西南印度洋中脊热液区岩石声学特性

doi:10.3969/j.issn.1001-909X.2024.01.001

海洋学研究 ›› 2024, Vol. 42 ›› Issue (1): 1-12.DOI: 10.3969/j.issn.1001-909X.2024.01.001

• 研究论文 • 下一篇

西南印度洋中脊热液区岩石声学特性

揭天愚¹^,²(), 周建平¹^,²^,³^,^*(), 陶春辉¹^,², 王汉闯¹^,², 李倩宇¹^,²^,⁴, 吴涛¹^,², 刘隆⁵

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.自然资源部海洋智能观测技术创新中心,浙江杭州 310012
4.中国地质大学(武汉) 地球物理与空间信息学院,湖北武汉 430074
5.中国地质调查局西安地质调查中心,陕西西安 710054

收稿日期:2022-11-27 修回日期:2023-05-18 出版日期:2024-03-15 发布日期:2024-05-11
通讯作者: * 周建平(1974—),男,研究员,主要从事海洋地球物理方面的研究,E-mail:zhoujp@sio.org.cn。
作者简介:揭天愚(1997—),男,浙江省衢州市人,主要从事海洋岩石声学物性方面的研究,E-mail:nathan_jie@163.com。
基金资助:
国家自然科学基金项目(42127807);浙江省重点研发计划(2021C03016);上海交通大学-自然资源部第二海洋研究所联合基金“深蓝计划”(SL2020ZD205);上海交通大学-自然资源部第二海洋研究所联合基金“深蓝计划”(SL2020MS033)

Acoustic characteristics of rocks from the SWIR hydrothermal fields

JIE Tianyu¹^,²(), ZHOU Jianping¹^,²^,³^,^*(), TAO Chunhui¹^,², WANG Hanchuang¹^,², LI Qianyu¹^,²^,⁴, WU Tao¹^,², LIU Long⁵

1. Second Institute of Oceanography, MNR, Hangzhou 310012, China
2. Key Laboratory of Submarine Geosciences, MNR, Hangzhou 310012, China
3. Technology Innovation Center for Intelligent Ocean Observation,MNR, Hangzhou 310012, China
4. School of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China
5. Xi’an Center of Geological Survey, China Geological Survey, Xi’an 710054, China

Received:2022-11-27 Revised:2023-05-18 Online:2024-03-15 Published:2024-05-11

摘要/Abstract

摘要：

西南印度洋中脊(Southwest Indian Ridge, SWIR)热液区具有潜在发育的大规模硫化物矿床,当前正在开展SWIR硫化物矿产资源评价。测量分析硫化物和不同围岩的声速等物性特征是硫化物近底地震勘探资料处理和解释的基础。该文对西南印度洋中脊热液区的硫化物和围岩等样品进行了系统的物性测量,结合岩石物性(包括密度、孔隙度、P波速度)与矿物组成,深入分析了西南印度洋中脊热液区岩石声速变化特性及其影响因素。结果表明,SWIR热液区围岩的P波速度受到岩石骨架矿物、孔隙和围压的影响。由于岩石孔隙度总体偏小,对P波速度的影响并不显著,但围压的增加使岩石微裂缝和孔隙逐渐闭合,P波速度呈非线性指数变化。蚀变作用导致了矿物成分改变,是影响围岩声速的最关键因素。单一物性参数测量结果可能存在多解性,联合波速、密度、磁性和电性等多物性参数测量有利于岩性区分。该研究成果有助于识别硫化物和围岩,为我国西南印度洋合同区多金属硫化物地震勘探工作提供重要支撑。

关键词: 西南印度洋中脊, 深海热液区, 岩石声学特性, 岩石物性测量, P波速度

Abstract:

