Distribution characteristics of mineral deposits in Yunnan, China

GPS(全球定位系统)的可用性从三个方面进行了审查。第一个是固定点。测量值分散在离真实位置100米的范围内。选择第二个地区是因为出版了地形图(1/25000)。将每个GPS值与地形图上给出的位置进行比较。第三个地区是云南省，位于中国西南部，禁止外国人使用地形图。通过重现性检验其准确度。结果表明，当4颗卫星分布在大范围内时，测值散布在直径为200m的圆周内，当4颗卫星分布在狭小区域时，其直径为500m，当只发现3颗卫星时，其直径为1000m。结果表明，GPS可以为区域地学讨论提供足够精度的定位数据。W+Mo、铅+锌矿床的图解表明，矿值与累计矿石吨位的对数呈良好的线性关系。块状硫化物、正岩浆、砂岩、斑岩、交代和层控类型的图解也是线性的。因此，假设这些商品和这些类型中的每一种的存款属于一个单一的人口。相反，本文所分析的所有矿床的矿值-吨位关系都是用两个指数函数的组合来近似的。铜+钨+钼、铜+铅+锌、金+银等矿种、脉型和不整合面相关类型的矿床也具有相同的特征。这表明，属于每一类的存款被分为高价值组和低价值组。

The availability of GPS (Global Positioning System) has been examined in three areas. The first is a fixed point. Measured values are scattered within 100 m from the true position. The second area was selected because topographic maps (1/25000) are published. Each GPS value was compared with the position given from a topographic map. The deviation is within 300 m. The third area is Yunnan Province, southwestern China, where foreigners are prohibited to use topographic maps. The accuracy was checked by the reproducibility. When 4 satellites were found in wide areas, values were scattered in a circle whose diameter was 200 m. When 4 satellites were found in narrow areas, the diameter was 500 m. When only 3 satellites were found, the diameter was 1000 m. The result suggests that the GPS can provide location data with the accuracy enough to regional geoscience discussions.An ore value-tonnage diagram has been proposed for assessing mineral resources. Diagrams of W+Mo, and Pb+Zn deposits show a good linearity between ore value and logarithms of cumulative ore tonnage. Diagrams of the massive sulfide, orthomagmatic, placer, porphyry, replacement, and stratabound types are also linear. It is assumed, therefore, that deposits of each of these commodities and these types belong to a single population. In contrast, the ore value-tonnage relations of all the deposits analyzed here is approximated by the combination of two exponential functions. The same feature is seen for deposits of the Cu+W+Mo, Cu+Pb+Zn, and Au+Ag commodities, and of the vein and unconformity-related types. This suggests that deposits belonging to each of such categories are divided into the high and low value groups.