东南印度洋中脊(108°—134°E区域)断层构造与岩浆活动关系

doi:10.11978/2018110

热带海洋学报 ›› 2019, Vol. 38 ›› Issue (4): 70-80.doi: 10.11978/2018110CSTR: 32234.14.2018110

东南印度洋中脊(108°—134°E区域)断层构造与岩浆活动关系

刘守金^1,³,林间^1,²(),罗怡鸣^1,³

^1. 中国科学院南海海洋研究所边缘海与大洋地质重点实验室(南海海洋研究所), 广东广州 510301
^3. 中国科学院大学, 北京100049;

收稿日期:2018-10-19 修回日期:2018-11-16 出版日期:2019-07-20 发布日期:2019-07-21
作者简介:刘守金(1989—), 男, 山东沂水人, 在读博士研究生, 主要从事海洋地质研究。E-mail: shjliu@scsio.ac.cn
基金资助:
中国科学院前沿科学重点研究项目((QYZDY-SSW-DQC005););中国科学院南海海洋研究所所拨特聘研究员项目((Y4SL021001););中国科学院科研装备项目((YZ201325、YZ201534););中国大洋协会项目((DY135-S2-1-04););国家重点研发计划专项((2018YFC0309800);)

Variations in tectonic faulting and magmatism at the Southeast Indian Ridge at 108°-134°E

Shoujin LIU^1,³,Jian LIN^1,²(),Yiming LUO^1,³

^1. CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Guangzhou 510301, China
^2. Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA

Received:2018-10-19 Revised:2018-11-16 Online:2019-07-20 Published:2019-07-21
Supported by:
Chinese Academy of Sciences Project((Y4SL021001););Chinese Academy of Sciences Project((YZ201325、YZ201534););China Ocean Mineral Resources R&D Association((DY135-S2-1-04););National Key Research and Development Program of China((2018YFC0309800););National Natural Science Foundation of China((91628301, U1606401, 41706056).)

摘要/Abstract

摘要：

东南印度洋脊(Southeast Indian Ridge, 简称SEIR)是中速扩张洋中脊, 在其中的108°—134°E区域的全扩张速率为72~76 mm·a ^-1。但在接近澳大利亚-南极洲不整合带(Australian-Antarctic Discordance, 简称AAD)区内, 海底地貌沿洋中脊的变化强烈, 其变化范围涵盖了从慢速到快速扩张洋中脊上常见的例子, 且出现了明显的地球物理与地球化学异常, 说明洋中脊在AAD区附近的岩浆供应量极不均匀。文章定量分析了高精度多波束测深数据, 计算了洋中脊不同段的地形坡度、断层比例以及平面与剖面的岩浆参数M值, 结合研究区内剩余地幔布格重力异常以及洋中脊轴部地球化学指标Na_8.0、Fe_8.0等资料, 分析与讨论了研究区的断层构造与岩浆活动特征的关系。研究发现, 东南印度洋脊108°—134°E区域的B区(在AAD区内)及C5段(在AAD区外西侧)发育有大量的海洋核杂岩, 而且B区的海洋核杂岩单体规模更大, 其中最大的位于B3区, 沿洋中脊扩张方向延伸约50km。研究结果首次系统性地显示, 相比东南印度洋的其他区域, B和C5异常区具有偏低的平面与剖面M值、偏高的断层比例、偏正的地幔布格重力异常以及偏高的Na_8.0值与偏低的Fe_8.0值, 这些异常特征可能反映了B区和C5段的岩浆初始熔融深度较浅以及岩浆熔融程度较低, 因此导致其岩浆供应量异常少, 形成较薄的地壳。研究结果同时表明, 在岩浆供应量极少的洋中脊, 构造伸展作用有利于海洋核杂岩的发育, 导致地壳进一步减薄。

关键词: 东南印度洋脊, 澳大利亚-南极洲不整合带, 海底断层, 岩浆参数M值, 海洋核杂岩, 多波束测深, 剩余地幔布格重力异常

Abstract:

The Southeast Indian Ridge (SEIR) at 108°-134°E has a relatively constant intermediate full spreading rate of 72-76 mm·a ^-1 but exhibits significant variations in seafloor tectonic faulting and magmatism. This section of the SEIR encompasses the Australian-Antarctic Discordance (AAD), shows a wide range of seafloor morphology similar to the diverse examples from slow- to fast-spreading ridges, and is associated with significant geophysical and geochemical anomalies. We used high- resolution multi-beam bathymetry data to calculate seafloor topographic slopes, ratio of fault scarp areas, map view and profile M factors. Combining residual mantle Bouguer anomaly and geochemical factors of Na_8.0 and Fe_8.0, we analyzed the fault tectonics and magmatic characteristics in our study area. A large number of Oceanic Core Complexes (OCC) zones are observed in Zone B within the AAD and Segment C5 immediately to the west of the AAD. The OCC features in Zone B are in general larger in size than those of Segment C5. The largest OCC is located in Segment B3, which extends~50 km along the SEIR spreading direction. In comparison to other segments, Zone B and Segment C5 have more negative residual mantle Bouguer anomalies, higher Na_8.0 and lower Fe_8.0, more fault scarp areas, and lower plane and profile M factors. These anomalies may reflect shallower initial mantle melting and lower degree of partial melting in Zone B and Segment C5, resulting in anomalously low magma supply, thin crust, and the development of OCC features when the magma supply is severely limited.

