- Email: [email protected]
Preface to special issue of Precambrian Research on the impact of SHRIMP on understanding the Precambrian
Precambrian Research 183 (2010) vii–ix
Contents lists available at ScienceDirect
Precambrian Research journal homepage: www.elsevier.com/locate/precamres
Preface
Preface to special issue of Precambrian Research on the impact of SHRIMP on understanding the Precambrian
The SHRIMP-I instrument (Fig. 1; Sensitive High Resolution Ion Microprobe) was the mid-1970s brainchild and invention of Bill Compston, that was designed by Steve Clement and built by a team of the Research School of Earth Sciences (RSES) at the Australian National University. It was specifically designed to be capable for the first time of doing in situ U-Pb analyses on individual growth domains of zircons with a spatial resolution of ∼25 m and acceptable analytical precision. This project was possible because the funding and management environment of those times could foster such large scale, visionary projects within geochemistry. The design and construction of SHRIMP-I was also aided by the broad range of expertise available in RSES: ion optics theory and other branches of applied physics, mechanical engineering design, a mechanical engineering and instrument building workshop and an electronic design workshop (McDougall, 2008; Foster, 2010). In 1983 the risk-taking and years of development paid-off with the first SHRIMP-I peer-reviewed publication which was in Nature (Froude et al., 1983). This was a dramatic debut, as it reported terrestrial Hadean (>4000 Ma) zircons discovered in Archaean metasedimentary rocks at Mt. Narryer, Western Australia. After initial strong reservations from some quarters concerning the veracity of U-Pb ages obtained by SHRIMP-I (e.g., Schärer and Alègre, 1985), the SHRIMP U-Pb zircon dating method was progressively embraced by the Earth Sciences community. In fact, geologists (particularly those working in the Precambrian) were initially overall more enthusiastic about it than instrumentalists. Some of the reservation from the latter was founded in their quest for increasing precision and instrumental accuracy of age measurement. Conversely, geologists with a field background and their awareness of the complexity of Precambrian rocks had a primary desire for geological accuracy of age measurement in order to constrain important events. For many geologists, this had priority over improving precision (lessening ± x Ma). The revolutionary SHRIMP U-Pb zircon method held the immediate scientific advantage that, for the first time, it allowed complex geological histories to be elucidated through the in situ dating of separate growth domains within zircons. This provided the potential of determining the ages of multiple and separate zircon growth events, rather than being left with having to interpret those events from high precision measurements on composite crystals (i.e. an average not corresponding to an actual geological event). With the deployment of SHRIMP-I in the 1980s, these zircon growth domains, initially identified by simple optical microscopy (but then charted from 1995 by routine cathodoluminescence imaging) could now be dated separately (issue front cover). This gave unprecedented resolution and understanding of 0301-9268/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2010.09.004
Precambrian geological processes and their timescales. It immediately provided a highly efficient method that complemented the ability of conventional zircon methods (isotope dilution thermal ionisation mass spectrometry) to determine the age of simple crystals with high precision. An immediate application was the ability to date individually numerous detrital zircons at a rate of 1 every ∼10 min, allowing the source provenance of sedimentary rocks to be established (Froude et al., 1983; Compston and Pidgeon, 1986). SHRIMP was also able to reveal multiple igneous and metamorphic events within single migmatite samples (Black et al., 1986; Kinny, 1986). A corollary of this was that for a group of supposed cogenetic samples their consanguinity no longer had to be assumed, in order to try and establish their age via the whole rock isochron method. Instead, the