The hydrothermal fields of the Southwest Indian Ridge (SWIR) have the potential to develop large scale sulfide deposits, and the SWIR sulfide mineral resource evaluation is currently underway. Measurement and analysis of petrophysical characteristics such as P-wave velocity of sulfides and different host rocks are the basis for processing and interpretation of near-bottom seismic exploration data. Through the systematic measurement of the physical properties of sulfides and host rocks in the SWIR hydrothermal areas, we have analyzed the characteristics of rock P-wave velocity variation and its influencing factors by combining rock physical properties (including density, porosity, P-wave velocity) and minerals. The results show that the P-wave velocity of SWIR rocks is influenced by the rock skeleton minerals, pore space and confining pressure. Due to the overall small porosity of the rocks, the effect on P-wave velocity is not significant, but the increase of the confining pressure gradually closes the rock microfractures and pores, and the P-wave velocity varies non-linearly exponentially. The alteration causes the change of mineral composition, which is the most critical factor affecting the P-wave velocity of the confining rocks. The results of single physical parameter measurements may have multiple solutions, and the joint measurement of multiple physical parameters such as wave velocity, density, magnetic and electrical properties is beneficial for lithological differentiation. The research results help identifying sulfides and host rocks, and provide important support for the seismic exploration of polymetallic sulfides in the Southwest Indian Ocean contract area of China.

Key words: Southwest Indian Ridge, deep-sea hydrothermal fields, rock acoustic properties, petrophysical measurements, P-wave velocity

中图分类号:

P714⁺.8

揭天愚, 周建平, 陶春辉, 王汉闯, 李倩宇, 吴涛, 刘隆. 西南印度洋中脊热液区岩石声学特性[J]. 海洋学研究, 2024, 42(1): 1-12.

JIE Tianyu, ZHOU Jianping, TAO Chunhui, WANG Hanchuang, LI Qianyu, WU Tao, LIU Long. Acoustic characteristics of rocks from the SWIR hydrothermal fields[J]. Journal of Marine Sciences, 2024, 42(1): 1-12.

图/表 14

图1 硫化物及围岩样品位置

Fig.1 Location of sulfide and host rock samples

表1 Mineral mass fractions of selected rock samples in the study area单位:%

Tab.1

序号	样品类型	石英	斜长石	方解石	黄铁矿	蛇纹石	辉石	角闪石	磁铁矿	橄榄石	黏土矿物总量
B1	新鲜玄武岩	0	73.7	0	0	0	16.9	0	0	0	9.4
B2	新鲜玄武岩	0	84.2	0	0	0	10.1	0	0	2.0	3.7
B3	新鲜玄武岩	0	80.7	0	0	0	12.6	0	0	3.7	3.0
B4	新鲜玄武岩	0	68.6	0	0	0	20.1	0	0	11.3	0
B5	新鲜玄武岩	1.6	75.6	0	0	0	19.0	0	0	3.8	0
AB1	蚀变玄武岩	8.7	16.6	0	0	0	2.0	4.6	0	0	68.1
AB2	蚀变玄武岩	48.4	0	0	0	0	0	0	0	0	51.6
AB3	蚀变玄武岩	71.1	1.9	0	0	0	0	0	0	0	26.2
AB4	蚀变玄武岩	31.6	13.2	0	0	0	1.5	0	0	0	53.7
AB5	蚀变玄武岩	6.9	19.1	0	0	0	3.4	1.8	0	0	67.4
AB6	蚀变玄武岩	48.2	15.4	0	0	0	1.7	1.4	0	0	31.8
AB7	蚀变玄武岩	1.7	24.9	0	0	0	2.3	4.4	0	0	65.3
SR1	蛇纹岩	0	0	0	0	61.8	11.4	0	26.8	0	0
SR2	蛇纹岩	0	0	0	0	75.6	4.1	4.9	15.4	0	0
SR3	蛇纹岩	0	0	0	0	82.4	0	0	17.6	0	0
SR4	蛇纹岩	0	0	0	0	45.9	0	0	24.8	0	29.3
D1	辉绿岩	1.5	69.1	0	0	0	2.9	12.6	3.9	0	5.8
G1	辉长岩	1.2	66.8	0	0	0	4.1	19.7	3.2	0	2.5
G2	辉长岩	0.7	64.9	0	0	0	8.1	7.6	2.7	0	2.5
S1	硫化物	0	0	39.3	60.7	0	0	0	0	0	0
S2	硫化物	0	0	1.9	18.7	0	0	0	0	0	0
S3	硫化物	0	0	5.1	94.9	0	0	0	0	0	0
S4	硫化物	1.4	0	0	85.1	0	0	0	0	0	0
S5	硫化物	0.7	0	22.5	61.8	0	0	0	0	0	0

