| 华北地台马沟剖面寒武系苗岭统微生物岩的组构特征、沉积环境和地质意义 |
| |
| 引用本文： | 王龙,李伟强,王皓,吴海,辛浩.华北地台马沟剖面寒武系苗岭统微生物岩的组构特征、沉积环境和地质意义[J].沉积学报,2019,37(6):1193-1209. |
| |
| 作者姓名： | 王龙 李伟强 王皓 吴海 辛浩 |
| |
| 作者单位： | 中国地质大学(北京)地球科学与资源学院,北京 100083;中国石油长庆油田公司勘探开发研究院,西安 710018;中国石油勘探开发研究院,北京 100086;中国石油杭州地质研究院,杭州 310023;中国地质大学(北京)地球科学与资源学院,北京 100083;中国石油勘探开发研究院,北京 100086 |
| |
| 基金项目： | 国家自然科学基金项目（41472090，40472065） |
| |
| 摘 要： | 华北地台大约从寒武纪第二世的晚期开始接受沉积，超覆在前寒武-寒武纪“巨型不整合面”之上，形成了一套二级海侵背景下的厚层陆表海硅质碎屑岩-碳酸盐岩混积序列，这套特别的地层序列在苗岭统和芙蓉统中包含了多种多样的微生物岩。研究区苗岭统出露较为完整，包括毛庄组、徐庄组、张夏组和崮山组，分别构成4个三级层序即SQ1至SQ4。在SQ2的高位体系域和强迫型海退体系域中，以及SQ3的高位体系域中发育了较为特别的由微生物岩构成的生物层、生物丘或生物丘复合体。微生物岩的种类和沉积环境包括形成于正常浪基面以下、潮下带低能环境的类型I迷宫状微生物岩，潮下带上部至潮间带中-高能环境的类型II和类型III迷宫状微生物岩，风暴浪基面之上浅水环境中的均一石，潮间带短柱状叠层石和潮上带近水平缓波状叠层石，以及高能鲕粒滩中的小型叠层石生物丘。通常认为寒武系苗岭统的微生物岩（礁）以凝块石和树形石为特征，而本次研究在苗岭统中发现了迷宫状微生物岩和均一石，补充丰富了对寒武系微生物岩（礁）多样化和复杂化构成的认识。无论是在迷宫状微生物岩、均一石中，还是叠层石中，都见到了一种或多种钙化蓝细菌（鞘）化石，如葛万菌（Girvanella）、附枝菌（Epithyton）和基座菌（Hedstroemia）等，以及大量的钙化微生物席残余物，表明这些微生物岩是由蓝细菌所主导的微生物席的复杂的钙化作用产物，而大量呈弥散状分布的黄铁矿晶体或颗粒则表明硫酸盐还原菌等非光合作用细菌和异养细菌可能在促进碳酸盐沉淀过程中扮演了重要角色。
|
| 关 键 词： | 华北地台 寒武纪 苗岭统 微生物岩 钙化蓝细菌 |
| 收稿时间： | 2018-12-25 |
Fabric Characteristics,Depositional Environment and Geological Implications of Cambrian Miaolingian Microbialites at Magou Section,North China Platform |
| |
| Institution: | 1.School of Earth Sciences and Resources, China University of Geosciences(Beijing), Beijing 100083, China;2.Research Institute of Exploration and Development, PetroChina Changqing Oil field Company, Xi'an 710018, China;3.PetroChina, Research Institute of Petroleum Exploration and Development, Beijing, 100086, China;4.PetroChina Hangzhou Research Institute of Geology, Hangzhou 310023, China |
| |
| Abstract: | The North China Platform began to accept deposition following the late Cambrian Series 2,overlapping the ‘Great Unconformity’ between the Precambrian and Cambrian as a complete second-order cycle of transgression and regression. The depositional sequence of thick epeiric siliceous clastic-carbonate mixtures involves a variety of microbialites(reefs) formed against this background. The Miaolingian in the study area is well represented by outcrops of the Maozhuang Formation,Xuzhuang Formation,Zhangxia Formation and Gushan Formation,constitutes four third order sequences:SQ1 to SQ4. Particular biostromes,simple biomounds and biomound complexes composed of microbialites developed in the HST and FRST of SQ2,and in the HST of SQ3. Type I maceriate microbialites formed in the low-energy environment of the subtidal zone below the normal wave base;Types II and III formed in the upper subtidal to intertidal zone. Leiolites formed in shallow water above the storm wave base. Short-columnar stromatolites formed in the intertidal zone;stromatolites with gentle wavy and blurred laminae formed in the supratidal zone;and small stromatolitic mounds formed in high-energy oolitic banks. It is generdy believed that the microbialitic reefs of the Cambrian Miaolingian are characterized by thrombolites and dendrites. The discovery of maceriate microbialites in the Miaolingian enriches our understanding of the diversity and complexity of Cambrian microbialites. Fossils or fossil assemblages of calcified cyanobacteria Girvanella,Epiphyton and Hedstroemia were found in mazelike carbonates,leiolites and stromatolites,suggesting that these microbial rocks are the products of calcified microbial mats dominated by cyanobacteria,while a large number of dispersed pyrite crystals or particles indicate that nonphotosynthetic and heterotrophic bacteria such as sulfate-reducing bacteria may play important roles in facilitating carbonate precipitation. |
| |
| Keywords: | |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《沉积学报》浏览原始摘要信息 |
| 点击此处可从《沉积学报》下载免费的PDF全文 |
|
