puhekieltä An outcrop that is mined for the ore it contains.
1905, Waldemar Lindgren, The Copper Deposits of the Clifton-Morenci District, Arizona (page 207)
Their croppings are either entirely barren or contain only a moderate amount of copper, but much richer ore is ordinarily found just above the chalcocite zone.
1912, John Mason Boutwell, Lester Hood Woolsey, Geology and ore deposits of the Park City district, Utah (page 121)
The cropping of the Quincy ore-bearing bed, the equivalent of the Daly West bed, is stated to have been found at the east end of the present mine and just below the present wagon road.