摘要
蓟县桑树鞍村附近长城系高于庄组找到的宏观化石,呈单体,棕褐色带状含有机质薄膜。可能属于原始的藻类,定为1新属Sangshuania Du(gen.nov.),两个新种Sangshuania sangshuanensis Du(gen.et sp.nov.),S.linearis Du(gen.et sp.nov),前一种为旋曲状,后一种为直线状和蛇曲状。含化石层位的同位素年龄大约为1430Ma。化石的分类位置尚难确定,就其保存状态、形态、大小和时代等,可与北美贝尔特超群的腊瓦里群格雷松页岩大型藻类相近似,但也不能排除为其他生物或遗迹化石的可能性,该化石可能为我国晚前寒武纪,时代最老的宏观化石。
Rich well-preserved megafossils were recently found from the dolomitic marl in the fifth member of the Gaoyuzhuang Formation of the Middle Proterozoic Changchengian System,near Sangshuan Village,Jixian,Tianjin,with an approximate age of 1400 Ma BP.The fossils,being brown in colour,simple in structure and probably allied to primitive algae are attributed to a new genus Sangshuania,which contains two species,Sangshuania sangshuanensis and Sangshuania linearis.Sangshuania sangshuanensis has a width of 1-2 mm and is usually of a regular whorl shape with a diameter of about 8-18 mm.Sangshuania linearis,shaped like a meandering belt,has a length of 30-50 mm and a width of about 1 mm.These megafossils are probably the oldest in age so far found in the Late Precambrian of China,and probably also the oldest in the world.The present discovery shows the Presence of advanced life as early as 1400 Ma BP,and enriches our knowledge of the record of organic life in the classical Upper Precambrian section of the Jixian region,and helps in correlating the Jixian stratigraphic section with those in other parts of China and of the world as well.Judged by the state of preservatian,the shape,size and age Sangshuania is closely related to the mega-algae of the Greyson shale Ravalli Group,Belt Supergroup of North America.
作者
杜汝霖
田立富
李汉棒
Du Rulin;Tian Lifu;Li Hanbang(Hebei College of Geology)
出处
《地质学报》
1986年第2期115-120,215,共7页
Acta Geologica Sinica
