福建东山岛第四纪微体化石群及其地质意义

QUATERNARY MICROFAUNA AND THEIR GEOLOGYCAL SIGNIFCANCE IN DONGSHAN ISLAND OF FUJIAN

本文对东山岛9个钻孔70块样品进行了有孔虫和介形虫等微体化石群分析,并参考有关资料,探讨了该岛第四纪地层的沉积时代、沉积相和古环境演变。

Based on the results of micropateontological analyses and study of 70 samples from nine drilling cores in Dongshan Island,Fujian Province,the microfauna there may be categorized into two assemblages of foraminifera.Ⅰ.A.beccarii var.-Q.praelonga Assemblage in the late Holocene Changle formation.Ⅱ.A.beccarii var.-Bulimina spp.Assemblage in the early Holocene Dongshan formation.Three subassemblages may be further acknowledged:Ⅱ1.A.beccarii var.-E,nakanokawaense Subassemblage.Ⅱ2.Bulimina spp.-Sch,globosa Subassemblage.Ⅱ3.Buccella frigida(Cushman)Subassemblage.The Assemblages are of warm water of the inner continental shelf.Since the late Pleistocene,the paleogeography has evolutes from continental facies→marine facies→marine-continental transitional facies to continental facies,and the paleoclimatic from warm dry→hot wet towarm wet-dry in Dongshan Island.In that period,there happened a sea transgression in quite a large scale,a result of the overlapping of global sea level variation and the neotectonic movement on the island.