【摘要】 提取该钻孔岩心地球化学信息的综合分析研究初步表明,深圳湾北岸新民孔岩心是一套3万年以来的晚第四纪沉积层序,大致可划分5个古环境演变阶段。第1、第3和第5阶段对应高海面、气候湿热时期。这些阶段相应出现了指示海相的贝类介壳残体,孢粉组合以湿热植被为主,各类粘土矿物也增加,石英减少,沉积以氧化环境为主导。第2和第4阶段对应低海面、气候偏干冷,各项地球化学指示情况相反。该钻孔岩心下部杂色花斑粘土所记录的短期降温和升温事件可能表明在第四纪末次冰期—冰消期中,气候曾强烈波动,并逐渐由晚冰期向冰后期过渡。更多还原

【Abstract】 Xinmin core in the northern coast of the Shenzhen Bay is a set of the late Quaternary sedimentary series since the last 30 ka. The results of comprehensive geochemical analyses of the core indicate that there have been five paleoenvironmental evolution stages since the late Quaternary. Among them, two stages of climatic and environmental evolutions can be identified in the middle Holocene (about 30 000 aBP). The first, third and fifth stages were higher sea level and warmwet climate periods. Marine shells and sporopollen representative of these stages indicate higher sea level and warmwet climate. Meanwhile, increase of clay minerals and decrease of quartz content mainly show an oxidation sedimentary environment. Whereas, the second and fourth stages correspond to lower sea level and relatively cooldry climate. The geochemistry indicators of the stages also imply the sea level and the climatic environment. The short events of temperature rising and dropping recorded in the variegated clay in the lower part of the core imply strong climatic fluctuations during the last glaciationdeglaciation of Quaternary and indicate a transition from the late glaciation to the postglaciation.更多还原