银根—额济纳旗盆地白垩纪地层、古生物群和古环境研究

利用盆地周缘露头、盆内钻井资料系统总结了银根—额济纳旗盆地白垩纪的地层、古生物特征,探讨了白垩纪的古环境.白垩系划分为下统巴音戈壁组、苏红图组及银根组,上统乌兰苏海组.地层特征盆地各区差异明显,巴音戈壁组北、东部以含烃源岩,西南部以不含烃源岩为特征;苏红图组西部以不含火山岩系和含煤层,东部以含火山岩系为特征.白垩系地层中发育介形类、双壳类、叶肢介、轮藻、藻类、腹足类、鱼类、昆虫、古植物和孢粉等多门类古生物化石.白垩纪可分为早白垩世的暖温带—亚热带干湿交替过渡性气候和晚白垩世的亚热带—热带半干旱—干旱气候.

Study on Cretaceous stratum, palaeobiota and palaeoclimate of Yin'gen-Ejinaqi Basin

The characteristics of Cretaceous stratum and the palaeobi ota of Yin'g en-Ejinaqi Basin, and the palaeoclimate of the basin are studied based on the o u tcrops in its periphery and the drilling data in the basin. The Cretaceous strat um is divided into the Lower Cretaceous and the Upper Cretaceous. The Lower Cret aceous consists of Bayin'gebi Formation, Suhongtu Formation and Yin'gen Formatio n, and the Upper Cretaceous consists of Wulansuhai Formation. The formation char acteristics of these formations in this basin are different. Bayin'gebi Formatio n contains hydrocarbon source rock in the north and the east, and it doesn't con tain hydrocarbon source rock in the southwest; Suhongtu Formation contains volca nic rock in the east and it contains coal bed but no volcanic rock in the west. A great many kinds of palaeontological fossils, such as ostracoda, bivalcia, con chostraca, charophyta, alga, gastropods, fish, insect, micropalaeontologica, spo ropollen etc. are found in the Cretaceous stratum. The climate of Cretaceous can be divided into two sorts: the warm--semitropical transient climate in the Lo we r Cretaceous; the semitropical-tropical hot and dry climate in the Upper Cretac eous.