Electrical Structure of Sea-Floor Hydrothermal Sulfide Deposits
-
摘要: 深海热液金属硫化物矿位于水深数千米的大洋洋底，其形态、规模及电性参数难为人知，迄今尚未有由实测数据推导其电性结构的研究.依托于“大洋一号”，在大西洋洋中脊、西南印度洋洋中脊实施了多次深海热液金属硫化物矿探测试验，实地采集热液金属硫化物矿瞬变电磁响应数据，并对试验数据进行反演分析.分析表明：大西洋TAG(trans-Atlantic geotraverse)热液区及西南印度洋49°4′E，37°5′S热液区内，深海热液金属硫化物矿形似生长于洋壳内的“蘑菇”，矿体呈透镜状或似层状结构，分布于热液喷口的卤水池内，电阻率约为0.1 Ω·m，规模为50~250 m，厚度范围为20~50 m；热液烟囱直径为10~50 m，周围岩石发生热液蚀变，蚀变岩石电阻率在0.2~0.5 Ω·m，以热液通道为中心呈圈层状变化.依据深海热液金属硫化物矿的形态特征及电性参数，矿体的电性结构模型可简化为T型异常体.
-
关键词:
- 深海热液金属硫化物矿 /
- TAG热液区 /
- 西南印度洋热液区 /
- 电性结构 /
- 海底地球物理
Abstract: The deep-sea hydrothermal metallic deposits are located on seafloor at depth about several kilometers, and it is difficult to determine their shape, scale and electrical parameters, and the electrical structure based on field data remains unknown. Using research vessel "DaYang-Ⅰ", several detection tests were implemented at Atlantic ridge and Southwest Indian ridge, and the electromagnetic response data of deep-sea hydrothermal metallic sulfide deposits have been observed and analyzed. The analysis show that in the Atlantic TAG (trans-Atlantic geotraverse) hydrothermal area and Southwest Indian Ocean 49°4′E, 37°5′S hydrothermal area, deep-sea hydrothermal metallic sulfide deposits are like'mushroom' in the oceanic crust, located in the brine pool around the hydrothermal vents with lenticular structure or stratoid structure, the resistivity is about 0.1 Ω·m, the scale changes from 50 to 250 m, and the thickness is from 20 to 50 m. The diameter of hydrothermal channel ranges from 10 to 50 m, and hydrothermal alternation took place within and outside the hydrothermal channel. The resistivity of the alternation rocks is in the range of 0.2 to 0.5 Ω·m, and concentrically changes around the hydrothermal channel. Based on the shape and electrical parameters of hydrothermal metallic sulfide deposits, the ore body can be simplified as a T-shaped target for electrical structure model. -
图 2 TEM06测线AB段的数据处理
a.瞬变电磁响应多测道剖面；b.视电阻率剖面
Fig. 2. Data process of section AB of line TEM06
图 4 TEM01测线CD段的数据处理
a.瞬变电磁响应多测道剖面；b.视电阻率剖面
Fig. 4. Data process of section CD of line TEM01
图 5 深海热液金属硫化物矿电性结构模型
Fig. 5. Electrical structure model of deep-sea hydrothermal metallic sulfide deposits
-
Cheesman, S.J., Edwards, R.N., Chave, A.D., 1987.On the Theory of Sea-Floor Conductivity Mapping Using Transient Electromagnetic Systems.Geophysics, 52(2):204-217.doi: 10.1190/1.1442296 Cheesman, S.J., Edwards, R.N., Law, L.K., 1990.A Test of a Short-Baseline Sea-Floor Transient Electromagnetic System.Geophysical Journal International, 103(2):431-437.doi: 10.1111/j.1365-246X.1990.tb01782.x Constable, S., Srnka, L.J., 2007.An Introduction to Marine Controlled-Source Electromagnetic Methods for Hydrocarbon Exploration.Geophysics, 72(2):WA3-WA12.doi: 10.1190/1.2432483 Cox, C.S., 1981.On the Electrical Conductivity of the Oceanic Lithosphere.Physics of the Earth and Planetary Interiors, 25(3):196-201.doi: 10.1016/0031-9201(81)90061-3 Deng, X.G., 2007.The Deposits and Mineral Compositions of Hydrothermal Sulphides in Mid-Ocean Ridge.Geological Research of South China Sea, 54-64 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-NHDZ200700009.htm Edwards, R.N., Law, L.K., DeLaurier, J.M., 1981.On Measuring the Electrical Conductivity of the Oceanic Crust by a Modified Magnetometric Resistivity Method.Journal of Geophysical Research, 86(B12):11609.doi: 10.1029/JB086iB12p11609 Eidesmo, T., Ellingsrud, S., Macgregor, L.M., et al., 2002.Sea Bed Logging (SBL), a New Method for Remote and Direct Identification of Hydrocarbon Filled Layers in Deepwater Areas.First Break, 