西南印度洋中脊地质构造特征及其地球动力学意义

doi:10.6038/cjg2020N0230

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (11429 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要西南印度洋中脊（SWIR）增生的洋壳面积仅占印度洋的15%左右，但其具有比东南印度洋中脊和西北印度洋中脊更悠久而复杂的演化历史.基于已有的地质、地球物理和地球化学等资料，系统总结了SWIR的地质构造特征，并讨论了SWIR的演化过程、洋脊地幔的不均一性、洋脊周边海底高原成因等核心问题.SWIR地形中段高、东西两段低，空间重力异常基本与地形变化一致.按转换断层一级边界可将SWIR划分为20个一级段.SWIR的磁异常条带呈现两端渐进式分布和中段带状分布特征，对应洋脊的三期演化历史.SWIR的地幔源区极不均一，尤其是中新元古代造山带根部集中拆离的中段.源区地幔的不均一性与大陆裂解和洋脊演化过程密切相关.SWIR的东端与西北印度洋中脊和东南印度洋中脊的邻近洋脊段具有地球化学亲缘性，西端与大西洋中脊和南美洲—南极洲洋中脊的邻近洋脊段具有地球化学亲缘性，这与SWIR的渐近式扩张有关.SWIR周边海底高原普遍具有较大的地壳厚度，其成因除了陆壳基底之外，可能与热点火山作用、热点-洋脊相互作用或热点-三联点相互作用有关，目前尚未形成统一的认识.SWIR的形成演化及其作用域内的熔融异常（如海底高原）是冈瓦纳大陆裂解、残留岩石圈地幔、软流圈地幔和深部地幔热柱物质共同作用的结果.了解SWIR的演化过程对揭示冈瓦纳大陆的裂解过程和印度洋的演化具有重要意义.

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	余星
	迪克·亨利
	李小虎
	初凤友
	董彦辉
	胡航

关键词 ：西南印度洋中脊, 洋中脊玄武岩, 地质构造特征, 地球化学, 海底高原

Abstract：The Southwest Indian Ridge (SWIR) has a more complex evolution than the Southeast Indian Ridge (SEIR) and the Northwest Indian Ridge (NWIR), even though it takes up only 15% of the total area of Indian Ocean crust. On the base of existing geological, geophysical and geochemical data, we systematically summarized the geotectonic characteristics of SWIR, and tried to address the issues of evolution process of SWIR, the mantle heterogeneity beneath the ridge and the origin of adjacent oceanic plateau. The bathymetry of the ridge shows obvious shoaling up in the Mid-section of SWIR, while the East-section and West-section are relatively deeper. The free-air gravity anomaly is consistent with the topography. Base on the gravimetric and topographic features, SWIR can be subdivided into 20 first-order segments according to the first-order boundaries, like transform faults. The magnetic anomaly of SWIR shows propagating spreading at both ends and horizontal zoning distribution in the Mid-section, suggesting a three-stage evolution history for the ridge. The mantle sources of SWIR are extremely heterogeneous, especially in the Mid-section, where the delamination could most probably happen beneath the Meso- to Neoproterozoic orogenic belt. The heterogeneity of the source is closely related to the continental breakup and ridge evolution. Both ends of SWIR show geochemical affinities with the adjacent ridge segments of Mid-Atlantic Ridge and South America-Antarctica Ridge, SEIR and NWIR, respectively. The oceanic plateaus close to SWIR generally have large crustal thickness, which may be related to the hotspot magmatism, hotspot-ridge interaction, or even hotspot-triple junction interaction, apart from the ghostly stranded continental fragment trapped in the asthenospheric mantle. Understanding the evolution history of SWIR is of great importance for revealing the break-up process of Gondwana supercontinent and the evolution of the Indian Ocean.

Key words： Southwest Indian Ridge Mid-ocean ridge basalt Geotectonic features Geochemistry Oceanic plateau

收稿日期: 2019-06-04

PACS:

P541

基金资助:国家自然科学基金项目（41872242），大洋"十三五"资源环境专项（DY135-S2-1-02）和自然资源部第二海洋研究所基本科研业务费专项（JT2001和JG2001）联合资助.

