摘要
依据禄丰县川街剖面修订了昆明小区曾经使用半个多世纪的上、下禄丰系(群、组)岩石地层单位,厘定并重新命名了禄丰组(包括沙湾段和张家坳段),新建川街组、老罗村组、麻地山组,沿用安宁组,首次在禄丰区域内划分出上侏罗统。结合各组产出的化石,建立起侏罗纪早、中、晚3套脊椎动物群序列。进一步的考察研究又确认出昆明小区存在上三叠统舍资组和侏罗系的连续沉积。通过对比,确定昆明小区中侏罗统川街组底部和上侏罗统安宁组顶部,缺失楚雄小区张河组下部“绿砂岩段”和妥甸组上部“黄色泥岩段”。首次发现晚侏罗世妥甸组昆虫化石,昆虫化石的类型和叶肢介等门类化石有别于北方动物群。依据这些研究成果提出康滇地层分区侏罗系对比方案。
Based on the Chuanjie section at Lufeng County, the lithological units of the Upper and Lower Lufengian System (group and formation) used for the Kunming stratigraphic area for more than half a century are revised; the Lufeng Formation (including the Shawan Member and Zhangjia'ao Member) is redefined and renamed; the Chuanjie Formation, Laoluocun Formation and Madishan Formation are newly erected besides the Anning Formation that is still used; and the Upper Jurassic is separated in the Lufeng area for the first time. Based on fossil vertebrate faunas occurring in various formations, the Early, Middle and Late Jurassic are erected respectively. By further investigation and study, the authors confirm that the Upper Triassic Shezi Formation and the Jurassic were continuously deposited in the Kunming area. By correlation, the authors determine the base of the Middle Jurassic Chuanjie Formation and the top of the Upper Jurassic Anning Formation in the Kunming area, while the 'green sandstone member' of the Zhanghe Formation and the 'yellow mudstone member' of the Tuodian Formation are lacking in the Chuxiong basin. In addition, fossil insects are first discovered in the Late Jurassic Tuodian Formation. The insects fossils are associated with Estheria. The types of the insects and Estheria are different from those of the boreal faunas. Based on those new research results, the authors propose a scheme of stratigraphic correlation of the Jurassic in the Kangdian (Xikang-Yunnan) stratigraphic subregion.
出处
《地质通报》
CAS
CSCD
北大核心
2004年第2期154-159,共6页
Geological Bulletin of China
基金
科技部2001年度基础研究快速反应支持项目资助
关键词
侏罗系
界线
生物-岩石地层
滇中
Jurassic
boundary
biostratigraphy and lithostratigraphy
central Yunnan
