Characteristics And Causes Of Mineralization And Alteration In Lao Qiaoling Gold Deposit

Pha Beng gold mine located in Luang Prabang Province Bau County Pha Beng Village area. Mining geographical coordinates:E102°23’31" -E102°24’48", N20° 08’50"-N20°10’24", an area of 232km2. The mountain range towards in the southwest to the northeast for the main. Cutting the terrain is relatively large. The mountain is steep. There are many caves. Mine geological structure is complex. Tectonic movement has been developed from the late Paleozoic to Cenozoic. Various geological age structure superimposed intertwined. The main gold-bearing carbonate vein gold deposits type prominent features. There is no direct reference to compare gold type.This paper analyzes and summarizes the results of previous studies at first. Combined with the actual situation in the area, take the mineralization and alteration features as a starting point. Focusing on Pha Beng gold mine stratigraphy, alteration features, physical and metallogenicing chemical conditions, forming fluids were analyzed. Checked out the mining complicated stratigraphic. Solved the Permian limestone "float" above the Triassic sandstone mystery before. Identified the main mineralization and alteration minerals are carbonate minerals, and a small amount of natural gold metal sulfide, silicate minerals. The main types of mineralization mining include:silicification, carbonatization, limonite and so on. By the hang alteration catalog, it is clear to the alteration zonation patterns.The results of the mineral inclusions test revealed the deposit fluid salinity is not high. Ore-forming fluids is significantly lower than the basin salinity hot brine in the salinity (>20%). The Mineralization fluid’s temperature is between 140-295℃. The ore formating depth is less than 1 kilometer (0.48～0.960km). So Pha bong Gold should fall into the shallow epithermal deposits.Calcite inclusions water hydrogen isotope test results reveal the ore-forming fluids is not just a simple magmatic water. It is mainly a mixture of water and formation of magmatic fluid sequestration ancient meteoric.Finally Pha bong Gold mineralization pattern was established. Determine the type of sandstone and carbonate ore for the same type of ore mineralization process, different manifestations of the same mineralization in different surrounding rock.