A reduced crustal magnetization zone near the first observed active hydrothermal vent field on the Southwest Indian Ridge

View/ Open
Date
2010-09-21Author
Zhu, Jian
Concept link
Lin, Jian
Concept link
Chen, Yongshun J.
Concept link
Tao, Chunhui
Concept link
German, Christopher R.
Concept link
Yoerger, Dana R.
Concept link
Tivey, Maurice A.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/3950As published
https://doi.org/10.1029/2010GL043542DOI
10.1029/2010GL043542Abstract
Inversion of near-bottom magnetic data reveals a well-defined low crustal magnetization zone (LMZ) near a local topographic high (37°47′S, 49°39′E) on the ultraslow-spreading Southwest Indian Ridge (SWIR). The magnetic data were collected by the autonomous underwater vehicle ABE on board R/V DaYangYiHao in February-March 2007. The first active hydrothermal vent field observed on the SWIR is located in Area A within and adjacent to the LMZ at the local topographic high, implying that this LMZ may be the result of hydrothermal alteration of magnetic minerals. The maximum reduction in crustal magnetization is 3 A/M. The spatial extent of the LMZ is estimated to be at least 6.7 × 104 m2, which is larger than that of the LMZs at the TAG vent field on the Mid-Atlantic Ridge (MAR), as well as the Relict Field, Bastille, Dante-Grotto, and New Field vent-sites on the Juan de Fuca Ridge (JdF). The calculated magnetic moment, i.e., the product of the spatial extent and amplitude of crustal magnetization reduction is at least −3 × 107 Am2 for the LMZ on the SWIR, while that for the TAG field on the MAR is −8 × 107 Am2 and that for the four individual vent fields on the JdF range from −5 × 107 to −3 × 107 Am2. Together these results indicate that crustal demagnetization is a common feature of basalt-hosted hydrothermal vent fields at mid-ocean ridges of all spreading rates. Furthermore, the crustal demagnetization of the Area A on the ultraslow-spreading SWIR is comparable in strength to that of the TAG area on the slow-spreading MAR.
Description
Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 37 (2010): L18303, doi:10.1029/2010GL043542.
Suggested Citation
Geophysical Research Letters 37 (2010): L18303Related items
Showing items related by title, author, creator and subject.
-
Mineralogical and geochemical features of sulfide chimneys from the 49°39′E hydrothermal field on the Southwest Indian Ridge and their geological inferences
Tao, Chunhui; Li, Huaiming; Huang, Wei; Han, XiQiu; Wu, GuangHai; Su, Xin; Zhou, Ning; Lin, Jian; He, YongHua; Zhou, JianPing (Springer, 2011-08-24)During January–May in 2007, the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR). This was also the first active hydrothermal ... -
Hydrothermal venting in magma deserts : the ultraslow-spreading Gakkel and Southwest Indian Ridges
Baker, Edward T.; Edmonds, Henrietta N.; Michael, Peter J.; Bach, Wolfgang; Dick, Henry J. B.; Snow, Jonathan E.; Walker, Sharon L.; Banerjee, Neil R.; Langmuir, Charles H. (American Geophysical Union, 2004-08-18)Detailed hydrothermal surveys over ridges with spreading rates of 50–150 mm/yr have found a linear relation between spreading rate and the spatial frequency of hydrothermal venting, but the validity of this relation at ... -
Magnetic mineral populations in lower oceanic crustal gabbros (Atlantis Bank, SW Indian Ridge): implications for marine magnetic anomalies
Bowles, Julie A.; Morris, Antony; Tivey, Maurice A.; Lascu, Ioan (American Geophysical Union, 2020-02-28)To learn more about magnetic properties of the lower ocean crust and its contributions to marine magnetic anomalies, gabbro samples were collected from International Ocean Discovery Program Hole U1473A at Atlantis Bank on ...