河南省方城县双山玉矿地质特征及找矿标志

Geological Characteristics and Prospecting Indicator of Shuangshan Jade Deposit in Fangcheng County,Henan Province

河南省方城县双山玉矿为新发现的碳酸盐类玉石矿床,因产于河南省方城县双山地区,故被命名为"双山玉"。结合矿区地质工作成果,详细分析了区域成矿地质背景、矿区及矿床地质特征。研究表明:(1)矿体主要赋存于栾川群三川组大理岩与南泥湖组大理岩中,玉化以透闪石化、透辉石化、蛇纹石化为主,总体位于与新元古代黑云正长岩外接触带附近,部分地段呈大捕虏体形式产出;(2)矿区玉石可划分为白双山玉、绿双山玉、黄双山玉、青双山玉等4类;(3)玉石主要化学成分为SiO_2、MgO、CaO,主要致色元素为Ti^(4+)、Fe^(2+)、Fe^(3+)离子,玉石中K、Na含量较低,一般Na含量大于K;(4)双山玉矿床的成因类型为岩浆热液接触交代型矿床,其构造、颜色、粒度及矿物成分特征可以作为找矿标志。

Shuangshan jade deposit in Fangcheng County in Henan Province is the carbonate jade deposit newly found in recent years. The deposit is produced in Shuangshan area in Fangcheng County in Henan Province,therefore,it is named as ＂ Shuagnshan jade＂. Based on the geological working results of the mining area, the regional metallogenic geological background, geological characteristics of the mining area and deposit are studied. The study results indicated that ： ①ore-bodies are mainly distributed in the marble of Sanchuan Formation of Luanchuan Group and the marble of Nanhu Formation, jadify types are mainly for transmolite, diopsidization and serpentine, in general they are hosted near the external contact zone of biotite syenite in Neoproterozoic,besides that,they are distributed with the type of big xenolith in local region;②the jade types of the mining area can be summarized as white shuangshan jade, given shuangshan jade, yellow shuangshan jade, cyan shuangshan jade ; @the main components of jade ores are mainly for SiO2, MgO and CaO, the main colored elements are Ti^4 ＋ , Fe^2 ＋ and Fe^3＋ , contents of Na and K in jade ore are both low, besides that, the content of Na is generally higher than that of K;④the genetic type of shuangshan jade deposit is belongs to magmatic hydrothemal contact metasomatism deposit, struc-ture ,color,particle size and mineral composition characteristics can be regarded as the favorable prospec-ting indicators of the mining area.