马达加斯加岛西南陆缘CMD01剖面重震联合反演与地壳结构分析

doi:10.3969/j.issn.1001-909X.2024.04.008

海洋学研究 ›› 2024, Vol. 42 ›› Issue (4): 83-99.DOI: 10.3969/j.issn.1001-909X.2024.04.008

马达加斯加岛西南陆缘CMD01剖面重震联合反演与地壳结构分析

张永祺¹^,²(), 唐勇¹^,²^,³^,⁴^,^*(), 董崇志¹^,², 吴招才¹^,², 李赫¹^,², 郭楚枫¹^,²^,⁴, 任建业³, 巢鹏³, 杨天一¹^,²^,³

1.自然资源部第二海洋研究所,浙江杭州 310012
2.自然资源部海底科学重点实验室,浙江杭州 310012
3.中国地质大学(武汉) 海洋学院,湖北武汉 430074
4.上海交通大学海洋学院,上海 200030

收稿日期:2024-02-05 修回日期:2024-05-17 出版日期:2024-12-15 发布日期:2025-02-08
通讯作者: 唐勇
作者简介:*唐勇(1974—),男,研究员,主要从事海洋地球物理方面的研究,E-mail:tangyong@sio.org.cn。
张永祺(1999—),男,福建省福州市人,主要从事海洋地质方面的研究,E-mail:13960857464@163.com。
基金资助:
国家重点研发计划(2023YFE0126100);国家重点研发计划(2023YFC2808803);浙江省万人计划科技创新领军人才计划(22618);浙江省“高层次人才特殊支持计划”科技创新领军人才项目(2021R52058)

Joint inversion of gravity and seismic along the CMD01 profile on the southwestern margin of Madagascar and analysis of crustal structure

ZHANG Yongqi¹^,²(), TANG Yong¹^,²^,³^,⁴^,^*(), DONG Chongzhi¹^,², WU Zhaocai¹^,², LI He¹^,², GUO Chufeng¹^,²^,⁴, REN Jianye³, CHAO Peng³, YANG Tianyi¹^,²^,³

1. Key Laboratory of Submarine Geosciences, MNR, Hangzhou 310012, China
2. Second Institute of Oceanography, MNR, Hangzhou 310012,China
3. College of Marine Science and Technology, China University of Geosciences(Wuhan), Wuhan 430074, China
4. School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China

Received:2024-02-05 Revised:2024-05-17 Online:2024-12-15 Published:2025-02-08
Contact: TANG Yong

摘要/Abstract

摘要：

本文以2021年中马国际合作航次获得的实测重力、磁力和二维多道地震剖面资料为基础,对横穿马达加斯加岛西南陆缘的CMD01剖面进行解释分析和重震联合反演,研究马达加斯加岛西南陆缘的地壳结构、构造单元及其演化过程。通过建立马达加斯加岛西南陆缘地壳密度模型,发现该陆缘具有减薄的陆壳,部分区段存在岩浆底侵作用;由陆向洋可划分出减薄陆壳、洋陆过渡带和洋壳等构造单元。其中,由于戴维断裂带的走滑运动对陆缘的影响,洋陆过渡带呈现出典型的转换型陆缘的构造特征。结合地壳密度模型和板块重建研究,重建了马达加斯加岛西南陆缘的发育演化过程。研究成果对于深化冈瓦纳大陆的裂解分离、东非被动陆缘的发育演化和海域划界等均具有重要的理论意义和实际应用价值。

关键词: 东非大陆边缘, 戴维断裂带, 洋陆过渡带, 转换型陆缘, 重震联合反演, 深度地壳结构, 地壳密度模型, 下地壳高密度体

Abstract:

This study was based on the actual gravity, magnetic and multichannel seismic data obtained during the international cooperative survey in 2021. Through joint inversion of gravity and seismic along the CMD01 profile traversing the southwestern margin of Madagascar, combined with interpretation and analysis of seismic profiles, the crustal structure, tectonic units, and evolution of the southwestern margin of Madagascar were studied. A crustal density model of the southwestern margin of Madagascar was established, revealing thinned continental crust and the presence of magmatic underplating in certain segments. Structural units such as thinned continental crust, continental-ocean transition zone and oceanic crust domain can be delineated from land to sea, among which, due to the influence of Davie Fracture Zone strike-slip tectonics on the margin, the continental-ocean transition zone exhibited typical characteristics of a transform margin. By combining plate reconstruction and crustal density model, the developmental evolution of the southwestern margin of Madagascar was reconstructed. The research results have important theoretical significance and practical application value for deepening the understanding of the breakup and separation of the Gondwana, the developmental evolution of the East African passive margin, and maritime delineation.

