对西秦岭拉尔玛地区太阳顶群进一步划分的意见  

UNDEKSTANDING OF THF TAIYANGDING GROUP IN LAERMA DISTRICT OF GANSU, CHINA

作　　者：叶发荣 李亚东 崔志刚 

机构地区：[1]甘肃省地质矿产局第三地质队

出　　处：《甘肃地质学报》1994年第2期27-30,共4页Acta Geologica Gansu

摘　　要：太阳顶群是一套黑色含碳硅质碎屑岩系，化石贫乏。笔者１９８８年在拉尔玛地区该群拉尔玛组上部发现有ＣｙｌｉｎｄｒｏｃｈｉｔｅｓｄａｉｚｎｕａｎｇｚｉｅｎｓｉｓＬｉｕ和ＨｙｏＬｉｔｈｅｌｌｕｓｑｉｎｇｈｅｅｓｉｓＬｉｕ等微体小壳化石，分别相当于陕西宁强、湖北房县、四川峨嵋麦坪和云南昆明梅树村产的Ｈｙｏｌｉｔｈｅｓｓｐ。和Ａｕａｂａｒｉｔｅｓ－Ｃｉｒｃｏｔｈｅｃａ化石组合，是下寒武统底部梅树村阶的标准带。根据微体小壳化石组合和岩性特征，将原太阳顶群拉尔玛组的上部，以铁质条带硅质板岩风化壳为标志的沉积间断为底界，时代定为下寒武统。将拉尔玛组中下部以下地层，时代定为上震旦统。The Taiyangding Group is a set of black carbonaceous silica clastic rock and in which fossil is rarely. In 1988,author have foun[-[\d Cylindrochites daiznuangziensis Liu and Hyolithellus qingheesis Liu mi-croshell fossil in the top of the Taiyangding Group Laerma formation. These respectively bore relationto Hyolithes sp. and Auabarites circotheca combination at Ningqiang,Shaanxi,Fangxian Hubei,Maiping,Sichuan and Meishucun, Yunnan,and that is the standard-zone of the Lower Cambrian Meishucun stage.On the basis of the microshell fassil assemblage and character of the rock,by the ferruginousbanding siliceous slate as the base of deposition break,the Taiyangding Group,the top of Laerma for-mation should divided into the Lower Cambrian and the middle -lower of Laerma formation should di-vided into Upper Sinian.

关 键 词：拉尔玛地区 太阳顶群 划分 地层 

分 类 号：P535.2[天文地球—古生物学与地层学]