Study of Bitumen in the Huayuan Lead -Zinc Deposit—Organic geochemistry study of MVT Lead -Zinc deposit

Key words: 
• MVT lead -Zinc /
• deposit /
• bitumen

Abstract: The Huayuan Pb -Zn deposi t is one of the large MVT Pb -Zn deposits in western Hunan.w hich is controlled by the carbonate rock in the Upper part of the Qingx udong Format ion of the Low er Cambrain.Thehost rock is algal limestone 、oolite limestone wi th dark zebra argillaceous limestone of continental margin facies.The bitumen is of frequent occurrence in ores and peripheral Cambrain of mining area.The bitumen fill the interg ranular po res or cracks in f ine grain or acaly forms and associated with sphalerite o r galena in ores.The peripheral bitumen is f illing in fault s or crystal interatic of quxrz-barite vein.On the basis of analysis and measure :R_omax 、H/C(Atomic ratio), T_max ℃, Py -Gc, δ¹²C 、REE and t race elements.The heat-evolutionay grade of bitumen is higher in mining area which is corresponding with g rahamite -Ⅱ stage and also consistent with mineralization-temperature(rang :80 -200 ℃, mean :135 -151 ℃).The type of bitumen is syngenetic-identical strata ty pe and the organic mat ter is possible to come f rom host rock and participated the mineralization of this deposit.