摘要
梨树组是梨树断陷下白垩统最下部地层,因建组时古生物依据不充分,致使地层划分与区内外对比困难。本文通过对孢粉化石和地层接触关系的研究,修正了梨树组原来的定义,明确其岩性为以湖相沉积为主的一套暗色砂泥岩沉积。该组厚约900m,最厚可达1500m。孢粉组合为紫萁孢-无口器粉-古松柏粉组合和桫椤孢-无突肋纹孢组合。该组与上覆登娄库组和下伏火石岭组为假整合或不整合接触。本文重新描述了建组剖面,确认其地质时代为早白垩世。
Lishu formation is the basal stratum of Lower Cretaceous in Lishu fault depression.It was difficult to divide and correlate the strata because the paleontological evidenceswere not enough. Thirough the study on the spormorph and the contact relation of thestrata, the original definition of Lishu formation is corrected in the paper, it is con-firmed that the strata are the sedimentary formation where lake phase melanocraticsandstone and mudstone are primary. The thickness is about 900m, the thickest stra-tum is 1500m. The spormorph assemblage is Osmundacidites-Inaperturopollenites-Protoconiferus and Cyathidites-Cicatricosisporites. The contact relation of the formation withthe overlying Denglouku formation and the underlying Huoshiling formation is discon-formity or unconformity. The established formation section is described again, the geo-logic age is Lower Cretaceous.
出处
《大庆石油学院学报》
CAS
北大核心
1993年第4期30-35,共6页
Journal of Daqing Petroleum Institute
关键词
孢粉组合
早白垩世
地层
Dehui-Lishu fault depression
Lower Cretaceous
Lishu formation
spormorph assemblage
