Ore genesis and loses its metal carrying capacity. Ore deposits rarely fit neatly into the categories in which geologists wish to place them. Many may be formed by one or more of the basic genesis processes above, creating ambiguous classifications and much argument and conjecture. Often ore deposits are classified after examples of their type, for instance Broken Hill type lead-zinc-silver deposits or Carlin–type gold deposits. Classification of hydrothermal ore deposits is also achieved by classifying according to the temperature of formation, which roughly also correlates with particular mineralising fluids, mineral associations and structural styles. This scheme, proposed by Waldemar Lindgren (1933)
Galena, South Dakota Galena, South Dakota Galena (also Galena City) is an unincorporated community in Lawrence County, South Dakota, United States. It is often considered to be a ghost town, even though a few families still live in the area. It is not tracked by the U.S. Census Bureau. The town was named after the galena found in the ore in the surrounding mines. In 1875, gold was discovered in the Black Hills and drew settlers to the area. The mines in the area were originally intended to be gold mines, but other metals were more plentiful in the hills. Most of the