表2 研究区岩石样品物性参数

Tab.2 Physical properties of rock samples in the study area

岩石类型	样品数量	数据统计	饱水密度/(g·cm^-3)	孔隙度/%	P波速度/ (m·s^-1)
岩石类型	样品数量	数据统计	饱水密度/(g·cm^-3)	孔隙度/%	常压	5 MPa	10 MPa	20 MPa	30 MPa
新鲜玄武岩	74	平均值	2.85	0.60	5 826	5 914	5 932	5 991	6 045
		最大值	2.93	3.69	6 552	6 589	6 626	6 651	6 762
		最小值	2.68	0	4 911	5 058	5 136	5 249	5 343
		标准差	0.05	0.87	360	329	347	337	328
蚀变玄武岩	19	平均值	2.69	1.37	4 929	5 166	5 054	5 114	5 162
		最大值	2.96	2.76	6 754	6 828	6 929	7 033	7 086
		最小值	2.51	0	3 968	4 044	4 097	4 150	4 178
		标准差	0.12	0.69	841	915	831	835	829
蛇纹岩	4	平均值	2.58	0.13	4 945	5 007	5 068	5 105	5 134
		最大值	2.63	0.30	5 289	5 324	5 383	5 431	5 467
		最小值	2.54	0	4 529	4 632	4 712	4 914	4 785
		标准差	0.04	0.14	362	337	326	326	326
辉长岩	3	平均值	2.91	0.28	5 812	5 988	5 990	6 076	6 195
		最大值	2.97	0.84	6 363	6 568	6 732	6 816	6 962
		最小值	2.81	0	5 376	5 407	5 471	5 537	5 638
		标准差	0.09	0.49	503	821	659	663	687
硫化物(块状硫化物和硫化物烟囱)	5	平均值	2.93	20.02	3 935
		最大值	3.23	28.72
		最小值	1.80	9.65
		标准差	0.56	6.57

图2 不同类型岩石的P 波速度箱线图

Fig.2 P-wave velocity box line diagrams of different rocks

图3 研究区围岩P波速度-饱水密度-孔隙度的相关性

Fig.3 Correlation of P-wave velocity, saturated density and porosity of the host rocks in the study area

图4 研究区岩石样品P波速度与饱水密度的相关性

Fig.4 Correlation between P-wave velocity and saturated density of the rock samples in the study area

图5 硫化物饱水密度与孔隙度的相关性 (部分硫化物数据来源于文献[11]。)

Fig.5 Correlation between saturated density and porosity of sulfides (Partial data are from reference[11].)

图6 部分岩石样品的TIMA矿物相图

Fig.6 TIMA phase map of the partial rock samples

图7 研究区岩石样品P波速度与围压的相关性

Fig.7 Correlation between P-wave velocity and confining pressure of rock samples in the study area

图8 研究区岩石样品P波速度变化幅值与围压的相关性

Fig.8 Correlation between P-wave velocity gradient and confining pressure of rock samples in the study area

图9 玄武岩P波速度与饱水密度的相关性 (SWIR数据为本文测试结果;U1301数据来自文献[29];504B数据来自文献[30];ODP Site 864数据来自文献[25]。)

Fig.9 Correlation between P-wave velocity and saturated density of basalts (The data of SWIR is the test result of this article; the data of U1301 are from reference [29]; the data of 504B are from reference [30]; the data of ODP Site 864 are from reference [25].)

