Geochemistry and sedimentary background of the Middle-Upper Permian cherts in the Penglaitan section,Laibin,Guangxi Province
2011; Science Press; Linguagem: Inglês
ISSN
2095-8927
Autores Tópico(s)Geological formations and processes
ResumoThe Middle-Upper Permian cherts occur extensively in Laibin area,Guangxi Province,in which the Penglaitan section and the Tieqiao section well expose them.In this study,28 bedded chert samples(3 samples from the Maokou Formation of the Middle Permian and 25 samples from the Heshan Formation of the Upper Permian) were analyzed for major and rare earth elements.Based on the results of major and rare earth element contents of these samples and lithofacies characteristics of them,we considered that bedded cherts from the Heshan Formation in the Penglaitan section deposited in marginal sea basin environment influenced by terrigenous materials and silica of them derived from siliceous organism as biogenic origin,whereas,those from the Maokou Formation deposited in marginal sea basin environment without influence of terrigenous materials and silica of them primarily derived from hydrothermal fluid as hydrothermal origin.Comparing sedimentary background of bedded cherts in the Penglaitan section with those as hydrothermal origin in the Tieqiao section,this study showed that Laibin area developed a marginal sea basin environment rich in silica during the Middle-Late Permian and discrepancy in influence of terrigenous materials controlled the different origin of bedded cherts in Laibin area.
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