海南岛西北岸三万年前后浅海相地层的发现及其意义

在海南岛西北部神尖沿岸地区,广泛出露一套富含海相化石的粉细砂—砾石沉积层,组成了高达20米左右的沿岸台地。该地层中所含化石组合主要有海扇、曼氐孔楯海胆、舌骨牡蛎和个体很大的盖虫。根据岩性、沉积相及~(14)C年代数据可知,在距今三万年前后,这里是一个环境比较稳定的热带浅海湾。海水的温度比现在高。我国其它沿海地区,在0—-27米也普遍存在三万年前后的海相沉积层。不同的是,海南岛西北岸三万年前后的海相层,因受后期火山作用而被抬升至高于现代海面20米左右。

MARINE STRATA AROUND COAST OF NORTHWEST PART OF HAINAN ISLAND

A set of strata, which belongs to the shallow marine facies, is exposured in a isle, Sejian, been situated near the coast of northwast purt of Hainan Island. The set of strata contains a great number of fossils of marine life, such as Chlaimys Satoi Yokvyama, Pecten (Aequipecten) inaequwalves Sowerby, Astriclypeus manni verrill, Mio-Rec, Ostrea hyotis Linne and(oper-culina bartsehi Var Cushman, consists of silt-sand-gravel and forms the coastal platform as high as about 2Om. According to the characteristics of rocks, deposits facies and ~(14)C dating, it is apparent that there was a tropical shallow bay with rather stable environment about 30,000 Yr. B. P. here. The temperature of seawater at that time was higher than at present. In coastl zone of China, there is abroad the marine deposits been Iocated in the highness of 0-27m. The dating of the deposits is about 30,000 Yr.B.P. But it is interest that the deposts around the isle have risen to about 20m above present sealevel by later valcanicackivity.