age and geological history of individual samples could now be established independently and compared with each other. Overall, 1980s SHRIMP U-Pb zircon dating brought about a major leap in the understanding of the Precambrian. The success of SHRIMP-I heralded more technical advances with the building of the SHRIMP-II, -RG, Cameca 1270 and 1280 instruments and the establishment of many large ion microprobe facilities around the world. These developments have also been accompanied by the advent and spread of Laser Ablation ICMPS U-Pb zircon dating facilities. A further advantage of SHRIMP-I was that it allowed geologists for the first time to perform their own geochronology, with as little as 15 min initial training. Thus for the first time it allowed ordinary geologists to perform their own geochronology without the necessity of being a skilled chemist. This Precambrian Research issue celebrates the important contribution that the development of SHRIMP-I and its successors made by opening-up the possibility of copious geologically accurate U-Pb zircon geochronology on complex Precambrian rocks. The papers collected here are diverse, and are not completely restricted to U-Pb zircon geochronology, for which SHRIMP is most known. Foster’s paper follows SHRIMP-I from being the brainchild of Bill Compston in 1974, through the technical design by Steve Clement, to its transformation into a working reality by a broad team of mechanical engineers, electronic engineers and Earth scientists at RSES. This paper shows the blood, sweat, tears and dollars behind the introduction of a major piece of novel analytical equipment that has now become an accepted part of the Earth Sciences landscape. The next three papers cover three fields were SHRIMP first made an impact – detrital zircon dating, unravelling migmatites and lunar chronology. The paper by Wilde (2010) revisits the Jack Hills metasedimentary rocks – famous for their Hadean detrital zircons. This demonstrates there is still much to be learned about these
viii
Preface / Precambrian Research 183 (2010) vii–ix
Fig. 1. SHRIMP-I in January 2010, with Bill Compston in the centre and Steve Clement to the right. SHRIMP-I is still productive, with a recent electronic and mechanical upgrade to perform automatic data acquisition, particularly applicable to large detrital zircon populations. The source chamber where samples are held during analysis is in the foreground, and magnetic sector of the mass analyser is the black object at the back of the room, with the ion counter (collector) just out of sight to its left. Source: Photograph courtesy of Peter Lanc.
intensely studied rocks, including their age of deposition. The paper by Horie et al. (2010-a) addresses extracting reliable chronological information out of the complex migmatites which dominate Precambrian crystalline basement. Horie et al. examine migmatites from the Itsaq Gneiss Complex of Greenland, which constitute Earth’s most studied Eoarchaean rocks. There has been much controversy surrounding these rocks – often sparked by the publication of SHRIMP U-Pb zircon geochronological results. Pidgeon et al. (2010) cover the contribution to lunar science made by in situ dating of zircons identified within thin sections (Compston et al., 1984). This includes some new results and also covers another important revolutionary capability with SHRIMP I – the ability if necessary to obtain isotopic analyses of minerals within their petrologic context by working directly on polished sections. The next tranche of four papers covers the contribution of SHRIMP in establishing reliable regional geological syntheses within complex Precambrian terranes. Such work exploits the ability to undertake with reasonable cost and ease the dating of a large number of samples, in order to build up a regional geological picture. In some cases the question can be as fundamental as how much of the terrane consists of Proterozoic versus Archaean rocks. Kröner et al. (2010) describe the evolution of the Epupa Complex in Namibia, where they recognise a series of closely-spaced rock-forming and metamorphic events in the Palaeoproteroic. In combination with whole-rock Nd isotopic data, they demonstrate that although the rocks are Palaeoproteroic in age, their source materials separated out of a mantle reservoir a
