The Calcareous nannofossil record and its geological significance in the Jurassic black shales from the Qiangtang Basin, northern Tibetan Plateau
The Calcareous nannofossil record and its geological significance in the Jurassic black shales from the Qiangtang Basin, northern Tibetan Plateau
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发表时间：
2006-08
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通讯作者：
L. Chen;hsiao yi;H. Zhong;R. Hu;Yin;Jk Yang
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作者：
L. Chen;hsiao yi;H. Zhong;R. Hu;Yin;Jk Yang
摘要西藏北方羌塘盆地侏罗系黑色页岩中发现钙质超微化石新记录，包括两个系列，分别代表陆棚-盆地环境。通过显微镜观察，首次发现了Watznaueriaceae科，将Watznaueria fossacincta与Watznaueria britannica区分开来。从生物地层和化学地层上看，沉积物具有组合少、球粒发育、有机质含量较高的特点。有两种保存类型：保存较差和保存较好的组合。总超微化石丰度和物种多样性显示较低的值内钙质床，泥质。泥灰岩和泥质岩的组合成分与灰岩有很大的不同。化石的丰度和保存程度在一定程度上取决于成岩作用、选择性溶解作用和沉积环境。底水缺氧或缺氧条件是由球菌球指示的。
Abstract A new record of calcareous nannofossils in Jurassic black shales from the Qiangtang Basin, northern Tibet comprises two series, representing shelf to basin settings. By microscopic observation, the first discovery of the family Watznaueriaceae had been made: Watznaueria fossacincta is distinguished from Watznaueria britannica. From the biostratigraphy and chemostratigraphy, the sediments are characterized by paucity of assemblages, prevalence of coccospheres, and a relatively high organic content. There are two classes of preservation: poorly and moderately preserved assemblages. Total nannofossil abundance and species diversity show lower values within calcareous beds, compared to the argillaceous. Assemblage composition appears quite different in the marls and argillaceous rocks compared with limestones. Fossil abundance and preservation are partly determined by diagenesis, selective dissolution and sedimentary environment. Dysaerobic or anoxic bottom-water conditions are indicated by coccosphe...