Tectonic division of the Offshore Indus Basin by integrated gravity and magnetic study
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摘要:
印度扇近海盆地是巴基斯坦海域重要的油气勘探目标区，但盆地尚处于勘探早期，受限于勘探资料的数量和品质，对盆地内部结构认识不够清晰，制约了该地区油气调查工作的进一步深入。以新一代卫星测高重力异常数据（V29.1）和EMGA2地磁网格数据（V2）为基础，利用重、磁场融合技术得到印度扇近海盆地及邻区重磁场融合结果，并对该研究区盆地内部油气构造格架进行研究。通过研究表明，重磁场融合结果能够很好刻画印度扇近海盆地内部结构：低磁低重对应盆地沉积坳陷区，高磁低重对应有岩浆岩侵入的坳陷区，高磁高重对应盆地隆起区，低磁高重对应碳酸盐岩台地区；结合钻井和二维地震资料，推断印度扇近海盆地呈现“三坳两隆”的构造格架，且受不同期次构造运动的影响，盆地“东西分块”特征明显。本次新划定盆地西南部的西部坳陷、西部隆起，南部坳陷面积增大，盆地南缘位于帕拉蒂纳脊附近。该研究成果为印度扇近海盆地及邻区基础地质、油气勘探研究提供依据。
Abstract:The Offshore Indus Basin (OIB) is an important oil and gas exploration target area in Pakistan sea area. The exploration of the basin, limited by the quantity and quality of exploration data, is still in the early stage, which restricts the oil and gas investigation in this area. Based on the new generation of satellite altimetry gravity anomaly data (V29.1) and magnetic data from the Earth Magnetic Anomaly Grid (EMAG2-V2), the integrated gravity and magnetic field technique was applied to study the tectonic framework of the OIB, with which the integrated gravity and magnetic field was established and the structure of the OIB was interpreted. Results show that the areas of low-value magnetic and low-value gravity correspond to the sedimentary depressions, while those of high-value magnetic and low-value gravity correspond to the depressions with magma intrusions, whereas the areas of high-value magnetic and high-value gravity correspond to the uplift areas of the basin, and the areas of low-value magnetic and high-value gravity correspond to the carbonate platforms. Combined with the ocean drilling and 2D seismic profile data, three depressions and two uplifts in E-W in the OIB were inferred. Based on the previous tectonic division, the western depression and the western uplift in the southwestern corner of the basin were re-defined, the scope of the southern depression was expanded, and the southern edge of the basin was extended to near the Palatina ridge. This study provided evidence for basic geological and oil-gas exploration in the OIB and its adjacent areas.
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图 3 印度扇近海盆地卫星测高重力异常图
Figure 3. Map of the satellite altimetry gravity anomaly in the Offshore Indus Basin
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图 4 印度扇近海盆地ΔT磁力异常图
Figure 4. Map of the ΔT magnetic anomaly in the Offshore Indus Basin
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图 5 印度扇近海盆地布格重力异常图
Figure 5. Map of the Bouguer gravity anomaly in the Offshore Indus Basin
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图 6 印度扇近海盆地剩余布格重力异常图
Figure 6. Map of the residue Bouguer gravity anomaly of the Offshore Indus Basin
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图 7 印度扇近海盆地化极磁力异常图
Figure 7. Map of the RTP magnetic anomaly in the Offshore Indus Basin
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图 8 印度扇近海盆地剩余化极磁力异常图
Figure 8. Map of the residue RTP magnetic anomaly in the Offshore Indus Basin
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图 9 印度扇近海盆地重磁场融合结果图
Figure 9. Result of integrated gravity and magnetic field in the Offshore Indus Basin
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图 10 印度扇近海盆地油气构造划分结果
a：剩余布格重力异常图，b：剩余化极磁力异常图，c：重磁融合结果图。
Figure 10. The hydrocarbon structure division in the Offshore Indus Basin
a: The residue Bouguer gravity anomaly, b: the residue RTP magnetic anomaly, c: the integrated result of gravity and magnetic field.
