摘要
本文通过岩石的结构构造、岩石化学、矿物学、微量元素地球化学、同位素地质学等研究认为,滇西云龙铁厂锡矿区含锡围岩是崇山群(前寒武纪)在加里东期经过混合岩化作用形成的;混合岩成岩方式以交代作用为主,主要表现为多期多阶段的钾化、钠化、硅化。早期深部来源的热液诱发了混合岩化作用的发生,混合岩化热液主要来源于原岩本身分异出的富含钾、钠、硅的流体,交代作用的过程中硅、钠、钾起主导作用。空间上与混合岩密切伴生的锡矿床是混合岩化作用的最终产物。崇山群是锡的矿源层,混合岩化作用使地层中锡活化转移并富集在有利部位形成工业矿床。笔者将这类矿床称之为混合岩型锡矿。
The studies on rock structure and texture, petroehemistry, mineralogy, trace element, geochemistry, isotopic geology, etc. show that the host rock to the Tiechang tin deposit. western Yunnan province, was formed by migmatization of the Chongshan Group (Precambrian) during the Caledonian orogeny. The formation mechanism of migmatites is mainly replacement of multiple-periodic and multiple-stage potash-alteration, sodium-alteration and silica-alteration. The early deep-source hydrothermal fluid induced the generation of migmatization. The migmatization hydrothermal fluid was mainly derived from the differentiation of original rocks, and was rich in Si, Na and K which predominated in the process of replacement. Tin deposits spatially associated with migmatites were the final products of migmatization. The Chongshan Group was the source of tin. Migmatization caused the tin to mobilize and to transfer form the source to from economic deposits in the favourable locations. This kind of tin deposits is called migmatite type tin deposit.
出处
《大地构造与成矿学》
EI
CAS
CSCD
1989年第3期264-275,共12页
Geotectonica et Metallogenia
关键词
混合岩
锡矿化
滇西
云龙
migmatites, tin mineralization, Yunlong, western Yunnan.