Key words: The continental edge of East Africa, Davie Fracture Zone, continental-ocean transition zone, transform margin, joint inversion of gravity and seismic, deep crustal structure, crustal density model, lower crustal high-density body

中图分类号:

P736.1

张永祺, 唐勇, 董崇志, 吴招才, 李赫, 郭楚枫, 任建业, 巢鹏, 杨天一. 马达加斯加岛西南陆缘CMD01剖面重震联合反演与地壳结构分析[J]. 海洋学研究, 2024, 42(4): 83-99.

ZHANG Yongqi, TANG Yong, DONG Chongzhi, WU Zhaocai, LI He, GUO Chufeng, REN Jianye, CHAO Peng, YANG Tianyi. Joint inversion of gravity and seismic along the CMD01 profile on the southwestern margin of Madagascar and analysis of crustal structure[J]. Journal of Marine Sciences, 2024, 42(4): 83-99.

图/表 13

图1 马达加斯加岛西南部陆缘周边区域构造图

Fig.1 The tectonic map of the region around the southwestern margin of Madagascar Island

表1 马达加斯加岛西南陆缘层序地震反射特征

Tab.1 Seismic reflection characteristics of sequence in the southwestern margin of Madagascar Island

层序	内部反射特征	频率	振幅	连续性
U₅(T₀~T₁)	平行-亚平行	高频,变化较小	低-中振幅,局部空白	好-中等
U₄(T₁~T_b)	亚平行,局部嘈杂状	中频	低-中振幅,局部空白	中等-差
U₃(T₁~T₂)	平行-亚平行,局部波状	高-中频,局部有变化	中振幅,局部空白	好-中等
U₂(T₂~T₃)	亚平行,局部嘈杂状	中频	中振幅	好
U₁(T₃~T₄)	亚平行,局部嘈杂状	变化较大	高-中振幅	好-中等

图2 马达加斯加岛西南陆缘地层格架图 (T4形成于晚石炭世陆内裂谷开始初期,未在图中标注。图件根据文献[16]修改。)

Fig.2 Stratigraphic framework of the southwestern margin of Madagascar Island (T4 was formed at the beginning of the Late Carboniferous intracontinental rift period and is not noted in the figure. Figure is modified from reference [16].)

图3 CMD01二维地震剖面 (U表示地层,其中U1为T3与T4之间的地层,U2为T2与T3之间的地层,U3为T1和T2之间的地层,U4为T1和Tb之间的地层,U5为T0和T1之间的地层。)

Fig.3 CMD01 2D seismic profile (U represents stratum, U1 is the stratum between T3 and T4, U2 is the stratum between T2 and T3, U3 is the stratum between T1 and T2, U4 is the stratum between T1 and Tb, U5 is the stratum between T0 and T1.)

表2 马达加斯加岛西南部陆缘地壳密度与速度模型[7,28-29]

Tab.2 Crustal density model and velocity model of the southwestern margin of Madagascar Island[7,28-29]

地层	密度/(g·cm^-3)	层速度/(m·s^-1)
海水	1.03	1 500
沉积层1	2.20	2 000
沉积层2	2.30~2.45	3 300
沉积层3	2.52~2.56	3 500
沉积层4	2.57~2.64	4 000
洋壳	2.93	6 500
上地壳	2.67~2.74	5 700~6 300
下地壳	2.90~2.94	6 400~7 000
下地壳高密度体	3.10~3.16	7 000~7 500
地幔	3.30	8 000~8 100

图4 马达加斯加岛西南陆缘自由空间重力异常(a)与地形图(b)

Fig.4 The free-space gravity anomaly (a) and topographic map (b) of the southwestern margin of Madagascar Island

图5 CMD01的二维地震剖面(a)、磁力异常曲线(b)和自由空间重力异常曲线(c)

Fig.5 CMD01 2D seismic profile (a), magnetic anomaly curve (b) and gravity anomaly curve (c)

图6 测线CMD01洋陆边界的地震剖面

Fig.6 Continental-ocean boundary in CMD01 seismic profile

图7 测线CMD01海盆内拗陷区与岩浆侵入的地震剖面

Fig.7 Rift area and magmatic intrusions within the basin in CMD01 seismic profile

图8 测线CMD01陆缘区地层抬升的地震剖面

Fig.8 Uplift stratigraphic in CMD01 seismic profile

图9 测线CMD01陆缘区地堑构造的地震剖面

Fig.9 Graben structure in CMD01 seismic profile

图10 CMD01剖面地壳密度模型界面反演结果 (D表示密度。)

Fig.10 The inversion results of the crustal density model interface for CMD01 (D represents density.)

