爆裂法作为快速测定流体包裹体中二氧化碳(和其它气体)含量的手段及其在勘探中的使用:以中国山东和河北省金矿为例
Acoustic decrepitation as a means of rapidly determining CO_2(and other gas)contents in fluid inclusions and its use in exploration,with examples from gold mines in the Shandong and Hebei provinces,China作者机构:Burlinson Geochemical ServicesDarwin NT.Australia
出 版 物:《岩石学报》 (Acta Petrologica Sinica)
年 卷 期:2007年第23卷第1期
页 面:65-71页
核心收录:
学科分类:081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程]
主 题:爆裂法 含量快速测定 流体包裹体 二氧化碳 其它气体 勘探 使用 金矿
摘 要:The acoustic decrepitation method heats a small monomineralic sample and counts pressure impulses as the inclusions burst when they develop high internal *** aqueous fluids,the decrepitation temperature is correlated with the homogenisation temperature,but gas rich fluids give a distinct and characteristic low temperature decrepitation peak which can be used to recognize gas rich fluid *** information is useful in exploration for Au deposits,which are frequently associated with CO_2 rich and sometimes CH_4 rich fluids. This distinctive decrepitation occurs because the CO_2 rich inclusion fluids expand according to the gas law and develop internal pressures high enough to burst the host mineral grain at temperatures well below their homogenisation *** contrast,aqueous fluids condense to a liquid and vapour phase during post-entrapment *** subsequent heating their internal pressures do not increase significantly until after homogenisation to a single phase occurs and hence they do not decrepitate prematurely as gas rich inclusions do. This behaviour is usually regarded as an annoyance in conventional microthermometric homogenisation studies,but can readily be used as an exploration aid to find mineralisation deposited from such gas rich *** results on samples from Cowra Ck, NSW,Australia,which have also been microthermometrically measured for CO_2 content,show that amounts of less than 5 mole % CO_2 are easily distinguished by decrepitation and amounts as low as 1 mole % CO_2 may be determinable. Examples of the use of acoustic decrepitation in the study of 6 gold mines in the Shandong and Hebei provinces of China are discussed.