australia Received 31 May 2000; accepted 26 June 2000

Abstract In the last 1000 million years, Australia has been part of two supercontinents: Palaeozoic Gondwanaland and Neoproterozoic Rodinia. Neoproterozoic Australia was covered by shallow epicontinental seas, and, in the late Neoproterozoic, by low-latitude glaciers. The breakup of Rodinia along the Tasman Line occurred at the end of the Sturtian glaciation Ž760 Ma. giving rise to the Palaeo-Pacific Ocean. Gondwanaland formed in the Early Cambrian, at the same time as the Tarim block broke away from northwestern Australia. Westward subduction of the Palaeo-Pacific Ocean along the eastern margin of Australia–Antarctica commenced during the Early Cambrian in northern Victoria Land and in the Middle Cambrian in South Australia, and culminated to the Late Cambrian–Early Ordovician Ross–Delamerian Mountains. In the Ordovician, the magmatic arc retreated from Australia’s then-eastern continental margin, forming a marginal sea and offshore island arc. A shallow seaway across Australia in the Late Cambrian and Ordovician gradually gave way to desert-like conditions in Central Australia and the adjacent Canning Basin by Silurian time. The Silurian to mid-Devonian was an interval of rapidly changing palaeogeography in eastern Australia with deep volcanogenic troughs formed in a dextral transtensional tectonic setting. Widespread deformation in the Tasman orogenic zone in the Middle Devonian to Early Carboniferous, was accompanied by the development of an Andean-style magmatic arc along the Pacific continental margin of Australia. The most widespread Phanerozoic mountain-building stage in Central Australia occurred in the Late Devonian to mid-Carboniferous, as part of a world-wide Variscan orogenic episode associated with the collision of Gondwanaland with Laurussia to form Pangea. In the late Visean, Australia drifted rapidly southward from previous low latitudes to a near-polar position. Glacial conditions dominated the Late Carboniferous and earliest Permian. Transtensional basins associated with dextral oroclinal shear along the Panthalassan eastern margin of Australia developed in the Late Carboniferous and persisted until the Late Permian, when an Andean-style magmatic arc was re-established. Large foreland basins inboard of the Late Permian to Early Triassic magmatic arc accumulated major coal deposits during Late Permian volcanic phases, but drastic climatic changes at the end of the Permian, possibly caused by global greenhouse conditions, led to red-bed deposition in the Early Triassic.

)

Corresponding author. Tel.: q61-8-9380-2652; fax: q61-8-9380-1090. E-mail addresses: [email protected] ŽZ.X. Li., [email protected] ŽC.McA. Powell.. 1 Tel.: q61-8-9380-2778; fax: q61-8-9380-1090.

0012-8252r01r$ - see front matter q 2001 Elsevier Science B.V. All rights reserved. PII: S 0 0 1 2 - 8 2 5 2 Ž 0 0 . 0 0 0 2 1 - 0

238

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Pangea began to rift in the mid-Triassic, and by the Late Triassic, the Cimmerian blocks, which lay off northwestern Australia throughout the Palaeozoic, had departed the northern margin of Gondwanaland. A new Andean-style continental magmatic arc became established along the Pacific Ocean margin of Australia. Breakup between Australia–Antarctica and the northern part of Greater India commenced ca. 130 Ma, and between Australia and Antarctica around 96 Ma. At the beginning of the Palaeogene, Australia commenced its northward drift towards its present position. Seafloor spreading between Australia and Antarctica was at first slow, but increased to ca. 5 cm per year around 45 Ma. By 35 Ma, the circum-Antarctic current became established, thereby triggering glaciation in Antarctica. Northern Australia reached the tropics by the beginning of the Miocene, and Australia has progressively moved northwards at 7 to 8 cm per year since. q 2001 Elsevier Science B.V. All rights reserved. Keywords: Australasia; Gondwanaland; palaeogeography; Rodinia; Neoproterozoic; Phanerozoic

1. Introduction Putting a continent in its correct palaeogeographic position is crucial for a proper understanding of its geological record such as its basin history, mountain building events, magmatic activity, fauna and flora, and its geophysical and geochemical characteristics. However, how AcorrectB a palaeogeographic reconstruction can be made depends on how much of the geological record we know, how it is used, and how well it explains new information that becomes available. The process is cyclic. For any given group of continents at a particular geological time, there is normally a number of competing reconstructions, each having its merits. However, consensus can be reached where there is sufficient information available, as in the case regarding the configuration and evolution of Gondwanaland. In this paper, we provide a set of palaeogeographic reconstructions for the Australasian region based on current palaeomagnetic and geological information. Each palaeogeographic reconstruction comprises a global view of the setting of Australia: the upper one or two global maps show the palaeogeography of the hemisphere of which Australasia is part, and the lower map is an enlarged Australia-centred map showing the main palaeogeographic elements. We hope these maps will serve a dual purpose in that they can be used as base maps on which others can plot information to facilitate data interpretation, and in that others can test these reconstructions using the particular information they have. We have structured the paper around four major time intervals: the late Mesoproterozoic and Neoproterozoic, which records the formation and later breakup of the Rodinia supercontinent, the Cambrian

to Early Permian which records the formation of Gondwanaland and Pangaea, the Late Permian to Middle Jurassic when Australia was part of Pangea and then Gondwanaland, and the Late Jurassic to Recent which records the breakup of Gondwanaland and formation of the modern continental margins of Australia. Palaeomagnetic and geological information is discussed only briefly; readers are referred to the primary literature referenced for more details. The boundaries and present locations of the major continental elements referred to in the text are shown in Fig. 1. In the account below we have concentrated on a map view of the major tectonic events that have shaped Australia in the past 1 billion years, with sources and supporting details being given briefly in the figure captions. Palaeolatitudes are derived from sources indicated in tables and apparent polar wander paths ŽAPWPs..

2. Late Mesoproterozoic to Neoproterozoic 2.1. Australia in Rodinia The similarities between the Neoproterozoic rift successions in the Adelaide Fold Belt of southeastern Australia and western Laurentia Že.g. Bond et al., 1984; Bell and Jefferson, 1987., and in South China Že.g. Eisbacher, 1985., have long been recognised, and interpreted as representing formerly contiguous regions in a late Precambrian supercontinent. However, views about the shape of such a supercontinent varied greatly until the development of the ‘SWEAT’ ŽSouthwest U.S.–East Antarctica. hypothesis by Moores Ž1991., Dalziel Ž1991. and Hoffman Ž1991.,

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

239

Fig. 1. Mercator map showing the major continental elements discussed in this paper.

which suggested that East Gondwanaland was connected with Laurentia along the Transantarctic Mountains–East Australian margin from as early as ca. 1.9 Ga until the late Precambrian. Together with most Žif not all. of the other continental fragments, this supercontinent has been named Rodinia from the Russian word AroditB meaning to beget or to grow. McMenamin and McMenamin Ž1990. considered Rodinia as the supercontinent that Abegat all subsequent continents, and the edges Žcontinental shelves.

were the cradle of the earliest animalsB. Fig. 2 shows a version of Rodinia modified after Li et al. Ž1995, 1996.. The major differences between this configuration, and the SWEAT ŽMoores, 1991. and AUSWUS ŽAustralia–Southwest U.S.. Že.g. Karlstrom et al., 1999; Burrett and Berry, 2000. models, are: Ž1. the Yangtze ŽY. and Cathaysia ŽC. blocks of South China lie between Australia and Laurentia–Siberia; Ž2. the North China Žor Sino-Korea. Block lies adjacent to Siberia but facing Baltica; and Ž3. the Tarim

240

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 2. Ža. Rodinia Žafter Li et al., 1995, 1996.. Easternmost Madagascar and Arabia are interpreted to be part of the India–Australia– Antarctica block and South China is interpreted to have lain between eastern Australia and Laurentia. Palaeolatitude according to the 1050 Ma pole of Australia ŽTable 2.. Individual South American and African blocks are not distinguished because of uncertainty about their location in Rodinia. Possible Rodinian assembly suture zones are distinguished from other fold belts reactivated during the late Mesoproterozoic by red lines. B ŽBelt Basin., Y ŽYangtze Block.. Žb. Late Mesoproterozoic orogenic belts in Australia and adjacent parts of Rodinia. P ŽPinjarra., A ŽAlbany., F ŽFraser., M ŽMusgrave., R ŽRudall. and Y ŽYampi. in Australia; EG ŽEastern Ghats. in India; S ŽSibao. in South China. LB in Siberia is Lake Baikal. In this and succeeding maps, oranges emergent continent above sea level today, pale yellows emergent continent below sealevel today, deep yellows terrestrial sedimentary basin, purples mafic volcanic rocks, bright blue s shallow marine, pale blue s continental ice cover, pale greyish blue s oceanic area, green s fold belt, mauves submarine turbidite fan. Grey is used for continental areas for which no palaeogeography is shown: dark grey s above sealevel today, light grey s undifferentiated above and below sealevel. Filled D are glacial deposits, brick tile s carbonate platform, inverted red Vs s volcanic island arc, red cones are Andean-style magmatic arc, hatched red lines are normal faults Žteeth on down-faulted side., arrows are palaeocurrent directions, barbed red lines mark thrust zones Žteeth on overthrust side., barbed maroon lines mark subduction zones Žteeth on overriding side..

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Block of northwestern China is adjacent to the Cimmerian blocks and northwestern Australia. We note that the Rodinia of McMenamin and McMenamin Ž1990. is different from these configurations, and more like the possible younger supercontinent, Pannotia, that might have existed at the end of the Precambrian Žsee below.. There is some disagreement as to when the SWEAT connection began. Hoffman Ž1991. suggested that the SWEAT connection might have started as early as ca. 1.9 Ga. If this were the case, it would imply that a Gondwana-size supercontinent, including East Gondwanaland, Laurentia, Siberia and possibly North China ŽLi et al., 1996., existed for 900 Ma before it was joined by the African and South American cratons, and Baltica, around ca. 1.0 Ga, for another 250 Ma. Such a long-lived Ž; 1200 Ma. supercontinent would have profound implications for the geodynamic system in the Earth’s early history. Li Ž1997a,b. presented a possible alternative in which the SWEAT connection did not begin until Laurentia and East Gondwanaland were sutured around 1 Ga on the following bases: Ž1. The 1.6–1.9 Ga and 1.0–1.5 Ga basement provinces underlying the Neoproterozoic Transantarctic Mountains ŽTM. rift margin truncate the Archaean–Mesoproterozoic basement provinces in Laurentia ŽBorg and DePaolo, 1994.. Evidence for the allochthonous origin of these terranes is tenuous, and removing these terranes from their present location would also take away the Neoproterozoic rifting successions, which are used to supporting the SWEAT hypothesis. Ž2. Detrital zircon grains in the Neoproterozoic successions along the TM are dominantly of 1.0–1.2 Ga ages, and the age spectrum of the total zircon population suggests that Laurentia is an unlikely origin ŽWalker, 1996.. Ž3. Sedimentary provenance study of the Belt Supergroup in the Belt Basin requires a western source region with 1.0–1.2 Ga crustal materials ŽRoss et al., 1992.. Ž4. No 1.3–1.5 Ga granites, which are widespread in the ATranscontinental Proterozoic provinceB of southern Laurentia, have been reported in the corresponding provinces in East Antarctica. The AUSWUS model of Karlstrom et al. Ž1999. provides an alternative view of the relationship be-

241

tween Australia and Laurentia in Rodinia. In their view, the southwest-trending late Paleoproterozoic Yavapai and early Mesoproterozoic Mazatzal provinces of Laurentia were continuous with the Arunta and Musgrave Provinces of Australia, which thus placed the then-eastern margin of Australia adjacent to the southwestern USA part of Laurentia. In this model, the SWEAT connection of Moores Ž1991. does not exist, and Antarctica is displaced southward with respect to Laurentia to face an unknown continent outboard of the eastern margin of Laurentia in Rodinia. To the north of Australia, the AUSWUS model for Rodinia has several thousand kilometers of late Neoproterozoic rift margin in Laurentia for which there is also no known counterpart. Multi-disciplinary investigations are required to test competing Rodinia models further. The sparse palaeomagnetic data are consistent with the original SWEAT connection of Laurentia to Australia ŽPowell et al., 1993a, updated by Li, 2000 and Wingate and Giddings, 2000., and we have used this model in our reconstructions. The distribution of early Neoproterozoic rocks in Australia can be related to the Centralian Superbasin ŽWalter et al., 1995., a large sedimentary epicontinental basin that overlaps all the late Mesoproterozoic sutures ŽPowell et al., 1994.. The Centralian Superbasin contains four supersequences ŽWalter and Veevers, 1997., the first of which was deposited prior to the breakup of Rodinia ŽPowell et al., 1994; Walter et al., 1995.. Deposition could have commenced as early as 840 Ma ŽWalter et al., 2000. with quartzose, locally feldspathic, arenite mantling the old Rodinian sutures ŽHeavitree Quartzite in Central Australia., and passing upward into evaporitic carbonate ŽBitter Springs Formation in Central Australia.. The Centralian Superbasin extended onto all the major older Precambrian cratons in Australia demonstrating the integrity of Australia by that time. Possible extensions of the Centralian Superbasin in Laurentia could be the Succession ABB of the Mackenzie Mountains and Windermere Supergroups ŽRainbird et al., 1996.. 2.2. Breakup of Rodinia Palaeomagnetic results from East Gondwanaland and Laurentia are compatible with the existence of

242

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Rodinia during the ca. 1100–760 Ma interval ŽLi, 2000; Wingate and Giddings, 2000. ŽFigs. 3 and 4., but not for the Vendian and younger time ŽFig. 5a.. The latter conclusion contradicts some suggestions, based mainly on stratigraphic analysis Že.g. Bond et al., 1984; Veevers et al., 1997., which prefer a 550–560 Ma age for the supercontinent breakup. As shown in Fig. 3, palaeomagnetic poles from Australia and Laurentia are incompatible with a SWEAT connection after the Sturtian glaciation interval Žca. 770–750 Ma., indicating that the younger breakup recognized on stratigraphic grounds is after the separation of Australia from Laurentia. Indeed, Australia remained in intermediate to low northerly latitudes throughout the Neoproterozoic while Laurentia had moved to a southerly polar position by the Vendian ŽFig. 5a.. Continental rifting that led to the breakup of Rodinia was probably initiated by a ca. 830 Ma mantle plume Že.g. Park et al., 1995; Wingate et al., 1998; Li et al., 1999.. The separation of Australia–Antarctica and Laurentia is marked by the second supersequence of the Centralian Superbasin, which begins with the Sturtian tillite. During the rifting stage preceding breakup,

mafic volcanic and syn-rift sediments were deposited in the Adelaide region and along the western margin of Laurentia. In Australia, the rift–drift transition is recorded in the transgressive clastic blanket overlying the rift deposits and fining upward to mudrock of the Tapley Hill Formation, which in turn passes upward into carbonate, siltstone and shale. In western Laurentia, a similar rift–drift transition can be inferred in the lower Windermere Supergroup where the glacigenic Rapitan Group was deposited in rift valleys, and passes upward into the overlying mudrock, with minor sandstone and carbonate, of the Twitya and Keele Formations ŽRoss, 1991, Young, 1992, 1995.. We interpret this rift–drift transition to mark the birth of the Palaeo-Pacific Ocean ŽPowell et al., 1994; Preiss, 2000.. Recent palaeomagnetic results Žsee summary in Evans et al., 2000. also indicate that Rodinia breakup could have started by Sturtian time. Australia lay just north of the tropics during the Sturtian glaciation, with the possible coeval Walsh Tillite in southern Kimberley on a palaeolatitude of 45 " 128N ŽLi, 2000., but the correlative Rapitan glaciation occurred at tropical latitudes ŽPark, 1997. ŽFig. 4b..

