Unravelling a Proterozoic basin history through detrital zircon geochronology: The case of the Espinha?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
• 出版时间：July, 2012
• 年：2012
• 卷：22
• 期：1
• 页码：200-206
• 全文大小：1389 K

文摘

New U-Pb in situ zircon dating provides a new approach for the study of the Espinha?o Supergroup units exposed in the S?o Francisco Craton and Ara?ua¨ª Orogen. Located in Southern Espinha?o, Minas Gerais, the following two basins were formed in intraplate conditions: (i) the Lower Espinha?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?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¨¦ (Neoarchean) and Transamazonian (Paleoproterozoic), which are associated with the stability period from 1.8 Ga to 0.91 Ga in the S?o Franscico Craton, and record deposition during at least the three basinal cycles. The Stenian-Tonian ages of the Upper Espinha?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?o Franscico Craton and adjacent areas.