表 1 研究区内构造单元的重磁特征
Table 1 The gravity and magnetic characteristics of each tectonic unit in the study area
构造单元 构造走向 重力场特征 磁力场特征 重磁融合 马克兰增生楔 近EW 条带状低重力异常，西宽东窄，两侧重力梯级带特征明显 磁力低异常区，分布2个磁力低异常圈闭。异常区南侧为明显的磁力梯级带 低磁低重 阿曼深海平原 NE向 “三角状”低重力异常区，西宽东窄。剩余布格重力异常上分布3个重力高异常圈闭 高低相间条带状磁力异常，北高南低。高磁力异常条带自西向东分为4段；低磁力异常条带向西与北默里脊的西南段相连 北侧为高磁低重、南侧为低磁低重，局部分布高磁高重 默里脊系统 北默里脊 NE向 条带状重力高异常带，自西向东分为3段。西段与中段之间为 NW 向重力低，东段异常走向转为 NNE 向，截止于查曼走滑断裂 条带状磁力异常，分为东西两段。东段为高磁力异常条带，南段为低磁力异常条带，两段之间磁力异常梯级带 东段为高磁高重
西段为低磁高重达尔林普尔
海槽NE向 条带状重力低异常，海槽东端被NW向高重力异常条带截断 高磁力异常 低磁低重 真纳海槽 NE向 条带状重力低异常，向东延伸异常转为NNE向 分布2个块状低磁力异常圈闭，之间为NW向高磁力异常条带 低磁低重 南默里脊 NE向 狭长重力低异常条带，向东北延伸至查曼走滑断裂 自西向东分为2段，西段为条带状磁力高异常，东部为3个串珠状磁力高异常，不同磁力高异常之间为NW向磁力低异常 高磁高重 印度扇近海盆地 东部NW向
西部NE-NEE向分为东西两个异常区，中间以 NW 向重力高异常带为界，北宽南窄。东部为重力低异常带，呈 NW 走向；西部为高低相间重力异常分布，自北向南异常走向由 NE 向逐渐转为 NEE 向。 分为东西两个异常区，中间以狭长的磁力高异常条带为界。东部为磁力低异常区，局部发育NE向磁力高异常条带；西部高低相间磁力异常特征，可细分为北中南3个异常区，北区位于南默里脊南侧，表现为条带状磁力低异常；中区以磁力高异常为主；南区以磁力低异常为主，局部发育块状磁力高异常 东部低磁低重；
中部高磁高重；
西部以低磁低重、高磁高重相间分布
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表 2 印度扇近海盆地新旧构造划分对比
Table 2 Comparison of new and old structure division in Offshore Indus Basin
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[1] Carmichael S M, Akhter S, Bennett J K, et al. Geology and hydrocarbon potential of the offshore Indus Basin, Pakistan[J]. Petroleum Geoscience, 2009, 15(2):107-116. doi: 10.1144/1354-079309-826
[2] Gaina C, VAN HINSBERGEN D J J, SPAKMAN W. Tectonic interactions between India and Arabia since the Jurassic reconstructed from marine geophysics, ophiolite geology, and seismic tomography[J]. Tectonics, 2015, 34:875-906. doi: 10.1002/2014TC003780
[3] Clift P D, Shimizzu N, Layne G D, et al. Development of the Indus Fan and its significance for the erosional history of the Weatern Himalaya and Karakorma[J]. Geological Society of America Bulletin, 2001, 113(8):1039-1051. doi: 10.1130/0016-7606(2001)113<1039:DOTIFA>2.0.CO;2
[4] 廖晶, 龚建明, 陈建文, 等. 印度扇近海盆地重力滑动构造新发现[J]. 海洋地质前沿, 2020, 36(6): 76-79 LIAO Jing, GONG Jianming, CHEN Jianwen, et al. New Discovery of Gravity Sliding Structures in the Offshore Indus Basin[J], Marine Geology Frontiers, 2020, 36(6): 76-79.]
[5] 程昊皞, 索艳慧, 李三忠, 等. 印度西部洋陆过渡区结构特征及构造演化[J]. 大地构造与成矿学, 2021, 45(5):851-860 CHENG Haohao, SUO Yanhui, LI Sanzhong, et al. Structural Properties and Tectonic Evolution of the Western Indian Continental Margin[J]. Geotectonica et Metallogenia, 2021, 45(5):851-860.]
[6] Solangi S H, Naeer A, Abbasi S A, et al. Morphological features of shelf margin: Examples from the Pakistan Offshore[J]. Geodesy and Geodynamics, 2019, 10:77-91. doi: 10.1016/j.geog.2018.09.004
[7] MCHARGUE T R, WEBB J E. Internal geometry, seismic facies, and petroleum potential of canyons and inner fan channels of the Indus submarine fan[J]. AAPG bulletin, 1986, 70(2):161-180.