作者简介: 余星,男,1981年生,副研究员,从事岩石大地构造学研究.E-mail:yuxing@sio.org.cn

链接本文:

http://www.geophy.cn//CN/10.6038/cjg2020N0230 或 http://www.geophy.cn//CN/Y2020/V63/I10/3585

Baines A G, Cheadle M J, Dick H J B, et al. 2007. Evolution of the Southwest Indian Ridge from 55°45'E to 62°E:Changes in plate-boundary geometry since 26 Ma. Geochemistry, Geophysics, Geosystems, 8(6):Q06022, doi:10.1029/2006GC001559.
Ben-Avraham Z, Hartnady C J H, Le Roex A P. 1995. Neotectonic activity on continental fragments in the Southwest Indian ocean:Agulhas plateau and Mozambique ridge. Journal of Geophysical Research:Solid Earth, 100(B4):6199-6211.
Bergh H W, Norton I O. 1976. Prince Edward fracture zone and the evolution of the Mozambique basin. Journal of Geophysical Research, 81(29):5221-5239.
Bernard A, Munschy M, Rotstein Y, et al. 2005. Refined spreading history at the Southwest Indian Ridge for the last 96 Ma, with the aid of satellite gravity data. Geophysical Journal International, 162(3):765-778.
Breton T, Nauret F, Pichat S, et al. 2013. Geochemical heterogeneities within the Crozet hotspot. Earth and Planetary Science Letters, 376:126-136.
Cannat M, Rommevaux-Jestin C, Sauter D, et al. 1999. Formation of the axial relief at the very slow spreading Southwest Indian Ridge (49° to 69°E). Journal of Geophysical Research:Solid Earth, 104(B10):22825-22843.
Cannat M, Sauter D, Mendel V, et al. 2006. Modes of seafloor generation at a melt-poor ultraslow-spreading ridge. Geology, 34(7):605-608.
Cao H. 2010. Hydrothermal Mineralization and Geological and Geochemical Characteristics of SWIR[Master's thesis] (in Chinese). Qingdao:Ocean University of China.
Dick H J B, Lin J, Schouten H. 2003. An ultraslow-spreading class of ocean ridge. Nature, 426(6965):405-412.
Dick H J B, Zhou H Y. 2015. Ocean rises are products of variable mantle composition, temperature and focused melting. Nature Geoscience, 8(1):68-74.
Escrig S, Capmas F, Dupré B, et al. 2004. Osmium isotopic constraints on the nature of the DUPAL anomaly from Indian mid-ocean-ridge basalts. Nature, 431(7004):59-63.
Ewing M, Heezen B C. 1960. Continuity of mid-oceanic ridge and rift valley in the southwestern Indian Ocean confirmed. Science, 131(3414):1677-1679, doi:10.1126/science.131.3414.1677.
Fischer M D, Uenzelmann-Neben G, Jacques G, et al. 2017. The Mozambique Ridge:a document of massive multistage magmatism. Geophysical Journal International, 208(1):449-467, doi:10.1093/gji/ggw403.
Gautheron C, Moreira M, Gerin C, et al. 2015. Constraints on the DUPAL anomaly from helium isotope systematics in the Southwest Indian mid-ocean ridge basalts. Chemical Geology, 417:163-172.
Georgen J E, Lin J, Dick H J B. 2001. Evidence from gravity anomalies for interactions of the Marion and Bouvet hotspots with the Southwest Indian Ridge:effects of transform offsets. Earth and Planetary Science Letters, 187(3-4):283-300.
Georgen J E, Kurz M D, Dick H J B, et al. 2003. Low ³He/⁴He ratios in basalt glasses from the western Southwest Indian Ridge (10°-24°E). Earth and Planetary Science Letters, 206(3-4):509-528.
Gohl K, Uenzelmann-Neben G. 2001. The crustal role of the Agulhas Plateau, southwest Indian Ocean:evidence from seismic profiling. Geophysical Journal International, 144(3):632-646.
Goslin J. 1979. Résultats de gravimétrie sur les monts sous-marins du Marion Dufresne, de la Léna et de l'Ob (Océan Indien austral). C. R. Acad. Sci., Paris, 288(B):241-244.
Goslin J, Segoufin J, Schlich R, et al. 1980. Submarine topography and shallow structure of the Madagascar Ridge, Western Indian Ocean. GSA Bulletin, 91(12):741-753.
Goslin J, Recq M, Schlich R. 1981. Emplacement and evolution of the Madagascar ridge and Crozet submarine Plateau. Bull. Soc. Geol. Fr., 23:609-618.
