宁夏中卫、中宁地区纳缪尔期贫氧生物相特征  

CHARACTERISTICS OF THE NAMURIAN DYSAEROBIC BIOFACIES FROM ZHONGWEI AND ZHONGNING REGIONS,NINGXIA,CHINA

作　　者：杨逢清[1] 

机构地区：[1]中国地质大学地质系

出　　处：《地球科学（中国地质大学学报）》1992年第3期271-279,共9页Earth Science-Journal of China University of Geosciences

摘　　要：宁夏中卫、中宁地区纳缪尔期动物群以游移的软体动物为主,伴以底栖固着的珊瑚、苔藓动物、腕足类和棘皮动物;个体小;具有以食肉或食腐肉及食沉积物为主的独特营养结构,食悬浮物的滤食性生物较少;有些化石已黄铁矿化。上述特征均直接与贫氧环境的含氧度低有关。根据岩石学特征分析,本区纳缪尔期的古地理环境为温暖、贫氧、盐度不稳定、水动力较弱、能量较小的浅海深水盆地。Characteristics of Namurian faunas in Zhongwei and Zhongning regions of Ningxia are as follows : dominance by vagile molluscs, associated with benthic corals. bryozoans, bra-chiopods and echinoderms small body size as the result of high juvenile mortality and possible stunting; the trophic structure dominated by carnivorous or scavenging and deposit feeders, and less the filter feeders; some fossils were pyritized. All these characteristics are directly linked to the low oxygen levels. According to analysis of the features of litho-logy, Namurian palaeogeographic environment in the regions might be a deep basin in the shallow sea, in which the water was quiet and warm, dysaerobic, unstable and weak dynamic.

关 键 词：纳缪尔期 贫氧 生物相 石炭世 

分 类 号：Q911.645[天文地球—古生物学与地层学]