苏丹Muglad盆地Fula坳陷白垩系Abu Gabra组层序地层及沉积体系
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摘要
Fula坳陷白垩系Abu Gabra组是Muglad盆地第一裂谷旋回中形成的同裂谷期地层,它可以分为3个二级层序,自下而上是K1SSⅠ、K1SSⅡ和K1SSⅢ,它们分别与断陷期早期地层、断陷期中期地层和断陷期晚期地层相对应。其中二级层序K1SSⅠ和K1SSⅢ各分为2个三级层序,K1SSⅡ则可进一步划分为3个三级层序。综合应用地震和钻/测井资料,以三级层序为单元,完成了AbuGabra组沉积相分布与沉积体系预测工作。研究认为,阿加组的主要沉积类型包括:河流相、三角洲相、扇三角洲相、辫状河三角洲相、近岸水下扇相、滨浅湖亚相、半深湖—深湖亚相。各沉积相带在Fula坳陷内的演化形成了5个主要沉积体系,分别是东北部的扇三角洲体系,西北部的三角洲体系、西部近岸水下扇体系、东南部辫状河三角洲体系以及早期的河流沉积体系。沉积体系的分布与演化受构造活动强度变化的控制,也受古地形和古地貌的影响。
Abu Gabra Formation of Cretaceous Fula depression, which is formed during the first rifting cycle, can be divided into three second-order sequences, namely, sequence K1SSI, sequence K1SSⅡ and sequence K1SSⅡI. They can correspond separately to the strata deposited in the early, middle and late rift period. Of the three second-order sequences, the sequence K1SSI and sequence K1SSⅡI can be subdivided into two third-order sequences, the sequence K1SSⅡ into three third-order sequences. Based on the integrated analysis of seismic data, core and well logging, the distribution of sedimentary facies and the prediction of sedimentary system are achieved. Through investigation, 7 types of sedimentary facies are recognized, namely, fluvial deposit, delta, fan delta, braided delta, proximal sublacustrine fan, lacustrine facies. Due to the evolution of their sedimentary facies, five chief depositional systems are established in the Fula depression. They are fan delta system in the NE, delta system in the NW, proximal sub-lacustrine fan in the west, braided delta system in the ES and fluvial system produced in the early period. The distribution and evolution of the depositional systems is controlled by tectonics, probably influenced by paleotopography and paleogeography.
Abu Gabra Formation of Cretaceous Fula depression, which is formed during the first rifting cycle, can be divided into three second-order sequences, namely, sequence K1SSI, sequence K1SSⅡ and sequence K1SSⅡI. They can correspond separately to the strata deposited in the early, middle and late rift period. Of the three second-order sequences, the sequence K1SSI and sequence K1SSⅡI can be subdivided into two third-order sequences, the sequence K1SSⅡ into three third-order sequences. Based on the integrated analysis of seismic data, core and well logging, the distribution of sedimentary facies and the prediction of sedimentary system are achieved. Through investigation, 7 types of sedimentary facies are recognized, namely, fluvial deposit, delta, fan delta, braided delta, proximal sublacustrine fan, lacustrine facies. Due to the evolution of their sedimentary facies, five chief depositional systems are established in the Fula depression. They are fan delta system in the NE, delta system in the NW, proximal sub-lacustrine fan in the west, braided delta system in the ES and fluvial system produced in the early period. The distribution and evolution of the depositional systems is controlled by tectonics, probably influenced by paleotopography and paleogeography.