Fig. 3. Latest Mesoproterozoic to Cambrian apparent polar wander paths of East Gondwanaland Žorange with black dots and numbers. and Laurentia Žgreen with yellow squares. rotated to their postulated Rodinia configuration. Note the coincidence of the palaeomagnetic poles for ca. 1100 and 760 Ma for both continental blocks, and their marked separation by the Vendian Žca. 600 Ma., which demonstrates that the Rodinian configuration was permissible from 1100 to ca. 760 Ma, but had broken up before the Vendian, possibly as early as 755 Ma. Laurentia and its poles were rotated to present day Australia by 1278 clockwise around Ž358N, 1358E. Žafter Powell et al., 1993a.. IAR s Mt Isa dykes ŽTanaka and Idnurm, 1994.; KD s Kulgera dike swarm ŽCamacho et al., 1991.; YB s YB dykes of western Yilgarn Craton ŽGiddings, 1976.; WTC s Acap dolomiteB of the Walsh Tillite ŽLi, 2000.; MDS s Combined NDD and Mundine Well dyke swarm data ŽEmbleton and Schmidt, 1996; Wingate and Giddings, 2000.; Vendian, 540 and 510 Ma poles are mean poles from Li Ž2000, Table 2..

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

243

Fig. 4. Ža. Mid-Neoproterozoic breakup of Rodinia around 760 Ma. Palaeolatitude according to the 760 Ma pole of Australia ŽTable 2.. Žb. Pattern of rifting in Australia, South China, and western Laurentia, associated with the ca. 760 Ma breakup of Rodinia. Rift orientations in Australia from Powell Ž1996., in South China from Li et al. Ž1995., and in western Laurentia interpreted by Powell from isopach and lithological patterns in Stewart Ž1972..

The second glacial episode forms the base of supersequence 3 in the Centralian Superbasin, and is marked by the Marinoan deposits in Australia, the Ice Brook Formation in western Laurentia and possibly by the Varangian glacial rocks in Baltica. Based on a possible age for the Varangian glacial rocks of

610–600 Ma ŽKnoll and Walter, 1992., supersequence 3 is inferred to have been deposited between 610 and 580 Ma ŽWalter et al., 1994.. The youngest supersequence in the Centralian Superbasin contains the Ediacara fauna, and is capped by an unconformityrdisconformity at the Precam-

244

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

brian boundary. This unconformity can be correlated with a similar unconformity at the top of the Windermere Group in western Laurentia ŽRoss, 1991., which

we interpret as representing minor plate reorganisation accompanying the latest Precambrian breakup along the eastern Laurentian margin. We discount

Fig. 5. Ža. Vendian reconstruction Ž; 600 Ma. showing wide Palaeo-Pacific Ocean, and the beginning of continental separation between North China block and Laurentia. Tasmania, which has no record of the Marinoan glaciation, could have been separated from the Australia–Antarctic margin as part of the continental ribbon extending equatorward from the South China block. Rifting also began between east Laurentia and the South American blocks that lay to the east, though breakup did not occur until ; 550 Ma, which is approximately the same time as the inferred breakup of Siberia from Laurentia Žsee Pelechaty, 1996.. Palaeopoles used are: 600 Ma pole for East Gondwanaland ŽTable 2., and 580 Ma pole for Laurentia ŽPowell et al., 1993a, Table 2.. Žb. Vendian palaeogeography of Australasia, showing the extent of the Marinoan glacial rocks. Arrows indicate direction of grounded ice transport interpreted from striated pavements.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

the suggestion by Veevers et al. Ž1997. that the latest Precambrian unconformity represents the breakup of the Australian margin of Rodinia because, apart from the palaeomagnetic evidence outlined above, there is a major space problem if Veevers et al.’s reconstruction is considered at a global scale. The problem is that Laurentia is interpreted by most people to have occupied a different position on the other side of the globe during the assembly of Gondwanaland at the end of the Precambrian. No matter whether the eastern margin of Laurentia is placed adjacent to the Rio de la Plata and Amazonia cratons ŽDalziel, 1997. or Amazonia and Baltica ŽHoffman, 1991., there are many thousands of kilometres between a position adjacent to western Gondwanaland and the Veevers et al. Ž1997. position off eastern Australia. We interpret the widespread latest Precambrian rifting event to represent the breakup between eastern Laurentia and its fellow travellers, between northern Laurentia and Siberia, and between the Tarim Block and northwestern Australia, after the birth of the Palaeo-Pacific Ocean around 750 Ma Žcf. Figs. 4a and 5a..

3. Cambrian to Early Permian

3.1. Formation of Gondwanaland The breakup of Rodinia during the late Neoproterozoic turned Gondwanan continents Ainside-outB, and led to the formation of Gondwanaland in the Cambrian Že.g. Hoffman, 1991; Unrug, 1997.. Palaeomagnetic APWPs for six of the major Gondwanan continental blocks shown in the Gondwanaland framework show that the most crucial data on the timing of formation of Gondwanaland come from Australia and Africa ŽTable 1, Fig. 6.. Earlier palaeomagnetic analysis had suggested that Gondwanaland was formed by the end of the Cambrian Že.g. McWilliams, 1981; Li and Powell, 1993., but recent dating of the Ntonya Ring Complex in eastern Africa at 522 " 13 Ma ŽBriden et al., 1993., which gives a pole position Žpole NR in Fig. 6e. concordant with the contemporaneous East Gondwanan results

245

Žpoles BWA and LFG 1 and 2 in Fig. 6a. brings the time by which Gondwanaland had assembled to just before the end of the Early Cambrian Žca. 520 Ma.. Whether Gondwanaland existed even earlier is debatable. Geological evidence is equivocal: the Mozambique Belt, which is considered the main suture between East Gondwanaland and the Congo block of Africa, has widespread granulite metamorphism and granite generation in the 580 to 550 Ma interval, with cooling events continuing to 500 Ma Ždata summarised in Grunow et al., 1996.. On the southwestern margin of the Congo block, stratigraphic and sedimentological evidence suggests that the Congo and Kalahari blocks may not have been sutured until ca. 550 Ma ŽPrave, 1996.. To the west of the Sao Francisco–Congo block, the Rio de la Plata block may have sutured with the Congo before 600 Ma ŽPrave, 1996., and there is evidence in the Brazilide orogenic belt between the Rio de la Plata– Sao Francisco block and Amazonia, of convergence and oceanfloor subduction in the late Neoproterozoic, possibly leading to continental collision around 600 Ma ŽPimentel and Fuck, 1992; Trompette, 1994.. Li and Powell Ž1993. argued that since the pole from the ca. 550–560 Ma Mulden Group in southern Congo craton ŽMcWilliams and Kroner, 1981; pole ¨ DM in Fig. 6e. lies clearly away from the coeval pole from East Gondwana, Gondwanaland could not have existed then. However, Meert and Van der Voo Ž1996. reported an 547 " 4 Ma pole Žpole SD in Fig. 6e. from the Sinyai metadolerite in Kenya, which agrees with the East Gondwanan pole, and they thus argued that Gondwanaland was assembled before ca. 550 Ma. More data from Africa are required to test the two interpretations. Moreover, even if the Congo–San Francisco–Rio de la Plata blocks are shown to have amalgamated with East Gondwanaland by the end of the Neoproterozoic, the issue of whether Amazonia was part of Gondwanaland at that time needs to be tested. It is possible that Amazonia was still attached to Laurentia up to 550 Ma, and that breakup of Amazonia from the Laurentian margin at the end of the Neoproterozoic pre-dated final closure of the Brazilide Ocean ŽGrunow et al., 1996.. Gondwanaland would thus not have finally assembled until later, possibly in the late Early Cambrian. A related issue is whether there was a short-lived supercontinent, named Pannotia by Powell ŽPowell

246

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Table 1 Selected Palaeozoic palaeomagnetic poles from Gondwanan continents Rock formation

Pole name

Age ŽMa.

Plat Ž8N.

Plong Ž8E.

DPr A 95 Ž8.

DM Ž8.

Q

ReferencerGPMDB result no a

Southeast Australia Dundee Ignimbrite Dundee Rhyodacite Upper Marine latites Kiah Limestone OP Werrie Basalt Overprint NE Queensland

DI DDR UM KL WB NQO

P2 –Tr1 P2 Ž247. P2 P2 P C 2 –P1

y36.9 y25.8 y44 y38.0 y57.2 y42.1

154.8 136.3 132 162.3 170.3 135.9

7 12 7 10.0 20.2 14.7

7 13

B C C C B C

Featherbed ; 280Ma

FBA

C 2 –P1

y43.5

129.9

6

7

C

2566 2566 995 2973 2973 After Klootwijk and Gidings Ž1993. Klootwijk and Giddings Ž1993.

Volcanic Field ; 290 Ma ; 305 Ma Rocky Creek Conglomerate Main Glacial Stage Dotswood redbeds Hervey Group Worange Point Formation Comerong Volcanics Snowy River Volcanics Silurian volcanics Compilation Compilation Stony Point redbeds

FBD FBC RC MG DR HG WP CV SRV SV G3 G2 SP

C 2 –P1 C 2 –P1 C2 C2 C 2? D3 D3 D 2 –D 3 D1 S 2 –S 3 S 2 –S 3 S1 –S 2 E3

y40.1 y45.6 y52 y53 y46.1 y54.4 y67.9 y76.9 y74.3 y54 y47.3 y38.2 y19.4

145.4 17.2 138 148 135.6 24.1 28.6 330.7 222.7 271 357.5 34.6 28.9

10 9 17 11

10 11

C C A A C B B B A C C C C

MPO KDO EL1 EL2 MES BC CB1 CB2 HS ME BOP1 BH JF TS BM LFG2 LFG1 AS BWA

P–C ; 320 ; 320 ; 320 Visean latest D D3 D3 D 2 –D 3 S–D1 S? 490–486 O1 SrO? –CrO –C2 –C2 –C2 mid-–C

y45.9 y30 y33.8 y32.1 y37.6 y47.1 y49.1 y62.0 y61.0 y15.7 y57.2 y37.5 y13 y26.7 3.1 y31.4 y16 y32.5 y37.4

149.5 138 121.2 119.5 52.6 41.0 38.0 23.2 0.9 242.7 359.3 34.4 25 33.7 54.1 26.9 25 11.5 20.1

12.8 24 19.2 11.9 8.7 6.4 4.7 14.6 15.6 23.7 11.5 3.2 11 2 7.4 5.1 12.5 5.1 7.2

KI

–C1

y33.8

15.1

HKG TAE

–C1 –C1

y26.7 y43.2

AD

–C1

y37.8

Cratonic Australia Mt Painter Mean OP Kulgera Dyke Swarm Mount Eclipse Sandstone OP Mount Eclipse Brewer Conglomerate Canning Basin limestone Hermansburg Sandstone Mereenie Sandstone Black Mountain OP Black Hill Norite Jinduckin Formation Tumblagooda Sandstone Black Mountain carbonates Lake Frome Group Lake Frome Group Areyonga Section Billy Creek Fm Wirrealpa Lst. and Aroona Creek Lst. Camb. rocks in the Kangaroo Island Hawker Group Todd River Dolomite; Allua Fm and Eninta Sandstone Albany Mobile Belt dolorite intrusives

8.4 10.9 7.2 10.9 7 4.7 4.3 5.3

15 16.2

14.5 9.3 8.6 10.5

304 304 406 1579 2191 1565 1365 182 1612 1612 3155 2698 b

14.4

C C C C A B B A C C C C C B A C C C B

2866 2726 1345 2942 2574 2574 3082 2971 202 2437 3082 1769 206 1769 1769

6.2

12.3

C

1769

2.3 339.9

8.1 4.5

14.3 7.7

C A

1769 1070

346.9

11.7

C

2920

19.7

8.6

22.7

3 14.8 10.1

2185

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

247

Table 1 Ž continued . Rock formation Eastern Antarctica Lamprophyre Dykes from Taylor Valley South Victoria Land igneous rocks Sør Rondane igneous intrusions Wright Valley granitic rocks Vanda porphyry of Wright Valley Charnockitic rocks from Mirnyy Station

Pole name

Age ŽMa.

Plat Ž8N.

Plong Ž8E.

LD

; 470

y9.3

26.7

5.5

SVL

475 " 10

y3.5

22.7

5.9

IR

; 480

y28.5

9.5

WG VP

500–480 500–480

5.4 5.8

18.5 24.9

CR

520 q 25

y1.5

28.5

8

137.5 120.5 129.6 134.3 31.7 32 42.7 33.5 19.0

5.1 9 2.8 2.6 6.8 11 11.2 3 3.1

7 15.5

India (excluding data from the Himalayas) Speckled Sandstone SP Panchet clay beds PA Kamthi Beds KB Talchir Series TA Salt Pseudomorph Beds SPB Purple Sandstone PS Bhander Series BS3 BS2 BS1

P1 P2 –Tr1 P2 C 2 –P mid-–C –C1 –C? –C? –C?

13.0 7.5 21.1 31.5 y22.1 y28 y51.3 y48.5 y31.5

Africa P2 redbeds K3 beds

P2 K3b

P2 P2

y26 y27

86 89

K3 beds

K3a

P2

y45.5

40.0

Upper Serie d’Abadla Chougrane Red Beds Illizi Basin limestones

US CR IB3 IB2 IB1 CS HB AEC SR MRO MC1 BZ HM GN BG GC GB AIR PCS

P1? P1 P C 2 –P1 C2 mid-C–C 2 mid-C mid-C D1 –C 1 C 1? C1 Famennian D 2 ŽC 2 OP?. D1 – 2 D1 – 2 ŽD3 OP?. 377 " 5 ŽC1?. C 2 Ž377 " 5?. 407 " 8 OrdrSil

y29 y32.2 y42.0 y38.5 y28.7 y28 y26.8 y22.9 y42.0 y40.5 y4.8 y19.2 y16.2 y35.2 10 25.9 y48.8 y43.4 25

60 64.0 65.1 57.5 55.8 58 56.6 51.8 55.7 49.9 55.5 19.8 61.7 43.6 15 11.6 23.5 8.6 343

SA GW

460–466 O1

Carboniferous sediments Hassi Bachir Formation Aın ¨ Ech Chebbi Formation Sabaloka ring complex Mejeria red sandstone OP C 1 results compilation Ben-Zireg limestones Hazzel Matti Formation Gneiguira supergroup Bokkeveld Group Gilif Hills ring complexes Gilif Hills ring complexes Air Ring Complexes PakhuisrCedarberg Shale Fms Salala ring complex Graafwater Formation

40 28

330 14

DPr A 95 Ž8.

6

DM Ž8.