图11 马达加斯加岛西南部陆缘演化示意图 (图件据文献[19]和[53]修改。)

Fig.11 Evolution map of the southwestern margin of Madagascar Island (Figure is modified from references [19] and [53].)

参考文献 53

[1]	张光亚, 刘小兵, 赵健, 等. 东非被动大陆边缘盆地演化及大气田形成主控因素:以鲁武马盆地为例[J]. 地学前缘, 2018, 25(2):24-32. DOI
	ZHANG G Y, LIU X B, ZHAO J, et al. Passive continental margin basin evolution of East Africa and the main controlling factors of giant gas fields: An example from the Rovuma Basin[J]. Earth Science Frontiers, 2018, 25(2): 24-32. DOI
[2]	REEVES C V, TEASDALE J P, MAHANJANE E S. Insight into the Eastern Margin of Africa from a new tectonic model of the Indian Ocean[J]. Geological Society, London, Special Publications, 2016, 431(1): 299-322.
[3]	温志新, 王兆明, 宋成鹏, 等. 东非被动大陆边缘盆地结构构造差异与油气勘探[J]. 石油勘探与开发, 2015, 42(5):671-680.
	WEN Z X, WANG Z M, SONG C P, et al. Structural architecture difference and petroleum exploration of passive continental margin basins in East Africa[J]. Petroleum Exploration and Development, 2015, 42(5): 671-680.
[4]	许志刚, 韩文明, 孙玉梅. 东非大陆边缘构造演化过程与油气勘探潜力[J]. 中国地质, 2014, 41(3):961-969.
	XU Z G, HAN W M, SUN Y M. Tectonic evolution and petroleum exploration prospect of East Africa[J]. Geology in China, 2014, 41(3): 961-969.
[5]	COFFIN M F, RABINOWITZ P D. Reconstruction of Mada-gascar and Africa: Evidence from the Davie fracture zone and western Somali Basin[J]. Journal of Geophysical Research, 1987, 92(B9): 9385-9406.
[6]	SINHA S T, SAHA S, LONGACRE M, et al. Crustal archi-tecture and nature of continental breakup along a transform margin: New insights from Tanzania-Mozambique margin[J]. Tectonics, 2019, 38(4): 1273-1291.
[7]	VORMANN M, JOKAT W. The crustal structure of the Kerimbas Basin across the offshore branch of the East African Rift System[J]. Geophysical Journal International, 2021, 226(3): 2073-2102.
[8]	MEERT J G, TAMRAT E. Paleomagnetic evidence for a stationary Marion hotspot: Additional paleomagnetic data from Madagascar[J]. Gondwana Research, 2006, 10(3/4): 340-348.
[9]	STOREY M, MAHONEY J J, SAUNDERS A D, et al. Timing of hot spot: Related volcanism and the breakup of Madagascar and India[J]. Science, 1995, 267(5199): 852-855.
[10]	JOURDAN F, BERTRAND H, FÉRAUD G, et al. Litho-spheric mantle evolution monitored by overlapping large igneous provinces: Case study in southern Africa[J]. Lithos, 2009, 107(3/4): 257-268.
[11]	CATUNEANU O, WOPFNER H, ERIKSSON P G, et al. The Karoo Basins of south-central Africa[J]. Journal of African Earth Sciences, 2005, 43(1/2/3): 211-253.
[12]	COX K G. Karoo igneous activity, and the early stages of the break-up of Gondwanaland[J]. Journal of the Geological Society, 1992, 68(1): 137-148.
[13]	EAGLES G, HOANG H H. Cretaceous to present kinematics of the Indian, African and Seychelles plates[J]. Geophysical Journal International, 2014, 196(1): 1-14.
[14]	COLLIER J S, SANSOM V, ISHIZUKA O, et al. Age of Seychelles-India break-up[J]. Earth and Planetary Science Letters, 2008, 272(1/2): 264-277.
[15]	GEIGER M, CLARK D N, METTE W. Reappraisal of the timing of the breakup of Gondwana based on sedimentological and seismic evidence from the Morondava Basin, Madagascar[J]. Journal of African Earth Sciences, 2004, 38(4): 363-381.
[16]	覃阳亮, 何幼斌, 蔡俊, 等. 东非海岸Davie构造带的构造演化特征及其成因机制[J]. 岩性油气藏, 2021, 33(2):104-115.
	QIN Y L, HE Y B, CAI J, et al. Tectonic evolution and formation mechanism of Davie Fracture Zone in East Africa coast[J]. Lithologic Reservoirs, 2021, 33(2): 104-115.
[17]	KLIMKE J, FRANKE D, MAHANJANE E S, et al. Tie points for Gondwana reconstructions from a structural inter-pretation of the Mozambique Basin, East Africa and the Riiser-Larsen Sea, Antarctica[J]. Solid Earth, 2018, 9(1): 25-37.
