珠江口盆地晚第四纪地层及环境初步研究

LATE QUATERNARY STRATIGRAPHY ANDENVIRONMENT IN THE ZHUJIANG RIVER MOUTH BASIN

本文利用珠江口盆地四个工程钻井的古生物、古地磁、同位素及沉积物资料，对钻孔所揭露的地层进行划分，认为所钻遇的地层包括下更新统（上部）、中更新统、上更新统及全新统。依据古生物分异度及含量作出海平面变化曲线，识别出十个海侵期，利用钙质超微化石特征种的初现面和末现面资料，将本区海平面变化曲线与太平洋Ｖ＿（２８－２３９）氧同位素曲线对比，分析了本区晚第四纪以来的沉积环境和气候，认为早更新世晚期，中更新世中期，晚更新世早期及全新世本区气候温暖，沉积环境属陆架浅海环境。

The lithology and micropaleontology in this paper are described by using cores,mi-crofossils and seismic data from four engineering wells at the Zhujiang River mouth basin.Ten transgressive stages can be recognized in the Quaternary of this region.The correlation between the sea-level change curve of the basin and the oxygen isotope of V_(28-239) in the south Pacific,based on the first and last appearance of index calcareous nan-nofossils,indicates that the last transgressive bed can be correlated with oxygen isotope stages 21-23,and strata revealed by drilling are the Lower Pleistocene(upper part),Middle Pleistocene,Upper Pleistocene and Holocene.The bottom boundary between Middle Pleistocene and Upper Pleistocene is Brunhes/Matuvama boundary and also the bottom bounary of the third transgressive bed.The boundary of Holocene is located at the bottom boundary of the first transgressive bed.This paper discusses about sedimen-tary environment and paleoclimate since Late Quaternary and indicates that 10 warm pe-riods and 9 cold ones have been alternated in this region.The late Early Pleistocene,mid-dle Mid-pleistocene,early Late Pleistocene and Holocene are obvious warm peroids.And the sedimentary environment belongs to continental shelf neritic environment.