| 摘要: |
| 风化壳古岩溶的发育是四川盆地上震旦统灯影组获得新突破的重要因素。基于大量野外剖面、钻井岩心及薄片观察、地震、测井及地球化学分析,在论证灯影组两套风化壳古岩溶发育的基础上,进行古岩溶相带特征研究及差异分析,进而建立相应的风化壳古岩溶发育模式。结果表明,灯影组两套风化壳古岩溶均符合缓坡模式,但受古地貌坡降差异的影响,灯四段不整合面附近岩溶作用强烈,发育大洞穴及角砾、泥岩充填物,垂向分带结构以水平潜流带和深部缓流带为主;灯二段不整合面附近岩溶作用相对和缓,溶洞充填物主要由小粒径的角砾云岩、白云岩组成,盆地范围内其垂向分带结构以垂向渗流带、水平潜流带及深部缓流带为主。 |
| 关键词: 风化壳古岩溶 古岩溶结构 古岩溶模式 上震旦统 灯影组 四川盆地 |
| DOI：10.3969/j.issn.1673-5005.2015.03.002 |
| 分类号::TE 121 |
| 基金项目:国家科技重大专项(2011ZX05007-002) |
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| Characteristics and models of weathering paleo-karst in Upper Sinian, Sichuan Basin |
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LUO Beiwei1, JIA Chengzao2, WEI Guoqi3, YANG Wei3, XIE Wuren3, XU Hailong1
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(1.Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China;2.China National Petroleum Corporation, Beijing 100724, China;3.Langfang Branch of Petroleum Exploration and Development Research Institute, PetroChina, Langfang 065007, China)
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| Abstract: |
| The development of ancient weathering crust karst in Sinian is the main factor of the breakthrough in Dengying Formation of Sichuan Basin. With a lot of outcrops, drilling coring, thin sections, seismic and well logging data, geochemistry analysis, and on the basis of the comprehensive arguments about the two sets of weathering paleo-karst in Dengying Formation, weathering paleo-karst characteristics and differences between the vertical and horizontal structures were studied to further establish corresponding weathering paleo-karst models. It is concluded that the weathering paleo-karsts in Dengying Formation can be described by the ramp model. However, affected by the different palaeogeomorphology gradient, the strata near the unconformity of the fourth Member of Dengying Formation has the strongest karstification and easy to develop caverns, breccia and mudstone filling. The horizone-phreatic zone and deep-slow-flowing zone are the main part of the karst vertical zonation. The strata near the unconformity of the second Member of Dengying Formation has a relatively slow karstification, with the small size of the dolomite breccia, dolomite as its cave fillings, and mainly develop vertical vadose zone, horizone-phreatic zone and deep-slow-flowing zone. |
| Key words: weathering paleo-karst paleo-karst structure paleo-karst models Upper Sinian Dengying Formation Sichuan Basin |
