豫西鲁山寒武系馒头组微生物岩旋回及其演化
THE MICROBIALITE CYCLES AND THEIR EVOLUTION FROM THE CAMBRIAN MANTOU FORMATION, LUSHAN,WESTERN HENAN PROVINCE, CENTRAL CHINA
齐永安 1孙晓芳 1代明月 1张喜洋1
作者信息
- 1. 河南理工大学资源环境学院,焦作454000
- 折叠
摘要
河南鲁山地区寒武系第三统馒头组三段上部碳酸盐岩中发育了大量微生物岩,包括3种类型核形石和2种类型凝块石,其内发现了大量钙化的蓝细菌化石Girvanella(葛万菌)和Epiphyton(附枝菌).根据凝块石-核形石-鲕粒的演化关系,可识别出5个微生物岩旋回.凝块石总是位于微生物岩旋回的底部,形成于潮下低能环境中;核形石位于旋回的中部,形成于潮下低-高能周期性变化的环境中;鲕粒灰岩出现在旋回的顶部,发育于持续搅动的潮下高能环境中.水动力条件的逐渐增强是微生物岩类型及其旋回演化的主控因素.
Abstract
Abundant microbialites including three types of thrombolites and two types of oncolites occur in the upper carbonates of the second member of the Mantou Formation(Series 3,Cambrian),Lushan,western Henan Province,central China.A large number of calcified cyanobacteria fossils Girvanella and Epiphyton are found in these microbialites.Five microbialite cycles can be recognized in the carbonates based on the evolutionary relationship among thrombolites,oncolites and ooids.The thrombolites are always located in the bottom of each cycle,which formed in low energy subtidal environments.The oncolites are more common in the middle part of the cycles from the subtidal environments with periodic changes between low and high energy.Ooilitic limestones occur in the top of the cycles,formed in an agitated high energy shallow subtidal environments.The gradual increase of sea water dynamic condition is the main controlling factor for the variation of microbialite types and the evolution of microbialite cycles.
关键词
核形石/凝块石/水动力条件/微生物岩旋回/馒头组三段/寒武系/鲁山/河南Key words
oncolite/thrombolite/sea water dynamic condition/microbialite cycles/the third member of the Mantou Formation/Cambrian/Lushan/Henan Province/Central China引用本文复制引用
基金项目
本研究得到国家自然科学基金(41472083)
出版年
2017
NETL
NSTL
维普
万方数据