南海北部珠江口盆地PY30井早中新世-更新世钙质超微化石生物地层及沉积环境  

EARLY MIOCENE TO PLEISTOCENE CALCAREOUS NANNOFOSSIL STRATIGRAPHY AND PALAEOENVIRONMENT OF WELL PY30 IN THE PERAL RIVER MOUTH BASIN,NORTHERN SOUTH CHINA SEA,CHINA

作　　者：赵飞 祝幼华[2] 马瑞芳 

机构地区：[1]中海油能源发展股份有限公司工程技术分公司中海油实验中心,惠州516082 [2]中国科学院资源地层学与古地理学重点实验室(南京地质古生物研究所),南京210008 [3]Universite Paris-Saclay,Rue du Belvedere,Bat.504,91405 Orsay,France

出　　处：《微体古生物学报》2017年第3期332-342,共11页Acta Micropalaeontologica Sinica

基　　金：国家自然科学基金(No.41272014)资助~~

摘　　要：本文对南海北部珠江口盆地PY30井早中新世―更新世地层中的钙质超微化石进行了系统研究,发现490-690m和1 040-1 170m井段化石丰度和分异度均较高,700-1 035m和1 179-1 809m化石丰度中等,井段下部1 818-3 478m化石稀少,种类单调。根据钙质超微化石标志种的存在,对该井的生物地层进行了划分。在490—3 478m地层中识别出12个钙质超微化石带或联合化石带,地层时代为早中新世―更新世,据此建立了该井的钙质超微化石生物地层框架,探讨了下中新统与中中新统、中中新统与上中新统、上中新统与上新统以及上新统与更新统界线划分的钙质超微化石标志。根据钙质超微化石总丰度、分异度及特征性环境指示种丰度的变化,划分了8个沉积环境演化阶段,从而讨论了早中新世至更新世沉积环境演化特征。A total of 328 cutting samples and 21 catcher core samples have been analyzed for calcareous nannofossils from the interval of 490--3 478 m in Well PY30, Peral River Mouth Basin, northern South China Sea, China. Twelve calcareous nannofossils zones or combine zones are recognized depending on the marker species. The bounda- ries of the lower Miocene to the middle Miocene, the middle Miocene to the upper Miocene, the upper Miocene to the Pliocene and the Pliocene to the Pleistocene, and the key species are discussed. According to the statistics of calcare- ous nannofossils abundance, diversity and assemblage characteristics, the evolution of sedimentary environments and the change of water temperature in the well from the early Miocene to Pleistocene are also discussed in detail. In the early stage of the early Miocene, the sea water invaded, however the sea water was not so deep, it seemed to be an inter neritic environment. Until the middle part of Zones NN2-NN1, the sea water became shallow and evolved to be a coastal deposit environment. In the middle-late stage of the early Miocene to the early stage of the middle Miocene, the sea level rised again, and the environment became also an inter neritic environment. After that, in the late stage of the middle Miocene to middle stage of the late Miocene, marine transgression was stronger, suggesting a middle to outer continental shelf of neritic environment. And in the late stage of the late Miocene to the early Pleistocene, the sea water became slightly shallow and the environment became the outer middle to outer continental shelf of neritic environment. Finally, in the late Pleistocene, a highest abundance and diversity of the calcareous nannofossils indica- ted an continental slope deposit environment.

关 键 词：钙质超微化石 生物地层 沉积环境 早中新世-更新世 珠江口盆地 南海北部 

分 类 号：Q913.2[天文地球—古生物学与地层学]