[18]	REEVES C. The position of Madagascar within Gondwana and its movements during Gondwana dispersal[J]. Journal of African Earth Sciences, 2014, 94: 45-57.
[19]	KLIMKE J, FRANKE D. Gondwana breakup: No evidence for a Davie Fracture Zone offshore northern Mozambique, Tanzania and Kenya[J]. Terra Nova, 2016, 28(4): 233-244.
[20]	MAHANJANE E S. A geotectonic history of the northern Mozambique Basin including the Beira High—A contribution for the understanding of its development[J]. Marine and Petroleum Geology, 2012, 36(1): 1-12.
[21]	LEINWEBER V T, JOKAT W. The Jurassic history of the Africa-Antarctica corridor—New constraints from magnetic data on the conjugate continental margins[J]. Tectonophysics, 2012, 530/531: 87-101.
[22]	KÖNIG M, JOKAT W. The Mesozoic breakup of the Weddell Sea[J]. Journal of Geophysical Research: Solid Earth, 2006, 111: B12102.
[23]	SCHANDELMEIER H, BREMER F, HOLL H G. Kinematic evolution of the Morondava rift basin of SW Madagascar—From wrench tectonics to normal extension[J]. Journal of African Earth Sciences, 2004, 38(4): 321-330.
[24]	SALMAN G, ABDULA I. Development of the Mozambique and Ruvuma sedimentary basins, offshore Mozambique[J]. Sedimentary Geology, 1995, 96(1/2): 7-41.
[25]	NAIRN A E M, LERCHE I, ILIFFE J E. Geology, basin analysis, and hydrocarbon potential of Mozambique and the Mozambique Channel[J]. Earth-Science Reviews, 1991, 30(1/2): 81-123.
[26]	WARNER M R. Seismic reflections from the Moho—The effect of isostasy[J]. Geophysical Journal International, 1987, 88(2): 425-435.
[27]	KLIMKE J, FRANKE D, GAEDICKE C, et al. How to identify oceanic crust—Evidence for a complex break-up in the Mozambique Channel, off East Africa[J]. Tectono-physics, 2016, 693: 436-452.
[28]	VORMANN M, FRANKE D, JOKAT W. The crustal structure of the southern Davie Ridge offshore northern Mozambique—A wide-angle seismic and potential field study[J]. Tectonophysics, 2020, 778: 228370.
[29]	MUELLER C O, JOKAT W, SCHRECKENBERGER B. The crustal structure of Beira High, central Mozambique—Combined investigation of wide-angle seismic and potential field data[J]. Tectonophysics, 2016, 683: 233-254.
[30]	于璇, 侯贵廷, 代双河, 等. 东非大陆边缘构造演化与油气成藏模式探析[J]. 地质科技情报, 2015, 34(6):147-154,158.
	YU X, HOU G T, DAI S H, et al. Tectonic evolution and hydrocarbon pooling patterns analysis in East Africa continental margin[J]. Bulletin of Geological Science and Technology, 2015, 34(6): 147-154, 158.
[31]	黄国平, 胡清乐, 陈冬明, 等. 马达加斯加地质矿产概况[J]. 资源环境与工程, 2014, 28(5):626-632.
	HUANG G P, HU Q L, CHEN D M, et al. General situation of geology and mineral resources in Madagascar[J]. Resources Environment & Engineering, 2014, 28(5): 626-632.
[32]	COLLINSA S, WINDLEY B F. The tectonic evolution of central and northern Madagascar and its place in the final assembly of Gondwana[J]. The Journal of Geology, 2002, 110(3): 325-339.
[33]	RYZHOVA D A, KOSNYREVA M V, DUBININ E P, et al. The structure tectonosphere of the Mozambique and Mada-gascar ridges by geophysical data[J]. Moscow University Geology Bulletin, 2022, 77(1): 18-27.
[34]	FUNCK T, HOPPER J R, LARSEN H C, et al. Crustal structure of the ocean-continent transition at Flemish Cap: Seismic refractionresults[J]. Journal of Geophysical Research, 2003, 108: 2531.
[35]	BOILLOT G, GRIMAUD S, MAUFFRET A, et al. Ocean-continent boundary off the Iberian margin: Aserpentinite diapir west of the Galicia Bank[J]. Earth and Planetary Science Letters, 1980, 48(1): 23-34.
