The Colider and Roosevelt olcanic rocks (sw amazonian craton): geochemistry and sm-nd isotope characteristics of a silicic large igneous province

作     者：Bruna Saar de Almeida Mauro César Geraldes Carlos Augusto Sommer Felipe Corrales Antonio Joāo Paes de Barros Bruna Saar de Almeida;Mauro César Geraldes;Carlos Augusto Sommer;Felipe Corrales;Antonio Jo(a)o Paes de Barros

作者机构：Universidade do Estado do Rio de JaneiroRio de JaneiroBrazil University of GenevaGenevaSwitzerland Universidade Federal do Rio Grande do SulRio Grande do SulBrazil METAMAT(Mato Grosso State Geological Survey)CuiabaBrazil 

出 版 物：《Acta Geochimica》 (地球化学学报（英文）)

年 卷 期：2021年第40卷第6期

页      面：1023-1049页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 0819[工学-矿业工程] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 0708[理学-地球物理学] 

基　　金：the result of a doctoral project by the first author,financed by the Rio de Janeiro Research Council(FAPERJ#100.173/2014) CAPES Brazilian Council(Sandwich fellowship No.99999.006532/2015–02) 

主　　题：Amazonian craton Geochemistry Sm-Nd isotopes Paleoproterozoic Volcanism 

摘      要：The volcanic rocks of the Colíder and Roosevelt formations are extensively exposed in the south-central portion of the Amazonian Craton where effusive and pyroclastic rocks have been *** units,topped by chemical sediments and oceanic facies as rhyolite and andesite lavas,rhyodacite,and porphyritic dacite,with frequent intercalations of pyroclastic and epiclastic ***-rock geochemistry for 55 samples of rhyolitic to andesitic composition suggests the involvement of fertile mantle-derived components with E-MORB to OIB *** analyzed rocks display calc-alkaline to shoshonitic affinity consistent with generation related to an active continental *** whole-rock Sm-Nd isotope data from selected felsic volcanic rocks of the Colíder and Roosevelt formations yield negative initial eNd values between–3 and–9,indicating the predominantly crustal nature of the parental magmas with early Archean to late Paleoproterozoic(ca.2.5–2.0 Ga)depleted mantle model ages.