few hundreds of millions of years earlier. Mueller et al. (2010) with SHRIMP U-Pb zircon dating and whole-rock Nd and Sr isotopic data document a major, Andean arc-like event in the Neoarchaean geological record of Wyoming, again with indications of remelting of older crust. These papers demonstrate another application of copious SHRIMP U-Pb zircon dating – the ability to calculate initial Nd and Sr radiometric isotopic ratios directly, with the least built-in assumptions. The paper by Love et al. (2010) revisits a classic area of Archaean geology – the Lewisian Gneiss Complex of Scotland. They show that this Complex is divided into a series of tectonostratigraphic terranes, in which superficially similar orthogneisses are found to occur in mylonite-bounded domains with different protolith and metamorphic histories. This is an example of a study showing how a superficially monotonous body of gneisses can reveal a complex magmatic and tectonothermal history. Basei et al. (2010) describe how SHRIMP U-Pb zircon data assembled from far-flung localities across Brazil has been of great use in building up an understanding of Brazil’s Neoproterozoic evolution. Important questions have been answered – the relative ages of different strands of Neoproterozoic fold belts and the delineation of domains of Neoproterozoic arc-related rocks and Palaeoproterozoic-Archaean continental blocks. The final two papers cover other aspects of the application of SHRIMP. The first is the study of crustal architecture by the dating of xenocrystic zircons within granitic rocks. It has often been found that granites are not sourced from sedimentary rocks like the ones they intrude at the present erosion level, but from unseen
Preface / Precambrian Research 183 (2010) vii–ix
rocks with a different zircon age signature at depth. Thus Horie et al. (2010-b) document the presence of abundant 3750–3550 Ma zircon xenocrysts in some Mesozoic granites in Japan – a place not wellknown for Archaean geology! In the last paper Hidaka and Kikuchi (2010) cover SHRIMP’s ability to undertake in situ isotopic ratios, other than U-Th-Pb. They examine REE, Pb and U isotopic variations (i.e. deviations of 238 U/235 U from the expected modern terrestrial value) from around the Oklo and Bangombé (Africa) Palaeoproterozoic natural reactors, with the aim of assessing materials for nuclear waste management. Whilst this issue is not exhaustive concerning the contributions of SHRIMP to the understanding of Precambrian geology, nonetheless we think that the assembled papers demonstrate the breadth of study possible. It is thus an apt recognition of the contribution to the Precambrian scientific community from the 1970s–1980s effort of Bill Compston, Steve Clement and the team at RSES in conceiving and giving birth to SHRIMP-I.
ix
Kröner, A., Rojas-Agramonte, Y., Hegner, H., Hoffmann, K.-H., Wingate, M.T.D., 2010. SHRIMP zircon dating and Nd isotopic systematics of Palaeozoic migmatitic orthogneisses in the Epupa metamorphic complex of northwestern Namibia. Precambrian Research 183, 50–69. Love, G.J., Friend, C.R.L., Kinny, P.D., 2010. Palaeoproterozoic terrane assembly in the Lewisian Gneiss Complex on the Scottish mainland, south of Gruinard Bay: SHRIMP U-Pb zircon evidence. Precambrian Research 183, 89–111. McDougall, I., 2008. Brief history of isotope geology at the Australian National University. Australian Journal of Earth Sciences 55, 727–736. Mueller, P.A., Wooden, J., Mogk, D., Henry, D., Bowes, D., 2010. Rapid growth of an Archean continent by arc magmatism. Precambrian Research 183, 70–88. Pidgeon, R.T., Nemchin, A.A., Meyer, C., 2010. The contribution of the Sensitive High Resolution Ion Microprobe (SHRIMP) to lunar geochronology. Precambrian Research 183, 44–49. Schärer, U., Alègre, C.J., 1985. Determination of the age of the Australian continent by single-grain zircon analysis of Mt Narryer metaquartzite. Nature 315, 52–55. Wilde, S.A., 2010. Proterozoic volcanism in the Jack Hills Belt, Western Australia: some implications and consequences for the world’s oldest zircon population. Precambrian Research 183, 9–24.