图10 不同区域的块状硫化物饱水密度(a)和孔隙度(b)与P波速度的相关性 (SWIR研究区部分数据来自文献[11];TAG研究区数据来自文献[28];EPR和OT研究区数据来自文献[26];研究者Spagnoli的全球数据来自文献[21]。)

Fig.10 Correlation between saturated density (a) and porosity (b) with P-wave velocity of massive sulfides in different study areas (Partial data of SWIR study area are from reference [11]; the data of TAG study area are from reference [28]; the data of EPR and OT study area are from reference [26]; the global data of researcher Spagnoli are from reference [21].)

图11 蚀变玄武岩饱水密度(a)和P波速度(b)与矿物含量的相关性

Fig.11 Correlation between saturated density (a) and P-wave velocity (b) with mineral content of altered basalts

表3 方程(2)和(3)的相关系数R2以及方程(2)的回归系数a,b,c

Tab.3 The correlation coefficient R2 of equation (2) and (3) and the regression coefficient a, b, c of equation (2)

数据统计	方程(3)	方程(2)
数据统计	R²	R²	a	b	c
平均值	0.935	0.991	6 053	317	0.05
最大值	0.990	0.998	7 189	1 037	0.13
最小值	0.822	0.991	4 781	111	0.01
标准差	0.047	0.003	491	175	0.03