Q

ReferencerGPMDB result no a

10.9

C

1079

A

2966

C

546

C C

1599 1599

16

C

207

9.5 10 3.7 3.2 11.3

C? C C C B C C C C

172 162 593 545 209 577 1084 212 254

7

6 5.9

B C

8 5 2.3 2.6 2.1 2.9 3.7 6.3 7.3 6.9 6.1 3.7 4.2 3.0 8.9 19.6 5.1 6.2 12.5 8 8.8

4.7

13.5 5.3 5.6 11.1 20.6 8.4 21.0 12

2736 324 435 C 324 435 B 1459 B 723 C 2540 C 2540 B? 2540 C 1794 A 1629 C 1629 C 2188 C 1761 C 1080 C 2521 C 2884 C 1761 C 1416 A? 2189 CrA? 2189 A 1364 D 1416 A C

2715 1416 (continued on next page)

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

248 Table 1 Ž continued . Rock formation

Pole name

Age ŽMa.

Plat Ž8N.

Plong Ž8E.

DPr A 95 Ž8.

Africa Qena-Safaga dyke swarm Um Rus dyke swarm Ntonya Ring Structure Volc. and sed., Morocco Nama Group overprint Upper Nama Group Sinyai dolerite Mulden Group

QS UR NR VS N3 N2 SD DM

- late P–C) 480 - late P–C) 464 522 " 13 532 " 18 - N2 –C1 547 " 4 560–550

87.3 85.9 27.8 46.9 y04 05 y29 13

304.2 193.0 344.9 42.2 335 271 319 270

5.0 6.2 1.9 6.8 12 9 3 10

Madagascar Lower Sakamena Gp Sakoa Gp: Red Series Glacial Series

LSG RSG GSG

P2 P1 C2

y64.9 y60.0 y47.9

113.9 74.5 84.1

5.6 9.0 8.1

South America Sierra Grande Fm ŽOP. Horcajo Formation Tambillos Formation Paganzo Gp Žmiddle. La Colina Formation Hoyada Verde Fm OP, Cambro-Ord. carb.

SG3 HF TF PG LCA HV SJ

P2? P2 Mid-P Mid-P P C 2 –P1 P1

y77.3 y72.4 y78.9 y78 y81 y41.9 y68.9

310.7 264.8 319.6 249 327 356.2 346.9

8 12 6.5 3 4 6.0 15.3

OP, Alcaparrosa Fm

AF

C 2 rP1

y50.8

25.8

8.0

La Colina Formation Piaui Formatiom Pular and Cas Formations Lago Ranco granites Tepuel Gp, Patagonia Lipeon Formation OP in Pre-Sil. lavas Pre-Devonian plutons Ordovician sediments at Salta and Jujuy Ord. sediments Bolivia

LCB PF PC LR TP LP SOP PDP OSS

C2 C2 C2 310–295 mid-C S1 ŽTr-J?. S? O 2 –S1 O

y49 y50 y57 y57.4 y31.7 y74.8 y25.2 0.0 11

343 345 350 323.5 316.1 215.1 260.5 271.0 333

5 10.4 6 18.8 15.0 10.1

OSB

O

302

13.8

4

8.7

DM Ž8.

Q

ReferencerGPMDB result no a

C C A C C C A? B

1229 1229 404 1042 1703 1703 3106 1242

C C C

749 773 749

8.3 20.3

C B B A B C C

13.7

A

16.0

B C A C ArB C C C B

Rapalini Ž1998. 2475 2475 1132 166 2648 Rapalini and Tarling Ž1993. 1137 b and Rapalini and Tarling Ž1993. 1144 613 1420 2285 2805 2934

4.8 5.4

16 16 5 18

11.0

7

C

2912 613 613

Ages: –Cs Cambrian, O s Ordovician, S s Silurian, D s Devonian; C s Carboniferous, P s Permian. Q s quality classification according to Li and Powell Ž1993.. a McElhinny and Lock Ž1996.. b Data not listed in, or different from, the GPDB.

and Young, 1995., between the breakup of Rodinia and the formation of Gondwanaland. Such a supercontinent would have been possible only if Gondwanaland were formed before 550 Ma, and if Laurentia were still attached to Amazonia at that time ŽPowell et al., 1995.. If Pannotia existed, it comprised Gondwanaland plus Laurentia adjacent to Amazonia.

3.2. Palaeozoic palaeomagnetism of Australia and Gondwanaland While biogeography, tectonostratigraphy and palaeoclimatic record are important factors to consider when reconstructing palaeogeography, palaeomagnetism is by far the most powerful tool in determining the palaeolatitude of a continent, and its

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

249

Fig. 6. Palaeozoic apparent polar wander path ŽAPWP. for Australia and Gondwanaland. Solid lines indicate parts of the APWP with which we have greatest confidence; dashed parts are less well constrained. Numbers are ages in Ma. All poles are listed in Table 1, and plotted in the present-day African coordinates. Gondwanaland is reconstructed following the parameters given in Powell and Li Ž1994, Table 1.. Q s quality classification according to Li and Powell Ž1993..

250

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

relationships with other continents. An important assumption for applying palaeomagnetism to tectonics is the geocentric axial dipole characteristics of the time-averaged palaeomagnetic field. Though the possibility of significant deviation from such an assumption cannot always be ruled out Že.g. Van der Voo, 1994., in this paper we adopt this assumption as a first-order approximation, as argued by the overwhelming evidence so far available Žsee discussion in Chapter 6 of Merrill et al., 1996.. There are three major competing models for the Palaeozoic APWP of Gondwanaland: Ž1. the APWP moved from northern Africa in Cambro-Ordovician time more-or-less directly to East Antarctica by Permo-Carboniferous Že.g. Hurley and Van der Voo, 1987., Ž2. the palaeo-South pole was off Gondwanaland during the early Palaeozoic owing to invoking of the polarity options ŽSchmidt and Morris, 1977., and Ž3. the APWP made a detour to southern South America during Silurian–Devonian, returned to central Africa towards the end of Devonian, and then moved to East Antarctica Že.g. Schmidt et al., 1987.. Both models Ž1. and Ž2. are inconsistent with the inferred migration path of glacial centres Žinterpreted to be polar-centred. through South America during the Silurian Že.g. Caputo and Crowell, 1985; Grahn and Caputo, 1992.. Model Ž1. is the least likely case as shown by recent results from Australia and Africa, discussed below. Fig. 6a shows palaeomagnetic poles from Australia which have a quality equal or better than a ACB class pole ŽTable 1., as defined by Li and Powell Ž1993.. The superior quality of the AAB and ABB class poles is defined mainly by their demonstrated tighter age constraints. The best-defined segment in the APWP is the Devonian part, which demonstrates a rapid apparent movement of the palaeo-South pole from southern South America to central Africa during the Devonian-earliest Carboniferous interval. Although the Early Devonian section is yet to be confirmed by data from cratonic Australia, the position of a high-quality pole from the Aır ¨ Ring Complexes, western Africa ŽHargraves et al., 1987., recently re-dated as 407 " 8 Ma ŽMoreau et al., 1994. Žpole AIR, Fig. 6e., strongly supports such an interpretation. Other reasonably well-defined parts of the APWP include the Early and Middle Cambrian and the Late Carboniferous–Early Permian intervals, al-

though details of the APWP for the latest Cambrian–Ordovician and the Late Permian intervals are poorly known. A summary of the Palaeozoic palaeomagnetic poles from other Gondwanan continents is given in Table 1, and plotted against the Australian APWP in

Table 2 Meanrinterpolated palaeomagnetic poles for Australiaa Age ŽMa.

Latitude Ž8N.

Longitude Ž8E.

Ž45 Ž95 175 Ž245 320 340 365 400 420 450 480 Ž490 505 530 600 760 1050

y64 y53 y51 y31 y48 y38 y61 y85 y58 y12 y10 3 y23 y33 y45 y21 y17

119. 143. 182 145. 122 053 026 325 357 016 031 054. 023 357 332 284 266

a The 1050–505 Ma poles are the same as those in Table 1 of Powell et al. Ž1993a. but are kept in Australian coordinates. The ca. 720 Ma pole in that table is now believed to be between 770 and 750 Ma ŽWingate and Giddings, 2000; Li, 2000.. The 490 Ma pole is from the Black Mountain carbonates of Australia Žpole BM in Fig. 6a and Table 1.. The 480 Ma is the mean of seven Early Ordovician poles from Gondwanaland, including pole JF from Australia, poles VP, WG, LD and SVL from East Antarctica, pole GW from Africa and pole OSS from South America ŽTable 1 and Fig. 6.. The 450 Ma pole is interpolated according to Fig. 6, and the 420 Ma pole interpolated from palaeopoles derived from palaeoclimatic information ŽScotese and Barrett, 1990.. The 400 Ma pole is the AIR pole from Africa Ž407"8 Ma, Hargraves et al., 1987; Moreau et al., 1994. rotated into the Australian coordinates. Poles for 365 Ma, 320 Ma and 280 Ma are interpolated from the APWP as shown in Fig. 6, and the 340 Ma pole is the ME pole from Central Australia ŽFig. 6a; Table 1.. The 245 Ma pole is from Embleton Ž1984. and Lackie Ž1988., and the 175, 95 and 45 Ma poles are based on the compilation of Li Žin Veevers and Li, 1991., but only the 175 Ma pole was used for producing maps. Paleopoles used for 95 and 45 Ma maps come from compilations used in PLATES maps provided by L. Gahagan, Univ. of Texas. Poles not used for producing maps are shown in brackets.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 6b–f. They are generally in agreement with the Australian data, with some interpreted Devonian poles from Africa as exceptions. However, as discussed by Li et al. Ž1993., the majority of the discordant African poles can have their ages reinterpreted to be consistent with the Australian data. The palaeopoles used for reconstructing the palaeolatitude of Gondwanaland through time are based on this APWP and listed in Table 2. 3.3. Palaeozoic palaeogeography 3.3.1. Cambrian platforms and marginal seas, and the Ross–Delamerian orogen The Palaeozoic map series starts from the Early Cambrian ŽFig. 7., when Gondwanaland was either already formed, or in its final stages of accretion. East Gondwanaland was in low palaeolatitude, with the palaeo-South pole traversing northwestern Gondwanaland ŽFig. 6.. Tarim probably broke away from the Cimmerian blocks and northwestern Australia at the time the extensive Antrim Plateau Basalts were erupted, with both Tarim and the Kimberley region of Australia having very similar Neoproterozoic stratigraphy ŽLi et al., 1996, Fig. 6.. Similarly, Siberia and the continental block that lay east of Laurentia throughout the Neoproterozoic, arguably Amazonia, broke aw ay from Laurentia around the PrecambrianrCambrian boundary ŽBond et al., 1984; Dalziel, 1997; Pelechaty, 1996.. The North China block ŽNCB. was probably converging with the South China block ŽSCB. in the Palaeo-Pacific, and subduction of the Palaeo-Pacific commenced along the Antarctic margin by 530 Ma ŽEncarnacion ´ and Grunow, 1996.. Within Australia, clastic wedges from the ; 610–540 Ma trans-continental Paterson–Petermann orogen were shed into marginal foreland basins ŽFig. 7b.. Away from the orogenic belt, the clastic wedges graded into shallow-marine platforms on which extensive carbonates were deposited in the Early Cambrian. To the east of the continental margin of Australia, carbonates were deposited in northwestern Tasmania, with deep-water turbiditic and cherty sediments in the Dundas Trough further east. By Middle Cambrian time Žca. 505 Ma, Fig. 8., Gondwanaland is certain to have formed. Tarim,

251

SCB and NCB are inferred to have lain close to Australia because of their close trilobite affinities until the Late Cambrian ŽPalmer, 1974; Jell, 1974; Burrett and Richardson, 1980.. Palaeomagnetic results ŽFig. 6. suggest that Gondwanaland rotated counterclockwise around an axis near North Victoria Land during the Cambrian, but the rotation stopped at the end of Cambrian Žcompare Figs. 7–9.. This change in sense of plate rotation coincides with the termination of the Ross– Delamarian Orogeny along the Transantarctic Mountains and southeastern Australia, which started during the Early Cambrian ŽEncarnacion ´ and Grunow, 1996. or possibly the latest Neoproterozoic ŽGoodge, 1997. along the Transantarctic Mountains, and in the Middle Cambrian in southeastern Australia ŽFlott¨ mann et al., 1993.. In Tasmania and North Victoria Land, obduction of an intra-oceanic island arc in the Middle Cambrian ŽCrawford and Berry, 1992; Findlay et al., 1991. and the oldest intrusion of granitoids in the Kanmantoo flysch wedge Žca. 516 Ma, Turner et al., 1993., are all related to the Ross–Delamerian Orogeny ŽStump, 1995; Goodge, 1997.. The position of the New England Fold Belt in the early Palaeozoic is uncertain. Dismembered suprasubduction ophiolites, dated as 530 Ma ŽAitchison et al., 1992., and Middle Cambrian arc debris including tuffs ŽCawood and Leitch, 1998., are the earliest evidence for subduction preserved in eastern Australia ŽLeitch, pers. commun., 2000.. There is, however, no evidence of where the New England oceanic subduction zone lay in relation to the Australian Palaeo-Pacific continental margin. The first evidence of possible connection between the New England Orogen and the Gondwanan margin of Australia is not until the latest Devonian, when a quartzose pebble, inferred to be possibly an Ordovician quartzose turbidite from the Lachlan Fold Belt, appeared in the dominantly mafic volcaniclastic succession ŽFlood and Aitchison, 1992.. This is a very tenuous connection of the New England orogen to the Gondwanan continental margin, which cannot be demonstrated firmly until the late Visean or Namurian, when widespread Lachlan Fold Belt clasts are shed into the Tamworth belt of western New England. It is possible that the New England Orogen was not in its current position relative to the rest of Australia until the Late Carboniferous, when the oldest units of

252

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 7. Ža. Early Cambrian reconstruction Ž; 530 Ma. showing the final sutures of Gondwanaland, closed in the 560 to 540 Ma interval, and the ; 530 Ma onset of subduction along the Paleo-Pacific margin. Tasmania, part of the southern extension of the continental ribbon including South China block, was overthrust by a west-facing intraoceanic island arc in the Middle Cambrian ŽCrawford and Berry, 1992.. The Tarim block broke away from northwest of Australia around the CambrianrPrecambrian boundary, around the same time as Siberia and Amazonia broke away from Laurentia. Palaeopoles used: 530 Ma pole ŽTable 2. for East Gondwanaland, average of poles No. 50 to 54 in Torsvik et al. Ž1996, Table 2. for Laurentia, Cambrian pole in Zhao et al. Ž1996, Table 1. for NCB, 541 Ma pole in Torsvik et al. Ž1992, Table 2. for Baltica, and 545 Ma pole of Smethurst et al. Ž1998. for Siberia. Žb. Early Cambrian paleogeography of Australia. The Paterson–Petermann orogenic belt formed by dextral shear of North Australia relative to the rest of Gondwanaland was bordered by foreland basins and clastic wedges in the latest Precambrian, and these subsided to give way to a broad carbonate platform in the Early Cambrian ŽPowell et al., 1994; Walter et al., 1995.. Tasmania ŽT. is postulated to be separated from the east Gondwanan margin by a marginal sea of unknown width.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

253

Fig. 8. Ža. Late Middle to early Late Cambrian reconstruction Žca. 505 Ma.. Tarim, SCB and NCB lay close to Australia and shared close trilobite affinities until the Late Cambrian. The Ross–Delamerian Orogeny began to affect the Australian continental margin. Palaeopoles used: 505 Ma pole of Table 2 for East Gondwanaland, mid- to Late Cambrian pole of Van der Voo Ž1990, Table 4. for Laurentia, Cambrian pole of Zhao et al. Ž1996, Table 1. for NCB, 520 Ma pole of Torsvik et al. Ž1992, Table 2. for Baltica, and 510 Ma pole of Smethurst et al. Ž1998, Fig. 5. for Siberia. Žb. Late Middle to earliest Late Cambrian palaeogeography of Australia. In southeastern Australia, the Kanmantoo flyschoid wedge deposited during the late Early and early Middle Cambrian, was beginning to contract, and early plutons were being intruded in the emerging Delamerides. In northeastern Australia, the Nebine volcanic island arc was separated by the ocean-floored Barcoo marginal sea ŽHarrington, 1974. from a broad epicontinental basin ŽGeorgina and eastern Amadeus basins. residual from the more extensive Early Cambrian marine transgression. The direction of convergence of the Paleo-Pacific ocean with Australia is constrained between E and SSE in its present day coordinates by reactivation on shear zones at ca. 500 Ma in the Broken Hill region ŽGlen et al., 1977..