20(20):144-152. https://www.mendeley.com/research-papers/sea-bed-logging-sbl-new-method-remote-direct-identification-hydrocarbon-filled-layers-deepwater-area/ Ellingsrud, S., Eidesmo, T., Johansen, S., et al., 2002.Remote Sensing of Hydrocarbon Layers by Seabed Logging (SBL):Results from a Cruise Offshore Angola.The Leading Edge, 21(10):972-982.doi: 10.1190/1.1518433 Evans, R.L., Everett, M.E., 1994.Discrimination of Hydrothermal Mound Structures Using Transient Electromagnetic Methods.Geophysical Research Letters, 21(6):501-504.doi: 10.1029/94GL00418 Key, K., Constable, S., 2002.Broadband Marine MT Exploration of the East Pacific Rise at 9°50′N.Geophysical Research Letters, 29(22):11-1-11-4.doi: 10.1029/2002GL016035 Liu, C.S., Lin, J., 2006.Transient Electromagnetic Response Modeling of Magnetic Source on Seafloor and the Analysis of Seawater Effect.Chinese Journal of Geophysics, 49(6):1891-1898 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQWX200606038.htm Myer, D.G., Constable, S., Key, K., 2006.Electromagnetic Exploration of the Loihi Seamount.American Geophysical Union, San Francisco. Swidinsky, A., Hölz, S., Jegen, M., 2012.On Mapping Sea Floor Mineral Deposits with Central Loop Transient Electromagnetics.Geophysics, 77(3):171-184.doi: 10.1190/geo2011-0242.1 Tada, N., Seama, N., Goto, T.N., et al., 2005.1-D Resistivity Structures of the Oceanic Crust around the Hydrothermal Circulation System in the Central Mariana Through Using Magnetometric Resistivity Method.Earth, Planets and Space, 57(7):673-677.doi: 10.1186/BF03351846 Wetheim, G.K., 1954.Studies of the Electric Potential between Key West, Florida, and Havana, Cuba.Earth and Space Science News, 35(6):872-882.doi: 10.1029/TR035i006p00872 Ye, J., 2010.Mineralization of Polymetallic Sulfides on Ultra-Slow Spreading Southwest Indian Ridge at 49.6°E (Dissertation).The Institute of Oceanology, Chinese Academy of Science, Qingdao (in Chinese with English abstract). Zhang, F.Y., Zhang, W.Y., Zhu, K.C., et al., 2011.Resource Estimation of Co-Rich Crusts of Seamounts in Pacific.Earth Science, 36(1):1-11 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX201101002.htm Zhou, S., Xi, Z.Z., Song, G., et al., 2012.Response of the Towed Transient Electromagnetic Sounding on Deep Seafloor.Journal of Central South University (Sicence and Technology), 43(2):605-610 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZNGD201202034.htm Zhu, K.C., Ren, J.B., Wang, H.F., et al., 2015.Enrichment Mechanism of REY and Geochemical Characteristics of REY-Rich Clay from the Central Pacific.Earth Science, 40(6):1052-1060 (in Chinese with English abstract). Богданов, Ю.A., 2007.Modern Ocean Sulphide Deposits Category.Translated by Chen B.Y., Marine Geology, (4):18-30 (in Chinese). 邓希光, 2007.大洋中脊热液硫化物矿床分布及矿物组成.南海地质研究, 54-64. http://www.cnki.com.cn/Article/CJFDTOTAL-NHDZ200700009.htm 刘长胜, 林君, 2006.海底表面磁源瞬变响应建模及海水影响分析.地球物理学报, 49(6): 1891-1898. http://www.cnki.com.cn/Article/CJFDTOTAL-DQWX200606038.htm 叶俊, 2010. 西南印度洋超慢速扩张脊49. 6°E热液区多金属硫化物成矿作用研究(博士学位论文). 青岛: 中国科学院海洋研究所. http://cdmd.cnki.com.cn/Article/CDMD-80068-1012411037.htm 张富元, 章伟艳, 朱克超, 等, 2011.太平洋海山钴结壳资源量估算.地球科学, 36(1): 1-11. http://earth-science.net/WebPage/Article.aspx?id=2059 周胜, 席振铢, 宋刚, 等, 2012.深海拖曳式瞬变电磁的响应规律.中南大学学报(自然科学版), 43(2): 605-610. http://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD201202034.htm 朱克超, 任江波, 王海峰, 等, 2015.太平洋中部富REY深海粘土的地球化学特征及REY富集机制.地球科学, 40(6): 1052-1060. http://earth-science.net/WebPage/Article.aspx?id=3106 尤·阿·博格达诺夫, 2007. 大洋现代硫化物矿藏分类. 陈邦彦, 译. 海洋地质, (4): 18-30. http://www.cqvip.com/Main/Detail.aspx?id=26267471 -
下载:
点击查看大图
图(6)
计量
- 文章访问数: 5531
- HTML全文浏览量: 2289
- PDF下载量: 24
- 被引次数: 0
