超慢速扩张洋中脊岩浆形成和迁移汇聚动力学研究

刘持恒; 李江海; 刘仲兰; 范庆凯; 何苗

doi:10.3969/j.issn.0253-4193.2019.03.009

超慢速扩张洋中脊岩浆形成和迁移汇聚动力学研究

doi: 10.3969/j.issn.0253-4193.2019.03.009

1.
北京大学地球与空间科学学院石油与天然气研究中心, 北京 100871;北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室, 北京 100871
2.
北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室, 北京 100871
3.
中国科学院大学地球与行星科学学院中国科学院地球动力学重点实验室, 北京 100049

基金项目: 多金属硫化物合同区资源勘探与评价（DY135-S1-1-03）；超慢速扩张洋中脊岩浆迁移及其动力学机制研究（gzck2018001）；印度洋靶区断裂系统及其控矿作用（DY135-S2-1-01）

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出版历程
- 收稿日期: 2018-01-11
- 修回日期: 2018-07-03

Geodynamic process of melt generation, migration and focusing at ultraslow mid-ocean ridges

1.
Institute of Oil and Gas, School of Earth and Space Sciences, Peking University, Beijing 100871, China;The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, China
2.
The Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences, Peking University, Beijing 100871, China
3.
CAS Key Laoboratory of Computational Geodynamics, College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China

摘要

摘要: 超慢速扩张洋中脊具有不同于其他扩张速率洋中脊的特征，表现为剧烈变化的洋壳厚度和典型的非岩浆段。本文对前人研究的洋中脊岩浆形成关键因素和迁移聚集模式进行综合分析，结合实际地球物理和地球化学的观测数据，探讨了超慢速扩张洋中脊岩浆从地幔源区形成、迁移汇聚、形成洋壳的整个地质过程，进一步指出了影响洋壳结构的关键控制因素。研究结果表明，超慢速扩张洋中脊沿轴洋壳厚度的变化受岩浆补给量和迁移汇聚的共同制约。其中，岩浆补给量受控于洋中脊的地幔潜热、地幔成分和扩张速率的变化；岩浆迁移和汇聚过程则与超慢速扩张洋中脊密集的分段特征和阻渗层的空间结构密切相关。
- 超慢速扩张洋中脊 /
- 洋壳厚度 /
- 部分熔融 /
- 岩浆迁移 /
- 分段性
Abstract: Accretion of oceanic crust has experienced the mantle partial melting by decompression, melt extraction, migration and focusing into the oceanic crust, which emplaced in the oceanic crust forming of dike and erupted on the bottom of sea after fractional crystallization. The dramatic variation of crustal thickness along the ultraslow mid-ocean ridge and ammagmatic segmentation is concerned to be the typical characteristics to others. Based on previous studies of melt generation key factors and migration model of mid-ocean ridge basalt, this paper discussed the process of melt at ultraslow mid-ocean ridge and analyzed the key factors controlling the crustal thickness. Besides, this process and its result is constrained by geophysical and geochemical observation. The result shows that the crustal thickness along the ultraslow mid-ocean ridge is constrained by melt volume and lateral migration collectively. Among this process, mantle potential temperature, mantle compositions and spreading velocity controlled the melt volume. The segmentation of ultraslow mid-ocean ridge and the corresponding permeability barrier construct guide the migration and focusing of melt.
- ultraslow mid-ocean ridge /
- oceanic crustal thickness /
- partial melting /
- ridge segmentation /
- melt migration

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参考文献(51)

Solomon S C, Toomey D R. The structure of mid-ocean ridges[J]. Annual Review of Earth and Planetary Sciences, 1992, 20: 329-366.

White R S, McKenzie D, O'Nions R K. Oceanic crustal thickness from seismic measurements and rare earth element inversions[J]. Journal of Geophysical Research: Solid Earth, 1992, 97(B13): 19683-19715.

Kuo Banyuan, Forsyth D W. Gravity anomalies of the ridge-transform system in the South Atlantic between 31 and 34.5°S: upwelling centers and variations in crustal thickness[J]. Marine Geophysical Researches, 1988, 10(3/4): 205-232.

Lin J, Purdy G M, Schouten H, et al. Evidence from gravity data for focused magmatic accretion along the Mid-Atlantic Ridge[J]. Nature, 1990, 344(6267): 627-632.

Grindlay N R, Madsen J A, Rommevaux-Jestin C, et al. 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)[J]. Earth and Planetary Science Letters, 1998, 161(1/4): 243-253.

Dick H J, Lin Jian, Schouten H. An ultraslow-spreading class of ocean ridge[J]. Nature, 2003, 426(6965): 405-412.

Zhou Huaiyang, Dick H J B. Thin crust as evidence for depleted mantle supporting the Marion Rise[J]. Nature, 2013, 494(7436): 195-200.