Allen P. Nutman a,b,∗ School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia b Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China a
References Basei, M.A.S., Brito Neves, B.B., Sigo Junior, O., Babinski, M., Pimental, M.M., Hollanda, M.H.B., Nutman, A.P., Cordani, U.G., 2010. Contribution of SHRIMP U-Pb zircon geochronology to unravelling the evolution of Brazilian Neoproterozoic belts. Precambrian Research 183, 112–144. Black, L.P., Williams, I.S., Compston, W., 1986. Four zircon ages from one rock: the history of a 3930 Ma-old granulite from Mount Sones, Enderby Land, Antarctica. Contributions to Mineralogy and Petrology 94, 427–437. Compston, W., Pidgeon, R.T., 1986. Jack Hills, evidence for more very old detrital zircons in Western Australia. Nature 321, 766–769. Compston, W., Williams, I.S., Meyer, C., 1984. U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe. In: Boynton, W.V., et al. (Eds.), Proceedings of the Fourteenth Lunar and Planetary Science Conference. Journal of Geophysical Research 89B, 525–534. Foster, J.J., 2010. The construction and development of SHRIMP I: an historical outline. Precambrian Research 183, 1–8. Froude, D.O., Ireland, T.R., Kinny, P.D., Williams, I.S., Compston, W., Williams, I.R., Myers, J.S., 1983. Ion microprobe identification of 4,100–4,200 Myr-old terrestrial zircons. Nature 304, 616–618. Hidaka, H., Kikuchi, M., 2010. SHRIMP in situ isotopic analyses of REE, 4 Pb and U in micro-minerals bearing fission products in the Oklo and Bangombé natural reactors: a review of a natural analogue study for the migration of fission products. Precambrian Research 183, 158–165. Horie, K., Nutman, A.P., Friend, C.R.L., Hidaka, K., 2010-a. SHRIMP and old rocks: the evidence for 3900-3840 Ma crust within the Itsaq Gneiss Complex (Greenland). Precambrian Research 183, 25–43. Horie, K., Yamashita, M., Hayasaka, Y., Katoh, Y., Tsutsumi, Y., Katsube, A., Hidaka, H., Kim, H., Cho, M., 2010-b. Eoarchean-Paleoproterozoic zircon inheritance in Japanese Mesozoic granites (Unazuki area, Hida Metamorphic Complex): unearthing more old crust and identifying source terranes. Precambrian Research 183, 145–157. Kinny, P.D., 1986. 3820 Ma zircons from a tonalitic Amîtsoq gneiss in the Godthåb District of southern West Greenland. Earth and Planetary Science Letters 79, 337–347.
Clark R.L. Friend a,b Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China b 45 Stanway Road, Headington, Oxford OX3 8HU, UK a
Dunyi Liu a Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China a
∗ Corresponding
author at: School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia. E-mail address:[email protected] (A.P. Nutman)
Contents lists available at ScienceDirect
Precambrian Research journal homepage: www.elsevier.com/locate/precamres
Preface
Preface to special issue of Precambrian Research on the impact of SHRIMP on understanding the Precambrian
The SHRIMP-I instrument (Fig. 1; Sensitive High Resolution Ion Microprobe) was the mid-1970s brainchild and invention of Bill Compston, that was designed by Steve Clement and built by a team of the Research School of Earth Sciences (RSES) at the Australian National University. It was specifically designed to be capable for the first time of doing in situ U-Pb analyses on individual growth domains of zircons with a spatial resolution of ∼25 m and acceptable analytical precision. This project was possible because the funding and management environment of those times could foster such large scale, visionary projects within geochemistry. The design and construction of SHRIMP-I was also aided by the broad range of expertise available in RSES: ion optics theory and other branches of applied physics, mechanical engineering design, a mechanical engineering and instrument building workshop and an electronic design workshop (McDougall, 2008; Foster, 2010). In 1983 the risk-taking and years of development paid-off with the first SHRIMP-I peer-reviewed publication which was in Nature (Froude et al., 1983). This was a dramatic debut, as it reported terrestrial Hadean (>4000 Ma) zircons discovered in Archaean metasedimentary rocks at Mt. Narryer, Western Australia. After initial strong reservations from some quarters concerning the veracity of U-Pb ages obtained by SHRIMP-I (e.g., Schärer and Alègre, 1985), the SHRIMP U-Pb zircon dating method was progressively embraced by the Earth Sciences community. In fact, geologists (particularly those working in the Precambrian) were initially overall more enthusiastic about it than instrumentalists. Some of the reservation from the latter was founded in their quest for increasing precision and instrumental accuracy of age