Some geochemical indicators for discrimination between diagenetic and hydrothermal metalliferous sediments

Two types of metalliferous sediments are known: hydrothermal (associated with tectonic faults) and diagenetic (enriched in precipitates from seawater). They are similar in their appearance and chemical composition. Only the first type is an indicator for hydrothermal discharge. Therefore, in exploration criteria for differentiating between the two are needed. Four possible indicators have been investigated and are discussed: (a) differences in P/Y correlation; (b) differences in Cr/Zr correlation; (c) different distribution patterns of REE; and (d) different As contents. The As content is easy to determine and seems to be (at the present time) the most suitable criterion for determining the genesis of the metalliferous sediments.