TROPICAL GEOGRAPHY ›› 2016, Vol. 36 ›› Issue (3): 343-354.doi: 10.13284/j.cnki.rddl.002841

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Major and Trace Elements Geochemistry and Paleoenvironmental Implications of Borehole ZK19 in the Lingdingyang Bay of the Pearl River Estuary

WAXI Lali,WANG Jianhua,CHEN Huixian,WU Jiaxue,TAO Hui.   

  1. 1.a.School of Earth Science and Geological Engineering;b.Research Center for Coastal Ocean Science and Technology,Sun Yat-sen University,Guangzhou 510275,China;2.Guangdong Provincial Key Laboratory of Geological Processes and Mineral Resources Survey,Guangzhou 510275,China
  • Online:2016-05-05 Published:2016-05-05

Abstract: The research on Late Quaternary sediments of borehole ZK19 in the Lingdingyang Bay of the Pearl River Estuary has shown that the formation of the borehole revealed mainly on the upper Pleistocene Series and Holocene Series. Bounded by the weathering layer formed during the last glacial period, it has demonstrated the two important transgressive events during the Late Pleistocene and Holocene respectively. The distribution of major, trace elements and their ratios (e.g. Al2O3/Na2O ratio, MgO/Al2O3 ratio, Sr/Ba ratio and V/Cr ratio), Chemical Index of Alteration (CIA) and Chemical Index of Weathering (CIW) were used to reconstruct the paleo-climate and environment changes. Paleo-environmental changes were reconstructed: 1) Middle Stage of Late Pleistocene MIS4-early MIS3: sedimentary facies changed from continental facies to coastal beach facies; gradually warming from cooler climate, sea level rose slowly; 2) MIS3 stage of Middle-late Stage of Late Pleistocene, sedimentary environment showed an estuarine facies, climate got warmer, sea level rose significantly; 3) Late Stage of Late Pleistocene MIS2 stage, during the Last Glacial Maximum the sea level dropped significantly, and the climate was cooler; 4) MIS1 (8-12 cal. ka B.P.), the climate was warmer, sea level rose fast, sedimentary environment consisted of fluvial facies-coastal tidal flat-estuarine shoal-estuarine facies; 5) The Middle Holocene sediment is lacked in the borehole, probably due to an underwater erosion of migration of estuarine shoal - channel; 6) Late Holocene (since 3 cal. ka B.P.) sedimentary environment was estuarine facies - delta front slope facies - delta front shoal facies, climate overall was relatively stable, and warmer than that in early Holocene.

Key words: the Pearl River Estuary, the Lingdingyang Bay, Late Quaternary, geochemistry, Paleo-environment