[8] Moin R K, Abid H, Muhammad S, et al. Mud Diapirism induced structuration and implications for the definition and mapping of hydrocarbon traps in Makran accretionary prism, Pakistan[C] // AAPG/SEG International Conference & Exhibition, Melbourne, Australia, 2015: 13-16.
[9] 龚建明, 廖晶, Muhammad Khalid, 等. 巴基斯坦海域油气勘探方向探讨[J]. 海洋地质前沿, 2019, 35(11):1-6 GONG Jianming, LIAO Jing, Muhammad K, et al. Preliminary study on the oil and gas exploration targets in Offshore Pakistan[J]. Marine Geology Frontiers, 2019, 35(11):1-6.]
[10] 刘金萍, 王改云, 简晓玲, 等. 巴基斯坦印度扇近海盆地油气地质条件分析[J]. 地质学刊, 2022, 46(4): 351-357 LIU Jinping, WANG Gaiyun, JIAN Xiaoling, et al. Analysis of petroleum geological condition in offshore Indus Basin, Pakistan[J]. Journal of Geology, 46(4): 351-357.]
[11] 梁杰, 李森, 陈建文, 等. 巴基斯坦东部海域中生代地层发现与油气意义[J]. 海洋地质与第四纪地质, 2024, 44(3):115-124 LIANG Jie, LI Sen, CHEN Jianwen, et al. Discovery of Mesozoic strata in the eastern region of offshore Pakistan and its oil and gas significance[J]. Marine Geology & Quaternary Geology, 2024, 44(3):115-124.]
[12] 李森, 梁杰, 龚建明, 等. 巴基斯坦东部海域中−新生代沉积研究进展[J]. 海洋地质前沿, 2022, 38(2):1-13 LI Sen, LIANG Jie, GONG Jianming, et al. Research progress of the Meso-Cenozoic sedimentary evolution in eastern Pakistan sea[J]. Marine Geology Frontiers, 2022, 38(2):1-13.]
[13] Sandwell D T, Smith W H F. Global marine gravity from retracked Geosat and ERS-1 altimetry: Ridge segmentation versus spreading rate[J]. Journal of Geophysical Research: Solid Earth(1978-2012), 2009, 114(B1): B01411.
[14] Sandwell D T, Garicia E, Soofi K, et al. Toward 1 mGal Global Marine Gravity from CryoSat-2, Envisat, and Jason-1[J]. The Leading Edge, 2013, 32(8):892-899. doi: 10.1190/tle32080892.1
[15] Sandwell D T, Muller R D, Smith W H F, et al. New global marine gravity model from GryoSat-2 and Jason-1 reveals buried tectonic structure[J]. Science, 2014, 346(6205):65-67. doi: 10.1126/science.1258213
[16] 张菲菲, 王皓, 张义蜜, 等. 西太平洋海域卫星测高重力数据精度分析[J/OL]. 武汉大学学报:信息科学版, 202305 ZHANG Feifei, WANG Hao, ZHANG Yimi, et al. Accuracy analysis of satellite altimetry gravity data in the Western Pacific Area [J]. Geomatics and Information Science of Wuhan University, 202305.]
[17] 张功成, 贾庆军, 王万银, 等. 南海构造格局及其演化[J]. 地球物理学报, 2018, 61(10):4194-4215 ZHANG Gongcheng, JIA Qingjun, WANG Wanyin, et al. On tectonic framework and evolution of the South China Sea[J]. Chinese Journal of Geophysics, 2018, 61(10):4194-4215.]
[18] Maus S, Barckhausen U, Berkenbosch H, et al. EMAG2: A 2-arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements[J]. Geochemistry, Geophysics, Geosystems, 2009, 10(8).
[19] 张春灌, 李想, 袁炳强, 等. 地球磁异常(EMAG2)数据中海域资料质量评估—以北极地区Kolbeinsey脊南段为例[J]. 地球科学进展, 2019, 34(3):288-294 ZHANG Chunguan, LI Xiang, YUAN Bingqiang, et al. Quality evaluation of offshore data in the Earth Magnetic Anomaly Grid (2-arc-Minute Resolution): Taking the southern section of the Kolbeinsey Ridge in the Arctic Region as an example[J]. Advances in Earth Science, 2019, 34(3):288-294.]
[20] 戴勤奋, 周良勇, 魏合龙. 南黄海卫星重力场及构造演化[J]. 海洋地质与第四纪地质, 2002, 22(4):67-71 DAI Qinfeng, ZHOU Liangyong, WEI Helong. Satellite gravity field and tectonic evolution of the South Yellow Sea[J]. Marine Geology & Quaternary Geology, 2002, 22(4):67-71.]
