长坑金银矿赋矿硅质岩的硅氧同位素地球化学特征及其成因意义

δ 30 Si,δ 18 O of Ore bearing Chert in Changkeng Large scale Au Ag Deposit,and lts Genetic Significances

长坑金银矿赋矿硅质岩的硅氧同位素地球化学特征及其成因意义孙晓明孙凯陈敬德陈炳辉（中山大学地球科学系，广州５１０２７５）关键词硅质岩δ３０Ｓｉδ１８Ｏ组成热水沉积长坑金银矿长坑大型金银矿是一种新型的浅成低温热液贵金属矿床，国内外尚未见类似者［１～２...

Silican and oxygen isotopic analyses showed that the δ 30 Si and δ 18 O of the ore bearing chert from Changkeng Au Ag deposit were -1 3‰～-0 1‰ and 13 6‰～18 8‰,respectively Comparative studies suggested that the Changkeng chert was deposited from hot water,101 0～154 9℃,calculated from the oxygen isotopic equilibration fractionation equation of chert water Diagenesis and recrystallization occurred after the amorphous silica deposited.Similarity of δ 30 Si composition between the chert and its wall rocks suggested that the silica derived from lixiviation of SiO 2 from the wall rocks by hot water,and then the silica was deposited rapidly and completely