胶东望儿山金矿床石英热释光和晶胞参数特征及其找矿意义

Characteristics and Prospecting Significance of the Thermoluminesence and Cell Parameters of Quartz from the Wang'ershan Gold Deposit,Jiaodong Peninsula,China

望儿山金矿的成矿过程可划分为黄铁矿-石英阶段、石英-黄铁矿阶段、多金属硫化物阶段和石英-碳酸盐阶段。分别对4个成矿阶段中的石英进行了热释光和晶胞参数测定。热释光结果表明,本区石英热发光曲线以中温峰明显的单峰和不对称的双峰为特征。主成矿阶段的石英发光曲线开始出现双峰,曲线复杂,发光强度最高,变化最大,这也是本区重要的找矿标志。Ⅲ号脉的深部石英热发光曲线出现肩峰和双峰,峰型复杂,推测其下部有较好的成矿前景。石英晶胞参数在时空上呈现规律性的变化,主成矿期石英晶胞参数a0、c0、v0都较大。（Δa0/a0）/（Δc0/c0）变化范围为1.65-4.40,说明本区微量元素进入石英有填隙和置换两种方式,以填隙为主。半高宽变化趋势和晶胞参数一致,因此半高宽也可以区分石英的含金性。深部石英晶胞参数和半高宽仍较大,所以推测下部仍有较好的成矿前景。

Gold mineralization of the Wang＇ershan deposit can be divided into 4 stages including pyrite-quartz stage,quartz-pyrite stage,polymetallic sulfide stage and quartz-carbonate stage. The thermoluminesence and cell parameters of quartz from the 4 stages were analyzed in this paper. The characteristics of the thermoluminesence curves show obvious single peak at middle temperatures for the quartz from the early and later stages and asymmetric twin peaks with strongest emitting intensity and complexity for the quartz from the main minerali-zation stage. It is an important prospecting criteria for gold in this area. At the depth of the veinⅢ,the thermoluminesence curves of the quartz appear to have shoulder-like and twin peaks,implying a good mineralization prospect downwards. The cell parameters of the quartz show a regular variation in time and space. In the main mineralization stage,the quartz cell parameters a0,c0 and v0are relatively large with（ Δa0/ a0） /（ Δc0/ c0） ranging from 1. 65 to 4. 40,suggesting that trace elements are combined into quartz by gap filling and replacement with interstitial mode as the major way. The change of half-peak bandwidth of the thermoluminesence is as the same as the cell parameters for quartz; therefore,the half-peak bandwidth can also be taken as a criteria for gold-rich and gold-poor quartz grains. According to the spatial variation tendency of the cell parameters and half-peak bandwidth of quartz,the authors infer that the unmined region at large depth is presumably profitable for further gold mineralization prospect.