Unravelling a Proterozoic basin history through detrital zircon geochronology: The case of the Espinha莽o Supergroup, Minas Gerais, Brazil

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• 作者：Farid Chemale Jr.^a ; ^{faridchemale@gmail.com} ; Ivo A. Dussin^b ; Fernando F. Alkmim^d ; Maximiliano Sousa Martins^c ; Glá ; ucia Queiroga^d ; Richard Armstrong^e ; Marcelo N. Santos^f
• 关键词：U&ndash ; Pb zircon geochronology ; Espinhaç ; o Basin ; Stenian ; Sã ; o Francisco Craton ; Rodinia
• 刊名：Gondwana Research
• 出版年：2012
• 期刊代码：3_1342937X
• 类别：ear
• 出版时间：July, 2012
• 卷：22
• 期：1
• 页码：200-206
• 文件大小：1389 K

摘要

New U-Pb in situ zircon dating provides a new approach for the study of the Espinha莽o Supergroup units exposed in the S茫o Francisco Craton and Ara莽ua铆 Orogen. Located in Southern Espinha莽o, Minas Gerais, the following two basins were formed in intraplate conditions: (i) the Lower Espinha莽o Basin is marked by a volcano-sedimentary sequence with alluvial, fluvial and eolian deposits that were formed from 1.68 Ga to 1.80 Ga; (ii) the overlying sequence, called the Upper Espinha莽o Basin, is a rift-sag basin that presents basal diamond-bearing continental deposits (the Sopa-Brumadinho Formation) with a younger zircon peak at 1192 Ma, which is the maximum age for deposition of the upper units. The obtained U-Pb detrital zircon data of the studied units show age groupings related to the orogenic cycles of Jequi茅 (Neoarchean) and Transamazonian (Paleoproterozoic), which are associated with the stability period from 1.8 Ga to 0.91 Ga in the S茫o Franscico Craton, and record deposition during at least the three basinal cycles. The Stenian-Tonian ages of the Upper Espinha莽o Basin units (906 Ma to 1192 Ma) suggest a direct link with the evolution of the Rodinia Supercontinent and represent a marker for Mesoproterozoic to Early Neoproterozoic evolution in the S茫o Franscico Craton and adjacent areas.