大小凌河扇形地第四纪地层与沉积物特征的初步研究

本文根据岩性特征、沉积旋回、接触关系、孢粉和微体古生物等资料,对大小凌河地区的第四纪地层进行初步研究,在此基础上探讨第四纪以来的沉积物及其特征,并分析晚第四纪以来的海相地层与海侵特征。

STUDY ON THE DIVISSION OF STRATIGRAPHY AND THE SEDIMENTAL FACIES OF QUATERNARY IN THE FANS OF DALINGHE RIVER AND XIAOLINGHE RIVER

Based on the data of lithology, spore and pollen, micropaleontology and C~(14) age dating of the CK_(42) drilling on the east side of the Dalinghe River and the CK_(33) drilling on the west side of the Dalinghe estuary, this paper preliminarily studies the stratigraphy, sediments and its characteristics of Quaternary, the marine deposition horizons and transgressive features since late Quaternary. The main charateristics of stratigra-phy of Quaternary is that the thickness of sediment accreted gradually from the northwest to the southeast, with the thickness of sediment reaching 302m in the CK_(40) drilling of Nanjingzi in the farthest southeast and the thickness of sediment becoming thinner and thinner from early period to late period. The data of CK_(42) drilling showed that the thickness of sediment is 61.46m of early Pleistocene series, 56.31m of middle Pleistocene series, 42.97m of late Pleistocene series and 35.14m of Holocene series. The types of contributing, factor of sediments of Quaternary are mainly fluvioglacial accumulation, alluvial proluvium, limnological accumulation, alluvium, marine deposition and aeolian deposition etc., The grain size of sediments changed from coarse to fine and the structure of horizon changed from single layer to multilayers from the northwest to the southeast. Three transgressions took place and resulted in 3 marine horizons of transgression in this area since late Pleistocene.