Vicinity Of Mineralization Research Articles

Paleozoic Amphibolites, Kreuzeck Mountains, Austria: Geochemical variations in the vicinity of mineralization

Strata-bound antimony, mercury, tungsten and massive sulfide mineralization occurs within a metamorphosed Paleozoic volcanosedimentary sequence in the Kreuzeck Mountains, Austria. Amphibolites are a significant constituent of that sequence; on the basis of stable trace element data, they can be classified as metamorphic equivalents of recent olivine tholeiites. In the ore environment of strata-bound mineralization, intensive alteration associated with submarine hydrothermal activity has affected the wall rocks. This includes depletion in SiO2, a change in the oxidation stage of iron and pronounced enrichment in Na, Sr, Ba and CO2. Microprobe analyses reveal lower MgO content in chlorites and higher Na2O content in feldspars in rocks from the ore environment. Hydrothermal halos are thus documented by changes in mineral and whole-rock compositions and represent guides to exploration.

Readily extractable copper in eruptive rocks as a guide for prospecting

This investigation explores the possibility of ascertaining the mineral potentialities of an area around an outcrop of limited size using rock analyses involving a chemical attack of moderate intensity. By using hot aqua regia, which does not substantially attack silicates, wide variations in the Cu content of plutonic rocks have been noted. In general, our preliminary results suggest that, in the vicinity of mineralization, the readily extractable Cu of plutonic rocks is from 5 to 10 times greater than that from rocks unrelated to mineralization. This technique may prove useful in exploration and prospecting.