HOW IS GOLD TRANSPORTED AND DEPOSITED DURING THE GEOLOGIC PROCESS?

Transportation and participation of gold during various geological processes has been a controversial subject for several decades, and has attracted attention of numerous economic geologists and geochemists. Based on the most recent geological and geochemical studies,the following subjects are discussed in this short note:(1)which aqueous species dissolves gold?(2)why is gold concentrated in vein-type deposits?(3)under which condition is the aqueous gold species soluble? and (4)why do the majority of gold deposits form over a narrow temperature ranging from 340℃ to 400℃? It is concluded that gold may be transported as AuHS(H₂S)₃⁰ in hydrothermal ore fluids. Cooling will result in precipitation of 90% of the dissolved gold as metallic gold. This may explain these gold-bearing quartz veins that were formed at a narrow temperature window.