地理科学 ›› 1984, Vol. 4 ›› Issue (2): 133-142.doi: 10.13249/j.cnki.sgs.1984.02.133

• 论文 • 上一篇    下一篇

珠江三角洲的第四纪地层

李平日, 黄镇国, 张仲英, 李孔宏   

  1. 广州地理研究所
  • 出版日期:1984-03-20 发布日期:1984-03-20

QUATERNARY STRATIGRAPHY IN THE ZHUJIANG DEITA

Li Pingri, Huang Zhenguo, Zhang Zhongying, Li Konghong   

  1. Guangzhou Institute of Geography
  • Online:1984-03-20 Published:1984-03-20

摘要: 珠江三角洲总面积8601.1平方公里,其中平原面积6932.5平方公里,占80.6%,其余为突起在平原上的岛丘,计160余座。关于珠江三角洲平原的第四纪地层,前人曾分为三段,即:下段为 Q41河流相沉积层和三角洲相沉积层,中段为Q:42风化层;上段为Q43三角洲相沉积层。或者下段为Q41—Q42的陆相层;中段为Q42-Q43的滨海相层;上段为Q43的河海混合相层。这些划分,因当时C14年代数据不足,多属推论。

Abstract: This peper deals with the Quateranry stratigraphy devision in Zhujiang Delta based on the analysis of the C14dating and stratigraphic correlation,sedimen-tary facies and cycles,as well as climatic variations reflected by spore-pollen analysis.It is concluded that six formations could be distinguished in chrono-logical order,since the Middle Late Pleistocene (Q32),namely: (1)Shipai (石排)formation(Q32-1),which is marked b the yfollowing features:C14dating about37,000±1480 years B.P.—30,000±2800 years B.P.; terrestrial gravel or thick sand with buried forests formed during a period of lowersea level;spore-pollen group representing colder climate. (2)Xinan (西南)formation (Q32-2),its lithological characteristics are mainly of dark grey clay with marine or brackish fossil acconding to C14dating (28,240±2220—15,000±550 years B.P.)and spore-pollen group representing warmer climate,it Can be concluded that this formation of deltaic facies was deposited under trangressive condition,during the late stage of Würm sub-inter-glaciation. (3)Sanjiao(三角)formation(Q33-Q41),which is characterized by deep weathering clay or alluvial thick sand and gravel interbedded with buried fo-rests.This formation is clearly the product of weathering in terrestrial environ-ment,during tile period of global lower sea level of the Late würm glaciation and Early Holocene. (4)Henglan(横栏)formation(Q42-1),its C14 dating are 8050±200— 5020±150 years B.P.,greyish black muds with abundant marine fossil.In addi-tion,the result of spore-pollen analysis indicates that the climate of that time was greatly warmer than that of Q33-Q41,and an extensive transgression exerted a strong effect on the Middle Holocene sedimentation in the Zhujiang Delta. (5)Wanqingsha(万顷沙)formation(Q42-2),similar to the 3rd stratum, is mainly composed of terrestrial sediments such as shallow-weathering clay, thick sand or fine sand interbedded with fresh water diatoms or shells and abun-dant buried forests.Horizontally,the facies turns to marine muds.Their C14 datings are 4940±250—2510±110 years B.P.and the spore-pollen group reflects a colder climate at that time.Thus,this formation might have been deposited un-der local regressive condition. (6)Denglongsha (灯笼沙)formation (Q43),which is mainly composed of derk grey mud and silt clay.From the C14dating (2350±110—1260±90 years B.P.),warmer spore-pollen composition and facies,this formation seems to be a part of the sediments of deltaic environment from about 2500 years B.P. up to the present.