STUDY ON THERMOLUMINESCENCE OF SOME STRATA-BOUND ICELAND SPAR DEPOSITS IN CHINA

It is of significance to study the formation conditions and thermal history of minerals andore deposits by measuring TL characters of minerals and the difference of TL between min-eralized zone and its wallrocks. Although many studies on TL of calcite have been made inrecent years, yet no report on the comparative investigation of calcites, iceland spars and thewallrock has been published. This study has systematically measured the TL of ore bodies and wallrocks of differentgenetic types. The comparative investigation of the TL measurements of the synthetic sampleshas been carried out. It is evident that the TL technique is significant in the study of thegenesis of minerals and ore deposits.     

我国层控冰洲石矿床热发光研究

本文报道四个地区,三种成因类型冰洲石矿床的岩石、矿物及工人合成方解石热发光特性。结果表明:(1)不同地区,不同成因类型的冰洲石和方解石具有不同的热发光性质;(2)由于蚀变与蚀变围岩受热的不均一性导至热发光性质有明显的差别;(3)同一地区的冰洲石和方解石由于热历史的不同致使它们具有不同的热发光表现;(4)在矿液沿倾斜裂隙上升成矿的过程中,由于上、下盘受热的差异,同样导至它们的热发光性质的截然不同;(5)人工合成样品的热发光测量验证了天然样品所测得的热发光结论。     

二滩坝址F-20断层泥中方解石的热发光年龄测定

本文研究了二滩坝址玄武岩中方解石的热发光性质。这些方解石是中温热液蚀变的产物,当受到新断裂活动作用时,方解石晶体发生变形。实验表明,方解石受压力作用时,其天然热发光逐渐衰减,直至全部消失。根据这种原理,可以用二滩坝址方解石变形后积累的天然热发光测定最新断层活动的年龄。利用这种方法测得方解石受压变形事件发生在距今140.3万年和115.5万年之间。据此推断F-20老断层复活时期不晚于距今115.5万年。     

THERMOLUMINESCENCE DATING OF CALCITE IN THE GOUGE OF F-20 FAULT AT ERTAN DAM SITE

The thermoluminescence of calcite in basalt from Ertan dam site is studied in this paper. The calcite is product of mesothermal action in late Permian. The deformation of the calcite crystals occurred during neofaulting. Experimental study indicates that the natural thermoluminescence of calcite declines under the action of pressure till exhaustion. On this basis, the age of the latest fault activity can be determined by the natural thermoluminescence accumulated since deformation of the calcite from Ertan dam site. By this method, it has been obtained that the deformation event of the calcite under pressure occurred between 1.403 and 1.155m.y. ago. Based on these results, it can be inferred that the active time of F-20 fault was not later than 1.155 m.y. ago.