Key words: Southeast Indian Ridge, Australian-Antarctic Discordance, submarine faults, magma factor M, Oceanic Core Complex, multi-beam bathymetry, residual mantle Bouguer anomaly

刘守金,林间,罗怡鸣. 东南印度洋中脊(108°—134°E区域)断层构造与岩浆活动关系[J]. 热带海洋学报, 2019, 38(4): 70-80.

Shoujin LIU,Jian LIN,Yiming LUO. Variations in tectonic faulting and magmatism at the Southeast Indian Ridge at 108°-134°E[J]. Journal of Tropical Oceanography, 2019, 38(4): 70-80.

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参考文献 36

[1]	BEHN M D, ITO G , 2008. Magmatic and tectonic extension at mid-ocean ridges: 1. Controls on fault characteristics[J]. Geochemistry, Geophysics, Geosystems, 9(8): Q08O10.
[2]	BONATTI E, LIGI M, BRUNELLI D , et al, 2003. Mantle thermal pulses below the Mid-Atlantic Ridge and temporal variations in the formation of oceanic lithosphere[J]. Nature, 423(6939):499-505. doi: 10.1038/nature01594
[3]	BUCK W R, LAVIER L L, POLIAKOV A N B , 2005. Modes of faulting at mid-ocean ridges[J]. Nature, 434(7034):719-723. doi: 10.1038/nature03358
[4]	CHRISTIE D M, WEST B P, PYLE D G , et al, 1998. Chaotic topography, mantle flow and migration in the Australian Antarctic Discordance[J]. Nature, 394(6694):637-644. doi: 10.1038/29226
[5]	CIAZELA J, KOEPKE J, DICK H J B , et al, 2015. Mantle rock exposures at oceanic core complexes along mid-ocean ridges[J]. Geologos, 21(4):207-231. doi: 10.1515/logos-2015-0017
[6]	COWIE P A, KARNER G D , 1990. Gravity effect of sediment compaction: examples from the North Sea and the Rhine Graben[J] Earth and Planetary Science Letters, 99(1-2):141-153. doi: 10.1016/0012-821X(90)90078-C
[7]	DICK H J B, LIN JIAN, SCHOUTEN H , 2003. An ultraslow- spreading class of ocean ridge[J]. Nature, 426(6965):405-412. doi: 10.1038/nature02128
[8]	DIVINS D L , 2003. Total sediment thickness of the World’s oceans and marginal seas[R]. Boulder, CO: NOAA National Geophysical Data Center.
[9]	ESCARTÍN J, MÉVEL C, MACLEOD C J , et al, 2003. Constraints on deformation conditions and the origin of oceanic detachments: the Mid-Atlantic Ridge core complex at 15°45'N[J]. Geochemistry, Geophysics, Geosystems, 4(8):1067.
[10]	GÉLI L, COCHRAN J R, LEE T C , et al, 2007. Thermal regime of the Southeast Indian Ridge between 88°E and 140°E: remarks on the subsidence of the ridge flanks[J]. Journal of Geophysical Research: Solid Earth, 112(B10):B10101. doi: 10.1029/2006JB004578
[11]	GURNIS M, MÜLLER R D, MORESI L , 1998. Cretaceous vertical motion of Australia and the Australian-Antarctic discordance[J]. Science, 279(5356):1499-1504.
[12]	HAYES D E , 1976. Nature and implications of asymmetric sea-floor spreading - “different rates for different plates”[J]. GSA Bulletin, 87(7):994-1002. doi: 10.1130/0016-7606(1976)87994:NAIOAS2.0.CO;2
[13]	KLEIN E M, LANGMUIR C H , 1987. Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness[J]. Journal of Geophysical Research: Solid Earth, 92(B8):8089-8115. doi: 10.1029/JB092iB08p08089
[14]	KLEIN E M, LANGMUIR C H, ZINDLER A , et al, 1988. Isotope evidence of a mantle convection boundary at the Australian- Antarctic discordance[J]. Nature, 333(6174):623-629. doi: 10.1038/333623a0
[15]	KLEIN E M, LANGMUIR C H, STAUDIGEL H , 1991. Geochemistry of basalts from the Southeast Indian Ridge, 115°E-138°E[J]. Journal of Geophysical Research: Solid Earth, 96(B2):2089-2107. doi: 10.1029/90JB01384
[16]	KOJIMA, Y, SHINOHARA M, MOCHIZUKI K , et al, 2003. Seismic velocity structure in the Australian-Antarctic Discordance, Segment B4 revealed by airgun-OBS experiment[J]. EOS Transactions, American Geophysical Union 2003 AGU Fall Meeting, 84(46):F1060.
