Marine mineral exploration with controlled‐source electromagnetics at the TAG hydrothermal field, 26°N Mid‐Atlantic Ridge.

Gehrmann, R. A. S. , North, L. A., Graber, Sebastian, Szitkar, Florent, Petersen, Sven , Minshull, T. A. and Murton, B. J. (2019) Marine mineral exploration with controlled‐source electromagnetics at the TAG hydrothermal field, 26°N Mid‐Atlantic Ridge. Open Access Geophysical Research Letters, 46 (11). pp. 5808-5816. DOI 10.1029/2019GL082928.

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Abstract

Seafloor massive sulphide (SMS) deposits are of increasing economic interest in order to satisfy the relentless growth in worldwide metal demand. The Trans‐Atlantic Geotraverse (TAG) hydrothermal field at 26°N on the Mid‐Atlantic Ridge hosts several such deposits. This study presents new controlled source electromagnetic (CSEM), bathymetric and magnetic results from the TAG field. Potential SMS targets were selected based on their surface expressions in high‐resolution bathymetric data. High‐resolution reduced‐to‐the‐pole magnetic data show negative anomalies beneath and surrounding the SMS deposits, revealing large areas of hydrothermal alteration. CSEM data, sensitive to the electrical conductivity of SMS mineralization, further reveal a maximum thickness of up to 80 m and conductivities of up to 5 S/m. SMS samples have conductivities of up to a few thousand S/m, suggesting that remotely inferred conductivities represent an average of metal sulphide ores combined with silicified and altered host basalt that likely dominates at greater depths.

Document Type: Article
Funder compliance: info:eu-repo/grantAgreement/EC/FP7/604500
Keywords: marine electromagnetics, electrical conductivity, seafloor massive sulphides, TAG, rock physics, magnetics
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems > FB4-MUHS Marine Mineralische Rohstoffe
JAMSTEC
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS Magmatic and Hydrothermal Systems
NOC
Refereed: Yes
Open Access Journal?: No
Publisher: AGU (American Geophysical Union), Wiley
Projects: Blue Mining
Expeditions/Models/Experiments:
Date Deposited: 07 May 2019 07:01
Last Modified: 31 Jan 2022 09:21
URI: https://oceanrep.geomar.de/id/eprint/46610

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