珠江三角洲△22孔的沉积特征及地层划分

SEDIMENTARY CHARACTERISTICS AND STRATA DIVISION OF CORE △22 OF THE ZHUJIANG RIVER DELTA

根据珠江三角洲中山市民众乡Δ22孔岩芯的粒度、重矿物、粘土矿物、古生物、地球化学及^(14)C测年等资料,探讨了晚更新世以来沉积层的沉积特征及其地层划分,Δ22孔地层可分为上更新统和全新统两大部分,各自还可划分为三层;并论证了珠江三角洲晚第四纪海进海退过程,认为珠江三角洲受到过两次海侵。

The sedimentary characteristics and strata division of the Zhujiang River Delta sedimentary bed since Late Pleistocene was studied based on grain size, heavy mineral, clay mineral, paleontology, geochemical and radiocarbon dating of the Minzhonog △22 cores to find the processes of transgression and regression of Late Quaternary in the Zhujiang River Delta.Strata in the core △22 may be divided into Late Pleistocene Series and Holocene Series and each of which may further be divided into three layers. Middle Pleistocene Series and Middle Holocene Series are characterized by containing forminifera, marine ostracoda, brackish water diaom Corbula sp. and glauconite, the average ratio of illite/kaolinite>1.4, and that of Ca/(Ca+Fe) in sedimentary phosphate>0.40.