In the west of the orogen, the Rogaland–Vest Agder sector is interpreted as a large shallow gneiss dome, formed slowly in two stages in a warm and structurally weak crust.
The first stage at 0.96–0.93 Ga was associated with intrusion of the post-collisional hornblende–biotite granite suite.
This tearing of the subduction slab caused the upwelling of asthenosphere and the resulting mantle–crust interaction.
The granitoid-related W ore systems in JNB resulted from the remelting of the Proterozoic crust.
The technique described in this paper represents the modification and combination of two previously existing methods, alkaline fusion and negative thermal ion mass spectrometry (NTIMS).
We have used this technique to analyze repeatedly a homogeneous molybdenite powder used as a reference standard in our laboratory.
The results show that the Re-Os isochron age is 229±38 Ma (MSWD=2.0, confidence level is 95%), with an initial Os value of 0.68±0.24 and a corresponding γOs value of 442±91.
This new level of resolution has allowed us to recognize real differences in ages for two grain-size populations of molybdenite from some Archean samples.
After strong differentiation it formed tungsten-bearing granitoids characterized by enrichment of high alkali, silicon and volatile components.
In the Yangchuling mine area the small monzogranitic porphyry stock has stronger fractionation, volatile content and ore-forming components than the older granodiorite, resulting in the development of the porphyry W–Mo ore system.
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Zhenyuan gold deposit is the largest super large gold deposit in the Ailaoshan gold belt, but its precise mineralization age is still lack.
Stockworks and disseminated W–Mo mineralization occur in the roof pendant of a 0.3 km monzogranitic porphyry stock that intruded into a granodiorite stock, hosted by Neoproterozoic phyllite and slate.