measurement. Conversely, geologists with a field background and their awareness of the complexity of Precambrian rocks had a primary desire for geological accuracy of age measurement in order to constrain important events. For many geologists, this had priority over improving precision (lessening ± x Ma). The revolutionary SHRIMP U-Pb zircon method held the immediate scientific advantage that, for the first time, it allowed complex geological histories to be elucidated through the in situ dating of separate growth domains within zircons. This provided the potential of determining the ages of multiple and separate zircon growth events, rather than being left with having to interpret those events from high precision measurements on composite crystals (i.e. an average not corresponding to an actual geological event). With the deployment of SHRIMP-I in the 1980s, these zircon growth domains, initially identified by simple optical microscopy (but then charted from 1995 by routine cathodoluminescence imaging) could now be dated separately (issue front cover). This gave unprecedented resolution and understanding of 0301-9268/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2010.09.004
Precambrian geological processes and their timescales. It immediately provided a highly efficient method that complemented the ability of conventional zircon methods (isotope dilution thermal ionisation mass spectrometry) to determine the age of simple crystals with high precision. An immediate application was the ability to date individually numerous detrital zircons at a rate of 1 every ∼10 min, allowing the source provenance of sedimentary rocks to be established (Froude et al., 1983; Compston and Pidgeon, 1986). SHRIMP was also able to reveal multiple igneous and metamorphic events within single migmatite samples (Black et al., 1986; Kinny, 1986). A corollary of this was that for a group of supposed cogenetic samples their consanguinity no longer had to be assumed, in order to try and establish their age via the whole rock isochron method. Instead, the age and geological history of individual samples could now be established independently and compared with each other. Overall, 1980s SHRIMP U-Pb zircon dating brought about a major leap in the understanding of the Precambrian. The success of SHRIMP-I heralded more technical advances with the building of the SHRIMP-II, -RG, Cameca 1270 and 1280 instruments and the establishment of many large ion microprobe facilities around the world. These developments have also been accompanied by the advent and spread of Laser Ablation ICMPS U-Pb zircon dating facilities. A further advantage of SHRIMP-I was that it allowed geologists for the first time to perform their own geochronology, with as little as 15 min initial training. Thus for the first time it allowed ordinary geologists to perform their own geochronology without the necessity of being a skilled chemist. This Precambrian Research issue celebrates the important contribution that the development of SHRIMP-I and its successors made by opening-up the possibility of copious geologically accurate U-Pb zircon geochronology on complex Precambrian rocks. The papers collected here are diverse, and are not completely restricted to U-Pb zircon geochronology, for which SHRIMP is most known. Foster’s paper follows SHRIMP-I from being the brainchild of Bill Compston in 1974, through the technical design by Steve Clement, to its transformation into a working reality by a broad team of mechanical engineers, electronic engineers and Earth scientists at RSES. This paper shows the blood, sweat, tears and dollars behind the introduction of a major piece of novel analytical equipment that has now become an accepted part of the Earth Sciences landscape. The next three papers cover three fields were SHRIMP first made an impact – detrital zircon dating, unravelling migmatites and lunar chronology. The paper by Wilde (2010) revisits the Jack Hills metasedimentary rocks – famous for their Hadean detrital zircons. This demonstrates there is still much to be learned about these
viii
Preface / Precambrian Research 183 (2010) vii–ix
Fig. 1. SHRIMP-I in January 2010, with Bill Compston in the centre and Steve Clement to the right. SHRIMP-I is still productive, with a recent electronic and mechanical upgrade to perform automatic data acquisition, particularly applicable to large detrital zircon populations. The source chamber where samples are held during analysis is in the foreground, and magnetic sector of the mass analyser is the black object at the back of the room, with the ion counter (collector) just out of sight to its left. Source: Photograph courtesy of Peter Lanc.
