伶仃洋ZK19孔晚第四纪沉积地球化学特征 及其古环境意义

依据对珠江口伶仃洋海域ZK19孔岩芯材料的沉积学、年代学和沉积地球化学研究，探讨了该海域古环境演变特征。该孔以末次盛冰期风化层为界，存在2个沉积旋回和2次海侵事件。微量元素质量分数、主量元素（Al2O3/Na2O值、MgO/Al2O3值、Sr/Ba值及V/Cr值等），化学蚀变指数（CIA）和化学风化指数（CIW）的变化特征，反映了MIS4晚期至MIS3初期，该地由陆相向滨海相过渡，气候从偏冷逐渐升温，海平面逐渐上升，但速度较慢；MIS3该地为河口湾相，气候进一步转暖，海平面以较大幅度上升；MIS2阶段（末次盛冰期）海平面大幅下降，气候变冷；MIS1的8―12 cal. ka B.P.气候逐渐转暖，海平面快速上升，为河流相―滨海潮滩相―河口湾浅滩相―河口湾相；中全新世大暖期，受水下滩槽地貌侧向迁移影响，该孔地层遭剥蚀；晚全新世3 cal. ka B.P.以来，气候整体相对稳定，较早全新世温暖，沉积环境依次为河口湾相―三角洲前缘斜坡相―三角洲前缘浅滩相。

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

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.