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Abstract

Summary

A new deep-sea frequency domain electromagnetic (FDEM) sounding system named GOLDEN EYE has been developed and applied to map active and relict hydrothermal vent fields in the German license areas at the Central and Southeastern Indian Ridges. The spectral electromagnetic data reveal electric conductivity distributions in the shallow subsurface (approx. 0–20 m below seafloor) and allow estimation of induced polarization and magnetic susceptibility of outcropping and buried seafloor massive sulfide (SMS) structures. In-situ mapping results are cross-analyzed with petrophysical data measured on rock samples using electrical impedance spectroscopy and rock magnetics. We will discuss persistent questions like: How electromagnetic methods serve to estimate the resource potential of SMS deposits? Which petrophysical properties are most meaningful and do they work as proxies for rock mineralogy? What are the uncertainties and how to unravel conductivity-depth-distribution, induced polarization and magnetic susceptibility in such geological and morphological complex deep-sea, mid-ocean ridge environments?

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/content/papers/10.3997/2214-4609.201802738
2018-09-09
2024-06-15
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