塔里木地块寒武纪台地相区生物群落时空分布及其地层意义

发布时间：2018-06-18 21:49

本文选题：生物地层 + 白云岩　；参考：《地层学杂志》2017年01期

【摘要】：塔里木地块寒武纪台地相区地层白云岩是油气勘探的主要目标之一,但是由于缺乏三叶虫等生物化石,地层的等时划分成为难点。虽然碳同位素曲线以及自然伽马曲线是两种较为有效的地层等时对比的手段,然而由于这两种数据的获得比较困难,限制了这些方法的广泛应用。通过肖尔布拉克露头剖面岩石及钻井方1、中深1、中深5、英买7、英买36和牙哈5等7个剖面的岩芯岩屑薄片中的所有生物化石碎片的研究,揭示了塔里木盆地寒武纪台地区生物群落的时空分布模式。揭示的不同剖面生物群落序列具有非常好的横向一致性,因此自下而上确定了9个具有区域地层意义的生物群落,它们分别为:1)海绵动物群落,分布于纽芬兰统幸运阶玉尔吐斯组底部;2)微生物-小壳生物群落,分布于纽芬兰统第二阶的玉尔吐斯组的顶部;3)三叶虫群落,主要分布于第二统第三阶的肖尔布拉克组和第四阶的吾松格尔组;4)包覆状-泡沫状微生物群落分布于第二统第三阶的肖尔布拉克组;5)席状-包覆状微生物群落,分布于第二统第四阶的肖尔布拉克组上部;6)棘皮类-三叶虫群落/三叶虫-棘皮类群落,首现层位位于第二统第四阶的吾松格尔组;7)棘皮类群落,主要分布于第三统鼓山阶的阿瓦塔格组,局部上延到第三统古丈阶的下丘里塔格组;8)微生物席群落,主要分布于第三统鼓山阶的阿瓦塔格组中上部,局部上延到第三统古丈阶的下丘里塔格组;9)云朵状微生物群落,主要分布于第三统古丈阶的下丘里塔格组,局部上延到芙蓉统排碧阶的蓬莱坝组,下延到阿瓦塔格组。这些群落为塔里木台地相区缺乏三叶虫化石的白云岩"哑地层"的再划分提供了依据。
[Abstract]:Stratigraphic dolomite in Cambrian platform facies area of Tarim block is one of the main targets of oil and gas exploration, but due to the lack of biofossils such as trilobites, isochronous stratigraphic division becomes difficult. Although carbon isotope curves and natural gamma curves are two effective methods for isochronous stratigraphic correlation, however, due to the difficulty of obtaining these two kinds of data, the wide application of these methods is limited. Through the study of all the biofossil fragments in the core cuttings of the Shaublak outcrop profile, including the rock and drilling sections 1, Zhongshen 1, Zhongshen 5, Yingmai 7, Yingmai 36 and Yaha 5, etc., The temporal and spatial distribution model of biota in Cambrian platform area of Tarim Basin is revealed. The sequence of biota revealed in different profiles has very good horizontal consistency, so nine communities of regional stratigraphic significance have been determined from the bottom up, which are respectively the community of sponges: 1). Distributed at the bottom of the Yultus formation of the lucky stage of Newfoundland (2) the microbe-shell biota, and on the top of the Yultux formation of the second order of the Newfoundland series) trilobites, Mainly distributed in the third order of the second system, Scholburak formation and the fourth order of the Usonger formation, the cladding and froth microbe communities were distributed in the third order of the second series, the Scholburak formation, and the third order of the second series, the table-shaped and the encrusted microbial communities. The acanthoderm-trilobite community / Trichoderm-echinoderm community distributed in the upper part of the Scholburak formation in the fourth order of the second series, and the first layer located in the fourth order of the second series, the Wusongger formation, 7) the acanthopanth community, the first layer of which is located in the fourth order of the second series. The Awa tag formation, which is mainly distributed in the Gushan stage of the third Series, partially extends to the Guzhang stage of the third Series, and is mainly distributed in the middle and upper parts of the Awa Tag formation of the third Gushan terrace. The cloud-like microbial community is mainly distributed in the lower Qiulitag formation of the third Paleozoic, the Pengleba formation of the Paleobitic stage of the Furong series and the Awa tag formation. These communities provide a basis for the subdivision of dolomite "dummy strata" in the Tarim platform, where there is a lack of trilobite fossils.
【作者单位】：中国石油天然气股份有限公司塔里木油田分公司勘探开发研究院;中国科学院油气资源研究重点实验室中国科学院地质与地球物理研究所;中国科学院大学;
【基金】：国家自然科学基金(No.41372121) 国家重点科技专项(2016ZX05004-004)共同资助
【分类号】：P534.41;Q911

【相似文献】