Charpentier, Johann (1738-1805). Mineralogische Geographie der Chursächsischen Lande. Leipzig: bey Siegfried Lebrecht Crusius, 1778.
Saxony, in eastern Germany, is a very rich mining district, with the Erzgebirge (Ore-bearing Mountains) bordering the region to the south. Charpentiers treatise on the minerals of Saxony included a large geological map of the area. The entire map is on display in the exhibition; we reproduce here a detail that shows the legend for the map. Major types of rock, such as granite and limestone, are indicated by colors, while other rocks are indicated by symbols. Basalt formations are denoted by the letter B; although it is hard to see them, there are many "B" symbols scattered about the eastern part of Saxony. It is interesting that the backdrop for the legend is a formation of columnar basalt.