This contribution presents new insights into the origin and age relationships of the Geyer tin deposit in the Erzgebirge, Germany. Tin mineralization occurs in skarns, greisen, and in cassiterite-bearing fluorite-quartz veins. Skarn alteration replaces marble layers of the Cambrian Jáchymov Group and occurs in two clearly distinct stages. The first skarn stage forms skarnoid textured assemblages of clinopyroxene, garnet, and wollastonite with no tin phases recognized. Garnet U-Pb ages of this skarn stage (~322 Ma) relate the earlier skarn stage to the emplacement of the Ehrenfriedersdorf granite (~324 to 317 Ma). The second stage of skarn alteration is marked by the occurrence of malayaite and cassiterite associated with garnet recording ages of 307 to 301 Ma. Greisen- and skarn-hosted cassiterite-bearing veins provide U-Pb ages in the range of 308 to 305 Ma, relating greisenization and vein formation to the same magmatic-hydrothermal event as the second skarn stage. This suggests that tin mineralization at Geyer is related to a distinctly younger magmatic-hydrothermal event, clearly postdating the Ehrenfriedersdorf granite, which was previously assumed as the source of the tin-rich fluids. Fluid inclusions show salinities in the range of 1.0 to 31.5 % eq. w(NaCl±CaCl₂) and homogenization temperatures between 255 and 340 °C. Cassiterite-associated fluid inclusions show indications for heterogeneous entrapment and dilution of hydrothermal with meteoric fluids. Dilution of high-salinity fluids with low-salinity fluids and cooling of the system was probably a decisive process in the precipitation of cassiterite in the Geyer Sn system.

这一贡献对德国埃尔茨山脉盖尔锡矿床的起源和年龄关系提出了新的见解。锡矿化发生在夕卡岩、云英岩和含锡石的萤石石英脉中。矽卡岩蚀变取代了寒武系雅希莫夫群的大理石层，并发生在两个明显不同的阶段。第一矽卡岩阶段形成单斜辉石、石榴石和硅灰石的类矽卡岩结构组合，没有识别出锡相。该夕卡岩阶段的石榴石 U-Pb 年龄（约 322 Ma）将早期夕卡岩阶段与 Ehrenfriedersdorf 花岗岩的侵位（约 324 至 317 Ma）联系起来。夕卡岩蚀变的第二阶段以马来亚石和锡石的出现为标志，石榴石记录年龄为 307 至 301 Ma。云英岩和夕卡岩含锡石矿脉提供了 308 至 305 Ma 范围内的 U-Pb 年龄，将云英岩化和矿脉形成与第二夕卡岩阶段相同的岩浆热液事件联系起来。这表明盖尔的锡矿化与明显较年轻的岩浆热液事件有关，其年代明显晚于埃伦弗里德斯多夫花岗岩，而埃伦弗里德斯多夫花岗岩此前被认为是富锡流体的来源。流体包裹体显示盐度在 1.0 至 31.5 % eq 范围内。w(氯化钠±氯化钙 此前被认为是富锡流体的来源。流体包裹体显示盐度在 1.0 至 31.5 % eq 范围内。w(氯化钠±氯化钙 此前被认为是富锡流体的来源。流体包裹体显示盐度在 1.0 至 31.5 % eq 范围内。w(氯化钠±氯化钙₂ ) 均质温度在 255 至 340 °C 之间。与锡石相关的流体包裹体显示出异质截留和热液被大气流体稀释的迹象。用低盐度流体稀释高盐度流体以及系统冷却可能是盖尔锡系统中锡石沉淀的决定性过程。