中国南海北部新生代古环境的变迁

Changes of Cenozoic Paleo-Environment in Northern South China Sea

为了解中国南海北部新生代古环境的变迁 ,在分析参考相关科学成果的基础上 ,综述该区域的古环境的变迁。早第三纪珠江口盆地以陆相、河湖相沉积为主 ,气温凉爽 ,属暖温带至北亚热带环境 ;晚第三纪 ,从晚渐新世到上新世晚期 ,该区域由淡水湖泊沉积环境 ,逐渐过渡到海、陆交互环境、潮间带或浅水滨海沉积环境、浅海环境等 ,气候也演变成潮湿的热带、亚热带气候。第四纪 ,随着冰期、间冰期的波动 ,沉积环境也分别呈近岸陆面剥蚀环境—浅水滨海沉积环境或浅海环境的交替。香港地区“岗岭山坡”区段属陆面风化剥蚀环境 ,而在“河谷平原”则由陆面风化剥蚀环境演变为陆面河、湖相或沼泽沉积环境。古环境的变迁主要受太阳幅射脉动状态等综合因素的影响。

On the basis of analyzing related scientific research results,the changes of Cenozoic Paleo environment in northern South China sea are summarized.In early Tertiary,the Zhujiang River mouth Basin was dominated by continental and fluviolacustrine deposits,with cool weather and an environment between warm temperate zone and north subtropical zone.In late Tertiary,from late Oligocene to late Pliocene, the deposit here had gradually changed from freshwater lake deposit to continental oceanic interactive deposit,intertidal zone or shallow water seashore deposit,and shallow sea deposit,with the climate changing to humid tropic and subtropical one.In the Quaternary Period,with the climate fluctuating between glacial and interglacial periods,the deposit environment showed an alternation of coastal erosion one and shallow water seashore or shallow sea one.The section of “Gangling Hillside” in Hong Kong area belongs to terrestrial weathering and erosion environment;while in “Valley Plain”,it changes to continental and fluviolacustrine or marshy depositional environment.The change of the Paleo environment is mainly affected by pulsant solar radiation and other factors.