Microfossils and chemical elements in bottom sediments of the Ashadze-1 Hydrothermal Field (tropical Mid-Atlantic Ridge)

The first thorough analysis of microfossils from ore-bearing sediments of the Ashadze-1 Hydrothermal Field in the Mid-Atlantic Ridge sampled during Cruise 26 of R/V Professor Logachev in 2005 revealed substantial influence of hydrothermal processes on preservation of planktonic calcareous organisms as well as on preservation and composition of benthic foraminifera. From lateral and vertical distribution patterns and secondary alterations of microfossils it is inferred that the main phase of hydrothermal mineralization occurred in Holocene. Heavy metals (Cu, Co, Cr, and Ag) were accumulated by foraminiferal tests and in their enveloping Fe-Mn crusts. Distribution of authigenic minerals replacing foraminiferal tests demonstrates local zoning related to hydrothermal activity. There are three mineral-geochemical zones defined: sulfide zone, zone with elevated Mg content, and zone of Fe-Mn crusts.

31 ground-penetrating radar lines of Area 3 - Beach ridge plain (high wave energy) from Maxwell Bay, King George Island, Antarctic Peninsula

During a field campaign in the Austral spring 2012 the sedimentary architecture of a polar gravel-beach system at the southern coast of Potter Peninsula (Area 3) was revealed using ground-penetrating radar (GPR, Geophysical Survey Systems, Inc. SIR-3000). 31 profiles were collected using a mono-static 200 MHz antenna operated in common offset mode. Trace increment was set to 0.05 m. A differential global-positioning system (dGPS, Leica GS09) was used to obtain topographical information along the GPR lines. GPR data are provided in RADAN-Format, dGPS coordinates are provided in ascii format; projection is UTM (WGS 84, zone 21S).

Mineral and chemical compositions of carbonates from the Lost Village hydrothermal field, Mid-Atlantic Ridge

During Cruise 50 of R/V Akademik Mstislav Keldysh on the south slope of the Atlantis massif (30°07'N, Middle Atlantic Ridge) an inactive hydrothermal field named Lost Village was discovered. This new field was composed of light carbonate rock and was located near the active Lost City hydrothermal field. Mineral associations of these fields were studied. A conclusion about participation of ocean water in changing of carbonate composition of the inactive hydrothermal field was made.