中山大学地球科学系,广东,广州,510275
纸质出版日期:2014,
网络出版日期:2014-11-25,
扫 描 看 全 文
吴洁, 刘春莲, 张素青, 等. 珠江三角洲东部晚第四纪微体动物群的古环境意义[J]. 中山大学学报(自然科学版)(中英文), 2014,53(6):45-52.
WU Jie, LIU Chunlian, ZHANG Suqing, et al. Palaeoenvironmental Significance of Late Quaternary Microfaunas in the Eastern Pearl River Delta[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2014,53(6):45-52.
吴洁, 刘春莲, 张素青, 等. 珠江三角洲东部晚第四纪微体动物群的古环境意义[J]. 中山大学学报(自然科学版)(中英文), 2014,53(6):45-52. DOI:
WU Jie, LIU Chunlian, ZHANG Suqing, et al. Palaeoenvironmental Significance of Late Quaternary Microfaunas in the Eastern Pearl River Delta[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2014,53(6):45-52. DOI:
珠江三角洲是世界上主要河口三角洲之一,自晚更新世开始形成,其沉积物中保存了丰富的微体动物壳体,它们是重建晚第四纪古环境极为有效的指标。本文对珠江三角洲东部PRD17孔的微体动物群(有孔虫和介形类)进行了分析,共发现有孔虫14属29种,介形类14属17种,将其分别划分为3种生态类型。根据微体动物群的组成特征,并结合测年数据、岩性、沉积物粒度及颜色反射率等特征,重建了PRD17孔晚第四纪以来的环境演化。约43 400 cal a B.P.以前,钻孔所在地发育河流相沉积。晚更新世玉木亚间冰期开始,南海海平面回升,本区开始形成第四纪以来的第一个海相层位。从微体动物群的组成和丰度可识别出3次小规模的海平面波动。约35 400~30 900 cal a B.P.为晚更新世最大海侵时期,微体动物群的丰度和分异度都达到峰值。约25 900 cal a B.P.以后,海水逐渐退出。末次冰盛期的海平面大幅下降,导致本区上更新统沉积物暴露地表遭受风化剥蚀,形成珠江三角洲普遍发育的花斑状黏土层。由于钻孔所在地地势相对较高,受全新世海侵的影响较珠江三角洲其它地区晚,直到6 000 cal a B.P.左右才重新接受沉积,初期发育上潮间带沉积。约3 700 cal a B.P.开始,逐渐变为受潮水影响较显著的潮坪环境。
The Pearl River Delta
formed since the Late Pleistocene
is one of the major delta in the world. There are abundant microfaunas preserved in sediments of the Pearl River Delta
which have been proved to be essential for reconstructing Quaternary environment. In this study
Microfaunas (foraminifers and ostracods) of borehole PRD17 from the eastern Pearl River Delta have been analyzed quantitatively. A total of 29 foraminiferal species belonging to 14 genera and 17 ostracod species referred to 14 genera were identified. They can be divided into three different groups with respect to their ecological ranges. Based on the comprehensive analysis of microfaunas
lithological and sediment grainsize characteristics of core samples
palaeoenvironmental changes since the Late Pleistocene can be reconstructed. Before ~43 400 cal a B.P.
a fluvial environment was recorded in the borehole until the late Wurm Interglacial Stage when the first Quaternary marine unit began to lie down. During this transgressive interval
three short-term environmental fluctuations of water depth can be recognized base on microfaunal data. A peak transgression of the Late Pleistocene was marked between ~35 400 and 30 900 cal a B.P.. Since about ~25 900 cal a B.P.
sea waters gradually retreated from the study area and the Upper Pleistocene sediments were subsequently subaerially exposed during the Last Glaciation Maximum
which is indicated by a mottled clay layer in the core. Around ~6 000 cal a B.P.
the postglacial sea level rise initiated a new phase of the Holocene sedimentation. This timing was later than in other parts of the Pearl River Delta because core site is located in the GuangzhouPanyu fault block with a higher elevation during the Early-Middle Holocene. A supralittoral-zone environment developed during the first phase of Holocene sedimentation. Since ~3 700 cal a B.P.
the study area gradually changed into a tide flat environment with microfossils sporadically present.
珠江三角洲有孔虫介形类晚第四纪古环境
the Pearl River DeltaforaminifersostracodsLate Quaternarypalaeoenvionment
0
浏览量
287
下载量
0
CSCD
关联资源
相关文章
相关作者
相关机构