TY - JOUR
T1 - Influence of Hadean crust evident in basalts and cherts from the Pilbara Craton
AU - Tessalina, Svetlana G.
AU - Bourdon, Bernard
AU - Van Kranendonk, Martin
AU - Birck, Jean Louis
AU - Philippot, Pascal
N1 - Funding Information:
We thank the Institut de Physique du Globe de Paris, the Institut des Sciences de l’Univers (INSU) and the Geological Survey of Western Australia for supporting the Pilbara Drilling Project. P.P. acknowledges financial support from the Agence Nationale de la Recherche (ANR-Blanc). S.T. acknowledges support of a Centre National de la Recherche Scientifique (CNRS) postdoctoral position. This is IPGP contribution number 2578.
PY - 2010/3
Y1 - 2010/3
N2 - Application of the 147 Sm- 143 Nd and 146 Sm- 142 Nd chronometers has suggested that the initial differentiation of Earths mantle into enriched and depleted reservoirs may have begun within the first 100-200 million years of Earths history. However, little is known about the differentiation of the early crust; although evidence has suggested the presence of enriched crustal material, data regarding the nature and composition of this crust are limited. Here we present 147 Sm- 143 Nd data from the weakly metamorphosed basalt and layered chert-barite successions from the Dresser Formation of the Pilbara Craton, Western Australia. The Sm-Nd isochron indicates an age of 3.49±0.10 billion years, in agreement with previous estimates from Pb-Pb (ref.6) and U-Pb (ref.7) dating, which indicates that the Sm-Nd system has not been reset. Our measured Nd value of -3.3±1.0 for the rocks at this site is consistent with formation from an older protolith. On the basis of our modelling of trace element and isotopic compositions from these rocks, we suggest that the older component was crustal in nature, and differentiated from the convective mantle more than 4.3 billion years ago.
AB - Application of the 147 Sm- 143 Nd and 146 Sm- 142 Nd chronometers has suggested that the initial differentiation of Earths mantle into enriched and depleted reservoirs may have begun within the first 100-200 million years of Earths history. However, little is known about the differentiation of the early crust; although evidence has suggested the presence of enriched crustal material, data regarding the nature and composition of this crust are limited. Here we present 147 Sm- 143 Nd data from the weakly metamorphosed basalt and layered chert-barite successions from the Dresser Formation of the Pilbara Craton, Western Australia. The Sm-Nd isochron indicates an age of 3.49±0.10 billion years, in agreement with previous estimates from Pb-Pb (ref.6) and U-Pb (ref.7) dating, which indicates that the Sm-Nd system has not been reset. Our measured Nd value of -3.3±1.0 for the rocks at this site is consistent with formation from an older protolith. On the basis of our modelling of trace element and isotopic compositions from these rocks, we suggest that the older component was crustal in nature, and differentiated from the convective mantle more than 4.3 billion years ago.
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U2 - 10.1038/ngeo772
DO - 10.1038/ngeo772
M3 - Article
AN - SCOPUS:77950528871
VL - 3
SP - 214
EP - 217
JO - Nature Geoscience
JF - Nature Geoscience
SN - 1752-0894
IS - 3
ER -