Metallogenesis and ore control in the Steynsdorp goldfield, Barberton mountain land, South Africa

Metallogeny of precious and base metal mineralization in the Murchison Greenstone Belt, South Africa: indications from U–Pb and Pb–Pb geochronology

“…(2) disseminated sulfide ores in veinlets of Na-rich porphyry; they could either be secretions from the country rock at the time of granite emplacement (Viljoen et al 1969(Viljoen et al 1970 or subvolcanic equivalents of the 5 VMS with gold being concentrated during differentiation (Saager 1973(Saager , 1974; and (3) gold-rich quartz veins, such as the Old Star mine, that would have formed from late volatile emanations of granites or metamorphic mobilization from the country rocks (Saager 1973(Saager 1974Viljoen et al 1969;1970). Saager and Köppel (1976) suggested that granites played an important role in the mineralization in the BGB, but that they could not be considered as the ultimate source of the gold.…”

Distribution of gold in igneous rocks

“…Unfortunately, only extremely limited quantitative abundance data on gold in rocks from such greenstone-granite associations are available to test these conflicting hypotheses. Viljoen, Saager, and Viljoen (1969) reported average values of gold for samples of the country rock of the Steynsdorp Goldfield, South Africa (metabasalt and ultramafic rocks, 5-20 ppb; tuffaceous shale, 75 ppb), higher than the average value for the Steynsdorp granite ( < 5 ppb) · which intrudes them. However, it should be noted that Viljoen, Saager, and Viljoen claimed only a sensitivity of 5 ppb fo:r their gold determinations.…”

Stress analysis, post-orogenic extension and 3.01Ga gold mineralisation in the Barberton Greenstone Belt, South Africa

“…Anhaeusser, 1984Anhaeusser, , 1986, and that similar stratiform gold enrichment may have occurred along other breaks or unconformities in the greenstone stratigraphy (e.g. Anhaeusser, 1986;Viljoen et al, 1969). It is certainly possible, even likely, that some stratigraphic horizons or portions of the greenstone belt were relatively enriched in gold soon after deposition e.g.…”