东濮凹陷早第三纪的海侵(泛)事件  

EARLY TERTIARY MARINE TRANSGRESSION IN DONGPU DEPRESSION

作　　者：任来义[1] 林桂芳[2] 赵志清[2] 王兴武[2] 

机构地区：[1]西北大学地质系,西安710069 [2]中原油田勘探开发科学研究院,河南濮阳457001

出　　处：《古生物学报》2000年第4期553-557,共5页Acta Palaeontologica Sinica

摘　　要：依据生物化石Sphenolithusciperoensis,Dictyococcitesabisectus,Coccolithuspelagicus,Reticulofenestrasp .,Sinocystaminuta ,S .subtilis,Cordosphaeridium ,Achomosphaera ,Spiniferites,Ophinomorphanodosa ,Cla dosiphoniasinensis ,Knightiasp .和石盐中的溴 (Br-)及溴氯系数 (Br-× 10 3/Cl-) ,碳酸盐岩中氧、碳同位素 (δ18O、δ13C)值 ,泥岩中的Th/U值 ,认为东濮凹陷早第三纪沙河街组三段、一段沉积期发生过海侵事件。This article demonstrates the characteristics of sedimentary period of ES 3 and ES 1 of Shahejie Formation (Early Tertiary, Dongpu depression), which relates to marine transgression with microfossils and some geochemical indexes. There is only report of marine sedimentary environment for representative dinoflagellate fossils Cordosphaeridium and Achomosphaera ; while Sinocysta minuta and S. subtilis are all found in marine formations of west Tarimu Basin in Xinjiang. Though Spiniferites puyangensis , which is abundant in ES 1, is an endemic species, most of the fossil dinoflagellate genus were marine origin. Among the calcareous nannofossils, Sphenolithus ciperoensis is a zonal guide fossil of marine calcareous nannofossil zone Np25 of Europeean Early Tertiary; Dictyococcites abisectus is an important element in this zone and Coccolithus pelagicus is common in ocean water body. Reticulofenestra bohaiensis is abundant but monotonic in ES 1, which is also shown in boring section of drilling location 372 in Mediterranean. Cladosiphonia sinensis is a kind of reef forming green algae fossil, and most of current reef forming green algae live on rocks of quiet shallow sea and intertidal zone in subtropics. Similar living species of fish fossil Knightia sp. lives in shallow sea and debouch gathering, which is an euryhalinous marine organism. There is only report of marine sand bank for common trace fossil Ophinomorpha nodosa . Geochemical indexes include: Th/U value of ratio between 2-6(2.23-4.10) or less than 2 (1.3- 1.75 ) for 3 of 13 shale samples respectively, which shows sea water influence; Br -×10 -3 /Cl - parameter analysis of halite, 3 of 6 samples from ES 1 being 0.16, 0.105 and 0.093 respectively, which exceed or approach the criterion (>0.11) of marine halite evaporation, while of 7 samples from ES 3 being more than 0.11(0.15), which shows salt resource of Dongpu depression derived from both sea and land. Oxygen and carbon isotope a

关 键 词：地球化学 沙河街组 东濮凹陷 早第三纪 海侵事件 

分 类 号：Q91[天文地球—古生物学与地层学]