GEOCHEMICAL BEHAVIOR OF GOLD IN COASTAL MARINE-SEDIMENTS FROM THE SOUTHEASTERN MARGIN OF JAPAN SEA

Two hundred thirty-one coastal argillaceous marine sediments collected from the southeastern margin of the Japan Sea were analyzed for gold by atomic absorption spectrometry using a graphite furnace atomizer after solvent extraction separation. Gold content varies greatly, from 0. 3 to 35 ppb with an average of 3.8 +/- 5.1 ppb. Anomalously high gold content of more than 10 ppb was found in the sediments around Sado Island. This anomalous gold is likely to have originated from the auriferous mineralization in the island together with anthropogenic mining activities. In the sediments from nonmineralization areas, gold is generally enriched in the fine fraction, and correlates positively with copper, lead, nickel, chromium, and water depth. Diagenetic or biogenetic concentration of gold to the sediments can be evaluated to be negligible. It is concluded that gold distribution in the coastal marine sediments has been controlled by the geologic characteristics of the catchment area of rivers, grain size of sediments, redox potential, and other geochemical and geographic marine environments.