哈尔滨东宾县凹陷白垩纪地层层序及其与松辽盆地的对比

根据实测剖面并结合前人研究成果厘定了宾县凹陷白垩纪地层层序:下白垩统板子房组、宁远村组、淘淇河组、泉头组和上白垩统青山口组、姚家组。综合运用岩性地层、生物地层、地质事件和同位素年龄的方法将宾县凹陷白垩系与松辽盆地进行了对比。根据同位素年龄对比,板子房组相当于沙河子组上部和营城组下部,宁远村组相当于营城组中上部。根据植物化石组合分析,淘淇河组可与营城组顶部、登娄库组和泉头组底部对比。“鸟河组”下部红层作为区域性气候事件的产物可与泉头组下部对比;该组以Triangulicypristorsuosus和Triangulicypristorsuosusvar.nota繁盛为特征的介形类化石组合与青山口组相似,轮藻类化石Atopocharatrivolvis、Aclistocharasongliaoensis和Obtusocharaniaoheensis在泉头组至嫩江组均有发现;因此将“鸟河组”分解为泉头组、青山口组、姚家组和嫩江组。

Cretaceous stratigraphic sequence of the Binxian subbasin east of Harbin,Heilongjiang,China and its correlation with that in the Songliao basin

The Cretaceous stratigraphic sequence of the Binxian subbasin is redefined according to the stratigraphic sections, combined with previous research. It is composed in ascending order of the Lower Cretaceous Banzifang Formation, Ningyuancun Formation, Taoqihe Formation and Quantou Formation and the Upper Cretaceous Qingshankou Formation, Yaojia Formation and Nenjiang Formation. Based on the lithostratigraphy, biostratigraphy, geological events and isotopic ages, the authors correlate Cretaceous strata of the Binxian subbasin with those in the Songliao basin. Isotopic dating of volcanic rocks indicates that the Banzifang Formation is equivalent to the upper part of the Shahezi Formation and the lower part of the Yingcheng Formation, while the Ningyuancun Formation is equivalent to the middle and upper parts of the Yingcheng Formation. The Taoqihe Formation may correlate with the top part of the Yingcheng Formation, Denglouku Formation and lowermost part of the Quantou Formation according to lithological and fossil plant assemblage evidence. The red bed in the lower part of the abolished "Niaohe Formation" as the product of the regional climatic event is equivalent to the lower part of the lower part of the Quantou Formation. The ostracod assemblage in this formation, which is characterized by prosperity of Triangulicypris torsuosus and Triangulicypris torsuosus var. nota, is similar to that in the Qingshankou Formation, and the charophytes Atopochara trivolvis, Aclistochara songliaoensis and Obtusochara niaoheensis are found in the Quantou, Qingshankou, Yaojia and Nenjiang formations; therefore the "Niaohe Formation" is divided into the Quantou, Qingshankou, Yaojia and Nenjiang formations.