254

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 9. Ža. Early Ordovician reconstruction Ž; 480 Ma. showing near-equatorial ESE-trending island arcs separated by marginal seas from the Palaeo-Pacific margin of Gondwanaland. PC is now the Precordillera terrane of South America, and in the Early Ordovician was either the westward extension of Laurentia in the Texas plateau of Dalziel Ž1997. or the detached part of Laurentia from the Ouachita–Oklahoma embayment migrating across Iapetus ŽAstini et al., 1995.. Subduction in the Iapetus Ocean between Laurentia and West Gondwanaland can be related to the peri-Laurentian ŽPL., Exploits ŽE. and Avalonian ŽA. intra-oceanic island arcs, at latitudes 10–208S, ca. 308S and 508S, respectively ŽMac Niocaill et al., 1997.. Palaeopoles used: 480 Ma pole of Table 2 for East Gondwanaland, 490 Ma pole of Mac Niocaill and Smethurst Ž1994, Table 4. for Laurentia, Ordovician pole of Zhao et al. Ž1996, Table 1. for NCB, Early to Middle Ordovician pole of Zhao et al. Ž1996, Table 1. for Tarim, 495 Ma pole of Smethurst et al. Ž1998, Fig. 5. for Siberia, and 481 Ma pole of Torsvik et al. Ž1992, Table 2. for Baltica. Žb. Early Ordovician palaeogeography of Australia. A mafic volcanic island arc was separated by a broad ocean-floored marginal sea from Australia, with the shallow Larapintine Sea of Webby Ž1978., connecting eastern Australia to the Canning Basin of NW Australia. Diagram modified from Powell Ž1984, Fig. 201..

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

the Sydney Basin onlap both the New England Orogen and the Gondwanan margin to the west. Palaeomagnetic studies by Li et al. Ž1997. suggested that northwestern Tasmania had become part of Gondwanaland by the Late Cambrian, but its relationship with East Gondwanaland before that time is yet to be examined. The record of the Ross–Delamerian Orogeny Že.g. Gibson and Ireland, 1996. and stratigraphic and geochemical analysis Že.g. Munker and Cooper, 1995. in western New Zealand ¨ suggest that the Buller and Takaka terranes may have been part of the active plate margin along the Australia–Antarctica Pacific margin during the Cambro-Ordovician time. 3.3.2. OrdoÕician arcs, marginal seas and clockwise Gondwanan rotation The counterclockwise rotation of Gondwanaland during the Cambrian was reversed during the Ordovician. The change in sense of rotation occurred at the Cambro-Ordovician boundary, marked by a sharp hairpin bend on the Gondwanan APWP at 490 Ma ŽFig. 6.. The change in sense of rotation of the supercontinent was accompanied by retreat of the magmatic arc from the eastern Gondwanan margin, thereby opening new marginal seas along the Palaeo-Pacific margin ŽFig. 9.. The North and South China blocks, and Tarim, remained in low latitudes, and rotated sinistrally along the Cimmerian margin of Gondwanaland towards positions they are inferred to have occupied later on the basis of faunal relationships Že.g. Young, 1990, 1993.. In northwestern Australia, the shallow-marine Canning Basin developed at the beginning of the Ordovician, and was connected to eastern margin of Australia by the shallow Larapintine Sea ŽWebby, 1978.. To the east, deep-marine conditions formed in a marginal sea behind a mafic island arc ŽPowell, 1984.. By the Late Ordovician ŽFig. 10., deformation and uplift in the northeastern Amadeus Basin had closed the Larapintine Sea, and desert conditions began to form in Central Australia. In northeastern Australia, the mafic volcanic arc was deformed in the mid-Ordovician, but in southeastern Australia the Wagga marginal sea survived to the end of the Ordovician. In the late Early Ordovician, a widespread quartzose turbidite sheet was deposited throughout southeastern Australia, fining upward into

255

a distal black shale. Carbonate fringes developed around the mafic volcanic pedestals of the offshore island arc, and these became quite extensive in the latest Ordovician. 3.3.3. Silurian to early DeÕonian clockwise Gondwanan rotation The movement of Gondwanaland during the Silurian can be described as a large clockwise rotation around an axis close to Australia ŽFigs. 11 and 12.. There is no good palaeomagnetic control on Gondwanaland during this rotation, but by the earliest Devonian Žca. 400 Ma., the palaeo-South pole lay off the southern tip of South America ŽHargraves et al., 1987; Moreau et al., 1994.. The orientation of the North China Block is constrained palaeomagnetically, but its latitudinal position has been adjusted within the palaeomagnetic error limit. There is no reliable palaeomagnetic control on the South China or Tarim blocks. On the basis of the high diversity and endemism of Siluro-Devonian freshwater-fish fauna in the SCB Že.g., Wang et al., 1984; Burrett et al., 1990; Young, 1990; Rich and Young, 1996., Young Ž1993. considered that the SCB may have straddled the Equator adjacent to, but separated from, Gondwanaland. The clockwise rotation of Gondwanaland could have set up transcurrent displacements between Gondwanaland and continental blocks lying on adjacent tectonic plates. Along the eastern margin of Australia, a dextral transtensional regime has been interpreted from the orientation and en-echelon arrangement of mid-Silurian to Early Devonian horst and graben in the eastern Lachlan Fold Belt ŽPowell, 1983.. Along the other side of Gondwanaland, there could have been oblique sinistral transpression between northwestern South America and Laurussia ŽLaurentia and Europe., marked as the Late Silurian stages of the Acadian and Caledonian Orogenies in North America and Europe, respectively. Similarly, the Late Ordovician–Silurian ACaledonianB Orogeny in both SCB and NCB could be caused by their being on the margin of the rotating Gondwanaland plate. In eastern Australia, there are two contrasting sedimentary regimes in the Silurian and earliest Devonian ŽFig. 12b.. The western domain is a largely clastic shoreline, which extends eastward into deep-

256

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 10. Ža. Late Ordovician reconstruction Žca. 450 Ma. showing closure of the peri-Gondwanan island arc and marginal seas off northeastern Australia, and along the Iapetan margin off South America. The Precordillera terrane was accreted to southern South America, either by the oblique collision of Laurentia with South America ŽDalziel, 1997., or by collision of a continental terrane rifted from southeastern Laurentia ŽAstini et al., 1995.. Palaeopoles used: 450 Ma pole in Table 2 for East Gondwana, Ordovician pole of Zhao et al. Ž1996, Table 1. for NCB, mid-Ordovician pole of Zhao et al. Ž1997. for Tarim, 450 Ma pole of Mac Niocaill and Smethurst Ž1994, Table 4. for Laurentia, 450 Ma pole of Torsvik et al. Ž1992, Table 2. for Baltica, and 450 Ma pole of Smethurst et al. Ž1998, Fig. 5. for Siberia. Žb. Late Ordovician palaeogeography of Australia, showing the deformation in northeastern Australia and uplift in northern Amadeus Basin that closed the Larapintine Seaway connection from eastern Australia to the Canning Basin.

marine conditions ŽBanks and Baillie, 1989; Powell, 1983, 1984.. The eastern domain is a zone of active volcanism, with several horst and graben ŽPowell,

1983.. On the horst, and adjacent to the landmass formed above the Early Silurian Wagga Metamorphic Belt, carbonate aprons and platforms developed.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

257

Fig. 11. Ža. Mid-Silurian reconstruction Žca. 420 Ma.. The Caledonian Orogeny in Europe was due to the collision between Laurentia and Baltica to form Laurussia. Coeval orogenic activities in NCB and SCB may be related to their interactions with Gondwanaland. Palaeopoles used: interpolated Žaccording to palaeoclimatic indicators. 420 Ma pole in Table 2 for Gondwanaland, mid-to Late Silurian pole of Zhao et al. Ž1996, Table 1. for NCB but with ca. 108 latitudinal adjustment toward the northern hemisphere as allowed by error limit; 420 Ma pole of Mac Niocaill and Smethurst Ž1994, Table 4. for Laurentia, 420 Ma pole I of Torsvik et al. Ž1992, Table 2., and 435 Ma pole of Smethurst et al. Ž1998, Fig. 5. for Siberia. Žb. Mid-Silurian palaeogeography of Australia, showing two contrasting tectonic provinces in eastern Australia: an east-facing passive margin in the western Tasman Fold Belt ŽTFB. and a zone of meridional volcanogenic horst and graben, possibly related to dextral shear along a NNW-trending master fault, in the eastern part of the TFB. Carbonate platforms fringed the horsts in the eastern TFB, but the main deposition in the western TFB was siliciclastic. Shallow-marine carbonate and evaporite deposition ŽE. occurred in the Canning and Bonaparte Basins of western Australia; central Australia was occupied by deserts.

The interpretation of the relationship of the eastern domain to the western one is speculative, but the

pattern of faults and fault movements suggests that the eastern domain could have been a continental

258

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 12. Ža. Early Devonian Žca. 400 Ma. reconstruction, with the position of Gondwanaland based on the Aır ¨ pole from Africa ŽHargraves et al., 1987; Moreau et al., 1994; Table 2.. There is no good palaeomagnetic control on the North and South China blocks, but on the evidence of the diversity and endemism of their Lower Devonian vertebrate fauna Že.g. Young, 1990, 1993., they are put close to the equator but separated from northern Gondwanaland. Other palaeopoles used: Devonian pole by Li et al. Ž1990. for Tarim, and interpolated north pole at Ž138N, 1038E. ŽLi et al., 1993. according to Van der Voo Ž1990, Table 7. for Laurussia. Žb. Early Devonian palaeogeography Ž; 400 Ma.. Convergence between the eastern and western Lachlan domains, and also between the New England Fold Belt ŽNE. and the eastern Lachlan domain ŽEL. was accompanied by dextral transpression. In northeastern Australia there was a continuation of subduction. Desert conditions existed in central and western Australia, with marine conditions confined to the offshore parts of the Canning and Bonaparte Basins. Based on Powell Ž1984, Fig. 219, and unpubl. data., with modifications from Bradshaw et al. Ž1994. and Gray Ž1997..

block, originally part of Gondwanaland, being displaced southward along the Palaeo-Pacific margin

from a more northerly location. Coeval Late Silurian subduction beneath the north Queensland segment of

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

the Gondwanan margin suggests that a southwardmigrating triple junction could have been involved. In northwestern Australia, the Canning and Bonaparte basins were very shallow and large accumulations of salt formed. Desert occupied the central part of Australia.

3.3.4. DeÕonian to earliest Carboniferous counterclockwise rotation The late Early Devonian to early Visean part of the Gondwanan APWP is well constrained by a series of palaeomagnetic poles, mostly from Australia, which define a pole path that moves from the southern tip of South America into central Africa ŽFig. 6.. The movement of the palaeo-South pole into Central Africa in the Late Devonian and Early Carboniferous reopened a wide ocean, the Rheic Ocean, between northwestern Gondwanaland and Laurussia, which remained at low latitudes ŽFigs. 13 and 14; see also Van der Voo, 1988; Kent and Van der Voo, 1990.. Armorica, which up to this time had been part of northwestern Gondwanaland, separated from Gondwanaland during the Devonian as the western part of the supercontinent rotated to higher southern latitudes. The endemism of freshwater-fish fauna indicates that both the North and South China blocks remained separate from Gondwanaland during the Early Devonian. Toward the end of Devonian, there appear to have been land connections between the NCB, SCB and East Gondwanaland as suggested by their similar AcontinentalB fish faunas ŽYoung, 1993; Rich and Young, 1996.. However, the wide Rheic Ocean makes connection of northwest Gondwanaland with North America tenuous, unless there were islands extending southward from North America, or Laurussia is plotted farther east relative to Gondwanaland than shown in Fig. 13. Convergence along the southern margin of Siberia and Kazakstan was complex, with several coeval subduction zones present Žsee Sengor ¨ et al, 1993, for details.. The Gondwanaland rotation was counterclockwise during this interval ŽFigs. 12–14., and thus the sense of shear during transpression against adjacent continental plates could have changed to dextral. In eastern Australia, the earliest Devonian was a continuation of the pattern developed in the Silurian,

259

but by the late Early Devonian ŽEmsian., convergence between the eastern and western domains in the Lachlan Fold Belt had led to subduction of the oceanic crust in between ŽFig. 12b, see also Gray, 1997; Soesoo et al., 1997.. Palaeocurrent and provenance evidence in the eastern Melbourne Zone and adjacent Mathinna Basin of northeastern Tasmania ŽPowell et al., 1993b, and unpubl. data. show that the eastern and western domains of the Lachlan Fold Belt were linked by the Emsian. The Tasman Orogenic zone off eastern Australia could thus have had been the site of three coeval subduction zones: Ži. a western zone dipping west beneath the Gondwanan margin of the western domain of the Lachlan Fold Belt, Žii. a middle zone dipping east beneath the western edge of the eastern Lachlan domain, and Žiii. an eastern zone dipping west beneath the New England Fold Belt. The Siluro-Devonian tectonic configuration could have been similar to the modern Philippines of the western Pacific, with both eastand west-directed subduction beneath parts of the Philippines Žs eastern Lachlan zone., and still oceanfloor between the Philippines and the Indosinian continent to the west Žcf. Gondwanaland.. During the Early Devonian, and certainly by the Emsian, the ocean floor between the eastern Lachlan domain and the Gondwanan continental margin was being subducted, with development of a magmatic arc in the Grampians area of the western Lachlan domain. By the Late Devonian, an Andean-type margin, with associated foreland basins, had developed farther east along the Pacific margin of Gondwanaland. The eastern and western Lachlan domains were fused by the Tabberabberan Orogeny, and thereafter a single subduction zone dipped westward beneath the Palaeo-Pacific margin of Gondwanaland. The continental block moving dextrally along the eastern margin of Australia in the Silurian and Early Devonian ŽFig. 11, lower figure. became accreted to the Gondwanan margin by the Emsian Tabberabberan deformation ŽFig. 12.. In central and Western Australia, the Early Devonian saw a continuation of the desert conditions which commenced during the latest Ordovician. Aeolian dunes with sporadic playa lake deposits and fluvial interlayers accumulated. Arid conditions also continued in the west in the Canning and Bonaparte Basins, in which there is generally a hiatus in the

