摘要
东濮凹陷老第三系沙河街组有八类痕迹化石组合:①Cylindricum-Scoyenia,②Ancorichnus-Cylindricum,③Tigillites-A型植物根迹,④Ophiomorpha-Ancorichnus,⑤ThalassinoidesPalaeophycus,⑥ Arenicolites-Polykladichnus,⑦ Teichichnus-Anconichnus,⑧Squamodictyon-Protopalaeodictyon的环境意义及其对应的测井曲线图型。剖面上重复出现的痕迹相及与其对应的测井图型的反复再现,表明在东濮凹陷利用直接观察到的岩心、痕迹化石证据和间接测得的曲线图型资料可以识别和预测出无岩心段的岩相及其变化。同时说明,沙河街组既有陆相、非海相沉积,亦有海相沉积,从而廓清了东濮凹陷老第三系是否存在海相沉积之迷雾。更为重要的是,它为在本区进行高精度地层对比和预测下切谷型储层相(如河口湾砂岩)和超覆型储层相(如潮坪砂岩相和海滩砂岩)的时空分布提供了研究途径。
Eight trace fossil associations in relation to eight depositional facies have been recognized in the Shahejie Formation (Tertiary) of the Dongpu Depression. These are ①Cylindricum-Scoyenia (Sand flat and mud flat), ②Ancorichnus-Cylindricum (distributary), ③Tigillites-root type A (Lagoon and marsh), ④Ophiomorpha-Ancorichnus (estuarine),⑤Thalassinoides-Palaeophycos (upper reach estuarine), ⑥ Arenicolites-Polykladichnus (tidal channel),⑦ Teichichnus-An-conichnus (shoreface) and ⑧Squamodictyon-Protoplaeodictyon (deep embayment). The environmental implications of the above mentioned trace fossil associations and the importance of the eight recurrent ichnofacies corresponding well log patterns are described. The trace fossil evidence strongly shows that the Shahejie Formation consists mainly of nonmarine deposits as well as marine deposits. Above all, it appears to be quite helpful in high resolution stratigraphic correlations and in predicting incised valley reservoir facies estuarine sand stones and shelf on lap reservoir facies (tidal flat and beach sandstones) in this area, and clean up the debatable blur on whether there are marine or no marine deposits in the Shahejie Formation.
出处
《古地理学报》
CAS
CSCD
1999年第3期50-64,共15页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金项目(4840053)
中国石油天然气总公司"八五"重点科技攻关项目"中国油气储层研究"(8510-03-01)
关键词
沙河街组
痕迹相
测井图型
东濮凹陷
Dongpu Depression, Shahejie Formation, ichnofacies, well log pattern
