石油与天然气地质 ›› 2022, Vol. 43 ›› Issue (4): 792-803.doi: 10.11743/ogg20220405

• 油气地质 • 上一篇    下一篇

华北龙山地区青白口系混积岩层序地层格架及发育模式

张琴1,2, 周琛3, 田寒云1, 朱筱敏1,2, 吴新松1,2, 宋泽平1, 王凯1   

  1. 1.中国石油大学(北京) 地球科学学院,北京 102249
    2.中国石油大学(北京) 油气资源与探测国家重点实验室,北京 102249
    3.中国石化 胜利油田分公司 胜利采油厂,山东 东营 257000
  • 收稿日期:2022-04-07 修回日期:2022-05-01 出版日期:2022-07-14 发布日期:2022-07-14
  • 第一作者简介:张琴(1973—),女,副教授、硕士生导师,沉积学及储层地质学。E?mail: zhangqin@cup. edu. cn。
  • 基金项目:
    国家自然科学基金项目(41872134)

Sequence stratigraphic framework and model of mixed siliciclastic-carbonate rocks in the Qingbaikouan System, Longshan area, North China

Qin Zhang1,2, Chen Zhou3, Hanyun Tian1, Xiaomin Zhu1,2, Xinsong Wu1,2, Zeping Song1, Kai Wang1   

  1. 1.College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China
    2.State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China
    3.Shengli Oil Production Plant,Shengli Oilfield Company,SINOPEC,Dongying,Shandong 257000,China
  • Received:2022-04-07 Revised:2022-05-01 Online:2022-07-14 Published:2022-07-14

摘要:

华北龙山地区新元古界出露完整,从下向上依次发育碎屑岩和碳酸盐岩,研究层序地层格架及其沉积相演化对恢复华北地区古地理环境具有重要指导意义。对龙山地区青白口系进行了系统的野外实测、岩石薄片鉴定、X射线衍射、微量元素等实验分析,在野外和室内岩性特征和沉积序列分析的基础上,结合区域构造运动背景,建立了等时层序地层格架,分析了各层序沉积相演化,并建立了层序地层发育模式。研究认为,依据不整合界面和岩性突变界面,将研究区青白口系自下而上依次划分为SQ1(下马岭组)、SQ2(长龙山组)和SQ3(景儿峪组)3个三级层序,每个层序都发育了TST和HST两个体系域。SQ1和SQ2以碎屑岩沉积为主,对应陆源碎屑供给充分;SQ3以混积岩沉积为主,对应相对清水沉积模式。根据岩性和沉积构造及其沉积序列等特征,SQ1层序TST以浅海陆棚沉积为主,HST以潮下带砂坪和潮间带砂-泥混合坪为主;SQ2层序TST以潮下带砂坪和潮道为主,HST以潮间带砂-泥混合坪和潮上带泥坪为主;SQ3层序TST发育潮下带砂质浅滩和泥质灰坪,HST以潮间含云灰坪和潮上灰质和泥质云坪为主。在层序划分和沉积相演化基础上,建立了以潮坪-浅海陆棚相为主的陆源碎屑-碳酸盐岩混积型层序地层发育模式,具有开阔陆表海特征。

关键词: 潮坪相, 层序地层格架, 层序地层发育模式, 混积岩, 青白口系, 新元古界, 龙山地区, 华北

Abstract:

The Neoproterozoic in the Longshan area, North China, is well exposed. With clastic rocks and carbonates developed successively from bottom to top, the strata serves as an ideal subject for the study of sequence stratigraphic framework and sedimentary facies evolution, which has been considered significant to the paleogeographic reconstruction of North China. Field and lab analyses of lithologic characteristics and sedimentary sequences of the strata are combined with the regional tectonic movement to establish the isochronous sequence stratigraphic framework, analyze the sedimentary facies evolution, and build up the sequence stratigraphic development model. The results show that according to the unconformities and lithologically abrupt interfaces, the Neoproterozoic Qingbaikouan System can be divided into three third-order sequences from bottom to top: the SQ1 (Xiamaling Formation), SQ2 (Changlongshan Formation) and SQ3 (Jingeryu Formation), each consisting of transgressive systems tract (TST) and highstand systems tract (HST). The SQ1 and SQ2 sequences are mainly composed of clastic rocks indicating sufficient input of terrigenous clastics. The SQ3 sequence is dominated by mixed siliciclastic-carbonate rocks against a relatively clear water depositional setting. The lithological characteristics, sedimentary structures and superposing styles, all point to shallow sea shelf facies for the SQ1-TST, and subtidal sand flat and intertidal mixed sand-mud flat for the SQ1-HST. The SQ2-TST mainly develops subtidal sand flats and tidal channels, while SQ2-HST mainly develops intertidal mixed sand-mud flats and supratidal mud flat. The SQ3-TST develops subtidal sandy shoal and argillaceous limestone flat, while SQ3-HST mainly develops intertidal dolomitic limestone flat and supratidal calcareous and argillaceous dolomite flat. Based on the understanding, a sequence stratigraphic development model of mixed siliciclastic-carbonate rocks dominated by tidal flat-shallow sea shelf facies is established, indicating the possibility of an open epicontinental sea with gentle slopes.

Key words: tidal flat facies, sequence stratigraphic framework, sequence stratigraphic development model, mixed siliciclastic-carbonate rock, Qingbaikouan System, Neoproterozoic, Longshan area, North China

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