| 湖北秭归庙河地区震旦系陡山沱组微化石的新发现 |
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| 引用本文：尹崇玉.1996.湖北秭归庙河地区震旦系陡山沱组微化石的新发现[J].地球学报,17(3):322-331. |
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| 基金项目:国家自然科学基金 |
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| 中文摘要:庙河地区震旦系陡山沱组燧石中的激化石，前人曾有过报道。但是，所报道的激化石组合与已知峡区的其他震旦系剖面陡山沱期微化石明显不同。具刺疑源类以ＭｉｃｒｈｙｓｔｒｉｄｉｕｍｔｌａｎｃｅｄｅｔｕｍＬ．Ｙｉｎ为主（样品号：Ｈｍ８０—１４—２，Ｙｉｎｂｏｒｎｉｎｇ，１９８５）。１９９２年作者等重新研究了庙河震旦系沿江剖面，系统采集了燧石样品。结果，并未在陡山沱组发现上述微化石组合，而在寒武系底界附近的燧石夹层中，发现了与其相同的微化石群，因而，对上述微化石组合出现的层位提出质疑。最近，作者再次对庙河地区陡山沱组燧石结核系统采样进行研究，首次在本区陡山沱组燧石结核中发现了与其他地区陡山沱组类似的微化石组合（包括具刺疑源类Ｔｉａｎｚｈｕｓｈａｎｉａｓｐｉｎｏｓａ（Ｌ．ＹｉｎｅｔＬｉ）Ｌ．Ｙｉｎ，？Ｃｙｍａｔｉｏｓｐｈａｅｒｏｉｄｅｓｓｐ，未定名ｆｏｒｍＡ及其他陡山沱期常见的球形和丝状藻类）。真正陡山沱期微化石群在庙河地区的发现，进一步证明前人所报道的，以ＭｉｃｒｈｙｓｔｒｉｄｉｕｍｌａｎｃｅｏｌａｔｕｍＬ．Ｙｉｎ为主的刺球类组合并非陡山沱期所有，而为早寒武世早期（梅树村阶）。纠正了前人资料出现的化石层位错误和对生物组合的 |
| 中文关键词:庙河地区 具刺疑源类 陡山沱期 晚震旦世 |
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| New Discovery of the Sinian Doushantuo Microfossils from Miaohe,Zigui,Hubei |
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| Abstract:icrofossils from the Upper Sinian Doushantuo Formation near Miaohe village, Zigui, Hubei,China are firstly described and their significance analyzed. All microfossils were observed in petrographic thin sections.Unlike the conclusion in the previous paper,the Doushantuo was found to contain large and morphologically complex acritarchs,similar to other fossiliferous localities of the Doushantuo in the Yangtze Gorges district. The assemblage includes large acanthomorphic acritarchs Tianzhushania spijnosa (L. Yin et Li) C. Yin, ? Cymatiosphaeroides sp., Unnamedform A and other common filamentous and coccoidal microfossils in Doushantuo. The assemblage dominated by Micrhystridium lanceolatum presents in the early Cambrian (Meishucun Stage). The discovery of bona fide Doushantuo assemblage at Miaohe provides important evidence-for the stratigraphic correlation of this section with Sinian sections in adjacent areas and confirms the distinctiveness of the Doushantuo biota.Description of the new species:Genus Megasphaera Chen & Liu 1986Type species Megasphaera inornata Chen & Liu 1986Megasphaera membrana sp. nov.(Pl.2, fig. 1- 3)Holotpe specimen P1. 2, fig. 1, thin section number. Ycy -712.Diagnosis Large spherical or irregularly spherical vesicle, double-walled, inner wall robust with indistinctly reticulate or granular texture, outer wall or membrane thinner than inner wall, psilate or very finely granular, often kept close to the inner wall and in some areas elevated to form a layered protuberant structure vesicles 1300 - 1800μm in diameter (average = 1600μm), inner wall 5. 7 - 7. μm in thickness (average = 6. 5μm). The outer wall is 2 - 3μm in thickness, with as many as & to 13 protuberances which are 20 - 150μm high.Horizon and locality The middle part of Doushantuo exposed near Miaohe village, ZiguiCounty, Hubei Province. |
| keywords:Miaohe area Acanthomorphic acritarch Doushantuo stage Late Sinian |
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