东海陆架盆地台北坳陷月桂峰组生物地层及古环境

BIOSTRATIGRAPHY AND PALEOENVIRONMENT OF THE YUEGUIFENG FORMATION IN THE TAIPEI DEPRESSION OF THE CONTINENTAL SHELF BASIN OF THE EAST CHINA SEA

月桂峰组分布于台北坳陷西带,上覆灵峰组、下伏石门潭组,由灰黑色泥岩、砂岩组成。在微体古生物和地球化学微量元素详细分析的基础上,确立它属古近纪古新世沉积,推测可能为古新世早期,该地层相当于苏北盆地阜宁组一段。月桂峰组所含孢粉、藻类化石组合及地球化学微量元素特征表明月桂峰组当时的沉积环境以淡水湖相为主,局部时期(晚期)可能演变成海陆交互相,或者受到海水的影响。

Yueguifeng Formation is distributed in the west part of the Taipei depression of the continental shelf basin of the East China Sea. The Formation is composed of grayish black mudstone and sandstone. It lies above the Shimentan Formation and beneath the Lingfeng Formation. Based on the analyses of microfossils and trace elements in the section, this Formation was assigned to a geological age of early Tertiary, possibly early Paleocene. The Formation is correlated with the first member of Funing Formation in the Subei basin. The characteristic sporepollen, algae fauna and trace elements in this Formation indicated that the sediment was formed under the lacustrine environment of freshwater. During the late period of the Formation, the sedimentary environment possibly changed into marine/fresh alternation, or was partly affected by the salty water.