Exploratory Studies on Deep Earth Sources of Methane: Hg as a Diagnostic and Prospecting Tool. Final Report April 1985-August 1988

摘要

Inorganic geochemistry was used to address the problem of abiotic hydrocarbons. (1) Using the depth-concentration profile of highly volatile Hg a 'production' zone permeated by fluids enriched in Hg between 4200 m and 4800 m is identified in the Gravberg 1, Siljan drillhole. (2) Weathered, i.e., fluid permeated, zones are identified using trends and Hg data. (3) Temperatures (approx. 800--950 C) related to the emplacement of granite and diabase at Siljan are determined. (4) The thermal release patterns of Hg for samples from shallow depths appears to monitor the impact generated thermal pulse. (5) Basic to the abiogenic gas theory is the presence of juvenile volatiles in the earth. To supplement (3)He and hydrocarbon inclusion observations, trace element correlations have been found in ocean ridge and ocean island tholeiitic glasses (Hg-5b, Cu-Zn) and South Greenland Garder formation rocks (Sb-Se), respectively.