参考文献 40

[1]	YU J Y, TAO C H, LIAO S L, et al. Resource estimation of the sulfide-rich deposits of the Yuhuang-1 hydrothermal field on the ultraslow-spreading Southwest Indian Ridge[J]. Ore Geology Reviews, 2021, 134: 104169.
[2]	张涛, LIN Jian, 高金耀. 西南印度洋中脊热液区的岩浆活动与构造特征[J]. 中国科学:地球科学, 2013, 43(11):1834-1846.
	ZHANG T, LIN J, GAO J Y. Magmatism and tectonic processes in Area A hydrothermal vent on the Southwest Indian Ridge[J]. Science China: Earth Sciences, 2013, 43(11): 1834-1846.
[3]	WU T, TIVEY M A, TAO C H, et al. An intermittent detachment faulting system with a large sulfide deposit revealed by multi-scale magnetic surveys[J]. Nature Communications, 2021, 12(1): 5642. DOI PMID
[4]	ZHU Z, TAO C, SHEN J, et al. Self-potential tomography of a deep-sea polymetallic sulfide deposit on Southwest Indian Ridge[J]. Journal of Geophysical Research: Solid Earth, 2020, 125(11): e2020JB019738.
[5]	JIAN H C, SINGH S C, CHEN Y J, et al. Evidence of an axial magma chamber beneath the ultraslow-spreading Southwest Indian Ridge[J]. Geology, 2017, 45(2): 143-146.
[6]	王伟, 牛雄伟, 阮爱国, 等. 西南印度洋中脊49.5°E离轴地壳结构[J]. 地球物理学报, 2018, 61(11):4406-4417. DOI
	WANG W, NIU X W, RUAN A G, et al. Off-axis crustal structure at the Southwest Indian Ridge (49.5°E)[J]. Chinese Journal of Geophysics, 2018, 61(11): 4406-4417.
[7]	MURTON B J, LEHRMANN B, DUTRIEUX A M, et al. Geological fate of seafloor massivesulphides at the TAG hydrothermal field (Mid-Atlantic Ridge)[J]. Ore Geology Reviews, 2019, 107: 903-925.
[8]	DOMENICO S N. Rock lithology and porosity determination from shear and compressional wave velocity[J]. Geophysics, 1984, 49(8): 1188-1195.
[9]	WILKENS R H, FRYER G J, KARSTEN J. Evolution of porosity and seismic structure of upper oceanic crust: Impor-tance of aspect ratios[J]. Journal of Geophysical Research: Solid Earth, 1991, 96(B11): 17981-17995.
[10]	黄威, 陶春辉, 邓显明, 等. 西南印度洋脊49°39'E热液活动区IODP钻探计划的科学意义[J]. 海洋学研究, 2009, 27(2):97-103.
	HUANG W, TAO C H, DENG X M, et al. Discussion and the scientific significance of IODP drilling to study in the 49°39'E vent field in Southwest Indian Ridge[J]. Journal of Marine Sciences, 2009, 27(2): 97-103.
[11]	TAO C H, WU T, JIN X B, et al. Petrophysical charac-teristics of rocks and sulfides from the SWIR hydrothermal field[J]. Acta Oceanologica Sinica, 2013, 32(12): 118-125.
[12]	GEORGEN J E, LIN J, DICK H J B. Evidence from gravity anomalies for interactions of the Marion and Bouvet hotspots with the Southwest Indian Ridge: Effects of transform offsets[J]. Earth and Planetary Science Letters, 2001, 187(3/4): 283-300.
[13]	陶春辉, 李怀明, 金肖兵, 等. 西南印度洋脊的海底热液活动和硫化物勘探[J]. 科学通报, 2014, 59(19):1812-1822.
	TAO C H, LI H M, JIN X B, et al. Seafloor hydrothermal activity and polymetallic sulfide exploration on the southwest Indian ridge[J]. Chinese Science Bulletin, 2014, 59: 2266-2276.
[14]	BAKER E T, EDMONDS H N, MICHAEL P J, et al. Hydrothermal venting in magma deserts: The ultraslow-spreading Gakkel and Southwest Indian Ridges[J]. Geoche-mistry, Geophysics, Geosystems, 2004, 5(8): Q08002.
[15]	LI J B, JIAN H C, CHEN Y J, et al. Seismic observation of an extremely magmatic accretion at the ultraslow spreading Southwest Indian Ridge[J]. Geophysical Research Letters, 2015, 42(8): 2656-2663.
[16]	TAO C H, LIN J, GUO S Q, et al. First active hydro-thermal vents on an ultraslow-spreading center: Southwest Indian Ridge[J]. Geology, 2012, 40(1): 47-50.
[17]	CANNAT M, SAUTER D, BEZOS A, et al. Spreading rate, spreading obliquity, and melt supply at the ultraslow spreading Southwest Indian Ridge[J]. Geochemistry, Geophysics, Geosystems, 2008, 9(4): Q04002.
[18]	SAUTER D, CANNAT M, MEYZEN C, et al. Propagation of a melting anomaly along the ultraslow Southwest Indian Ridge between 46°E and 52°20'E: Interaction with the Crozethotspot?[J]. Geophysical Journal International, 2009, 179(2): 687-699.
[19]	PLANKE S, CERNEY B, BÜCKER C J, et al. Alteration effects on petrophysical properties of subaerial flood basalts: Site 990, Southeast Greenland margin[C]// Proceedings of the Ocean Drilling Program, Scientific Results, 1999, 163: 17-28.
[20]	KASSAB M A, WELLER A. Study on P-wave and S-wave velocity in dry and wet sandstones of Tushka region, Egypt[J]. Egyptian Journal of Petroleum, 2015, 24(1): 1-11.