[36]	HIRSCH K K, BAUER K, SCHECK-WENDEROTH M. Deep structure of the western South African passive margin—Results of a combined approach of seismic, gravity and isostatic investigations[J]. Tectonophysics, 2009, 470(1/2): 57-70.
[37]	MINSHULL T A, LANE C I, COLLIER J S, et al. The relationship between rifting and magmatism in the north-eastern Arabian Sea[J]. Nature Geoscience, 2008, 1: 463-467.
[38]	MASINI E, MANATSCHAL G, MOHN G. The Alpine Tethys rifted margins: Reconciling old and new ideas to understand the stratigraphic architecture of magma-poor rifted margins[J]. Sedimentology, 2013, 60(1): 174-196.
[39]	PÉRON-PINVIDIC G, MANATSCHAL G. From microconti-nents to extensional allochthons: Witnesses of how continents rift and break apart?[J]. Petroleum Geoscience, 2010, 16(3): 189-197.
[40]	MAIA M, SICHEL S, BRIAIS A, et al. Extreme mantle uplift and exhumation along a transpressive transform fault[J]. Nature Geoscience, 2016, 9: 619-623.
[41]	VOLKER T L, FRAUKE K, SÖNKE N, et al. The crustal structure of the Central Mozambique continental margin—Wide-angle seismic, gravity and magnetic study in the Mozambique Channel, Eastern Africa[J]. Tectonophysics, 2013, 599: 170-196.
[42]	HUISMANS R, BEAUMONT C. Depth-dependent extension, two-stage breakup and cratonic underplating at rifted margins[J]. Nature, 2011, 473: 74-78.
[43]	AUTIN J, LEROY S, BESLIER M O, et al. Continental break-up history of a deep magma-poor margin based on seismic reflection data (northeastern Gulf of Aden margin, offshore Oman)[J]. Geophysical Journal International, 2010, 180(2): 501-519.
[44]	FRANKE D. Rifting, lithosphere breakup and volcanism: Comparison of magma-poor and volcanic rifted margins[J]. Marine and Petroleum Geology, 2013, 43: 63-87.
[45]	GEOFFROY L. Volcanic passivemargins[J]. Comptes Rendus Géoscience, 2005, 337(16): 1395-1408.
[46]	SINHA S T, NEMČOK M, CHOUDHURI M, et al. The role of break-up localization in microcontinent separation along a strike-slip margin: The East India-Elan Bank case study[J]. Geological Society, London, Special Publications, 2016, 431(1): 95-123.
[47]	PHETHEAN J J J, KALNINS L M, VAN HUNEN J, et al. Madagascar’s escape from Africa: A high-resolution plate reconstruction for the Western Somali Basin and implications for supercontinent dispersal[J]. Geochemistry, Geophysics, Geosystems, 2016, 17(12): 5036-5055.
[48]	DAVISON I, FAULL T, GREENHALGH J, et al. Trans-pressional structures and hydrocarbon potential along the Romanche Fracture Zone: A review[J]. Geological Society, London, Special Publications, 2016, 431(1): 235-248.
[49]	MUELLER C O, JOKAT W. The initial Gondwana break-up: A synthesis based on new potential field data of the Africa-Antarctica Corridor[J]. Tectonophysics, 2019, 750: 301-328.
[50]	FRANKE D, JOKAT W, LADAGE S, et al. The offshore East African Rift System: Structural framework at the toe of a juvenile rift[J]. Tectonics, 2015, 34(10): 2086-2104.
[51]	SAUTER D, UNTERNEHR P, MANATSCHAL G, et al. Evidence for magma entrapment below oceanic crust from deep seismic reflections in the Western Somali Basin[J]. Geology, 2016, 44(6): 407-410.
[52]	GAINA C, TORSVIK T H, VAN HINSBERGEN D J J, et al. The African Plate: A history of oceanic crust accretion and subduction since the Jurassic[J]. Tectonophysics, 2013, 604: 4-25.
[53]	VORMANN M, JOKAT W. Crustal variability along the rifted/sheared East African margin: A review[J]. Geo-Marine Letters, 2021, 41(2): 19.

马达加斯加岛西南陆缘CMD01剖面重震联合反演与地壳结构分析

Joint inversion of gravity and seismic along the CMD01 profile on the southwestern margin of Madagascar and analysis of crustal structure

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