Goslin J, Diament M. 1987. Mechanical and thermal isostatic response of the Del Cano Rise and Crozet Bank (southern Indian Ocean) from altimetry data. Earth and Planetary Science Letters, 84(2-3):285-294.
Grindlay N R, Madsen J A, Rommevaux-Jestin C, et al. 1998. A different pattern of ridge segmentation and mantle Bouguer gravity anomalies along the ultra-slow spreading Southwest Indian Ridge (15°30'E to 25°E). Earth and Planetary Science Letters, 161(1-4):243-253.
Honsho C, Tamaki K, Fujimoto H. 1996. Three-dimensional magnetic and gravity studies of the Rodriguez Triple Junction in the Indian Ocean. Journal of Geophysical Research:Solid Earth, 101(B7):15837-15848.
Hosford A, Tivey M, Matsumoto T, et al. 2003. Crustal magnetization and accretion at the Southwest Indian Ridge near the Atlantis Ⅱ fracture zone, 0~25 Ma. Journal of Geophysical Research:Solid Earth, 108(B3):2169, doi:10.1029/2001JB000604.
Jacques G, Hauff F, Hoernle K, et al. 2019. Nature and origin of the Mozambique Ridge, SW Indian Ocean. Chemical Geology, 507:9-22.
Janney P E, Le Roex A P, Carlson R W. 2005. Hafnium isotope and trace element constraints on the nature of mantle heterogeneity beneath the central southwest Indian ridge (13°E to 47°E). Journal of Petrology, 46(12):2427-2464.
King S D, Adam C. 2014. Hotspot swells revisited. Physics of the Earth and Planetary Interiors, 235:66-83.
König M, Jokat W. 2010. Advanced insights into magmatism and volcanism of the Mozambique Ridge and Mozambique Basin in the view of new potential field data. Geophysical Journal International, 180(1):158-180.
Kurz M D, Le Roex A P, Dick H J B. 1998. Isotope geochemistry of the oceanic mantle near the Bouvet triple junction. Geochimica et Cosmochimica Acta, 62(5):841-852.
Le Roex A P, Dick H J B. 1981. Petrography and geochemistry of basaltic rocks from the Conrad fracture zone on the America-Antarctica Ridge. Earth and Planetary Science Letters, 54(1):117-138.
Le Roux P J, Le Roex A P, Schilling J G, et al. 2002. Mantle heterogeneity beneath the southern Mid-Atlantic Ridge:trace element evidence for contamination of ambient asthenospheric mantle. Earth and Planetary Science Letters, 203(1):479-498.
Le Roex A P, Chevallier L, Verwoerd W J, et al. 2012. Petrology and geochemistry of Marion and Prince Edward Islands, Southern Ocean:Magma chamber processes and source region characteristics. Journal of Volcanology and Geothermal Research, 223-224:11-28.
Li J B, Jian H C, Chen Y J, et al. 2015. Seismic observation of an extremely magmatic accretion at the ultraslow spreading Southwest Indian Ridge. Geophysical Research Letters, 42(8):2656-2663.
Li J H, Zhang H T, Li H L. 2015. The tectonic setting and evolution of Indian Ocean-Research progress of tectonic map of Indian Ocean. Acta Oceanologica Sinica (in Chinese), 37(7):1-14, doi:10.3969/j.issn.0253-4193.2015.07.001.
Li S Z, Suo Y H, Yu S, et al. 2015. Morphotectonics and tectonic processes of the Southwest Indian Ocean. Geotectonica et Metallogenia (in Chinese), 39(1):15-29.
Liu C H, Li J H, Zhang H T, et al. 2018. Magma supply of the Southwest Indian Ocean:evidence from crustal thickness anomalies. Chinese Journal of Geophysics (in Chinese), 61(7):2859-2870, doi:10.6038/cjg2018L0395.
Livermore R A, Hunter R J. 1996. Mesozoic seafloor spreading in the Southern Weddell Sea. Geological Society, London, Special Publications, 108(1):227-241.
Mahoney J, Le Roex A P, Peng Z, et al. 1992. Southwestern limits of Indian Ocean Ridge Mantle and the origin of low ²⁰⁶Pb/²⁰⁴Pb mid-ocean ridge basalt:Isotope systematics of the central Southwest Indian Ridge (17°-50°E). Journal of Geophysical Research:Solid Earth, 97(B13):19771-19790.
Maus S, Barckhausen U, Berkenbosch H, et al. 2009. EMAG2:A 2-arc min resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne, and marine magnetic measurements. Geochemistry, Geophysics, Geosystems, 10(8):Q8005, doi:10.1029/2009GC002471.