260

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 13. Ža. Late Devonian Žca. 365 Ma. reconstruction, with position of Gondwanaland based on well-constrained APWP by Australian results ŽFig. 6, and Tables 1 and 2.. Palaeolatitude for Laurussia is plotted according to the palaeopole Ž298N, 1118E. given in Van der Voo Ž1990, Table 7., Siberia according to the DU pole in Khramov et al. Ž1981, Table 3., Armorica according to Bachtadse et al. Ž1983., and Tarim and NCB according to poles listed in Zhao et al. Ž1996, Table 1.. The high degree of similarity of freshwater-fish fauna in South China Block ŽSCB. and Australia Žreferences in Rich and Young, 1996. indicate that the SCB and Australia were in contact by the end of Devonian. Žb. Late Devonian palaeogeography Žca. 365 Ma. of Australia interpreted from Powell Ž1984, Fig. 223B. and Baillie et al. Ž1994, Fig. 7F.. A ŽAmadeus Basin., D ŽDrummond Basin., HC ŽHalls Creek Mobile Zone., L ŽLambian Basin., N ŽNgalia Basin., RH ŽRoss High..

on-shore parts. The palaeogeography began to change in the Emsian, with the first sign of uplift of the Arunta block on the northern edge of the Amadeus

Basin. Increasingly coarse, lithic detritus was shed off the emerging orogen, and marine deposition recommenced in the Canning Basin. By the Late

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

261

Fig. 14. Ža. Early Carboniferous reconstruction Žca. 340 Ma.. The position of Gondwanaland is based on the Visean pole determined from the Ngalia Basin in Central Australia ŽChen et al., 1994., and the position of Laurussia determined from Laurentian and European poles ŽVan der Voo, 1993, Table 7.. Tarim is plotted according to data by Li et al. Ž1990., and South China ŽSCB. and North China ŽNCB. are placed in positions consistent with their palaeofaunal distributions. SCB is inferred to have fused with the Indosinian block ŽI. in the Early Carboniferous ŽMetcalfe, 1996.. Žb. Early Carboniferous palaeogeography ŽVisean. of Australia. An Andean-type magmatic arc extended along the eastern continental margin of the Lachlan Fold Belt, which was deformed and stabilised in the Early Carboniferous. The magmatic arc extended north along the North Queensland margin. The New England Fold Belt lay east of the magmatic arc, with the Tamworth forearc basin facing eastward toward the Palaeo-Pacific above the west-facing subduction zone. Structural trends are a combination of Early Carboniferous Kanimblan fold trends in eastern Australia and mid-Carboniferous folds and thrusts in central Australia Žmodified from Veevers and Powell, 1984, Fig. 225..

Devonian, an intracontinental east-trending mountain belt ran across central Australia, with foreland basins

both to the north ŽNgalia. and south ŽAmadeus. ŽFig. 13b; cf. present-day Tien Shan and associated Jung-

262

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

gar and Tarim Basins.. In northwestern Australia, dextral transtension along the Halls Creek Mobile Zone opened a number of Late Devonian clastic

basins, while in eastern Australia the Drummond and Lambian foreland basins developed inboard of the continental-edge magmatic arc ŽPowell, 1984..

Fig. 15. Ža. Mid-Carboniferous Žca. 320 Ma. reconstruction ŽNamurianrWestphalian.. Gondwanaland collided with Laurussia to form Pangea at around that time. East Gondwanaland drifted toward the southern polar region, accompanied by the development of continental glaciation, whereas the East Asian continental blocks remained at low to equatorial positions at the eastern Palaeo-Tethys. Gondwanaland was plotted according to the 320 Ma pole in Table 2, Laurussia according to the Late Carboniferous pole given in Van der Voo Ž1990, Table 7., and Siberia according to the Cu pole in Khramov et al. Ž1981, Table 3.. Žb. There are very few mid-Carboniferous stratigraphic records for Australia, which is interpreted ŽPowell and Veevers, 1987; Veevers and Powell, 1987. to reflect the presence of a continental ice sheet over most of Australia. Diamictites and drop-stones in marine strata are known from Namurian deposits at the margin of the Carboniferous continent, which was also being deformed in this interval.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

The palaeo-South pole remained in Central Africa until at least the early Visean ŽChen et al., 1994.,

263

and the tectonic configuration in the Early Carboniferous ŽFig. 14. remained essentially the same as in

Fig. 16. Ža. Early Permian reconstruction Ž; 280 Ma.. Siberia has joined Laurussia to form Laurasia, and the major phase of continental collision between NCB and SCB started soon afterward Že.g. Li, 1998.. The 280 Ma pole in Table 2 is used for plotting Gondwanaland, and the Pl pole in Van der Voo Ž1990, Table 7. for Laurasia. Tarim, NCB and SCB were plotted according to palaeopoles given in Zhao et al. Ž1996, Table 2., but with minor adjustment to the palaeolatitude of NCB. Žb. The Andean-style mountain chain along the Panthalassan margin of Australia gave way to transtensional basins related to a dextral margin, and there was a brief marine transgression in the Asselian when the inferred continental ice sheet melted out ŽPowell and Veevers, 1987; Veevers and Powell, 1987.. Glacial flow in Australia can be related to three ice centres, and more regionally there was radial flow away from Antarctica ŽVeevers and Tewari, 1995a,b..

264

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

the Late Devonian ŽFig. 13.. The Rheic Ocean was probably at its widest in the Early Carboniferous Žcompare Figs. 13 and 14..

3.3.5. Mid-carboniferous Pangean collision and Early Permian dextral transtension Some time after the early Visean Ž; 340 Ma., Gondwanaland began to drift rapidly across the South Pole, and by 320–310 Ma, it had collided with Laurussia to form most of the supercontinent Pangea ŽFig. 15.. Australia, for the first time during the Palaeozoic, drifted close to the South Pole, as suggested by both the palaeomagnetic data ŽFig. 6a. and the sedimentary record ŽPowell and Veevers, 1987; Veevers and Powell, 1987.. Possibly reflecting the far-field effect of the Gondwana–Laurussia collision, the Alice Springs Orogeny in Central Australia peaked at around that time ŽWells and Moss, 1983; Shaw et al., 1991; Mortimer et al., 1987.. The major East Asian continental blocks remained in low to medium palaeolatitude, and started to develop their distinctive Cathaysia flora. The palaeogeography of the Early Permian Žca. 280 Ma. remained more or less the same as the mid-Carboniferous, except that northern Asia became part of Pangea by collision of Siberia with Laurussia along the Urals in the Asselian ŽZonenshain et al., 1990.. Mongolian terranes accreted to the NCB ŽZhao et al., 1996., and the first phase of continental collision between the NCB and SCB at their eastern ends started soon afterwards Že.g. Zhao and Coe, 1987; Yin and Nie, 1993; Li, 1998.. Pangea was complete at this time. Along the eastern margin of Australia, a continental Andean-type magmatic arc reflected westward subduction of Panthalassa in the Late Devonian to Namurian interval, after which the northeastern margin of Australia was subject to dextral transtension ŽVeevers and Powell, 1994.. Deep-marine basins in the New England Orogen of eastern Australia, commonly accompanied by mafic volcanic rocks, reflect the change from compressive to transtensile tectonics. A large megafold, the Texas–Coffs Harbour orocline, developed in the latest Carboniferous to Early Permian ŽFig. 16; Korsch and Harrington, 1987; Murray et al., 1987..

4. Late Permian to middle Jurassic Pangea endured from ; 280 Ma until ; 175 Ma, when the first seafloor spreading began in the North Atlantic Ocean. Along the South American sector of the Panthalassan margin of Gondwanaland, Andeantype subduction recommenced in the latest Carboniferous ŽLopez-Gamundi et al., 1994.. The progressively younger onset of Andean vulcanism along the Antarctica–Australia Panthalassan margin has been interpreted in term of a migrating triple junction that did not reach the New England orogen until the late Early Permian ŽVeevers and Powell, 1994.. The new Andean margin was backed by a foreland basin in which the extensive Gondwanan coals were deposited in the Late Permian. The Andean magmatic arc–foreland basin configuration, but not the coal deposition, persisted until the end of Early Triassic, when another global reorganisation of tectonic stresses saw the beginning of extension around 230 " 5 Ma prior to Pangean breakup ŽVeevers, 1989..

5. Mesozoic and Cenozoic: breakup of Gondwanaland and Pangea, and the birth of Australia A succession of continental strips has rifted away from the India–Australian margin of Gondwanaland since the late Palaeozoic: the Cimmerian in the Late Permian, the Lhasa Block in the Late Triassic, and the West Burma Block in the Late Jurassic ŽFig. 17; see also Sengor, ¨ 1987; Metcalfe, 1996.. Gondwanaland started to break up from around the Middle Jurassic Žca. magnetic anomaly M26: 160 Ma., with East Gondwanaland ŽAntarctica, Australia, India and Madagascar. rotating southward from West Gondwanaland ŽAfrica, Arabia and South America.. At the beginning of the Cretaceous Žca. M11, 130 Ma., the former Gondwanaland began to break into four continental blocks, South America, Africa–Arabia, India–Madagascar, and Australia–Antarctica ŽFig. 18; see also Veevers et al., 1980; Lawver et al., 1992.. India–Madagascar continued to rotate south from Africa until around M0 Ž119 Ma., when the seafloor spreading between Africa and Madagascar stopped. The Indian Ocean between India and Australia–Antarctica was about 800 km wide at this time, as was the South Atlantic Ocean ŽLawver et

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

265

Fig. 17. Ža. Mid-Jurassic reconstruction Žca. 175 Ma. just before Pangea breakup. The NCB and SCB have sutured together, but yet to accrete to Siberia. Gondwanaland was plotted according to the 175 Ma pole in Table 2, Laurasia according to the 170 Ma pole in Besse and Courtillot Ž1991, Table 2b., and NCB according to the pole given in Zhao et al. Ž1996, Table 2.. The Lhasa and West Burma Blocks were positioned following Metcalfe Ž1996.. N.Z. — New Zealand; LHR — Lord Howe Rise. Žb. Andean-type magmatic arc along the Pacific Ocean with broad foreland basin over central eastern Australia. Elevation of the eastern margin of Australia enabled transport of volcanogenic materials towards the Surat Basin in the interior of Australia. Early stages of rifting along the western and southern margins of Australia with approximate line of subsequent continental breakup shown in red line; arrows show directions of extension. Palaeogeography based on Baillie et al. Ž1994, Fig. 7J. and Powell Žunpubl. work..

al., 1992.. Seafloor spreading at relatively slow rates continued in the South Atlantic and Indian Oceans through the Early Cretaceous. There could have been

some relative transcurrent motion between India and Madagascar along the linear eastern margins of the two continental masses in this interval ŽPowell et al.,

266

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Fig. 18. Ža. Early Cretaceous Žca. 130 Ma. reconstruction based mainly on sea-floor magnetic anomalies and hot spot information Žafter Powell et al., 1988; Lawver et al., 1992 and PLATES.. East and West Gondwanaland had started to breakup, and the East Asian blocks had accreted to Eurasia. Seafloor spreading commenced between Greater India and Australia–Antarctica at about this time ŽM11, ca. 132 Ma.. Žb. The Jurassic Andean-type magmatic arc in eastern Australia had begun to collapse in the early Cretaceous, possibly as the Pacific subduction zone receded from the eastern margin, and a narrow seaway extended southward from a broad marine shelf in northern Australia. Dextral transform motion along a transform fault in southeastern Australia cut across the tectonic trends of the former Tasman Fold Belt at a low angle, and accommodated the continental stretch between Australia and Antarctica. This transform margin localised the site of the later continental breakup that gave rise to the Tasman Sea. Palaeogeography based on Veevers Ž1984. and Powell Žunpubl. work..

1980.. Dextral transcurrent motion may also have occurred along the southeastern coast of Australia, with the Lord Howe Rise ŽLHR. and part of New

Zealand moving southwest with respect to Australia. Early Cretaceous crustal extension related to this movement occurred along the southern margin of

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

267

Fig. 19. Ža. Mid-Cretaceous Žca. 96 Ma. reconstruction Žafter Powell et al., 1988; Lawver et al., 1992 and PLATES.. From ca. 117 to 96 Ma, the former Gondwanaland fragments were separating on three major plates, South America, Africa–India, and Australia. Around 96 Ma, a fourth plate, Antarctica, came into existence, and soon after, India moved rapidly north on a fifth plate. Žb. Palaeogeography of the Australian region. The abandoned spreading ridge in the Indian Ocean is shown as a black double line connected by single line transforms, and the line of the new seafloor spreading is shown as red lines. Volcanism in Queensland is related to extension, as the subduction zone is about to step further east from the Australian continental margin. Highlands in southeastern Australia and Queensland provided sediment for the depocentres along the southern margin of Australia. Numbered closed lines are postulated topographic contours with elevations in km. Note the postulated transform fault along the southeastern margin of Australia is depicted as a rift feature in anticipation that it had become slightly transtensional Žcf. Levant transform margin to the Arabian plate.. Continental stretching in New Zealand occurred between 130 Ma and approximately 110 Ma; it is possible that early seafloor spreading between New Zealand Žattached to the Lord Howe Rise. and Antarctica had started before 96 Ma. Palaeogeography based on Veevers Ž1984. and Powell Žunpubl. work..

268

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Australia and in the Nelson and Fiordland regions of New Zealand. A major change in the pattern and rate of seafloor spreading in the Indian Ocean occurred around 95

Ma, during the long Cretaceous normal interval. India began to rotate rapidly northward from middle southern latitudes ŽKlootwijk et al., 1992., and slow seafloor spreading was initiated between Australia

Fig. 20. Ža. Middle Eocene Žca. 45 Ma. reconstruction Žafter Veevers et al., 1991; Lawver et al., 1992 and PLATES.. Seafloor spreading between Australia and Antarctica was slow Ža few millimetres per year. between ca. 96 Ma and magnetic anomaly A21 Žold. Žca. 45 Ma., after which the modern phase of spreading in the Indian Ocean began to open the Southern Ocean at a rate of ca. four centimetres per year. Žb. Palaeogeography of the Australian region. Land contact between Australia and Antarctica was maintained up to ca. 40 Ma through the South Tasman Rise, after which the Southern Ocean was fully open to the Pacific. Palaeogeography based on Veevers Ž1984., Lawver et al. Ž1992., PLATES and Powell Žunpubl. work..

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

and Antarctica. No significant change in spreading pattern was noted in the South Atlantic Ocean. Africa, South America, Australia, Antarctica and India– Madagascar were independent continental blocks at

269

this time, although there were still land connections between South America and Antarctica through the Antarctic Peninsula, and between Australia and Antarctica through Tasmania ŽFig. 19.. Madagascar

Fig. 21. Ža. and Žb. Present-day plate tectonic configuration showing complex zone of interaction between the northern margin of the Australian block and island arcs that formerly extended east from Sundaland. Australia arrived at the subduction zone related to these island arcs between 25 and 20 Ma, and has continued to move northward at a rate of between 7 and 8 cm per year. Australia’s arrival at, and crossing of, the Sunda subduction zone had profound effects on the deformation patterns in Papua New Guinea and the marginal basins of Australia. Reactivation of many of Australia’s hydrocarbon-bearing marginal basins, and the onset of displacement on the Alpine Fault in New Zealand Žeither Late Oligocene, Kamp, 1991 or mid-Miocene, Lamarche et al., 1997., are broadly at the same time as the arrival of the northern margin of Australia at the Sunda subduction zone Žsee Keep et al., 1998..

