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现代地质 ›› 2020, Vol. 34 ›› Issue (04): 718-731.DOI: 10.19657/j.geoscience.1000-8527.2020.021

• 构造地质学与地层学 • 上一篇    下一篇

南华北地区及其北部邻区上石炭统—中二叠统高分辨率层序地层

李杨1(), 阮壮1, 李中明2, 于炳松1, 宋南南1, 董果果2, 张栋2   

  1. 1.中国地质大学(北京) 地球科学与资源学院,北京 100083
    2.河南省地质调查院,河南 郑州 450001
  • 收稿日期:2018-07-22 修回日期:2020-01-13 出版日期:2020-08-31 发布日期:2020-09-03
  • 作者简介:李 杨,男,硕士,1990年出生,地质工程专业,主要从事沉积环境分析,层序地层学研究。Email: liy288634@gmail.com
  • 基金资助:
    河南省国土资源厅科技攻关项目“河南省平原区晚古生代页岩气层岩相古地理研究”(2015-1992-20);河南省重大科技专项项目“河南页岩气勘查开发及示范应用研究”(151100311000)

High-resolution Stratigraphy of Upper Carboniferous-Middle Permian in Southern North China and Its Northern Surroundings

LI Yang1(), RUAN Zhuang1, LI Zhongming2, YU Bingsong1, SONG Nannan1, DONG Guoguo2, ZHANG Dong2   

  1. 1. School of Earth Sciences and Resources,China University of Geosciences, Beijing 100083,China
    2. Henan Institute of Geological Survey, Zhengzhou,Henan 450001,China
  • Received:2018-07-22 Revised:2020-01-13 Online:2020-08-31 Published:2020-09-03

摘要:

南华北地区石炭系—二叠系烃源岩广泛发育,是未来页岩气勘探的重要目标;然而,其研究程度低,区域地质构造复杂,岩性地层对比关系不清。基于高分辨率层序地层学及沉积学的相关理论,以区内12口井的钻测井资料和两口井的岩心资料为依据,开展了南华北地区及北部邻区上石炭统—中二叠统层序地层划分。结果显示,研究区内太原组、山西组和下石盒子组属于一个不完整的超长期旋回,内部可划分为5个长期旋回和14个中期旋回。中期基准面旋回结构样式可分为3类:(1)以上升半旋回为主的不完全对称类型,多发育在近岸三角洲背景下;(2)以下降半旋回为主的不完全对称类型,多发育在深水的潮间-潮下/潟湖环境;(3)上升半旋回与下降半旋回近于相等的近完全-完全相等的对称类型,在三角洲和潮坪相浅水区域均有发育。从南北向与东西向层序地层年代格架剖面分析可以发现,研究区内不存在大型的或者区域性的沉积间断与不整合面,但研究区因后期构造作用,南部与北部产生“翘板式”转换抬升,局部出现剥蚀间断,形成与上、下地层假整合接触。

关键词: 南华北地区, 上石炭统—中二叠统, 高分辨率层序地层, 基准面旋回

Abstract:

Permo-Carboniferous source rocks in southern North China are widely developed and become an important target for shale-gas exploration. However, regional study on the Carboniferous-Permian sequences is still inadequate due to the complex structure and unclear stratigraphic correlation. Based on high-resolution stratigraphy, sedimentology, core-logging, and seismic data from twelve wells, we first establish the stratigraphic sequence of the region. The results show that the Taiyuan, Shanxi and Xiashihezi formations belong to an incomplete super-long cycle, which could be divided into five long-term cycles and 14 medium-term cycles. The medium-term base-level circle structure patterns can be divided into three types:A and B, incomplete symmetrical type dominated by (A) ascending hemicycle and (B) descending semicircular gyrus; C, nearly half ascending and half descending with the same type of symmetry. A-type patterns are mostly developed in the nearshore delta sedimentary environment, whilst B-type patterns are mostly developed in the intertidal to subtidal/lagoon environment. Meanwhile, C-type patterns are common in shallow-water (deltaic or tidal) environments. Geostatistical analysis of the stratigraphic sequences (from north to south and from east to west) has found no regional discontinuities or unconformities.Due to local late-tectonic influence, the seesaw-style uplift may have generated local discontinuities, which formed the pseudo-unconformity between the upper and lower parts of the sequence.

Key words: southern North China, Upper Carboniferous-Midddle Permian, high-resolution stratigraphy, base-level cycle

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