摘要
<sup>40</sup>Ar/<sup>39</sup>Ar dating of plagioclases,pyroxene or/and amphibole of separated grains from Avanavero Dolerite located in the Guiana Shield,in Roraima State,Brazil yield plateau ages ranging from 1840±50 Ma to 1179±10 Ma.The highest ages are interpreted to represent the emplacement of dolerites within the sandstones ofRoraima Supergroup,while the younger results reveal partial argon loss during the cooling history of the samples related to a large
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2009年第S1期207-207,共1页
Earth Science Frontiers