[21]	SPAGNOLI G, WEYMER B A, JEGEN M, et al. P-wave velocity measurements for preliminary assessments of the mineralization in seafloor massive sulfide mini-cores during drilling operations[J]. Engineering Geology, 2017, 226: 316-325.
[22]	GRÖSCHEL-BECKER H M, DAVIS E E, FRANKLIN J M. Data report: Physical properties of massive sulfide from site 856, middle valley, northern Juan de Fuca ridge[C]// Proceedings of the Ocean Drilling Program, Scientific Results, 1994, 139: 721-724.
[23]	WANG S S, CHANG L, WU T, et al. Progressive dissolution of titanomagnetite in high-temperature hydrothermal vents dramatically reduces magnetization of basaltic ocean crust[J]. Geophysical Research Letters, 2020, 47(8): e87578.
[24]	刘隆, 周建平, 吴涛, 等. 大洋中脊玄武岩磁性特征[J]. 地球物理学进展, 2021, 36(5):1880-1890.
	LIU L, ZHOU J P, WU T, et al. Magnetic characteristics of basalt on mid-ocean ridge[J]. Progress in Geophysics, 2021, 36(5): 1880-1890.
[25]	JOHNSTON J E, FRYER G J, CHRISTENSEN N I. Velocity-porosity relationships of basalts from the East Pacific Rise[C]// Proceedings of the Ocean Drilling Program, Scientific results, 1995, 142: 51-59.
[26]	CARLSON R L. The effect of hydrothermal alteration on the seismic structure of the upper oceanic crust: Evidence from Holes 504B and 1256D[J]. Geochemistry, Geophysics, Geosystems, 2011, 12(9): Q09013.
[27]	CARLSON R L. The effects of alteration and porosity on seismic velocities in oceanic basalts and diabases[J]. Geochemistry, Geophysics, Geosystems, 2014, 15(12): 4589-4598.
[28]	LUDWIG R J, ITURRINO G J, RONA P A. Seismic velocity-porosity relationship of sulfide, sulfate, and basalt samples from the TAG hydrothermal mound[C]// Proceedings of the Ocean Drilling Program, Scientific Results, 1998, 158: 313-328.
[29]	TSUJI T, ITURRINO G J. Velocity-porosity relationships in oceanic basalt from eastern flank of the Juan de Fuca Ridge: The effect of crack closure on seismic velocity[J]. Exploration Geophysics, 2008, 39(1): 41-51.
[30]	CHRISTENSEN N I, WEPFER W W, BAUD R D. Seismic properties of sheeted dikes from Hole 504B, ODP Leg 111[C]// Proceedings of the Ocean Drilling Program, Scientific results, 1989, 111: 171-176.
[31]	CHEN H, TAO C, REVIL A, et al. Induced polarization and magnetic responses of serpentinized ultramafic rocks from mid-ocean ridges[J]. Journal of Geophysical Research: Solid Earth, 2021, 126(12): e2021JB022915.
[32]	CARLSON R L, JAY MILLER D. Influence of pressure and mineralogy on seismic velocities in oceanicgabbros: Implications for the composition and state of the lower oceanic crust[J]. Journal of Geophysical Research: Solid Earth, 2004, 109(B9): B09205.
[33]	CHRISTENSEN N I. Elasticity of ultrabasic rocks[J]. Journal of Geophysical Research, 1966, 71(24): 5921-5931.
[34]	SEYLER M, CANNAT M, MÉVEL C. Evidence for major-element heterogeneity in the mantle source of abyssal peridotites from the Southwest Indian Ridge (52° to 68°E)[J]. Geochemistry, Geophysics, Geosystems, 2003, 4(2):9101.
[35]	徐浩波, 管清胜, 许明珠, 等. 蛇纹岩化作用对超慢速洋中脊拆离断层发育的影响[J]. 海洋学研究, 2021, 39(3):21-30.
	XU H B, GUAN Q S, XU M Z, et al. The effect of serpentinization on detachment faults at ultra-slow spreading mid-ocean ridge[J]. Journal of Marine Sciences, 2021, 39(3): 21-30. DOI
[36]	KHAKSAR, GRIFFITHS, MCCANN. Compressional- and shear-wave velocities as a function of confining stress in dry sandstones[J]. Geophysical Prospecting, 1999, 47(4): 487-508.
[37]	EBERHART-PHILLIPS D, HAN D H, ZOBACK M D. Empirical relationships among seismic velocity, effective pressure, porosity, and clay content in sandstone[J]. Geophysics, 1989, 54(1): 82-89.
[38]	FREUND D. Ultrasonic compressional and shear velocities in dry clastic rocks as a function of porosity, clay content, and confining pressure[J]. Geophysical Journal International, 1992, 108(1): 125-135.
[39]	JONES S M. Velocities and quality factors of sedimentary rocks at low and high effective pressures[J]. Geophysical Journal International, 1995, 123(3): 774-780.
[40]	BIRCH F. The velocity of compressional waves in rocks to 10 kilobars: 1[J]. Journal of Geophysical Research, 1960, 65(4): 1083-1102.

西南印度洋中脊热液区岩石声学特性

Acoustic characteristics of rocks from the SWIR hydrothermal fields

RichHTML

PDF

可视化

摘要/Abstract

引用本文

使用本文

图/表 14

参考文献 40

相关文章 1

编辑推荐

Metrics