The Characteristics of Granite Associated with Tin and Mineralization in Northwest China
Northwest China is one of superior conditions area for tin ore formation and rich mineral resources in China,but tin ore output is less than 2%,and scattered distribution and small scale in the area.Because tin is not a dominant mineral,it has not received much attention.Previous research mainly focused on the geochemi-cal and genesis of typical deposits,lacking a summary and understanding of regional mineralization characteris-tics and patterns.This paper selects the granite related to tin ore as the research object.The authors put forward some new comprehension of tin prospecting by analyzing the characteristics of the granite.The paper shows that tin is not only enriched in late melt but also from mantle to crust.The more crustal material in granulite base-ment,it is the more favorable for tin mineralization.A-type granite has a more obvious specificity to tin mineral-ization.It found that granites related to tin mineralization generally have higher Sn abundance,especially the peraluminous and calc-alkaline granites formed in the environment of continental collision,oceanic or crust sub-duction and ocean-continent transition are more conducive to tin enrichment.The high Sn abundance is also an essential factor for tin mineralization.For example,in the East Junggar and Tianshan regions,the tin abundance is reached 7×10-6,higher than the crustal tin abundance value of(1.7×10-6).Tin ore is finally formed at a certain temperature,continuous mobilized,migrated,enriched,and magmatic crystallization differentiation.Based on the above views,the paper describes the characteristics of the 6 tin metallogenic belts in Northwest China,which are considered to be tin prospecting potential area.
tin oregranite related to tinmetallogenic conditionsmetallogenic environmentNW China