Sauter D, Cannat M, Rouméjon S, et al. Continuous exhumation of mantle-derived rocks at the Southwest Indian Ridge for 11 million years[J]. Nature Geoscience, 2013, 6(4): 314-320.

Schmidt-Aursch M C, Jokat W. 3D gravity modelling reveals off-axis crustal thickness variations along the western Gakkel Ridge (Arctic Ocean)[J]. Tectonophysics, 2016, 691: 85-97.

White R S, Minshull T A, Bickle M J, et al. Melt generation at very slow-spreading oceanic ridges: constraints from geochemical and geophysical data[J]. Journal of Petrology, 2001, 42(6): 1171-1196.

Weir N R W, White R S, Brandsdóttir B, et al. Crustal structure of the northern Reykjanes Ridge and Reykjanes Peninsula, southwest Iceland[J]. Journal of Geophysical Research: Solid Earth, 2001, 106(B4): 6347-6368.

Klingelhöfer F, Géli L, Matias L, et al. Crustal structure of a super-slow spreading centre: a seismic refraction study of Mohns Ridge, 72°N[J]. Geophysical Journal International, 2000, 141(2): 509-526.

Muller M R, Minshull T A, White R S. Segmentation and melt supply at the Southwest Indian Ridge[J]. Geology, 1999, 27(10): 867-870.

Muller M R, Minshull T A, White R S. Crustal structure of the Southwest Indian ridge at the atlantis Ⅱ fracture zone[J]. Journal of Geophysical Research: Solid Earth, 2000, 105(B11): 25809-25828.

Niu Xiongwei, Ruan Aiguo, Li Jiabiao, et al. Along-axis variation in crustal thickness at the ultraslow spreading Southwest Indian Ridge (50°E) from a wide-angle seismic experiment[J]. Geochemistry, Geophysics, Geosystems, 2015, 16(2): 468-485.

Jokat W, Ritzmann O, Schmidt-Aursch M C, et al. Geophysical evidence for reduced melt production on the Arctic ultraslow Gakkel mid-ocean ridge[J]. Nature, 2003, 423(6943): 962-965.

Lin Jian, Morgan J P. The spreading rate dependence of three-dimensional mid-ocean ridge gravity structure[J]. Geophysical Research Letters, 1992, 19(1): 13-16.

Sauter D, Sloan H, Cannat M, et al. From slow to ultra-slow: how does spreading rate affect seafloor roughness and crustal thickness？[J]. Geology, 2011, 39(10): 911-914.

Klein E M, Langmuir C H. Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness[J]. Journal of Geophysical Research: Solid Earth, 1987, 92(B8): 8089-8115.

Niu Yaoling, O'Hara M J. Global correlations of ocean ridge basalt chemistry with axial depth: a new perspective[J]. Journal of Petrology, 2008, 49(4): 633-664.

Sparks D W, Parmentier E M, Morgan J P. Three-dimensional mantle convection beneath a segmented spreading center: implications for along-axis variations in crustal thickness and gravity[J]. Journal of Geophysical Research: Solid Earth, 1993, 98(B12): 21977-21995.

Meyzen C M, Toplis M J, Humler E, et al. A discontinuity in mantle composition beneath the southwest Indian ridge[J]. Nature, 2003, 421(6924): 731-733.

Standish J J, Dick H J B, Michael P J, et al. MORB generation beneath the ultraslow spreading Southwest Indian Ridge (9°-25°E): major element chemistry and the importance of process versus source[J]. Geochemistry, Geophysics, Geosystems, 2008, 9(5): Q05004.

Liu Chuanzhou, Snow J E, Hellebrand E, et al. Ancient, highly heterogeneous mantle beneath Gakkel ridge, Arctic Ocean[J]. Nature, 2008, 452(7185): 311-316.

Niu Yaoling, Hékinian R. Spreading-rate dependence of the extent of mantle melting beneath ocean ridges[J]. Nature, 1997, 385(6614): 326-329.

Mckenzie D, Bickle M J. The volume and composition of melt generated by extension of the lithosphere[J]. Journal of Petrology, 1988, 29(3): 625-679.

Rey P F. Research focus: the geodynamics of mantle melting[J]. Geology, 2015, 43(4): 367-368.

Katz R F, Spiegelman M, Langmuir C H. A new parameterization of hydrous mantle melting[J]. Geochemistry, Geophysics, Geosystems, 2003, 4(9): 1073.

Becker T W, Boschi L. A comparison of tomographic and geodynamic mantle models[J]. Geochemistry, Geophysics, Geosystems, 2002, 3(1): 1003.

Parmentier E M, Morgant J P. Spreading rate dependence of three-dimensional structure in oceanic spreading centres[J]. Nature, 1990, 348(6299): 325-328.

