摘要
在辽宁金州寒武系长山组顶部,发育一层厚约15 m的生物丘。宏观上,生物丘主要由凝块石和均一石组成;微观上,由致密泥晶组构和各种类型的颗粒组成。在生物丘内部,各种类型的颗粒如钙化微生物、底栖鲕粒、核形石、生物碎屑和凝块等的发育,显示了生物丘复杂的显微组构。其中,三叶虫碎屑表面的泥晶结壳,表现出建设性和破坏性泥晶化作用。泥晶中分散分布的生物碎屑,反映了生物丘形成过程中泥晶较强的黏聚作用。致密泥晶中大量黄铁矿颗粒的发育,反映了异养细菌活动对泥晶形成的贡献。生物丘内部各种类型的颗粒与黄铁矿颗粒的共生,反映了生物丘形成过程中存在复杂的微生物作用,这为微生物沉积作用的研究提供了基础素材,也为生物丘内部各种类型颗粒的研究提供了重要实例和线索。
A bioherm 15m in thickness is exposed at the top of Cambrian Changshan Formation in Jinzhou area,Liaoning Province.Macroscopically,the bioherm is made up of thrombolite and leiolite,and microscopically,it is mainly composed of dense micrites and different kinds of grains.There are different types of grains,such as calcified microbes,benthic oolites,oncolites,bioclasts and clots,in the inner part of the bioherm,which indicates complex microfabric of the bioherm.The surface of trilobite skeletal clastics encrusted by micrites shows constructive and destructive micritization.Bioclasts dispersedly distributed within the dense micrite reflect relatively strong binding during the development of the bioherm.Large quantities of pyrite crystals existent in the dense micrites demonstrate that the formation of dense micrite was genetically related to heterotrophy-bacteria activities.Together with pyrite crystals,all kinds of grains within the bioherm reflect complex microbial activities during the formation of the bioherm,which provides not only prerequisite for the study of microbial sedimentation but also an important example and clue for the research on different types of grains within the bioherm.
作者
贡云云
姜含璐
倪胜利
GONG Yunyun;JIANG Hanlu;NI Shengli(School of Earth Resources and Sciences,China University of Geosciences,Beijing 100083,China)
出处
《中国地质》
CAS
CSCD
北大核心
2018年第6期1271-1288,共18页
Geology in China
基金
中国地质调查项目(1212011121268)
国家自然科学基金(41472090
40472065)联合资助~~
关键词
沉积特征
生物丘
长山组
寒武系
辽宁金州
sedimentary features
bioherm
Changshan Formation
Cambrian
Jinzhou in Liaoning Province
