THE ROLE OF HIGH ORE BEARING SOLUTIONS IN THE FORMATION OF THE VERKHNEYE TIN ORE DEPOSIT (KARADOUBSKOYE ORE REGION)

The regularities of temperature, salinity and metal content of the ore forming solutions, the latter being isolated in fluid inclusions relat ed to rhree successive mineral assemblages of the Verkhneye tin ore de posit were studied. Thermometric, cryometric and laser spectral method s were applied. It was found that the studied mineral assemblages were formed by a number of impulses of fluids interrupted by periods of th e cooling of hot rock affected by the supply of low mineralised meteor ic(?) waters. The solutions of separate impulses are differing in the concentrations of some ore elements at the background of the bulk comp osition proximity. The economic ore mineralisation is corresponding to 8-13 g/kg tin content in the solution whereas the former of pre-ore a nd post-ore stages is estimated as 1-4 and less-than-or-equal-to 0,5 g /kg correspondingly. The deposition of the main mass of cassiterite is suggested to the decrease of SnO2 solubility as a result of meteoric water infiltration affected by the decompression of endogeneous fluid flux.