[17]	LAVIER L L, BUCK W R , 2002. Half graben versus large-offset low-angle normal fault: importance of keeping cool during normal faulting[J]. Journal of Geophysical Research: Solid Earth, 107(B6):2122. doi: 10.1029/2001JB000513
[18]	LIN J, PURDY G M, SCHOUTEN H , et al, 1990. Evidence from gravity data for focused magmatic accretion along the Mid-Atlantic Ridge[J]. Nature, 344(6267):627-632. doi: 10.1038/344627a0
[19]	MACDONALD K C , 1990. A slow but restless ridge[J]. Nature, 348(6297):108-109. doi: 10.1038/348108a0
[20]	MÜLLER R D, ROEST W R, ROYER J Y , et al, 1997. Digital isochrons of the world's ocean floor[J]. Journal of Geophysical Research: Solid Earth, 102(B2):3211-3214. doi: 10.1029/96JB01781
[21]	MÜLLER R D, SDROLIAS M, GAINA C , et al, 2008. Age, spreading rates, and spreading asymmetry of the world's ocean crust[J]. Geochemistry, Geophysics, Geosystems, 9(4):Q04006.
[22]	NEUMANN G A, FORSYTH D W, SANDWELL D , 1993. Comparison of marine gravity from shipboard and high- density satellite altimetry along the Mid-Atlantic Ridge, 30.5°-35.5°S[J]. Geophysical Research Letters, 20(15):1639-1642. doi: 10.1029/93GL01487
[23]	OHARA Y, YOSHIDA T, KATO Y , et al, 2001. Giant megamullion in the Parece Vela backarc basin[J]. Marine Geophysical Researches, 22(1):47-61. doi: 10.1023/A:1004818225642
[24]	OKINO K, MATSUDA K, CHRISTIE D M , et al, 2004. Development of oceanic detachment and asymmetric spreading at the Australian-Antarctic discordance[J]. Geochemistry, Geophysics, Geosystems, 5(12):Q12012.
[25]	OLIVE J A, BEHN M D, TUCHOLKE B E , 2010. The structure of oceanic core complexes controlled by the depth distribution of magma emplacement[J]. Nature Geoscience, 3(7):491-495. doi: 10.1038/ngeo888
[26]	PARKER R L , 1973. The rapid calculation of potential anomalies[J]. Geophysical Journal International, 31(4):447-455. doi: 10.1111/j.1365-246X.1973.tb06513.x
[27]	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[J]. Science, 346(6205):65-67. doi: 10.1126/science.1258213
[28]	SHAW W J, LIN JIAN , 1996. Models of ocean ridge lithospheric deformation: dependence on crustal thickness, spreading rate, and segmentation[J]. Journal of Geophysical Research: Solid Earth, 101(B8):17977-17993. doi: 10.1029/96JB00949
[29]	SMITH D , 2013. Mantle spread across the sea floor[J]. Nature Geoscience, 6(4):247-248. doi: 10.1038/ngeo1786
[30]	TUCHOLKE B E, LIN JIAN, KLEINROCK M C et al, 1997. Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25’-27°10’N and 0-29 m.y.[J]. Journal of Geophysical Research: Solid Earth, 102(B5):10203-10223. doi: 10.1029/96JB03896
[31]	TUCHOLKE B E, LIN JIAN, KLEINROCK M C , 1998. Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge[J]. Journal of Geophysical Research: Solid Earth, 103(B5):9857-9866. doi: 10.1029/98JB00167
[32]	TUCHOLKE B E, BEHN M D, BUCK W R , et al, 2008. Role of melt supply in oceanic detachment faulting and formation of megamullions[J]. Geology, 36(6):455-458. doi: 10.1130/G24639A.1
[33]	TURCOTTE D L, SCHUBERT G , 2014. Geodynamics[M]. Cambridge: Cambridge University Press: 848.
[34]	WANG TINGTING, LIN JIAN, TUCHOLKE B , et al, 2011. Crustal thickness anomalies in the North Atlantic Ocean basin from gravity analysis[J]. Geochemistry, Geophysics, Geosystems, 12(3): Q0AE02, doi: 10.1029/2010GC003402.
[35]	WEISSEL J K, HAYES D E , 1971. Asymmetric seafloor spreading south of Australia[J]. Nature, 231(5304):518-522. doi: 10.1038/231518a0
[36]	YOUNG M , 1978. Statistical characterization of altitude matrices by computer. Report 5. Terrain analysis: program documentation[R]. Durham: Durham University.

东南印度洋中脊(108°—134°E区域)断层构造与岩浆活动关系

Variations in tectonic faulting and magmatism at the Southeast Indian Ridge at 108°-134°E

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