引文
1Ahmed Y M.Organic matter characterization and environmental control on organic facies and lithofacies of early Cretaceous Lake Assalam,NW Muglad Basin,Sudan[D].Tokyo:University of Tokyo,1996:110
2窦立荣.苏丹被动裂谷盆地的油气成藏机理和成藏模式[D].中国石油大学,2003:13-23[Dou Lirong.The reservoir forming me-chanic and model of inactive rift basins in Sudan[D].University of Pe-troleum,2003:13-23]
3樊太亮,刘慧峰,赵中平.苏丹六区福拉凹陷层序地层分析与砂体预测[R].科研报告,2002:66-68[Fan Tailiang,Liu Huifeng,Zhao Zhongping.The sequence stratigraphy and sand-body prediction in Fula subbasin,Sudan[R].Scientific Report,2002:66-68]
4Schull T J.Rift basins of interior Sudan:Petroleum exploration and discovery[J].AAPG Bulletin,1988,72:1128-1142
5Abdalla Y Mohamed,Ashcroft W A,Whiteman AJ.Structural develop-ment and crustal stretching in the Muglad Basin,southern Sudan[J].Journal of African Earth Sciences,2001,32(2):179-191
6Gian Battista Vai.Development of the palaeogeography of Pangaea from Late Carboniferous to Early Permian[J].Palaeogeography,Palaeocli-matology,Palaeoecology,2003,196(2003):125-155
7Pletsch T,Erbacher J,Holbourn AE L.Cretaceous separation of Africa and south America:the view from the West Africa margin(ODP Leg159)[J].Journal of South America Earth Sciences,2001,14(2001):147-174
8Abdalla Y Mohamed,Michael J Pearson,William AAshcroft.Petrole-um maturation modelling,Abu Gabra Sharaf area,Muglad Basin,Su-dan[J].Journal of African Earth Sciences,2002,35:331-344
9Atalay Ayele.Active compressional tectonics in central Africa and im-plications for plate tectonic models:evidence from fault mechanism studies of the1998earthquakes in the Congo Basin[J].Journal of Af-rican Earth Sciences,2002,35:45-50
10朱筱敏,康安,王贵文.陆相坳陷型和断陷型湖盆层序地层样式探讨[J].沉积学报,2003,21(2):283-287[Zhu Xiaomin,Kang An,Wang Zhongping.Sequence stratigraphic models of depression and faulted-down lake basins[J].Acta Sedimentologica Sinica,2003,21(2):283-287]
11Bosence D W J.Stratigraphic and sedimentological models of rift ba-sins[C]∥Sedimentation and Tectonics in Rift Basins,1998:9-25
12Herrn Ali Sayed Mohammed Ibrahim.Sedimentology and Reservoir Geology of the Middle-Upper Cretaceous Strata in Unity and Heglig Fields in SE Muglad Rift Basin,Sudan[D].Khartoum,Sudan:Uni-versity of Khartoum,2003
2窦立荣.苏丹被动裂谷盆地的油气成藏机理和成藏模式[D].中国石油大学,2003:13-23[Dou Lirong.The reservoir forming me-chanic and model of inactive rift basins in Sudan[D].University of Pe-troleum,2003:13-23]
3樊太亮,刘慧峰,赵中平.苏丹六区福拉凹陷层序地层分析与砂体预测[R].科研报告,2002:66-68[Fan Tailiang,Liu Huifeng,Zhao Zhongping.The sequence stratigraphy and sand-body prediction in Fula subbasin,Sudan[R].Scientific Report,2002:66-68]
4Schull T J.Rift basins of interior Sudan:Petroleum exploration and discovery[J].AAPG Bulletin,1988,72:1128-1142
5Abdalla Y Mohamed,Ashcroft W A,Whiteman AJ.Structural develop-ment and crustal stretching in the Muglad Basin,southern Sudan[J].Journal of African Earth Sciences,2001,32(2):179-191
6Gian Battista Vai.Development of the palaeogeography of Pangaea from Late Carboniferous to Early Permian[J].Palaeogeography,Palaeocli-matology,Palaeoecology,2003,196(2003):125-155
7Pletsch T,Erbacher J,Holbourn AE L.Cretaceous separation of Africa and south America:the view from the West Africa margin(ODP Leg159)[J].Journal of South America Earth Sciences,2001,14(2001):147-174
8Abdalla Y Mohamed,Michael J Pearson,William AAshcroft.Petrole-um maturation modelling,Abu Gabra Sharaf area,Muglad Basin,Su-dan[J].Journal of African Earth Sciences,2002,35:331-344
9Atalay Ayele.Active compressional tectonics in central Africa and im-plications for plate tectonic models:evidence from fault mechanism studies of the1998earthquakes in the Congo Basin[J].Journal of Af-rican Earth Sciences,2002,35:45-50
10朱筱敏,康安,王贵文.陆相坳陷型和断陷型湖盆层序地层样式探讨[J].沉积学报,2003,21(2):283-287[Zhu Xiaomin,Kang An,Wang Zhongping.Sequence stratigraphic models of depression and faulted-down lake basins[J].Acta Sedimentologica Sinica,2003,21(2):283-287]
11Bosence D W J.Stratigraphic and sedimentological models of rift ba-sins[C]∥Sedimentation and Tectonics in Rift Basins,1998:9-25
12Herrn Ali Sayed Mohammed Ibrahim.Sedimentology and Reservoir Geology of the Middle-Upper Cretaceous Strata in Unity and Heglig Fields in SE Muglad Rift Basin,Sudan[D].Khartoum,Sudan:Uni-versity of Khartoum,2003
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