摘要
本文描述了采自太行山北段山西境内高于庄组二段含锰叠层状藻席的一种建造者——直链古念珠藻(新种)(Veteronostocale moniliforme Xu et Gao,p.nov.),首次提出念珠藻科(No stocaceae)植物和其它叠层石造礁者一样是晚前寒武纪藻席的主要建造者之一。同时,详细研究了微化石保存的状态与产出层位,证明当时的沉积速度每年在1mm以上;论述了化石产地处于低能的海底或潮下带沉积环境;并根据现存念珠藻科植物的生长条件,推断前寒武纪的海水可能为淡水型。
Abundant and preserved chain algal micrnfossils have been discovered in cherty stroma-tolitic mats from the second member of Gaoyuzhuang Formation (about 1,500 Ma old), Ling-qiu county of Shanxi province, China. They are described as Veteronostocalc mondiforme Xu et Gao sp. nov.. The small diametral trichomes resemble the Family Nostocaceae in possessing specilized cells resembling the classic heterocysis and akinetes. This paper gives emphasis to the following remark: (1) The Gaoyuzhuang strotnatolitic mats were products of microbial ( Ve-teronostocale moniliforme) activity and the plant Nostocaceae was one of the main stromato-litic builders as both modern and Precambrian stromatolite-forming microorganisms; (2) Based on the fact that the chain fossils are preserved perpendicularly to the laminations the rates of sedimentation and algal growth were probably equal and each small sedimentary rhythm could be completed in about one or two months; (3) According to the environment and habits of living Nostoc Precambrian hydrosphere might be of a fresh water type.
基金
青年科学基金资助项目
中国科学院基础学科特别支持费资助
关键词
直链古念珠藻
藻席
晚前寒武纪
Veteronostocale moniliforme Xu et Gao sp. nov.
Algal mats
Late Preca-mbrian
