松辽盆地松科1井嫩江组磁极性带及其地质时代  

MAGNETOPOLARITY ZONE AND GEOLOGICAL AGE OF THE NENJIANG FORMATION AT THE CCSD-SK-1 DRILL CORE IN THE SONGLIAO BASIN

作　　者：蒙启安[1] 黄清华[1] 万晓樵[2] 邓成龙[3] 贺怀宇[3] 

机构地区：[1]大庆油田有限责任公司勘探开发研究院黑龙江大庆163712 [2]中国地质大学地球科学与资源学院北京100083 [3]中国科学院地质与地球物理研究所北京100029

出　　处：《地层学杂志》2013年第2期139-143,共5页Journal of Stratigraphy

基　　金：国家重点基础研究发展计划“973”项目(2012CB822000)资助成果

摘　　要：松科1井是中国白垩纪大陆科学钻探工程井,由松科1井南孔和松科1井北孔组成,获取了嫩江组888.18m长的完整岩芯资料。通过对嫩江组1550块岩芯样品的热退磁和或交变退磁分析,获得了嫩江组完整的古地磁极性剖面,即由嫩江组下部的正极性带和其中、上部的反极性带构成。综合浮游有孔虫产出层位的地质时代分布、嫩江组二段斑脱岩锆石U-Pb同位素年龄和嫩江组磁极性带构成分析,认为嫩江组二段下至嫩江组一段的正极性磁条带对应于地质年代表中白垩纪静磁带CNS(C34n带)上部,嫩江组二段中部至嫩五段的反极性带对应于白垩纪静磁带之上的第一个反极性带C33r,嫩江组对应的地质时限为中Santonian期至早Campanian期。Abstract The Chinese Continental Scientific Drilling Project completed two drill cores （CCSD-SK-1-North and CCSD-SK-1-South） that penetrated the Cretaceous System of the Songliao Basin and recovered 888.18m core material of the Nenjiang Formation. To establish the magnetostratigraphy of the Nenjiang Formation, 1550 samples were collected and analyzed through stepwise thermal and/or alternating field de- magnetization of the natural remanent magnetization （NRM）. Two magnetic polarity zones have been iden- tified, including a normal polarity zone in the lower Nenjiang Formation, and a reverse polarity zone in the middle and upper Nenjiang Formation. Based on a comprehensive analysis of the chronostratigraphic distri- bution of planktonic foraminifers, bentonite U-Pb zircon ages and the magnetostratigraphy, the normal magnetopolarity zone of the first member to the lower part of the second member of the Nenjiang Forma- tion can be correlated with the upper of the Cretaceous Normal Superchron （CNS, C34n） in the geomag- netic polarity timescale. The reverse magnetopolarity zone, from the middle part of the second member to the fifth member of the Neniiang Formation can be correlated with chron C33r. Thus, the Nenjiang For- mation is of middle Santonian to early Campanian in age.

关 键 词：磁性地层学 磁极性带 白垩纪 嫩江组 松科1井 松辽盆地 

分 类 号：P539.3[天文地球—古生物学与地层学] P534.53[天文地球—地质学]