Distribution characteristics of mineral deposits in Yunnan, China

全球定位系统（GPS）的可用性在三个方面进行了审查。第一个是固定点。测量值分散在距离真实位置100米的范围内。选择第二个区域是因为出版了地形图（1/25000）。将每个GPS值与地形图给出的位置进行比较。偏差在300m以内。第三个区域是中国西南部的云南省，那里禁止外国人使用地形图。通过再现性检验其准确性。当在大范围内发现4颗卫星时，数值分散在一个直径为200 m的圆内。当在狭窄区域发现4颗卫星时，直径为500米。当只发现3颗卫星时，直径为1000米。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。提出了一种评价矿产资源的矿石价值-吨位图。W+Mo和Pb+Zn矿床图显示，矿值与累计矿吨位对数呈良好的线性关系。块状硫化物、正岩浆型、砂矿型、斑岩型、替代型和层控型的图解也是线性的。因此，我们假定每一种商品和每一种类型的矿藏都属于一个单一的群体。相反，本文分析的所有矿床的矿值-吨位关系都近似为两个指数函数的组合。Cu+W+Mo、Cu+Pb+Zn、Au+Ag等矿脉型和不整合相关矿脉型的矿床也具有相同的特征。这表明，属于每一类的矿床可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.