ABSTRACT:

In 2004, a vertical electrical probing in VEP modification, using a towed submergible "Rift-3", was performed on the MAR at 0°- 40°N. Along four profiles geo-electric sections were made and charts of distribution of ρk in seven horizontal planes down to the depth of 25 m were drawn. It was found out that deep-sea sulfide crusts are forming vertical columnar bodies with the dimensions 40x50 m. A spatial distribution of ore formations is controlled by two fault systems - of the NW (290°) and NNW (345–350°) geological strikes. The maximum concentration of the ore bodies is bound to their junction point. Basing on the transversal structure of the ore bodies and the depths of occurrence, the ore mass volume and predicted resources of contained metals have been calculated.

INTRODUCTION

The work describes the method of studies of deep-sea oceanic sulfides, including an installation for vertical dipole probing, towed along the sea bottom. The region of the survey is 14º45' N - 45º00'W. The North-Atlantic Ridge (NAR) in the range 0°- 40°N, regarding the abundance of sulfide ores, is one of the most promising links of the MAR. By today over 20 hydrothermal centers have been discovered here, 13 of these containing DSPS - deep-sea polymetallic sulfides (Fig.1). Five centers, including the ore show 24°-30° N., «Logatchev- 1» and « Logatchev-2», 12°-58°N and an ore show 16°-38°N [1], have been discovered by Russian geologists. Accumulations of sulfides include compact and ingrained sulfide ores containing pyrite, chalcopyrite, black jack, covellite, bornite and chalcosine. These minerals are known to have both electronic and ionic conductivity. On the seabed, around ore shows, one may find hydrothermal ferromanganese crusts and aureoles of detrital ore minerals - products of destruction of a chimney complex, - and aureoles of proximal metalliferous sediments.

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