[21] 纪晓琳, 王万银, 杜向东, 等. 利用重磁资料研究西非中南段含盐盆地构造区划[J]. 地球物理学报, 2019, 62(4):1502-1514 JI Xiaolin, WANG Wanyin, DU Xiangdong, et al. Tectonic division by gravity and magnetic data of salt-bearing basins, south-central section of West Africa[J]. Chinese Journal of Geophysics, 2019, 62(4):1502-1514.]
[22] Martín‐Español A, Zammit‐Mangion A, Clarke P J, et al. Spatial and temporal Antarctic Ice Sheet mass trends, glacio‐isostatic adjustment, and surface processes from a joint inversion of satellite altimeter, gravity, and GPS data[J]. Journal of Geophysical Research: Earth Surface, 2016, 121(2):182-200. doi: 10.1002/2015JF003550
[23] Yang M, Wang W, Zhang G, et al. Relationship between the Extent of Igneous Rocks and Deep Structures as Determined by Gravitational and Magnetic Data in the South China Sea[J]. Acta Geologica Sinica‐English Edition, 2021, 95(1):294-304. doi: 10.1111/1755-6724.14642
[24] Dobslaw H, Bergmann-Wolf I, Dill R, et al. A new high-resolution model of non-tidal atmosphere and ocean mass variability for de-aliasing of satellite gravity observations: AOD1B RL06. Geophysical Journal International, 2017, 211(1): 263-269.
[25] MA J, WANG W, DU X, et al. Study on System of Faults in the Gulf of Mexico and Adjacent Region based on Gravity Data[J]. Acta Geologica Sinica-English Edition, 2021, 95(1):305-318. doi: 10.1111/1755-6724.14643
[26] 雷受旻. 重力广义地形改正值和均衡该正值的一种计算方法[J]. 海洋地质与第四纪地质, 1984, 4(1):101-111 LEI Shoumin. Calculation of generalized topographic and isostatic gravity corrections[J]. Marine Geology and Quaternary Geology, 1984, 4(1):101-111.]
[27] 刘芬, 王万银, 纪晓琳. 空间域和频率域平面位场延拓影响因素和稳定性分析[J]. 物探与化探, 2019, 43(2): 320-328 LIU Fen, WANG Wanyin, JI Xiaolin. Influence factors and stability analysis of plane potential field continuation in space and frequency domains. Geophysical and Geochemical Exploration, 2019, 43(2): 320-328.
[28] He T, Xiong S Q, Wang W Y. Three-dimensional transformation of magnetization direction and magnetic field component at low latitudes based on vertical relationship[J]. Applied Geophysics, 2022, 19(1):91-106. doi: 10.1007/s11770-022-0928-4
[29] 纪晓琳, 王万银, 邱之云. 最小曲率位场分离方法研究[J]. 地球物理学报, 2015, 58(3):1042-1058 JI Xiaolin, WANG Wanyin, QIU Zhiyun. The research to the minimum curvature technique for potential field data separation[J]. Chinese Journal of Geophysics, 2015, 58(3):1042-1058.]
[30] 纪晓琳, 王万银, 邱之云. 最小曲率位场分离方法参数选择试验研究[J]. 地球物理学进展, 2019, 34(4):1441-1452 doi: 10.6038/pg2019AA0098 JI Xiaolin, WANG Wanyin, QIU Zhiyun. Parameter choose experimental research to the minimum curvature technique potential field data separation method[J]. Progress in Geophysics, 2019, 34(4):1441-1452.] doi: 10.6038/pg2019AA0098
[31] 鲁宝亮, 马涛, 熊盛青, 等. 基于重磁异常相关分析的场源位置及属性识别方法[J]. 地球物理学报, 2020, 63(4): 1663-1674 LU Baoliang, MA Tao, XIONG Shengqing, et al. A new recognition method for source locations and attributes based on correlation analysis of gravity and magnetic anomalies. Chinese Journal of Geophysics, 2020, 63(4): 1663-1674.
[32] He T, Wang W Y, Bai Z Z, et al. Integrated gravity and magnetic study on patterns of petroleum basin occurrence in the China seas and adjacent areas[J]. Acta Oceanologica Sinica, 2023, 42(3):201-214. doi: 10.1007/s13131-022-2139-5
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