摘要
宁夏灵武直罗组植物化石及泥岩地球化学特征记录了灵武龙生活时代直罗组沉积期的地质信息。通过对灵武地区中侏罗统直罗组孢粉和植物化石的采集分析,对直罗组泥岩的常量及微量元素分析,针对该区古气候、古盐度、古氧化还原环境进行探讨并简要分析古沉积环境演化。直罗组孢粉类型以湿生为主,茎秆类植物化石大都为湿生蕨类植物,反映了当时温暖湿润的气候,相比延安组植物化石组合,直罗期开始向炎热干旱气候演化。泥岩元素地球化学分析显示从直罗组沉积早期到晚期,古气候由温湿气候逐渐变得干旱,整体处于弱还原环境,沉积环境氧化作用减弱,而在直罗晚期氧化作用具增强之势,同直罗组呈微咸水相的淡水环境并且晚期水体古盐度增大一致,揭示直罗组沉积晚期相比早期气候更加干旱,且相比延安组气候开始向炎热干旱气候演化,直罗组沉积时期处于由温暖潮湿变得炎热干旱的过渡期。
Plant fossils and mudstone geochemical characteristics of the Zhiluo Formation in Lingwu,Ningxia recorded the geological information of the sedimentary period of Zhiluo Formation in Lingwulong s life time.Based on the collection and analysis of palynology and plant fossils of Zhiluo Formation of middle Jurassic in Lingwu area,the major and trace elements of mudstone of Zhiluo Formation were analyzed,and the paleo-climate,paleo-salinity and paleo-redox environment in this area were discussed,the evolution of paleo-sedimentary environment was analyzed briefly.The palynological types of Zhiluo Formation were mainly wet,and most of the fossilized stem plants were wet ferns,which reflected the warm and humid climate at that time.Compared with the fossil assemblages of Yanan Formation,Zhiluo Formation began to evolve into a hot and dry climate.The geochemical analysis of mudstone elements shows that from the early sedimentary period of Zhiluo Formation to the late sedimentary period,the paleo-climate gradually changes from warm and humid to dry,and the overall paleo-climate is in a weak reducing environment,the oxidation of the sedimentary environment is weakened,and the oxidation of the sedimentary environment in the late period of Zhiluo Formation tends to increase,which is the same with the freshwater environment of the Zhiluo Formation.It shows that the late Zhiluo Formation is more arid than the early climate in the late sedimentary period,and the climate has started to evolve into a hot and arid climate compared to the Yanan Formation.The deposition period of the group is in the transition period from warm and humid to hot and dry.
作者
宋扬
海连富
梅超
马一平
李海峰
SONG Yang;HAI Lian-fu;MEI Chao;MA Yi-ping;LI Hai-feng(Ningxia Institute of Mineral Geology,Yinchuan 750021,China)
出处
《科学技术与工程》
北大核心
2020年第26期10592-10597,共6页
Science Technology and Engineering
基金
宁夏自然科学基金(2019AAC03310)。
关键词
灵武恐龙
孢粉
地球化学特征
古气候
Lingwu dinosaur
palynological
geochemical characteristics
the ancient climate
