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Tasman Fold Belt System or orogenic system—introduction
Tectonophysics, 48 (1978) 153-157 @I Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
TAS~A~ FOLD BELT SYSTEM OR OROGE~IC INTRODUCTION *
153
SYSTEM -
E. SCHEIBNER Geological Survey
of New
South Wafes, Sydney,
N.S. W. ~~u~trQt~ff~
(Received for publication January 5, 1978)
ABSTRACT Scheibner, E., 1978. Tasman Fold Belt System or Orogenic System - Introduction. In: E. Scheibner (Editor), The Phanerozoic Structure of Australia and Variations in Tectonic Style. Tectonophysics, 48: 153-157. The Tasman Fold Belt System and its segments are defined. THE TASMAN FOLD BELTS SYSTEM AND ITS SEGMENTS
The Tasman FoEd Belt System (Scheibner, 1974) or Orogenic System is a composite tectogenic or structural feature constituting the eastern part of Australia (Fig. 1). It is composed of several fold belts, erogenic belts, orogenie zones or orogens (these are synonyms) which developed during the Palaeozoic. Because of its composite character it is called a system. The erogenic system is divided by major lineaments, which appear to be fossil fracture zones, into several segments (Fig. 2). These segments perhaps represent remains of individual lithospheric blocks and subplates which were active from time to time during the Palaeozoic. Today these subp? xs are welded together into the Australian plate. The Hodgkinson segment is north of the Clark River and Burdekin River Lineaments. The northern or Queensland segment, occurs between the above-mentioned lineaments and the Darling River and Cobar-Inglewood Lineaments, and large parts of it are concealed under the Meso-Cainozoic cover. The central or New South WaiesVictorian segment occurs between the Darling River and Cobb-Inglewood Lineaments on the north and the hypothetical fracture zone bounding the southern continental margin or simply the southern coast on the south. The remaining segment to the south is the southern or Tasmanian segment (Fig. 2).
* Published with the permission of the Under-Secretary, Mines Department of New South Wales.
Palmerville Burciekin Weatherby Cork
i?eult River
Structure
Fault
Diamrmtina Lake
River
Blanche
Par&ma
Lineament
Fait
Fault
Nundooka
Fault
Anabama-R&an Cygnet
Fault
Fault
________-_--
Fault
I I I I I / /
155
Differences in stratigraphy, igneous activity, structural deformation and generally in tectonic history can be observed between the segments. As is usual with classifications of regional geological features there are problems with details. For example, there are differences between the sections of the New England Fold Belt which lie in the northern and central segments. The central segment of the Tasman Fold Belt System is internally complicated and can be further subdivided into smaller blocks bounded by the Lachlan River and Murray River Lineaments. The eastern part of the Tasman Fold Belt System or Orogenic System is described by Day et al. who call this system the Tasman Orogenic Zone. These authors recognize from north to south the Hodgkinson-Broken River Orogen and the New England Orogen. The Sydney-Bowen Basin separates this eastern zone from the areas to the west. The Thomson Fold Belt makes up the western part of the northern or Queensland segment and is described by Murray and Kirkegaard for the Symposium. The Lachlan Fold Belt in New South Wales is described by Gilligan and Scheibner and in Victoria by VandenBerg. The Tasmanian segment is described by Williams. There is some disagreement in respect of the Early Palaeozoic Kanmantoo Fold Belt which occurs mainly in South Australia but also in northwestern New South Wales (Scheibner, 1974) and western Victoria (cf. VandenBerg, this Symposium). According to Thomson (this Symposium) the Kanmantoo and the Adelaide Fold Belt (Scheibner, 1972, 1974) represent one folded belt named the Delamerian Fold Belt (formed during the Cambrian-Ordovician Delamerian Orogeny). The problem is that the Adelaide Fold Belt developed as an intracratonic feature in the Australian platform, while the Kanmantoo Fold Belt developed at a plate margin from a marginal mobile zone and has an erogenic character. The Tasman Fold Belt or Orogenic System can be defined as a composite erogenic belt (tectogenic or structural category), which has developed from several pre-cratonic (equals geosynclinal of other authors) tectonic provinces ~stratote~toni~ catego~) during the Palaeozoic in eastern Australia. Tectonic analysis indicates that these pre-eratonic provinces were mobile zones marginal to the Australian plate, probably similar in tectonic setting to that of the present southwest Pacific. Tectogenic activity generally terminated in eastern Australia at the end of the Palaeozoic, although some activity continued during the Mesozoic in the present northeastern seaboard region (cf. Day et al., this Symposium). The eastern boundary of the Tasman Fold Belt System could be taken along the present margin of the continent. However, older elements of microcontinents found in the southwestern Pacific also belong to the mainland in a stratotectonic sense. -_ Fig. 1. Schematic map of the Tasman ent fold belts. Reference on Fig. 2,
Fold Belt System showing
distribution
of constitu-
REFERENCE
‘1
/’
Faults
/j jj
,,.-‘:::...