intensely studied rocks, including their age of deposition. The paper by Horie et al. (2010-a) addresses extracting reliable chronological information out of the complex migmatites which dominate Precambrian crystalline basement. Horie et al. examine migmatites from the Itsaq Gneiss Complex of Greenland, which constitute Earth’s most studied Eoarchaean rocks. There has been much controversy surrounding these rocks – often sparked by the publication of SHRIMP U-Pb zircon geochronological results. Pidgeon et al. (2010) cover the contribution to lunar science made by in situ dating of zircons identified within thin sections (Compston et al., 1984). This includes some new results and also covers another important revolutionary capability with SHRIMP I – the ability if necessary to obtain isotopic analyses of minerals within their petrologic context by working directly on polished sections. The next tranche of four papers covers the contribution of SHRIMP in establishing reliable regional geological syntheses within complex Precambrian terranes. Such work exploits the ability to undertake with reasonable cost and ease the dating of a large number of samples, in order to build up a regional geological picture. In some cases the question can be as fundamental as how much of the terrane consists of Proterozoic versus Archaean rocks. Kröner et al. (2010) describe the evolution of the Epupa Complex in Namibia, where they recognise a series of closely-spaced rock-forming and metamorphic events in the Palaeoproteroic. In combination with whole-rock Nd isotopic data, they demonstrate that although the rocks are Palaeoproteroic in age, their source materials separated out of a mantle reservoir a
few hundreds of millions of years earlier. Mueller et al. (2010) with SHRIMP U-Pb zircon dating and whole-rock Nd and Sr isotopic data document a major, Andean arc-like event in the Neoarchaean geological record of Wyoming, again with indications of remelting of older crust. These papers demonstrate another application of copious SHRIMP U-Pb zircon dating – the ability to calculate initial Nd and Sr radiometric isotopic ratios directly, with the least built-in assumptions. The paper by Love et al. (2010) revisits a classic area of Archaean geology – the Lewisian Gneiss Complex of Scotland. They show that this Complex is divided into a series of tectonostratigraphic terranes, in which superficially similar orthogneisses are found to occur in mylonite-bounded domains with different protolith and metamorphic histories. This is an example of a study showing how a superficially monotonous body of gneisses can reveal a complex magmatic and tectonothermal history. Basei et al. (2010) describe how SHRIMP U-Pb zircon data assembled from far-flung localities across Brazil has been of great use in building up an understanding of Brazil’s Neoproterozoic evolution. Important questions have been answered – the relative ages of different strands of Neoproterozoic fold belts and the delineation of domains of Neoproterozoic arc-related rocks and Palaeoproterozoic-Archaean continental blocks. The final two papers cover other aspects of the application of SHRIMP. The first is the study of crustal architecture by the dating of xenocrystic zircons within granitic rocks. It has often been found that granites are not sourced from sedimentary rocks like the ones they intrude at the present erosion level, but from unseen
Preface / Precambrian Research 183 (2010) vii–ix
rocks with a different zircon age signature at depth. Thus Horie et al. (2010-b) document the presence of abundant 3750–3550 Ma zircon xenocrysts in some Mesozoic granites in Japan – a place not wellknown for Archaean geology! In the last paper Hidaka and Kikuchi (2010) cover SHRIMP’s ability to undertake in situ isotopic ratios, other than U-Th-Pb. They examine REE, Pb and U isotopic variations (i.e. deviations of 238 U/235 U from the expected modern terrestrial value) from around the Oklo and Bangombé (Africa) Palaeoproterozoic natural reactors, with the aim of assessing materials for nuclear waste management. Whilst this issue is not exhaustive concerning the contributions of SHRIMP to the understanding of Precambrian geology, nonetheless we think that the assembled papers demonstrate the breadth of study possible. It is thus an apt recognition of the contribution to the Precambrian scientific community from the 1970s–1980s effort of Bill Compston, Steve Clement and the team at RSES in conceiving and giving birth to SHRIMP-I.
