USA HISTORY

Detailed explanation-1: -Mineral resources can be divided into two major categories-Metallic and Nonmetallic. Metallic resources are things like Gold, Silver, Tin, Copper, Lead, Zinc, Iron, Nickel, Chromium, and Aluminum. Nonmetallic resources are things like sand, gravel, gypsum, halite, Uranium, dimension stone.

Detailed explanation-2: -Sylvanite and calaverite are gold-bearing minerals. Gold is usually found embedded in quartz veins, or placer stream gravel. It is mined in South Africa, the USA (Nevada, Alaska), Russia, Australia and Canada.

Detailed explanation-3: -GEOPHYSICAL PROSPECTING Five major geophysical methods-magnetic, gravimetric, electrical, radiometric, and seismic-are successfully utilized in mineral exploration. Some of these methods require complex and costly instruments and highly trained operators. Others, however, are relatively simple and inexpensive.

Detailed explanation-4: -prospecting, search for economically exploitable mineral deposits. Until the 20th century prospecting involved roaming likely areas on foot looking for direct indications of ore mineralization in outcrops, sediments, and soils. Colours have been a traditional guide to ores.