白音查干凹陷早白垩世介形类组合特征与沉积环境  

OSTRACODA ASSEMBLAGES AND SEDIMENTARY ENVIRONMENTS OF THE LOWER CRETACEOUS IN THE BAIYINCHAGAN SEG

作　　者：蒋飞虎[1] 刘晓丽[1] 杨静[1] 

机构地区：[1]中原石油勘探局勘探开发研究院

出　　处：《石油勘探与开发》1996年第2期38-42,共5页Petroleum Exploration and Development

摘　　要：白音查干凹陷早白垩世介形类动物群以非女星介分子，如Ｌｉｍｎｏｃｙｐｒｉｄｅａ、Ｐａｒａｌｉｍ－ｎｏｃｙｔｈｅｒｅ、Ｃｌｉｎｏｃｙｐｒｉｓ、Ｌｙｃｏｐｔｅｒｏｃｙｐｒｉｓ等的繁盛为特征。自下而上分为３个化石组合：①Ｒｈｉｎｏｃｙｐｒｉｓｎｏｍｕｇｅｎｓｉｓ－Ｃｙｐｒｉｄｅａ（Ｄｙｐｒｉｄｅａ）ｄｅｌｎｏｖｉ－Ｃｙｐｒｉｄｅａ（Ｃｙｐｒｉｄｅａ）ｕｎｉｃｏｓｔａｔａ组合，产于腾格尔组；②Ｃｙｐｒｉｄｅａ（Ｙｕｍｅｎｉａ）ｓｕｂｒｅｍｏｔａ—Ｌｉｍｎｏｃｙｐｒｉｄｅａｔｒａｐｅｚｏｉｄｅａ－Ｃｌｉｎｏｃｙｐｒｉｓ组合，产于都红木组下部；③Ｌｉｍｎｏｃｙｐｒｉｄｅａｍｉｎｕｔａ富集组合，产于都红木组上部。各化石组合与二连盆地主体的同期化石组合可以对比，但差异颇大。推测早白垩世白音查干古湖盆有较高的盐度，与二连盆地主体可能并非同一水体。白音查干凹陷都红木组沉积期环境以稳定深湖为主，亦与盆地主体都红木组沉积期的沼泽化环境不同。The Early Cretaceous ostracode fauna from the Baiyinchagan seg is characterized by dominance of noncypridea elements, such as Limnocypridea, Paralimnocythere, Clinocypris, Lycopterocypris, etc. Three fossil assemblages are divided in ascending order as follows: (1) Rhinocypris nomugensis-Cypridea (Cypridea)delnovi-(Cypridea)unicostata assemblage from the Tenger formation ;(2) Cypridea (Yumenia ) subremota -Limnocypridea trapezoidea-Clinocypris assemblage from the lower part of the Duhongmu formation; (3)Limnocypridea minuta dominated assemblage from the upper part of the Duhongmu formation. The defferenees between these fossil assemblages and the corresponding assemblages in the Erlian basin are rather great. We infer the Baiyinchagan ancient lake was not a united water body with the main part of the Erlian basin during the Early Cretaceous. The salinity in the former was higher than in the later probably. Moreover, the stable deep-water environment during the Duhongmu formation sedimentary period in the area is also different from the marsh environment in the Erlian basin.

关 键 词：早白垩世 沉积环境 介形虫 古生态 白音查干凹陷 

分 类 号：P534.53[天文地球—古生物学与地层学] Q915.653[天文地球—地质学]