南雄盆地武台岗白垩系与古近系界线剖面研究进展  

New Advances in the Study of Cretaceous and Paleogene Boundary on the Wutaigang Section of the Nanxiong Basin, Guangdong Province

作　　者：张显球 张志军[2] 李宏博[2] 方晓思[2] 

机构地区：[1]中国新星石油广州公司,广东三水528133 [2]中国地质博物馆,北京100034

出　　处：《地球学报》2007年第3期299-308,共10页Acta Geoscientica Sinica

基　　金：国土资源部地质调查项目"新一轮全国地下水资源评价"(编号:0299209078)资助。

摘　　要：上湖洞、武台岗一带是上湖组命名的典型地区,富产哺乳动物化石,又是古新世早、中期哺乳动物群研究最早最详细的地区,但微体化石面貌不清,近年来在武台岗剖面浈水组上部至上湖组下部发现丰富的介形虫、腹足类和轮藻化石,介形虫属于扣星介动物群,可以划分出Porpocypris orbiculata带和P.sphaeroidalis带,并且P.sphaeroi-dalis与Bemalambda的始现点几乎一致,与大塘E/K界线剖面所见相同。建议以介形虫P.sphaeroidalis始现点来限定古近系的底界,把E/K界线划在P.sphaeroidalis带与P.orbiculata带之间。Shanghudong and Wutaigang are typical areas responsible for the name Shanghu Formation, where abundant mammal fossils occur. Although the Early and Middle Paleocene mammal fauna was studied in detail long ago, the microfossils in this area have not been reported till now. In recent years, a lot of ostracods, gastrepodas and charophytes were found from the Upper Member of Zhenshui Formation to the Lower Member of Shanghu Formation within the Wutaigang section. These ostracods belong to the Porpocypris assemblage and can be subdivided into the Porpocypris orbiculata zone and the P. sphaeroidalis zone. The first occurrence of the P. sphaeroidalis zone almost coincides with that of the Bemalambda zone. The authors suggest that the first occurrence of P. sphaeroidalis limits the bottom boundary of Paleocene, and hence the E/K boundary should lie between the P. sphaeroidalis zone and the P. orbiculata zone.

关 键 词：E/K界线 武台岗剖面 南雄盆地 广东 

分 类 号：P534.41[天文地球—古生物学与地层学]