小秦岭地区脉金矿床找矿评价的石英矿物学标志及模型

MINERALOGICAL MARKS OF QUARTZ AND MODEL FOR EXPLORATION AND EVALUATION OF QUARTZ VEIN TYPE GOLD DEPOSITS IN XIAOQINLING REGION

通过对区内 50 5和 53 0等主要矿脉石英红外吸收光谱、热爆裂及热发光特征的系统研究 ,总结了该区无矿、贫矿及矿体石英脉评价的石英矿物学标志 ,表现为 :①无矿石英起爆温度为 2 1 0～ 3 3 0℃ ,热爆裂曲线无明显峰型 ;石英热发光总强度大于 2 0 0 0 0cps,峰值强度大于 50 0cps;②贫金石英脉其石英红外吸收相对光密度DCO2 /DH2 O值大于 1 .1 ;起爆温度为 2 1 0～ 2 80℃ ,石英热爆裂曲线为明显单峰形态 ,主爆峰对应温度值为 4 2 0～ 4 40℃ ;石英热发光总强度介于 1 0 0 0 0～ 2 0 0 0 0cps之间 ,峰值强度介于 1 50～ 3 0 0cps之间 ;③矿体石英脉其石英红外吸收相对光密度DCO2 /DH2 O值小于 1 .0 ;起爆温度 1 0 0～ 1 60℃ ,热爆曲线为单峰型 ,主爆峰对应温度为 1 4 0～ 1 80℃ ;石英热发光总强度值小于 1 0 0 0 0cps,峰值强度小于 1 50cps。根据本区含金矿脉矿化理想分带模式及石英红外吸收光谱、热爆裂及热发光参数系统变化规律 ,建立了该区石英脉型金矿床找矿评价的石英矿物学标志模型。

By systematic studies on infrared absorption spectrum, thermal decrepitation and thermoluminescence of the main gangue mineral quartz collected from vein No.505 and No.530 major ore veins in the Xiaoqinling region, the mineralogical marks of quartz for evaluation of barren, gold\|poor and orebody quartz veins were summarized. It can be concluded: (1) For the barren quartz veins, their starting thermal decrepitation temperatures are between 210℃ and 330℃ and thermal decrepitation curves show no obvious peak values, their total thermoluminescent intensity is above 20 000 cps and thermoluminescent peak strength value is above 500 cps. (2) For the gold\|poor quartz veins, their relatively light density D\-\{CO\-2\}/D\-\{H\-2O\} values calculated from the infrared absorption spectra of quartz are above 1.1, their starting thermal decrepitation temperatures range from 210℃ to 280℃ while their thermal decrepitation curves are obviously unimodal in shape, with the peak decrepitation temperature being about 420～440℃, their total thermoluminescent intensities lie between 10 000 cps and 20 000 cps and thermoluminescent peak strength values are between 150 cps and 300 cps. (3) For the orebody quartz veins, their relatively light density D\-\{CO\-2\}/D\-\{H\-2O\} values calculated from the infrared absorption spectra of quartz are lower than 1.0, their starting thermal decrepitation temperatures range from 110℃ to 160℃ and the thermal decrepitation curves are also unimodal in shape with the correspondingly peak decrepitation temperatures ranging from 140℃ to 160℃, their total thermoluminescent intensity is usually lower than 10 000 cps and thermoluminescent peak strength values lower than 150 cps. According to the ideal mineralization zoning model and systematic variation regularities of infrared absorption spectra, thermal decreptitation and thermoluminescent parameters of quartz, the mineralogical mark model of quartz for exploration and evaluation of the quartz vein\|type gold deposits in this region have been established.