McDougall I, Verwoerd W, Chevallier L. 2001. K-Ar geochronology of Marion Island, Southern Ocean. Geological Magazine, 138(1):1-17.
Mendel V, Sauter D, Parson L, et al. 1997. Segmentation and morphotectonic variations along a Super Slow-spreading center:The Southwest Indian Ridge (57°E-70°E). Marine Geophysical Researches, 19(6):505-553.
Meyzen C M, Ludden J N, Humler E, et al. 2005. New insights into the origin and distribution of the DUPAL isotope anomaly in the Indian Ocean mantle from MORB of the Southwest Indian Ridge. Geochemistry, Geophysics, Geosystems, 6(11):Q11K11, doi:10.1029/2005GC000979.
Meyzen C M, Marzoli A, Bellieni G, et al. 2016. Magmatic activity on a motionless plate:the case of East Island, Crozet Archipelago (Indian Ocean). Journal of Petrology, 57(7):1409-1436.
Muller M R, Minshull T A, White R S. 1999. Segmentation and melt supply at the Southwest Indian Ridge. Geology, 27(10):867-870.
Niu X W, Ruan A G, Li J B, et al. 2015. Along-axis variation in crustal thickness at the ultraslow spreading Southwest Indian Ridge (50°E) from a wide-angle seismic experiment. Geochemistry, Geophysics, Geosystems, 16(2):468-485.
Pérez-Díaz L, Eagles G. 2014. Constraining South Atlantic growth with seafloor spreading data. Tectonics, 33(9):1848-1873, doi:10.1002/2014TC003644.
Parsiegla N, Gohl K, Uenzelmann-Neben G. 2008. The Agulhas Plateau:Structure and evolution of a large igneous province. Geophysical Journal International, 174(1):336-350.
Patriat P. 1979. L'ocean Indien:La dorsale ouest-Indienne.//Mémoire du Museum National d'Histoire Naturelle, série C, 43:49-52.
Patriat P, Sauter D, Munschy M, et al. 1997. A survey of the Southwest Indian Ridge axis between Atlantis Ⅱ Fracture Zone and the Indian Ocean Triple Junction:Regional setting and large scale segmentation. Marine Geophysical Researches, 19(6):457-480.
Recq M, Goslin J, Patriat P, et al. 1979. Profil de réfraction sur le plateau malgache, résultats préliminaires, 7ème Réunion Annuelle des Sciences de la Terre, Lyon, April 1979, Abstract.
Recq M, Goslin J, Charvis P, et al. 1998. Small-scale crustal variability within an intraplate structure:the Crozet Bank (southern Indian Ocean). Geophysical Journal International, 134(1):145-156.
Rommevaux-Jestin C, Deplus C, Patriat P. 1997. Mantle Bouguer anomaly along an ultra slow-spreading ridge:Implications for accretionary processes and comparison with results from Central Mid-Atlantic Ridge. Marine Geophysical Researches, 19(6):481-503.
Rothé J P. 1954. La zone séismique médiane Indo-Atlantique. Proc. Roy. Soc. A:Math. Phys. Eng. Sci., 222(1150):387-397.
Royer J Y, Patriat P, Bergh H W, et al. 1988. Evolution of the Southwest Indian ridge from the Late Cretaceous (anomaly 34) to the Middle Eocene (anomaly 20). Tectonophysics, 155(1-4):235-260.
Sandwell D T, Müller R D, Smith W H F, et al. 2014. New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure. Science, 346(6205):65-67.
Sauter D, Patriat P, Rommevaux-Jestin C, et al. 2001. The Southwest Indian Ridge between 49°15'E and 57°E:Focused accretion and magma redistribution. Earth and Planetary Science Letters, 192(3):303-317.
Sauter D, Carton H, Mendel V, et al. 2004. Ridge segmentation and the magnetic structure of the Southwest Indian Ridge (at 50°30'E, 55°30'E and 66°20'E):Implications for magmatic processes at ultraslow-spreading centers. Geochemistry, Geophysics, Geosystems, 5(5):Q05K08, doi:10.1029/2003GC000581.
Sauter D, Cannat M, Meyzen C, et al. 2009. Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E:interaction with the Crozet hotspot? Geophysical Journal International, 179(2):687-699.
Sauter D, Cannat M, Rouméjon S, et al. 2013. Continuous exhumation of mantle-derived rocks at the Southwest Indian Ridge for 11 million years. Nature Geoscience, 6(4):314-320.