270

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

and India separated soon afterward Žbetween 90 and 85 Ma; Storey et al., 1995., and thereafter Madagascar lost land connections with any other continental block of the former Gondwanaland. The Tasman Sea also began to open around 85 Ma, as the LHR including New Zealand rotated northeastward relative to Australia. By ca. 55 Ma, India started its collision with Eurasia Že.g. Klootwijk et al., 1992; Beck et al., 1995., and the Tasman Sea had completely opened. Seafloor spreading between India and Australia had stopped in the Middle Eocene, and a new spreading ridge extending from the Owen Fracture zone just east of Arabia into the Southern Ocean between Australia and Antarctica and then connecting with the East Pacific Rise developed ŽA20, Fig. 20.. The modern pattern of seafloor spreading between Australia and Antarctic began at this time, but Australia did not lose complete land connections with Antarctica until the Oligocene Žca. 35 Ma. when displacement along the transform fault between Tasmania and North Victoria Land was sufficient to allow the two continental blocks to separate. Australia and Antarctica were in middle to high southerly latitudes through most of the Cretaceous. Around 45 Ma, when the rate of seafloor spreading in the Southern Ocean increased from a few millimetres to a few centimetres a year, Australia began to rotate northwards while Antarctica stayed in high southerly latitudes. Australia continued its northward path and its leading edge in Papua–New Guinea crossed the line of volcanic island arcs and subduction zones that extended east from the Sundaland block of southeast Asia in the earliest Miocene Ž25 to 20 Ma.. This was also when seafloor spreading began in the Red Sea, as the Arabian block rotated slowly counterclockwise with respect to Africa. This time also corresponds with the onset of major underthrusting of India beneath Tibet along the Main Central Thrust and the rise of the Himalayas. Closer to Australia, the Alpine fault of New Zealand was established between 28 and 24 Ma ŽKamp, 1991. or possibly around 15 Ma ŽLamarche et al., 1997.. Five sets of palaeogeographic maps are provided for this time interval: mid-Jurassic Žca. 175 Ma, Fig. 17., Early Cretaceous Žca. 130 Ma, Fig. 18., midCretaceous Žca. 95 Ma, Fig. 19., Early Tertiary Žca. 45 Ma, Fig. 20., and present time ŽFig. 21.. Except

for the 175 Ma maps, the rest were derived mainly from sea-floor magnetic anomaly and hot-spot information Že.g., Powell et al., 1980, 1988; Veevers et al., 1991; Veevers and Li, 1991; Lawver et al., 1992 and references therein..

6. Summary Australia’s palaeogeographic evolution in the last billion years has been influenced by its position in two supercontinents, Rodinia and Gondwanaland, and by its palaeolatitude. The older supercontinent, Rodinia, assembled during the late Mesoproterozoic along sutures represented by fold belts extending from the Grenville Province in eastern Laurentia through the Eastern Ghats of India into the Albany– Fraser–Musgrave fold belts in Australia ŽFig. 2.. In Rodinia, Australia lay adjacent to Laurentia along the Tasman Line, with South China possibly in between. Australia was in mid-northern latitudes for most of the Neoproterozoic ŽFigs. 2 and 4., though by the late Neoproterozoic, the Equator lay close to what is now the southern margin of Australia ŽFig. 5.. Australia’s Neoproterozoic palaeogeography is dominated by the shallow intracratonic Centralian Superbasin, which may have extended into western Laurentia. In the latter half of the era, there was widespread low-latitude glaciation. The breakup of Australia’s eastern Rodinian margin, around the end of the Sturtian glaciation ŽFig. 4., gave rise to the Palaeo-Pacific Ocean. Closure in the late Neoproterozoic of the Mozambique and other oceans between Australia–East Antarctica–India and the Brazilian craton may have given rise to a fleeting supercontinent Pannotia. The second supercontinent to influence Australia’s palaeogeography was Gondwanaland, which formed at the beginning of the Phanerozoic, possibly as a result of the separation of Laurentia from Amazonia to create the early Iapetus Ocean. In the Early Cambrian, the eastern margin of Australia lay along the Tasman Line facing the Palaeo-Pacific Ocean ŽFig. 7.. Breakup in northwestern Australia, with the Tarim block possibly separating from the Kimberley, was related to global continental dispersion around the PrecambrianrCambrian boundary, and gave rise to

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

the Antrim Plateau basalts and the Bonaparte Basin ŽFig. 7b.. Westward subduction of the Palaeo–Pacific Ocean along the eastern margin of Australia– Antarctica commenced during the Early Cambrian in northern Victoria Land and in the Middle Cambrian in South Australia, and led to the Cambro-Ordovician Ross–Delamerian Mountains ŽFig. 8.. A new palaeogeographic cycle began in the Ordovician, with retreat of the magmatic arc from Australia’s then-eastern continental margin, as a marginal sea and offshore island arc developed ŽFig. 9.. A shallow seaway across Australia in the Late Cambrian persisted into the Ordovician, but gradually the sea regressed, and desert-like conditions formed in Central Australia and the adjacent Canning Basin ŽFig. 10.. The Silurian to mid-Devonian was an interval of rapidly changing palaeogeography in eastern Australia as carbonate platforms flanking narrow, deep volcanogenic troughs formed in a dextral transtensional tectonic setting ŽFig. 11.. On the Australian craton to the west, terrestrial desert conditions prevailed, with some shallow-marine areas in the Bonaparte and Canning Basins. Widespread deformation in the Tasman orogenic zone in the Middle Devonian to Early Carboniferous, was accompanied by the development of an Andean-style magmatic arc along the Pacific continental margin of Australia, and foreland and epicontinental basins in Central Australia ŽFigs. 12–14.. The most widespread Phanerozoic mountain-building stage in Central Australia occurred in the Late Devonian to mid-Carboniferous, as part of a world-wide Variscan orogenic episode associated with the collision of Gondwanaland with Laurussia ŽFigs. 14 and 15.. Assembly of the Pangean supercontinent was completed in the earliest Permian by the collision of Siberia with Laurussia along the Urals ŽFig. 16.. During the Cambrian to Early Carboniferous, Australia lay mainly in tropical latitudes, drifting slightly southward. In the late Visean, a rapid polar shift occurred, and, by the Westphalian, the South Pole lay less than 208 south of southeastern Australia. The Late Carboniferous and earliest Permian palaeogeography of Australasia was dominated by glacial conditions ŽFig. 15.. Large ice sheets covered much of interior Australia, though by the Asselian, these were diminishing and a brief shallow-marine transgression occurred in many marginal basins ŽFig.

271

16.. Transtensional basins associated with dextral oroclinal shear along the Panthalassan eastern margin of Australia developed in the Late Carboniferous and persisted until the Late Permian, when an Andean-style magmatic arc was reestablished. Large foreland basins inboard of the Late Permian to Early Triassic magmatic arc accumulated major coal deposits during Late Permian volcanic phases, but drastic climatic changes at the end of the Permian, possibly caused by global greenhouse conditions, led to red-bed deposition in the Early Triassic. Pangea began to rift in the mid-Triassic, and by the Late Triassic, the Cimmerian blocks, which lay off northwestern Australia throughout the Palaeozoic, had departed the northern margin of Gondwanaland. A new Andean-style continental magmatic arc became established along the Pacific margin of Australia, and continental sedimentation occurred in interior Australia ŽFig. 17.. The palaeolatitude of eastern Australia remained high. The breakup of Gondwanaland began between East ŽAustralia– Antarctica–India–Madagascar. and West ŽSouth America–Africa. Gondwanaland in the Callovian, with breakup between Australia–Antarctica and the northern part of Greater India commencing in the late Tithonian ŽFig. 18.. Continental extension between Australia and Antarctica began in the Late Jurassic and continued until mid-Cretaceous. The Andean-style magmatic arc along the Pacific Ocean margin of Australia persisted until the Late Jurassic, and was undergoing extension in the Cretaceous. An important change in palaeogeography occurred in the mid-Cretaceous. For most of the preceding 400 million years, a magmatic arc had lain either on the eastern continental margin of Australia, or was inferred to have been nearby off-shore separated by a marginal sea from the Gondwanan landmass. At 96 Ma, seafloor spreading began between Australia and Antarctica ŽFig. 19., and by 85 Ma the continental magmatic arc rotated eastward from Australia, initially as part of the LHR. Later, when the LHR split to form an interarc basin that grew into a marginal sea, the magmatic arc rotated farther east and is now an island arc recognised as the Tonga– Kermadec chain. On continental Australia, andesitic volcanism ceased, and the great foreland basin that had spread across Australia’s interior in the Early Cretaceous dried out. Australia’s palaeolatitude was

272

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

high throughout the Cretaceous, but, owing to global greenhouse conditions, no ice sheets were developed. At the beginning of the Palaeogene, Australia commenced its northward drift towards its present position. Seafloor spreading between Australia and Antarctica was at first slow, with a narrow Red Sea style of opening. Continental connections were maintained between Australia and Antarctica throughout most of the Palaeogene. Around 45 Ma, the rate of spreading between Australia and Antarctica increased sharply, possibly driven by the slow-down in India’s northward movement related to its collision with Asia ŽFig. 20.. By the mid-Oligocene, the Southern Ocean connected freely with the Pacific Ocean south of Tasmania, and the circum-Antarctic current became established, possibly triggering glaciation in Antarctica. Northern Australia reached the tropics by the beginning of the Miocene, and Australia has progressively moved northwards at 7 to 8 cm per year since ŽFig. 21.. Palaeoclimatic and palaeoenvironmental conditions in Australia in the Neogene can be related partly to this northern drift, and also to global climatic changes associated with the Pleistocene Ice Age. Acknowledgements The work summarised in this paper has been funded by project grants from the Australian Research Council over many years, and more recently by a grant to establish the Tectonics Special Research Centre. Jane Cunneen, Catherine Wetherley and Linden Wears assisted with drawing the diagrams. Lisa Gahagan at the Institute of Geophysics at the University of Texas kindly provided the base maps from the PLATES program to construct the Mesozoic–Cenozoic global palaeogeography. We wish to thank Professors M.W. McElhinny and E.C. Leitch for reviewing the manuscript constructively. Tectonics Special Research Centre publication No. 118, and a contribution to IGCP 440. References Aitchison, J.C., Ireland, T.R., Blake, M.C., Flood Jr., P.G., 1992. 530 Ma zircon age for ophiolite from the New England Orogen; oldest rocks known from eastern Australia. Geology 20, 125–128.

Astini, R.A., Benedetto, J.L., Vaccari, N.E., 1995. The early Paleozoic evolution of the Argentine Precordillera as a Laurentian rifted, drifted, and collided terrane: a geodynamic model. Geol. Soc. Am. Bull. 107, 253–273. Bachtadse, V., Heller, F., Kroener, A., 1983. Paleomagnetic investigations in the Hercynian mountain belt of western Europe. Tectonophysics 91, 285–299. Banks, M.R., Baillie, P.W., 1989. Late Cambrian to Devonian. In: Burrett, C.F., Martin, E.L. ŽEds.., Geology and Mineral Resources of Tasmania. Geol. Soc. Aust. Spec. Publ., vol. 15, pp. 182–237. Baillie, P.W., Li, Z.X., Powell, C.McA., Ryall, A.M., 1994. The tectonic framework of Western Australia’s Neoproterozoic to Recent sedimentary basins. In: Purcell, P.G., Purcell, R.R. ŽEds.., West Australian Basins Symposium, Proceedings of the Petroleum Exploration Society of Australia, Perth, pp. 45–62. Beck, R.A., Burbank, D.W., Sercombe, W.J., Riley, G.W., Barndt, J.K., Berry, J.R., Afzal, J., Khan, A.M., Jurgen, H., Metje, J., Cheema, A., Shafique, N.A., Lawrence, R.D., Khan, M.A., 1995. Stratigraphic evidence for an early collision between northwest India and Asia. Nature 373, 55–58. Bell, R.T., Jefferson, C.W., 1987. An hypothesis for an Australia–Canadian connection in the Late Proterozoic and the birth of the Pacific Ocean. Proceedings of Pacific Rim Congress 87, Gold Coast, Queensland, pp. 39–50. Besse, J., Courtillot, V., 1991. Revised and synthetic apparent polar wander path of the African, Eurasian, North American and Indian plates, and true polar wander since 200 Ma. J. Geophys. Res. 96, 4029–4050. Bond, G.C., Nickeson, P.A., Kominz, M.A., 1984. Breakup of a supercontinent between 625 Ma and 555 Ma: new evidence and implications for continental histories. Earth Planet. Sci. Lett. 70, 325–345. Borg, S.G., DePaolo, D.J., 1994. Laurentia, Australia, and Antarctica as a late Proterozoic supercontinent: constraints from isotopic mapping. Geology 22, 307–310. Bradshaw, M.T., Bradshaw, J., Murray, A.P., Needham, D.J., Spencer, L., Summons, R.E., Wilmot, J., Winn, S., 1994. Petroleum systems in West Australian basins. In: Purcell, P.G., Purcell, R.R. ŽEds.., West Australian Basins Symposium, Proceedings of the Petroleum Exploration Society of Australia, Perth, pp. 93–118. Briden, J.C., McClelland, E., Rex, D.C., 1993. Proving the age of a paleomagnetic pole: the case of the Ntonya Ring structure, Malawi. J. Geophys. Res. 98 ŽB2., 1743–1749. Burrett, C., Berry, R., 2000. Proterozoic Australia–Western United States ŽAUSWUS. fit between Laurentia and Australia. Geology 28, 103–106. Burrett, C., Long, J., Stait, B., 1990. Palaeozoic biogeography of Asian terranes derived from Gondwana. In: McKerrow, W.S., Scotese, C.R. ŽEds.., Palaeozoic Palaeogeography and Biogeography, Memoir, vol. 12. The Geological Society of London, pp. 163–174. Burrett, C., Richardson, R., 1980. Trilobite biogeography and Cambrian tectonic models. Tectonophysics 63, 155–192. Camacho, A., Symons, B., Schmidt, P.W., 1991. Geological and palaeomagnetic significance of the Kulgera Dyke Swarm, Musgrave Block, NT, Australia. Geophys. J. Int. 107, 37–45.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277 Caputo, M.V., Crowell, J.C., 1985. Migration of glacial centers across Gondwana during Paleozoic Era. Geol. Soc. Am. Bull. 96, 1020–1036. Cawood, P.A., Leitch, E.C., 1998. Initiation of subduction in the Proto-Pacific Ocean: constraints from eastern Gondwana. Geol. Soc. Aust. Abstr. 50, 11–14. Chen, Z., Li, Z.X., Powell, C.McA., Balme, B., 1994. An early Carboniferous paleomagnetic pole for Gondwanaland: new results from the Mount Eclipse Sandstone in the Ngalia Basin, central Australia. J. Geophys. Res. 99 ŽB2., 2909–2924. Crawford, A.J., Berry, R.F., 1992. Tectonic implications of Late Proterozoic–Early Palaeozoic igneous rock associations in western Tasmania. Tectonophysics 214, 37–56. Dalziel, I.W.D., 1991. Pacific margins of Laurentia and East Antarctica–Australia as a conjugate rift pair: evidence and implications for an Eocambrian supercontinent. Geology 19, 598–601. Dalziel, I.W.D., 1997. Neoproterozoic–Paleozoic geography and tectonics: review, hypothesis, environmental speculation. Geol. Soc. Am. Bull. 109, 16–42. Eisbacher, G.H., 1985. Late Proterozoic rifting, glacial sedimentation, and sedimentary cycles in the light of Windermere deposition, western Canada. Palaeogeogr., Palaeoclimatol., Palaeoecol. 51, 231–254. Embleton, B.J.J., 1984. Continental palaeomagnetism. In: Veevers, J.J. ŽEd.., Phanerozoic Earth History of Australia. Clarendon Press, Oxford, pp. 11–16. Embleton, B.J.J., Schmidt, P.W., 1996. Age and significance of magnetizations in dolerite dykes from the Northampton Block, Western Australia. Aust. J. Earth Sci. 32, 279–286. Evans, D.A., Li, Z.X., Kirschvink, J.J., Wingate, M.T.D., 2000. A high-quality mid-Neoproterozoic palaeomagnetic pole from South China, with implications for ice ages, regional stratigraphy, and the breakup configuration of Rodinia. Precambrian Res. 100, 313–334. Findlay, R.H., Brown, A.V., McClenaghan, M.P., 1991. Confirmation of the correlation between Lower Palaeozoic rocks in western Tasmania and northern Victoria Land, Antarctica, and a revised tectonic interpretation. Mem. Geol. Soc. Italy 46, 117–133. Flood, P.G., Aitchison, J.C., 1992. Late Devonian accretion of the Gamilaroi terrane to Gondwana: provenance linkage provided by quartzite clasts in the overlap sequence. Aust. J. Earth Sci. 39, 539–544. Flottmann, T., Gibson, G.M., Kleinschmidt, G., 1993. Structural ¨ continuity of the Ross and Delamerian orogens of Antarctica and Australia along the margin of the Paleo-Pacific. Geology 21, 319–322. Gibson, G.M., Ireland, T.R., 1996. Extension of Delamerian ŽRoss. orogen into western New Zealand: evidence from zircon ages and implication for crustal growth along the Pacific margin of Gondwana. Geology 24, 1087–1090. Giddings, J.W., 1976. Precambrian palaeomagnetism in Australia I: basic dykes and volcanics from the Yilgarn Block. Tectonophysics 30, 91–108. Glen, R.A., Laing, W.P., Parker, A.J., Rutland, R.W.R., 1977. Tectonic relationships between the Proterozoic Gawler and

