ABSTBACT: The upper 90 cm of Black Sea basin sediment with an aereal extension of 2,96X105 km2 has an U8O8 content of 6.7X106 tonnes, Plankton is the prime agent for uranium to accumulate over the past 5,000 yr. Energetically self-sufficient burning of the top 1-m strata will lead to U8O8 concentrations in the order öf 100 g per tonne ash.
ABSTRACT: Many of the Turkish kaolin deposits are hydrothermal type although some of the country`s major deposits are believed to have originated from weathering. Intensive silicification and limonitization and the associated hydrothermal ores such as mercury, antimony, fluorite and sulfur minerals are taken as indication to hydrothermal origin. The thickness of the hydrothermal kaolin deposits controlled by volcanic phenomena is, generally speaking, comparatively less, where as their lateral persistances often considerable* Those oecuring within the fault zones, however, attain considerable thickness locally as much as 100 meters. Bulk of the Turkish kaolin deposits formed by hydrothermal actions are presently considered uneconomic due to extensive alunitization, and the associated pyrite, and sulfur formations and 3b, Hg, Pb, Zn, Cu, Ni, and Co - sulfide minerals. Chemical processes associated with kaolinization are believed to have led to the high concentrations of metallic ores, which in turn caused considerable changes in the pH - conditions of the deposit, thus resulting in marked increases in the illite and montmorülonite content of these deposits*