Lineaments
157
Many parts of the western boundary are in dispute. If we separate the Kanmantoo Fold Belt from the Adelaide Fold Belt, then in the southwest the boundary could be chosen along the Cygnet Fault, then along the contact of the Kanmantoo complexes, the Anabama-Redan Fault Zone, and then along the Nundooka Fault. In the north the boundary could be chosen along the Palmerville Fault on the eastern side of the Cape York Peninsula this means along the “Tasman Line” of Hill (1951), further to the south along the Burdekin River Fault. In the section between the 3roken River Block and the Broek River Embayment, the western boundary of the Tasman Fold Belt System is very uncertain because it is concealed under the Late Palaeozoic and Meso-Cainozoic cover (cf. Marsden, 19’72). On Fig. 1 one of the possible choices of the position of this boundary is shown. REFERENCES Hill, D., 1951. Geology. In: Handbook of Queensland, Aust. N.Z. Assoc. Adv. Sci., Brisbane, pp. 13-24. Marsden, M.A.H., 1972. The Devonian history of northeastern Australia. J. Geol. Sot. Aust., 19 (l), 125-162. Scheibner, E., 1972. The Kanmantoo Pre-Cratonic Province in New South Wales. Q. Notes Geol. Surv. N.S.W., 7: l-10. Seheibner, E., 1974. Fossil fracture zones (transform faults); segmentation and correlation problems in the Tasman Fold Belt System. In: A.K. Demead, G.W. Tweedale and A.F. Wilson (Editors), The Tasman Geosyncline - A Symposium in Honour of Professor Dorothy Hill. Queensl. Div. Geol. Sot. Aust., Brisbane, pp. 65-96.
-. _.-____
---..-.-
___~_.
--. --_-
-.--
Fig. 2. Schematic map showing the segments of the Tasman Fold Belt System.
TAS~A~ FOLD BELT SYSTEM OR OROGE~IC INTRODUCTION *
153
SYSTEM -
E. SCHEIBNER Geological Survey
of New
South Wafes, Sydney,
N.S. W. ~~u~trQt~ff~
(Received for publication January 5, 1978)
ABSTRACT Scheibner, E., 1978. Tasman Fold Belt System or Orogenic System - Introduction. In: E. Scheibner (Editor), The Phanerozoic Structure of Australia and Variations in Tectonic Style. Tectonophysics, 48: 153-157. The Tasman Fold Belt System and its segments are defined. THE TASMAN FOLD BELTS SYSTEM AND ITS SEGMENTS
The Tasman FoEd Belt System (Scheibner, 1974) or Orogenic System is a composite tectogenic or structural feature constituting the eastern part of Australia (Fig. 1). It is composed of several fold belts, erogenic belts, orogenie zones or orogens (these are synonyms) which developed during the Palaeozoic. Because of its composite character it is called a system. The erogenic system is divided by major lineaments, which appear to be fossil fracture zones, into several segments (Fig. 2). These segments perhaps represent remains of individual lithospheric blocks and subplates which were active from time to time during the Palaeozoic. Today these subp? xs are welded together into the Australian plate. The Hodgkinson segment is north of the Clark River and Burdekin River Lineaments. The northern or Queensland segment, occurs between the above-mentioned lineaments and the Darling River and Cobar-Inglewood Lineaments, and large parts of it are concealed under the Meso-Cainozoic cover. The central or New South WaiesVictorian segment occurs between the Darling River and Cobb-Inglewood Lineaments on the north and the hypothetical fracture zone bounding the southern continental margin or simply the southern coast on the south. The remaining segment to the south is the southern or Tasmanian segment (Fig. 2).
* Published with the permission of the Under-Secretary, Mines Department of New South Wales.