273

Willyama orogenic domains, Australia. J. Geol. Soc. Aust. 28, 127–138. Goodge, J.W., 1997. Latest Neoproterozoic basin inversion of the Beardmore Group, central Transantarctic Mountains, Antarctica. Tectonics 16, 682–701. Grahn, Y., Caputo, M., 1992. Early Silurian glaciations in Brazil. Palaeogeogr., Palaeoclimatol., Palaeoecol. 99, 9–15. Gray, D.R., 1997. Structural and thermal considerations in the tectonic evolution of the Lachlan Fold Belt. In: Burg, J.P., Ford, M. ŽEds.., Orogeny Through Time. Geol. Soc. Lond. Spec. Publ., vol. 21, pp. 149–177. Grunow, A., Hanson, R., Wilson, T., 1996. Were aspects of Pan-African deformation linked to Iapetus opening? Geology 24, 1063–1066. Hargraves, R.B., Dawson, E.M., Van Houten, F.B., 1987. Palaeomagnetism and age of mid-Palaeozoic ring complexes in Niger, Western Africa, and tectonic implications. Geophys. J. R. Astron. Soc. 90, 705–729. Harrington, H.J., 1974. The Tasman Geosyncline in Australia. In: Denmead, A.K., Tweedale, G.W., Wilson, A.F. ŽEds.., The Tasman Geosyncline. Geological Society of Australia, Queensland Division, Brisbane, pp. 383–407. Hoffman, P.F., 1991. Did the breakout of Laurentia turn Gondwanaland inside-out? Science 252, 1409–1412. Hurley, N.F., Van der Voo, R., 1987. Paleomagnetism of Upper Devonian reefal limestones, Canning Basin, Western Australia. Geol. Soc. Am. Bull. 98, 138–146. Jell, P.A., 1974. Faunal provinces and possible planetary reconstruction of the Middle Cambrian. J. Geol. 82, 319–350. Kamp, P.J.J., 1991. Late Oligocene Pacific-wide tectonic event. Terra Nova 3, 65–69. Karlstrom, K.E., Williams, M.L., McLelland, J., Geissman, J.W., Ahall, K.I., 1999. Refining Rodinia: geological evidence for the Australia–western U.S. connection in the Proterozoic. GSA Today 9, 1–7. Keep, M., Powell, C.McA., Baillie, P.W., 1998. Neogene deformation of the North West Shelf, Australia. In: Purcell, P.G., Purcell, R.R. ŽEds.., The Sedimentary Basins of Western Australia 2: Proceedings of the Petroleum Exploration Society of Australia, Perth, pp. 81–91. Kent, D.V., Van der Voo, R., 1990. Palaeozoic palaeogeography from palaeomagnetism of the Atlantic-bordering continents. Palaeozoic Biogeography and Palaeogeography. In: McKerrow, W.S., Scotese, C.R. ŽEds.., Geol. Soc. London Memoir, vol. 12, pp. 49–56. Khramov, A.N., Petrova, G.N., Pechersky, D.M., 1981. Paleomagnetism of Soviet Union. In: McElhinny, M.W., Valencio, D.A. ŽEds.., Paleoreconstruction of the Continents. AGU Geodyn. Ser., vol. 2, pp. 177–194. Klootwijk, C.T., Gee, J.S., Peirce, J.W., Smith, G.M., McFadden, P.L., 1992. An early India–Asia contact: paleomagnetic constraints from Ninetyeast Ridge, ODP Leg 121. Geology 20, 395–398. Klootwijk, C., Giddings, J., 1993. Palaeomagnetic results of Upper Palaeozoic volcanics, northeastern Queensland, and Australia’s Late Palaeozoic APWP. NEO ’93 Conference Proceedings, pp. 617–627.

274

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

Knoll, A., Walter, M.R., 1992. Latest Proterozoic stratigraphy and earth history. Nature 356, 673–678. Korsch, R.J., Harrington, H.J., 1987. Oroclinal bending, fragmentation and deformation of terranes in the New England Orogen, eastern Australia. In: Leitch, E.C., Scheibner, E. ŽEds.., Terrane Accretion and Orogenic Belts. Am. Geophys. Union, Geodyn. Ser., vol. 19, pp. 129–139. Lackie, M.A., 1988. The palaeomagnetism and magnetic fabric of the Late Permian Dundee Rhyodacite, New England. In: Kleeman, L.D. ŽEd.., New England Orogen: Tectonics and Metallogenesis. University of New England, Armidale, pp. 157–165. Lamarche, G., Collot, J.-Y., Wood, R.A., Sosson, M., Sutherland, R., Deltiel, J., 1997. The Oligocene–Miocene Pacific– Australia plate boundary, south of New Zealand; evolution from oceanic spreading to strike–slip faulting. Earth Planet. Sci. Letts. 148, 129–139. Lawver, L.A., Gahagan, L.M., Coffin, M.F., 1992. The development of paleoseaways around Antarctica. Antarctic Res. Ser., Am. Geophys. Un. 56, 7–30. Li, Y., McWilliams, M., Sharps, R., Cox, A., Li, Y., Li, Q., Gao, Z., Zhang, Z., Zhai, Y., 1990. A Devonian paleomagnetic pole from red beds of the Tarim Block, China. J. Geophys. Res. 95, 19185–19198. Li, Z.X., 1997a. Did Rodinia form by the closure of a Mesoproterozoic Palaeo-Pacific Ocean? International Conference on Terrane Geology, Christchurch, pp. 99–102. Li, Z.X., 1997b. When was Rodinia born? Terra Nova 9, European Union of Geoscience EUG9, Strasbourg, France, p. 162. Li, Z.X., 1998. Tectonic evolution of the major East Asian lithospheric blocks since mid-Proterozoic — a synthesis. In: Martin, F.J., Chung, S.-L., Lo, C.-H., Lee, T.-Y. ŽEds.., Mantle Dynamics and Plate Interactions in East Asia. AGU Geodynamics Series, vol. 27. Am. Geophys. Un., Washington, DC, pp. 221–243. Li, Z.X., 2000. New palaeomagnetic results from the Acap dolomiteB of the Neoproterozoic Walsh Tillite, northwestern Australia. Precambrian Res. 100, 359–370. Li, Z.X., Baillie, P.W., Powell, C.McA., 1997. Relationship between northwestern Tasmania and East Gondwanaland in the Late CambrianrEarly Ordovician: Paleomagnetic evidence. Tectonics 16, 161–171. Li, Z.X., Chen, Z., Powell, C.McA., 1993. New Late Palaeozoic palaeomagnetic results from cratonic Australia, and revision of the Gondwanan apparent polar wander path. Explor. Geophys. 24, 263–268. Li, Z.X., Li, X.H., Kinny, P.D., Wang, J., 1999. The breakup of Rodinia: did it start with a mantle plume beneath South China? Earth Planet. Sci. Lett. 173, 171–181. Li, Z.X., Powell, C.McA., 1993. Late Proterozoic to early Paleozoic paleomagnetism and the formation of Gondwanaland. In: Findlay, R.H., Unrug, R., Banks, M.R., Veevers, J.J. ŽEds.., Gondwana. Assembly, Evolution and Dispersal, vol. 8. A.A. Balkema, Rotterdam, pp. 9–21. Li, Z.X., Zhang, L., Powell, C.McA., 1995. South China in Rodinia: part of the missing link between Australia–East Antarctica and Laurentia? Geology 23, 407–410. Li, Z.X., Zhang, L., Powell, C.McA., 1996. Positions of the East

Asian cratons in the Neoproterozoic supercontinent Rodinia. In: Li, Z.X., Metcalfe, I., Powell, C.McA. ŽEds.., Breakup of Rodinia and Gondwanaland and Assembly of Asia. Aust. J. Earth Sci., vol. 43, pp. 593–604. Lopez-Gamundi, O.R., Espejo, I.S., Conaghan, P.J., Powell, C.McA., 1994. Southern South America. In: Veevers, J.J., Powell, C.McA. ŽEds.., Permian–Triassic Pangean basins and foldbelts along the Panthalassan margin of Gondwanaland. Geol. Soc. Am. Memoir, vol. 184, pp. 281–329. Mac Niocaill, C., Smethurst, M.A., 1994. Palaeozoic palaeogeography of Laurentia and its margins: a reassessment of palaeomagnetic data. Geophys. J. Int. 116, 715–725. Mac Niocaill, C., van der Pluijm, B.A., van der Voo, R., 1997. Ordovician paleogeography and the evolution of the Iapetus ocean. Geology 25, 159–162. McElhinny, M.W., Lock, J., 1996. IAGA paleomagnetic database with Access. Serv. Geophys. 17, 575–591 ŽGPDB v.3.3 at http:rrwww.ngdc.noaa.govrsegrpotfldrpaleo.html.. McMenamin, M.A.S., McMenamin, D.L.S., 1990. The Emergence of Animals: the Cambrian Breakthrough. Colombia Univ. Press, New York. McWilliams, M.O., 1981. Palaeomagnetism and Precambrian tectonic evolution of Gondwana. In: Kroner, A. ŽEd.., Precam¨ brian Plate Tectonics, Developments in Precambrian Geology, vol. 4. Elsevier, Amsterdam, pp. 649–687. McWilliams, M.O., Kroner, A., 1981. Paleomagnetism and tec¨ tonic evolution of the Pan-African Damara Belt, South Africa. J. Geophys. Res. 86, 5147–5162. Meert, J.G., Van der Voo, R., 1996. Paleomagnetic and 40Arr39Ar study of the Sinyai Dolerite, Kenya: implications for Gondwana assembly. J. Geol. 104, 131–142. Merrill, R.T., McElhinny, M.W., McFadden, P.L., 1996. The magnetic field of the Earth. International Geophysics Series, vol. 63. Academic Press, San Diego, 531 pp. Metcalfe, I., 1996. Gondwanaland dispersion, Asian accretion and evolution of eastern Tethys. In: Li, Z.X., Metcalfe, I., Powell, C. ŽEds.., Breakup of Rodinia and Gondwanaland and Assembly of Asia. Aust. J. Earth Sci., vol. 43, pp. 605–623. Moores, E.M., 1991. Southwest U.S.–East Antarctic ŽSWEAT. connection: a hypothesis. Geology 19, 425–428. Moreau, C., Demaiffe, D., Bellion, Y., Boullier, A.-M., 1994. A tectonic model for the location of Palaeozoic ring complexes in Aır ¨ ŽNiger, West Africa.. Tectonophysics 234, 129–146. Mortimer, G.E., Cooper, J.A., James, P.R., 1987. U–Pb and Rb–Sr geochronology and geological evolution of the Harts Range ruby mine area of the Arunta Inlier, central Australia. Lithos 20, 445–467. Munker, C., Cooper, R.A., 1995. The island arc setting of a New ¨ Zealand Cambrian volcano-sedimentary sequence: Implications for the evolution of the SW Pacific Gondwana fragments. J. Geol. 103, 687–700. Murray, C.G., Fergusson, C.L., Flood, P.G., Whitaker, W.G., Korsch, R.J., 1987. Plate tectonic model for the Carboniferous evolution of the New England Fold Belt. Aust. J. Earth Sci. 34, 213–236. Palmer, A.R., 1974. Search for the Cambrian world. Am. Scientist 62, 216–224.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277 Park, J.K., 1997. Paleomagnetic evidence for low-latitude glaciation during deposition of the Neoproterozoic Rapitan Group, Mackenzie Mountains, N.W.T., Canada. Can. J. Earth Sci. 34, 34–49. Park, J.K., Buchan, K.L., Harlan, S.S., 1995. A proposed giant radiating dyke swarm fragmented by the separation of Laurentia and Australia based on paleomagnetism of ca. 780 Ma mafic intrusions in western North America. Earth Planet. Sci. Lett. 132, 129–139. Pelechaty, S.M., 1996. Stratigraphic evidence for the Siberia– Laurentia connection and Early Cambrian rifting. Geology 24, 719–722. Pimentel, M.M., Fuck, R.A., 1992. Neoproterozoic crustal accretion in central Brazil. Geology 20, 375–379. Powell, C.McA., 1983. Tectonic relationship between the Late Ordovician and Late Silurian palaeogeographies of southeastern Australia. J. Geol. Soc. Aust. 30, 353–373. Powell, C.McA., 1984. Ordovician–earliest Silurian: marginal sea and island arc; Silurian to mid-Devonian: dextral transtensional margin; Late Devonian and Early Carboniferous: continental magmatic arc along the eastern edge of the Lachlan and Thomson Fold Belts. In: Veevers, J.J. ŽEd.., Phanerozoic earth history of Australia. Clarendon Press, Oxford, pp. 290–340. Powell, C.McA., 1996. Breakup and dispersal of the Rodinia supercontinent: implications for resource exploration. 13th Geological Convention, Canberra. Geol. Soc. Aust. Abstr. 41, 351. Powell, C.McA., Baillie, P.W., Conaghan, P.J., Turner, N.J., 1993b. The turbiditic mid-Palaeozoic Mathinna Group, northeast Tasmania. Aust. J. Earth Sci. 40, 169–196. Powell, C.McA., Dalziel, I.W.D., Li, Z.X., McElhinny, M.W., 1995. Did Pannotia, the latest Neoproterozoic southern supercontinent, really exist? Eos Trans. 76 Ž46., 577. Powell, C.McA., Johnson, B.D., Veevers, J.J., 1980. A revised fit of East and West Gondwanaland. Tectonophysics 63, 13–29. Powell, C.McA., Li, Z.X., 1994. Reconstruction of the Panthalassan margin of Gondwanaland. In: Veevers, J.J., Powell, C.McA. ŽEds.., Permian–Triassic Pangean Basins and Foldbelts along the Panthalassan Margin of Gondwanaland. Geol. Soc. Am. Mem., vol. 184. Geol. Soc. Am., Boulder, Colorado, pp. 5–9. Powell, C.McA., Roots, S.R., Veevers, J.J., 1988. Pre-breakup continental extension in Eastern Gondwanaland and the early opening of the eastern Indian Ocean. Tectonophysics 155, 261–283. Powell, C.McA., Li, Z.X., McElhinny, M.W., Meert, J.G., Park, J.K., 1993a. Paleomagnetic constraints on timing of the Neoproterozoic breakup of Rodinia and the Cambrian formation of Gondwana. Geology 21, 889–892. Powell, C.McA., Preiss, W.V., Gatehouse, C.G., Krapez, B., Li, Z.X., 1994. South Australian record of a Rodinian epicontinental basin and its mid-Neoproterozoic breakup Ž ; 700 Ma. to form the Palaeo-Pacific Ocean. Tectonophysics 237, 113– 140. Powell, C.McA., Veevers, J.J., 1987. Namurian uplift in Australia and South America triggered the main Gondwanan glaciation. Nature 326, 177–179. Powell, C.McA., Young, G., 1995. Are Neoproterozoic glacial