Schlich R. 1982. The Indian Ocean:aseismic ridges, spreading centers, and oceanic basins.//Nairn A E M, Stehli F G eds. The Ocean Basins and Margins. Boston, MA:Springer.
Schreider A A, Schreider Al A, Bulychev A A, et al. 2006. Geochronology of the American-Antarctic ridge. Oceanology, 46(1):114-122.
Sclater J G, Fisher R L, Patriat P, et al. 1981. Eocene to recent development of the South-west Indian Ridge, a consequence of the evolution of the Indian Ocean Triple Junction. Geophysical Journal International, 64(3):587-604.
Sinha M C, Louden K E, Parsons B. 1981. The crustal structure of the Madagascar ridge. Geophysical Journal International, 66(2):351-377.
Standish J J, Dick H J B, Michael P J, et al. 2008. MORB generation beneath the ultraslow spreading Southwest Indian Ridge (9-25°E):Major element chemistry and the importance of process versus source. Geochemistry, Geophysics, Geosystems, 9(5):Q05004, doi:10.1029/2008GC001959.
Tao C H, Lin J, Guo S Q, et al. 2012. First active hydrothermal vents on an ultraslow-spreading center:Southwest Indian Ridge. Geology, 40(1):47-50.
Tapscott C R, Patriat P, Fisher R L, et al. 1980. The Indian Ocean triple junction. Journal of Geophysical Research:Solid Earth, 85(B9):4723-4739.
Veevers J J. 2012. Reconstructions before rifting and drifting reveal the geological connections between Antarctica and its conjugates in Gondwanaland. Earth-Science Reviews, 111(3-4):249-318.
Verwoerd W, Chevallier L, Thomson J W, et al. 1990. F. Oceanic islands on the Antarctic Plate.//LeMasurier W E, Thomson J W, Baker P E eds. Volcanoes of the Antarctic Plate and Southern Oceans. Washington DC:Antarctic Research Series, 396-463.
West B P, Fujimoto H, Honsho C, et al. 1995. A three-dimensional gravity study of the Rodrigues Triple Junction and the Southeast Indian ridge. Earth and Planetary Science Letters, 133(1-2):175-184.
Yang A Y, Zhao T P, Zhou M F, et al. 2017. Isotopically enriched N-MORB:A new geochemical signature of off-axis plume-ridge interaction-A case study at 50°28'E, Southwest Indian Ridge. Journal of Geophysical Research:Solid Earth, 122(1):191-213.
Yu X, Han X Q, Qiu Z Y, et al. 2019a. Definition of Northwest Indian ridge and its geologic and tectonic signatures. Earth Science (in Chinese), 44(2):626-639.
Yu X, Han X Q, Tang L M, et al. 2019b. The geotectonic features of the Southeast Indian Ridge and its current research progress. Chinese Science Bulletin (in Chinese), 64(17):1799-1816.
Yu X, Dick H J B. 2020. Plate-driven micro-hotspots and the evolution of the dragon flag melting anomaly, southwest Indian ridge. Earth and Planetary Science Letters, 531:116002, doi:10.1016/j.epsl.2019.116002.
Zhang T, Lin J, Gao J Y. 2011. Interactions between hotspots and the Southwest Indian Ridge during the last 90 Ma:Implications on the formation of oceanic plateaus and intra-plate seamounts. Science China Earth Sciences, 54(8):1177-1188.
Zhang T, Lin J, Gao J Y. 2013. Magmatism and tectonic processes in Area A hydrothermal vent on the Southwest Indian ridge. Science China Earth Sciences, 56(12):2186-2197.
Zhao M H, Qiu X L, Li J B, et al. 2013. Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49°39'E). Geochemistry, Geophysics, Geosystems, 14(10):4544-4563.
Zhou H, Dick H J B. 2013. Thin crust as evidence for depleted mantle supporting the Marion Rise. Nature, 494(7436):195-200.
附中文参考文献
曹红. 2010. 西南印度洋中脊热液成矿作用及其地质地球化学研究[硕士论文]. 青岛:中国海洋大学.
李江海, 张华添, 李洪林. 2015. 印度洋大地构造背景及其构造演化——印度洋底大地构造图研究进展. 海洋学报, 37(7):1-14, doi:10.3969/j.issn.0253-4193.2015.07.001.
李三忠, 索艳慧, 余珊等. 2015. 西南印度洋构造地貌与构造过程. 大地构造与成矿学, 39(1):15-29.
刘持恒, 李江海, 张华添等. 2018. 西南印度洋岩浆补给特征研究:来自洋壳厚度的证据. 地球物理学报, 61(7):2859-2870, doi:10.6038/cjg2018L0395.
余星, 韩喜球, 邱中炎等. 2019a. 西北印度洋脊的厘定及其地质构造特征. 地球科学, 44(2):626-639.
余星, 韩喜球, 唐立梅等. 2019b. 东南印度洋中脊地质构造特征及研究进展. 科学通报, 64(17):1799-1816.
张涛, Lin J, 高金耀. 2013. 西南印度洋中脊热液区的岩浆活动与构造特征. 中国科学:地球科学, 43(11):1834-1846.