Mining is the extraction of minerals and rocks from the earth. The history of mining stretches back to prehistoric times when gold, copper, and silver were apparently the first metals mined. Egyptians mined copper and tin as far back as 3700 b.c.. A German scholar, Gergius Agricola, wrote an early comprehensive study of mining methods in the Middle Ages in his De re metallica. In the United States, mining did not begin until the late 18th century, when a Missouri lead belt began continuous production. Metal ores were found in the western part of the United States in the middle of the nineteenth century causing the California gold rush. Mining is still a major industry in the United States.

There are several methods to find potential deposits for inspection. Trenching and testpitting are used when there is only loosely packed matter covering the deposit. If the surface is...