Distribution of rhenium in molybdenites from Japan

Abstract

The rhenium contents of about 200 molybdenites have been determined by the neutron-activation or the catalytic spectrophotometric analyses. The present authors developed these methodes for the determination of the rhenium content of a very wide range, taking only a small amount of each sample.The data obtained show that 1) the rhenium content of molybdenite covers the range from 10-8 to 7 X 10-3 in atomic ratio of Re/Mo, 2) the rhenium contents generally decrease with the following order of occurrence of the molybdenites: volcanic sublimate, porphyry copper deposits, contact-metasomatic deposits, disseminated deposits and quartz veins, 3) as far as plutonic type of molybdenites are concerned, rhenium increases generally with decrease in estimated temperature of molybdenite deposition, 4) the rhenium contents of the molybdenites from Daito area, Shimane Prefecture.as a whole are contrary to the above rule and are higher than those from similar deposits in other areas, 5) low rhenium contents are found in cavity molybdenites, 6) rhenium in an euhedral crystal of molybdenite shows a regular distribution which obeys the Doerner Hoskins' law, indicating that rhenium forms a solid solution with molybdenum.

RHENIUM-RICH MOLYBDENITE AND RHENIITE IN THE PAGONI RACHI Mo-Cu-Te-Ag-Au PROSPECT, NORTHERN GREECE: IMPLICATIONS FOR THE Re GEOCHEMISTRY OF PORPHYRY-STYLE Cu-Mo AND Mo MINERALIZATION

“…Electron-microprobe data (Table 1) show that molybdenite in quartzmolybdenite veinlets contain up to 4.7 wt% Re, which is consistent with the analyses of Arikas (1979) and Melfos et al (2001). There is an almost perfect linear correlation between the Mo and Re content of molybdenite, supporting the concept previously proposed (e.g., Fleischer 1959, Terada et al 1971, Stein et al 2001 that Re substitutes for Mo in the structure of molybdenite (Fig. 4).…”

“…The mechanism for the deposition of rhenium and the physicochemical conditions of sulfide deposition are considered in the context of fluid-inclusion data. Geological and geochemical comparisons will be made with the rheniite-and rhenian-molybdenite-bearing sublimates of active intRoDUCtion Molybdenite is the major repository of Re in the Earth's crust, where it occurs in a solid solution toward the end member ReS 2 (e.g., Terada et al 1971, McCandless et al 1993. In general, the Re content of molybdenite is of the order of ppb to a few thousand ppm.…”

Extremely Re-Rich Molybdenite from Porphyry Cu-Mo-Au Prospects in Northeastern Greece: Mode of Occurrence, Causes of Enrichment, and Implications for Gold Exploration

“…Table 1 also includes data from other Greek porphyry systems (e.g., Skouries, Fakos, Sardes, Stypsi) and from molybdenite in porphyry Cu, Cu-Au, Cu-Mo and Mo deposits elsewhere. The almost perfect linear correlation between the Mo and Re content of molybdenite (Figure 6b) indicates that Re substitutes for Mo in the structure of molybdenite as previously suggested [13,[21][22][23]. This is also evident from the homogeneous Re distribution in molybdenite (Figure 7a-c).…”

Re-Os geochronology of porphyry molybdenum deposit in south segment of Da Hinggan Mountains, Northeast China

“…Rhenium contents in molybdenites vary greatly (Terada et al, 1971;Fleischer, 1960). Mao et al (1999) suggested that the Re contents of molybdenite could reflect the source of the deposits with Re content decreasing from mantle to I type and to S type granite-related deposits.…”