| 四川江油马角坝地区上石炭统层序地层研究 |
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| 引用本文： | 徐锦龙,洪天求.四川江油马角坝地区上石炭统层序地层研究[J].沉积与特提斯地质,2015,35(3):1-10. |
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| 作者姓名： | 徐锦龙 洪天求 |
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| 作者单位： | 1. 安徽省地质调查院, 安徽 合肥 230001;2. 合肥工业大学资源与环境工程学院, 安徽 合肥 230009 |
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| 基金项目： | 国家自然科学基金面上项目(批准号41072085)资助 |
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| 摘 要： | 应用露头层序地层学基本原理和方法、结合碳酸盐岩微相、古生物学、成岩作用、沉积相和沉积事件等理论,对江油马角坝地区上石炭统碳酸盐岩地层进行了露头层序地层研究。研究表明,研究区晚石炭世为典型的陆表海沉积,地形平坦,地壳下降相对缓慢,海水较浅,沉积物界面与海平面接近,主体为碳酸盐岩开阔台地和浅滩沉积环境。水体主体深度为0~50m,为低幅高频低速的海平面变化。根据沉积层序界面的露头和镜下标志,共划分出7个三级层序,反映了研究区晚石炭世具有7次相对较大的海平面升降旋回。发育TST和HST,普遍缺失LST,局部CS难以识别。平均每个层序时限约为2.7Ma,并伴随着多次四级、五级乃至高频海平面变化,共同组成了研究区简单而复杂的碳酸盐岩地层格架。动力机制主要源于晚古生代冰川型全球海平面变化,其原因可能为晚古生代冰期(大洋水体积的周期型变化或大陆冰盖的增长和衰减)和风暴事件共同作用的结果,同时受到古地形、物源和沉积物供应量变化的制约。其中,CSQ1、CSQ3和CSQ4对应的海平面变化幅度较大,海平面变化速率主要为突发性的快递上升到缓慢下降或缓慢上升到相对下降的特点。CSQ2、CSQ5、CSQ6和CSQ7对应的海平面变化幅度不大,为缓慢上升和缓慢下降的特点。
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| 关 键 词： | 层序地层 上石炭统 海平面变化 江油马角坝地区 |
| 收稿时间： | 2014/7/2 0:00:00 |
| 修稿时间： | 2014/7/12 0:00:00 |
Sequence stratigraphy of the Upper Carboniferous strata in the Majiaoba region, Jiangyou, Sichuan |
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| XU Jin-long,HONG Tian-qiu.Sequence stratigraphy of the Upper Carboniferous strata in the Majiaoba region, Jiangyou, Sichuan[J].Sedimentary Geology and Tethyan Geology,2015,35(3):1-10. |
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| Authors: | XU Jin-long HONG Tian-qiu |
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| Institution: | 1. Anhui Institute of Geological Survey, Hefei 230001, Anhui, China;2. School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, Anhui, China |
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| Abstract: | The Upper Carboniferous strata in the Majiaoba region, Jiangyou, Sichuan are known for well-developed sections and abundant fossils, and thus selected as a classical area for the study of sedimentary characteristics of the Sichuan Basin and even the whole area of the Upper Yangtze area during the Late Carboniferous. Sequence stratigraphy of the Upper Carboniferous strata in the Majiaoba region, Jiangyou, Sichuan is based on the principles and methods of sequence stratigraphy, in integration of carbonate microfacies, palaeontology, diagenesis, sedimentary facies and depositional events. Seven third-order sequences have been distinguished, and represent seven major cycles of sea-level changes in this region. The transgressive and highstand systems tracts are recognized while the low stand systems tract is absent and condensed sections are seldom observed. Each sequence has recorded the time duration of ca. 2.7 Ma, and may be accompanied by several fourth-to fifth-order high-frequency sea-level changes, which may be constrained by the Late Palaeozoic glacial-type sea-level changes, storm events, palaeotopography, palaeoclimatology, provenance and sediment supply. |
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| Keywords: | sequence stratigraphy Upper Carboniferous sea-level change Majiaoba region in Jiangyou |
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