275

deposits preserved on the margins of Laurentia related to the fragmentation of two supercontinents?: comment and reply. Geology 23, 1053–1054. Prave, A.R., 1996. Tale of three cratons: tectonostratigraphic anatomy of the Damara orogen in northwestern Namibia and the assembly of Gondwana. Geology 24, 1115–1118. Preiss, W.V., 2000. The Adelaide Geosyncline of South Australia and its significance in Neoproterozoic continental reconstruction. Precambrian Res. 100, 21–63. Rainbird, R.H., Jefferson, C.W., Young, G.M., 1996. The early Neoproterozoic sedimentary Succession B of northwestern Laurentia: correlations and paleogeographic significance. Geol. Soc. Am. Bull. 108, 454–470. Rapalini, A.E., 1998. Syntectonic magnetisation of the midPalaeozoic Sierra Grande Formation: further constraints on the tectonic evolution of Patagonia. J. Geol. Soc. 155, 105–114. Rapalini, A.E., Tarling, D.H., 1993. Multiple magnetizations in the Cambrian–Ordovician carbonate platform of the Argentine Precordillera and their tectonic implications. Tectonophysics 227, 49–62. Rich, T.H., Young, G.C., 1996. Vertebrate biogeographic evidence for connections of the East and Southeast Asian blocks with Gondwanaland. Aust. J. Earth Sci. 43, 625–634. Ross, G.M., 1991. Tectonic setting of the Windermere Group revisited. Geology 19, 1125–1128. Ross, G.M., Parrish, R.R., Winston, D., 1992. Provenance and U–Pb geochronology of the Mesoproterozoic Belt Supergroup Žnorthwestern United States.: implications for age of deposition and pre-Panthalassa plate reconstructions. Earth Planet. Sci. Lett. 113, 57–76. Schmidt, P.W., Embleton, B.J.J., Palmer, H.C., 1987. Pre and post folding magnetization from the Devonian Snowy River Volcanics and Buchan Caves Limestone, Victoria. Geophys. J. R. Astron. Soc. 91, 155–170. Schmidt, P.W., Morris, W.A., 1977. An alternative view of Gondwana Palaeozoic apparent polar wander path. Can. J. Earth Sci. 14, 2674–2678. Scotese, C.R., Barrett, S.F., 1990. Gondwana’s movement over the South Pole during the Palaeozoic: evidence from lithological indicators of climate. In: McKerrow, W.S., Scotese, C.R. ŽEds.., Palaeozoic Palaeogeography and Biogeography. Geol. Soc. Mem., vol. 12. The Geological Society of London, pp. 75–85. Sengor, ¨ A.M.C., 1987. Tectonics of the Tethysides: orogenic collage development in a collisional setting. Annu. Rev. Earth Planet. Sci. 15, 213–244. Sengor, ¨ A.M.C., Natal’in, B.A., Burtman, V.S., 1993. Evolution of the Altaid tectonic collage and Palaeozoic crustal growth in Eurasia. Nature 364, 299–307. Shaw, R.D., Etheridge, M.A., Lambeck, K., 1991. Development of the Late Proterozoic to mid-Paleozoic intracratonic Amadeus Basin: a key to understanding tectonic forces in plate interiors. Tectonics 10, 688–721. Smethurst, M.A., Khramov, A.N., Torsvik, T.H., 1998. The Neoproterozoic and Palaeozoic palaeomagnetic data for the Siberian Platform: from Rodinia to Pangea. Earth Sci. Rev. 43, 1–24. Soesoo, A., Bons, P.D., Gray, D.R., Foster, D.A., 1997. Divergent

276

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277

double subduction: tectonic and petrologic consequences. Geology 25, 755–758. Stewart, J.H., 1972. Initial deposits in the Cordilleran geosyncline: evidence of a Late Precambrian Ž -850 Ma. continental separation. Geol. Soc. Am. Bull. 83, 1345–1360. Storey, M., Mahoney, J.J., Saunders, A.D., Duncan, R.A., Kelley, S.O., Coffin, M.F., 1995. Timing of hot-spot related volcanism and the breakup of Madagascar and India. Science 267, 852–855. Stump, E., 1995. The Ross Orogen of the Transantarctic Mountains. Cambridge Univ. Press, New York, 284 p. Tanaka, H., Idnurm, M., 1994. Palaeomagnetism of Proterozoic mafic intrusions and host rocks of the Mount Isa Inlier, Australia: revisited. Precambrian Res. 69, 241–258. Torsvik, T.H., Smethurst, M.A., Meert, J.G., Van der Voo, R., McKerrow, W.S., Brasier, M.D., Sturt, B.A., Walderhaug, H.J., 1996. Continental break-up and collision in the Neoproterozoic and Palaeozoic — a tale of Baltica and Laurentia. Earth Sci. Rev. 40, 229–258. Torsvik, T.H., Smethurst, M.A., Van der Voo, R., Trench, A., Abrahamsen, N., Halvorsen, E., 1992. Baltica, a synopsis of Vendian–Permian palaeomagnetic data and their palaeomagnetic implications. Earth Sci. Rev. 33, 133–152. Trompette, R., 1994. Geology of Western Gondwana. Balkema, Rotterdam, The Netherlands, 350 pp. Turner, S.P., Adams, C.J., Flottmann, T., Foden, J.D., 1993. ¨ Geochemical and geochronological constraints on the Glenelg River Complex, western Victoria. Aust. J. Earth Sci. 40, 275–292. Unrug, R., 1997. Rodinia to Gondwana: the geodynamic map of Gondwana supercontinent assembly. GSA Today 7, 1–6. Van der Voo, R., 1988. Paleozoic paleogeography of North America, Gondwana, and displaced terranes: comparison of paleomagnetism with paleoclimatology and biogeographical patterns. Geol. Soc. Am. Bull. 100, 311–324. Van der Voo, R., 1990. Phanerozoic paleomagnetic poles from Europe and North America and comparisons with continental reconstructions. Rev. Geophys. 28, 167–206. Van der Voo, R., 1993. Paleomagnetism of the Atlantic, Tethys and Iapetus Oceans. Cambridge Univ. Press, Cambridge. Van der Voo, R., 1994. True polar wandering during the middle Paleozoic? Earth Planet. Sci. Lett. 122, 239–243. Veevers, J.J. ŽEd.., 1984. Phanerozoic Earth History of Australia, Oxford, England. Clarendon Press, 418 pp. Veevers, J.J., 1989. Middlerlate Triassic Ž230"5 Ma. singularity in the stratigraphic record and magmatic history of the Pangean heat anomaly. Geology 17, 784–787. Veevers, J.J., Li, Z.X., 1991. Review of seafloor spreading around Australia, II, Marine magnetic anomaly modelling. Aust. J. Earth Sci. 38, 391–408. Veevers, J.J., Powell, C.McA., 1984. Comparative tectonics of the transverse structural zones of Australia and North America. In: Veevers, J.J. ŽEd.., Phanerozoic Earth History of Australia. Clarendon Press, Oxford, pp. 340–348. Veevers, J.J., Powell, C.McA., 1987. Late Palaeozoic glacial episodes in Gondwanaland reflected in transgressive-regres-

sive depositional sequences in Euramerica. Geol. Soc. Am. Bull. 98, 475–487. Veevers, J.J., Powell, C.McA., Johnson, B.D., 1980. Seafloor constraints on the reconstruction of Gondwanaland. Earth Planet. Sci. Lett. 51, 435–444. Veevers, J.J., Powell, C.McA., Roots, S.R., 1991. Review of seafloor spreading around Australia, I: synthesis of the patterns of spreading. Aust. J. Earth Sci. 38, 373–389. Veevers, J.J., Powell, C.McA., 1994. Permian–Triassic Pangean basins and foldbelts along the Panthalassan margin of Gondwanaland. Geol. Soc. Am. Mem. 184, 368 pp. Veevers, J.J., Tewari, R.C., 1995a. Permian–Carboniferous and Permian–Triassic magmatism in the rift zone bordering the Tethyan margin of southern Pangea. Geology 23, 467–470. Veevers, J.J., Tewari, R.C., 1995b. Gondwana master basin of Peninsular India between Tethys and the interior of the Gondwanaland province of Pangea. Geol. Soc. Am. 187, 72 pp. Veevers, J.J., Walter, M.R., Scheibner, E., 1997. Neoproterozoic tectonics of Australia–Antarctica and Laurentia and the 560 Ma birth of the Pacific ocean reflect the 400 Ma Pangean supercycle. J. Geol. 105, 225–242. Walker, N.W., 1996. Testing the ASWEATB hypothesis: ages of detrital zircons in upper Neoproterozoic siliciclastic rocks from east Antarctica and southwest Laurentia. Geol. Soc. Am. Abstr. Prog. 28, 121 pp. Walter, M.R., Grey, K., Williams, I., Calver, C.R., 1994. Stratigraphy of the Neoproterozoic to early Palaeozoic Savory Basin, Western Australia, and correlation with the Amadeus and Officer Basins. Aust. J. Earth Sci. 41, 533–546. Walter, M.R., Veevers, J.J., 1997. Australian Neoproterozoic palaeogeography, tectonics, and supercontinental connections. AGSO J. Aust. Geol. Geophys. 17, 73–92. Walter, M.R., Veevers, J.J., Calver, C.R., Grey, K., 1995. Neoproterozoic stratigraphy of the Centralian Superbasin, Australia. Precambrian Res. 73, 173–195. Walter, M.R., Veevers, J.J., Calver, C.R., Gorjan, P., Hill, A.C., 2000. Dating the 840–544 Ma Neoproterozoic interval by isotopes of strontium, carbon, and sulfur in seawater, and some interpretative models. Precambrian Res. 100, 371–433. Wang, Y., Boucot, A.J., Rong, J.Y., Yang, X.C., 1984. Silurian and Devonian biogeography of China. Geol. Soc.Am. Bull. 95, 265–279. Webby, B.D., 1978. History of the Ordovician continental platform and shelf margin of Australia. J. Geol. Soc. Aust. 25, 41–63. Wells, A.T., Moss, F.J., 1983. The Ngalia Basin, Northern Territory: stratigraphy and structure. Aust. Bur. Min. Res. Bull. 212, 88 p. Wingate, M.T.D., Campbell, I.H., Compston, W., Gibson, G.M., 1998. Ion micropobe U–Pb ages for Neoproterozoic basaltic magmatism in south-central Australia and implications for the breakup of Rodinia. Precambrian Res. 87, 135–159. Wingate, M.T.D., Giddings, J.W., 2000. Age and palaeomagnetism of the Mundine Well dyke swarm, Western Australia: implications for an Australia–Laurentia connection at 755 Ma. Precambrian Res. 100, 335–357.

Z.X. Li, C.McA. Powellr Earth-Science ReÕiews 53 (2001) 237–277 Yin, A., Nie, S., 1993. An indentation model for the North and South China collision and the development of the Tan-Lu and Honam fault systems, eastern Asia. Tectonics 12, 801–813. Young, G.C., 1990. Devonian vertebrate distribution patterns and cladistic analysis of palaeogeographic hypotheses. In: McKerrow, W.S., Scotese, C.R. ŽEds.., Palaeozoic Palaeogeography and Biogeography. Geol. Soc. Lond. Mem., vol. 12, pp. 243–255. Young, G.C., 1993. Vertebrate faunal provinces in the Middle Palaeozoic. In: Long, J.A. ŽEd.., Palaeozoic Vertebrate Biostratigraphy and Biogeogeography. Belhaven Press, London, pp. 293–323. Young, G.M., 1992. Late Proterozoic stratigraphy and the Canada–Australia connection. Geology 20, 215–218. Young, G.M., 1995. Are Neoproterozoic glacial deposits preserved on the margins of Laurentia related to the fragmentation of two supercontinents? Geology 23, 153–156. Zhao, X.X., Coe, R.S., 1987. Palaeomagnetic constraints on the collision and rotation of North and South China. Nature 327, 141–144. Zhao, X.X., Coe, R.S., Gilder, S.A., Frost, G.M., 1996. Palaeomagnetic constraints on the palaeogeography of China: implications for Gondwanaland. In: Li, Z.X., Metcalfe, I., Powell, C.McA. ŽEds.., Breakup of Rodinia and Gondwanaland and Assembly of Asia. Aust. J. Earth Sci., vol. 43, pp. 643–672. Zhao, X.X., Coe, R.S., Smith, R.M., Wu, X., Xie, D.K., Gilder, S.A., Pfoutz, H., 1997. New Cambrian and Ordovician paleomagnetic poles from Tarim and their paleogeographic implications. Eos Trans. 78 Ž46., F17. Zonenshain, L.P., Kuzmin, M.I., Natapov, L.M., 1990. Geology of the USSR: a plate tectonic synthesis. In: Page, B.M. ŽEd.., Geodynamics Series, vol. 21. Am. Geophys. Un., Washington, DC.

277

Chris Powell is the Professor of Geology at The University of Western Australia. He graduated with first-class BSc ŽHons. degree from the University of Queensland in 1964, and a PhD in Geology from the University of Tasmania in 1968. After a NASA Postdoctoral Fellowship at Northwestern University, Illinois, in 1967–1968 and an Assistant Professorship at the University of Cincinnati from 1968 to 1970, he joined Macquarie University as a Lecturer in 1970, becoming Associate Professor in 1979. In 1987, he became Head of the School of Earth Sciences, a position that he held until he took up the Chair of Geology at The University of Western Australia in 1990. He is the Director of the Tectonics Special Research Centre.

Zheng-Xiang Li obtained his BSc in seismological geology from Peking University in 1982, and PhD in palaeomagnetism and tectonics from Macquarie University in 1989. He moved to the Department of Geology and Geophysics at The University of Western Australia to establish a new palaeomagnetism laboratory in 1990. He is currently a Senior Research Fellow with the Tectonics Special Research Centre, which was established in 1997.