Palmerville Burciekin Weatherby Cork
i?eult River
Structure
Fault
Diamrmtina Lake
River
Blanche
Par&ma
Lineament
Fait
Fault
Nundooka
Fault
Anabama-R&an Cygnet
Fault
Fault
________-_--
Fault
I I I I I / /
155
Differences in stratigraphy, igneous activity, structural deformation and generally in tectonic history can be observed between the segments. As is usual with classifications of regional geological features there are problems with details. For example, there are differences between the sections of the New England Fold Belt which lie in the northern and central segments. The central segment of the Tasman Fold Belt System is internally complicated and can be further subdivided into smaller blocks bounded by the Lachlan River and Murray River Lineaments. The eastern part of the Tasman Fold Belt System or Orogenic System is described by Day et al. who call this system the Tasman Orogenic Zone. These authors recognize from north to south the Hodgkinson-Broken River Orogen and the New England Orogen. The Sydney-Bowen Basin separates this eastern zone from the areas to the west. The Thomson Fold Belt makes up the western part of the northern or Queensland segment and is described by Murray and Kirkegaard for the Symposium. The Lachlan Fold Belt in New South Wales is described by Gilligan and Scheibner and in Victoria by VandenBerg. The Tasmanian segment is described by Williams. There is some disagreement in respect of the Early Palaeozoic Kanmantoo Fold Belt which occurs mainly in South Australia but also in northwestern New South Wales (Scheibner, 1974) and western Victoria (cf. VandenBerg, this Symposium). According to Thomson (this Symposium) the Kanmantoo and the Adelaide Fold Belt (Scheibner, 1972, 1974) represent one folded belt named the Delamerian Fold Belt (formed during the Cambrian-Ordovician Delamerian Orogeny). The problem is that the Adelaide Fold Belt developed as an intracratonic feature in the Australian platform, while the Kanmantoo Fold Belt developed at a plate margin from a marginal mobile zone and has an erogenic character. The Tasman Fold Belt or Orogenic System can be defined as a composite erogenic belt (tectogenic or structural category), which has developed from several pre-cratonic (equals geosynclinal of other authors) tectonic provinces ~stratote~toni~ catego~) during the Palaeozoic in eastern Australia. Tectonic analysis indicates that these pre-eratonic provinces were mobile zones marginal to the Australian plate, probably similar in tectonic setting to that of the present southwest Pacific. Tectogenic activity generally terminated in eastern Australia at the end of the Palaeozoic, although some activity continued during the Mesozoic in the present northeastern seaboard region (cf. Day et al., this Symposium). The eastern boundary of the Tasman Fold Belt System could be taken along the present margin of the continent. However, older elements of microcontinents found in the southwestern Pacific also belong to the mainland in a stratotectonic sense. -_ Fig. 1. Schematic map of the Tasman ent fold belts. Reference on Fig. 2,
Fold Belt System showing
distribution
of constitu-
REFERENCE
‘1
/’
Faults
/j jj
,,.-‘:::...
Lineaments
157
Many parts of the western boundary are in dispute. If we separate the Kanmantoo Fold Belt from the Adelaide Fold Belt, then in the southwest the boundary could be chosen along the Cygnet Fault, then along the contact of the Kanmantoo complexes, the Anabama-Redan Fault Zone, and then along the Nundooka Fault. In the north the boundary could be chosen along the Palmerville Fault on the eastern side of the Cape York Peninsula this means along the “Tasman Line” of Hill (1951), further to the south along the Burdekin River Fault. In the section between the 3roken River Block and the Broek River Embayment, the western boundary of the Tasman Fold Belt System is very uncertain because it is concealed under the Late Palaeozoic and Meso-Cainozoic cover (cf. Marsden, 19’72). On Fig. 1 one of the possible choices of the position of this boundary is shown. REFERENCES Hill, D., 1951. Geology. In: Handbook of Queensland, Aust. N.Z. Assoc. Adv. Sci., Brisbane, pp. 13-24. Marsden, M.A.H., 1972. The Devonian history of northeastern Australia. J. Geol. Sot. Aust., 19 (l), 125-162. Scheibner, E., 1972. The Kanmantoo Pre-Cratonic Province in New South Wales. Q. Notes Geol. Surv. N.S.W., 7: l-10. Seheibner, E., 1974. Fossil fracture zones (transform faults); segmentation and correlation problems in the Tasman Fold Belt System. In: A.K. Demead, G.W. Tweedale and A.F. Wilson (Editors), The Tasman Geosyncline - A Symposium in Honour of Professor Dorothy Hill. Queensl. Div. Geol. Sot. Aust., Brisbane, pp. 65-96.
-. _.-____
---..-.-
___~_.
--. --_-
-.--
Fig. 2. Schematic map showing the segments of the Tasman Fold Belt System.