ix
Kröner, A., Rojas-Agramonte, Y., Hegner, H., Hoffmann, K.-H., Wingate, M.T.D., 2010. SHRIMP zircon dating and Nd isotopic systematics of Palaeozoic migmatitic orthogneisses in the Epupa metamorphic complex of northwestern Namibia. Precambrian Research 183, 50–69. Love, G.J., Friend, C.R.L., Kinny, P.D., 2010. Palaeoproterozoic terrane assembly in the Lewisian Gneiss Complex on the Scottish mainland, south of Gruinard Bay: SHRIMP U-Pb zircon evidence. Precambrian Research 183, 89–111. McDougall, I., 2008. Brief history of isotope geology at the Australian National University. Australian Journal of Earth Sciences 55, 727–736. Mueller, P.A., Wooden, J., Mogk, D., Henry, D., Bowes, D., 2010. Rapid growth of an Archean continent by arc magmatism. Precambrian Research 183, 70–88. Pidgeon, R.T., Nemchin, A.A., Meyer, C., 2010. The contribution of the Sensitive High Resolution Ion Microprobe (SHRIMP) to lunar geochronology. Precambrian Research 183, 44–49. Schärer, U., Alègre, C.J., 1985. Determination of the age of the Australian continent by single-grain zircon analysis of Mt Narryer metaquartzite. Nature 315, 52–55. Wilde, S.A., 2010. Proterozoic volcanism in the Jack Hills Belt, Western Australia: some implications and consequences for the world’s oldest zircon population. Precambrian Research 183, 9–24.
Allen P. Nutman a,b,∗ School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia b Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China a
References Basei, M.A.S., Brito Neves, B.B., Sigo Junior, O., Babinski, M., Pimental, M.M., Hollanda, M.H.B., Nutman, A.P., Cordani, U.G., 2010. Contribution of SHRIMP U-Pb zircon geochronology to unravelling the evolution of Brazilian Neoproterozoic belts. Precambrian Research 183, 112–144. Black, L.P., Williams, I.S., Compston, W., 1986. Four zircon ages from one rock: the history of a 3930 Ma-old granulite from Mount Sones, Enderby Land, Antarctica. Contributions to Mineralogy and Petrology 94, 427–437. Compston, W., Pidgeon, R.T., 1986. Jack Hills, evidence for more very old detrital zircons in Western Australia. Nature 321, 766–769. Compston, W., Williams, I.S., Meyer, C., 1984. U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe. In: Boynton, W.V., et al. (Eds.), Proceedings of the Fourteenth Lunar and Planetary Science Conference. Journal of Geophysical Research 89B, 525–534. Foster, J.J., 2010. The construction and development of SHRIMP I: an historical outline. Precambrian Research 183, 1–8. Froude, D.O., Ireland, T.R., Kinny, P.D., Williams, I.S., Compston, W., Williams, I.R., Myers, J.S., 1983. Ion microprobe identification of 4,100–4,200 Myr-old terrestrial zircons. Nature 304, 616–618. Hidaka, H., Kikuchi, M., 2010. SHRIMP in situ isotopic analyses of REE, 4 Pb and U in micro-minerals bearing fission products in the Oklo and Bangombé natural reactors: a review of a natural analogue study for the migration of fission products. Precambrian Research 183, 158–165. Horie, K., Nutman, A.P., Friend, C.R.L., Hidaka, K., 2010-a. SHRIMP and old rocks: the evidence for 3900-3840 Ma crust within the Itsaq Gneiss Complex (Greenland). Precambrian Research 183, 25–43. Horie, K., Yamashita, M., Hayasaka, Y., Katoh, Y., Tsutsumi, Y., Katsube, A., Hidaka, H., Kim, H., Cho, M., 2010-b. Eoarchean-Paleoproterozoic zircon inheritance in Japanese Mesozoic granites (Unazuki area, Hida Metamorphic Complex): unearthing more old crust and identifying source terranes. Precambrian Research 183, 145–157. Kinny, P.D., 1986. 3820 Ma zircons from a tonalitic Amîtsoq gneiss in the Godthåb District of southern West Greenland. Earth and Planetary Science Letters 79, 337–347.
Clark R.L. Friend a,b Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China b 45 Stanway Road, Headington, Oxford OX3 8HU, UK a
Dunyi Liu a Institute of Geology and Chinese International Centre for Precambrian Research, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, PR China a
∗ Corresponding
author at: School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia. E-mail address:[email protected] (A.P. Nutman)