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金章东1， 朱金初2， 季峻峰2， 李福春2， 卢新卫2
JIN Zhang-dong1;2, ZHU Jin-chu1, JI Jun-feng1, LI Fu-chun1, LU Xin-wei1
摘要： 德兴斑岩铜矿田内存在两种成因类型的伊利石：一是特征的热液蚀变矿物，它是在热液流体 作用过程中斜长石、云母类矿物通过伊利石化过程形成的，其结晶度(IC)和膨胀层含量受携 带矿质的热液流体量控制；二是浅变质作用自身的产物，其结晶度远较小于前者，具2M1 多型，且不含膨胀层，是原始蒙皂石完全伊利石化形成的。作者发现，在斑岩体和接触带内 ，伊利石结晶度小的部位，蚀变程度强，矿化品位也高。
Abstract: According to difference in features of illite such as spatia l distribution, crystallinity index, contents of swelling layer, 2M1 polytype a nd relationship between its index and copper grade, there exist two typical kind s of illite within Tongchang porphyry copper deposit, Dexing County. The one is a kind of altered mineral within the hydrothermal alteration zone. It is develop ed in the altered granodiorite-porphyry and altered metamorphic tuffaceous phyllite near the contact zone with the porphyry rock body. Its crystallinity va lue and expand ability are mainly effected by water/rock ratio or fluid influx. This kind is fo rmed by illitization of plagioclase and micas during the hydrothermal fluid evol ution and water-rock interaction within the porphyry body and the wall rocks n ear contact zone. The other kind is a product of low grade metamorphism by illitization of smectite. Its cr ystallinity index is lower than the former. It is 2M1 polytyped and witho u t swelling layer, developed in the altered metamorphic tuffaceous phyllite at ce rtain distance from the prophyry rock body (>2km). Moreover, because the illit ic crystallinity an d the degree of copper mineralization are both controlled by the water/rock rati os, the negative correlation between illite index value and copper grade indicat es that within the porphyry body and near the contact zone with wall rocks, the low er the illitic crystallinity value, the stronger the alteration degree, and the higher the copper grade. Consequently, the illitic crystallinity value could be used as an indica tor for mineral deposits research, such as for the porphyry copper deposits.
金章东， 朱金初， 季峻峰， 李福春， 卢新卫
. 德兴斑岩铜矿田两类伊利石的存在及其在蚀变分带中的意义[J]. J4.
JIN Zhang-dong1;2, ZHU Jin-chu1, JI Jun-feng1, LI Fu-chun1, LU Xin-wei1. Contrast between Two Illites of Different Origins and the Distinctive Significance of Illitic Alteration Zones at Dexing Porphyry Copper Ore Field[J]. J4.