Meyzen C M, Ludden J N, Humler E, et al. New insights into the origin and distribution of the DUPAL isotope anomaly in the Indian Ocean mantle from MORB of the Southwest Indian Ridge[J]. Geochemistry, Geophysics, Geosystems, 2005, 6(11): Q11K11.

Forsyth D W. Crustal thickness and the average depth and degree of melting in fractional melting models of passive flow beneath mid-ocean ridges[J]. Journal of Geophysical Research: Solid Earth, 1993, 98(B9): 16073-16079.

Langmuir C H, Forsyth D W. Mantle melting beneath mid-ocean ridges[J]. Oceanography, 2007, 20(1): 78-89.

Zhang Tao, Gao Jinyao, Chen Mei, et al. Mantle melting factors and amagmatic crustal accretion of the Gakkel ridge, Arctic Ocean[J]. Acta Oceanologica Sinica, 2015, 34(6): 42-48.

Sparks D W, Parmentier E M. Melt extraction from the mantle beneath spreading centers[J]. Earth and Planetary Science Letters, 1991, 105(4): 368-377.

Garapic G, Faul U H, Brisson E. High-resolution imaging of the melt distribution in partially molten upper mantle rocks: evidence for wetted two-grain boundaries[J]. Geochemistry, Geophysics, Geosystems, 2013, 14(3): 556-566.

Faul U H. Permeability of partially molten upper mantle rocks from experiments and percolation theory[J]. Journal of Geophysical Research: Solid Earth, 1997, 102(B5): 10299-10311.

Katz R F. Magma dynamics with the enthalpy method: benchmark solutions and magmatic focusing at mid-ocean ridges[J]. Journal of Petrology, 2008, 49(12): 2099-2121.

Hebert L B, Montési L G J. Generation of permeability barriers during melt extraction at mid-ocean ridges[J]. Geochemistry, Geophysics, Geosystems, 2010, 11(12): Q12008.

Montési L G J, Behn M D. Mantle flow and melting underneath oblique and ultraslow mid-ocean ridges[J]. Geophysical Research Letters, 2007, 34(24): L24307.

Montési L G J, Behn M D, Hebert L B, et al. Controls on melt migration and extraction at the ultraslow Southwest Indian Ridge 10°-16°E[J]. Journal of Geophysical Research: Solid Earth, 2011, 116(B10): 1-19.

Schlindwein V, Schmid F. Mid-ocean-ridge seismicity reveals extreme types of ocean lithosphere[J]. Nature, 2016, 535(7611): 276-279.

Carbotte S M, Smith D K, Cannat M, et al. Tectonic and magmatic segmentation of the Global Ocean Ridge System: a synthesis of observations[J]. Geological Society, London, Special Publications, 2015, 420(1): 249-295.

Sauter D, Patriat P, Rommevaux-Jestin C, et al. The Southwest Indian Ridge between 49°15'E and 57°E: focused accretion and magma redistribution[J]. Earth and Planetary Science Letters, 2001, 192(3): 303-317.

Bai Hailong, Montési L G J, Behn M D. MeltMigrator: a MATLAB-based software for modeling three-dimensional melt migration and crustal thickness variations at mid-ocean ridges following a rules-based approach[J]. Geochemistry, Geophysics, Geosystems, 2017, 18(1): 445-456.

Sauter D, Cannat M. The Ultraslow Spreading Southwest Indian ridge[M]//Rona P A, Devey C W, Dyment J, et al. Diversity of Hydrothermal Systems on Slow Spreading Ocean Ridges. Washington, DC: American Geophysical Union, 2010: 153-173.

Suo Yanhui, Li Sanzhong, Li Xiyao, et al. The potential hydrothermal systems unexplored in the Southwest Indian Ocean[J]. Marine Geophysical Research, 2017, 38(1/2): 61-70.

Dalton C A, Langmuir C H, Gale A. Geophysical and geochemical evidence for deep temperature variations beneath mid-ocean ridges[J]. Science, 2014, 344(6179): 80-83.

Fang Nianqiao, Niu Yaoling. Late palaeozoic ultramafic lavas in Yunnan, SW China, and their geodynamic significance[J]. Journal of Petrology, 2003, 44(1): 141-158.

Sandwell D T, Müller R D, Smith W H F, et al. New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure[J]. Science, 2014, 346(6205): 65-67.

刘持恒, 李江海, 张华添, 等. 西南印度洋岩浆补给特征研究:来自洋壳厚度的证据[J]. 地球物理学报, 2018, 61(7): 2859-2870. Liu Chiheng, Li Jianghai, Zhang Huatian, et al. Magma supply of the southwest Indian Ocean: evidence from crustal thickness anomalies[J]. Chinese Journal of Geophysics, 2018, 61(7): 2859-2870.

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