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The vein carries along the hill for some considerable distance, and has been trenched out. This method involved excavating the vein vertically down while keeping the top open. However, ventilation becomes a problem when fire-setting is used, so three long adits were driven in from the hillside to the north.
Sudbury Basin is the third-largest crater on Earth, after the 300 km (190 mi) Vredefort impact structure in South Africa, and the 180 km (110 mi) Chicxulub crater under Yucatán, Mexico. Geochemical evidence suggests that the impactor was likely a chondrite asteroid or a comet with a chondritic component.
White veins in dark rock at Imperia, Italy. In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation. The hydraulic flow involved is usually due to hydrothermal circulation. [1]
Six major bonanzas marked the first five years of the Comstock Lode. The Ophir bonanza was prosperous until 1864, producing 70,000 tons. Though rich, and having a length of 500 feet (150 m) at the surface, the ore body wedged out [] at a depth of 500 feet (150 m).
Tell Barri, northeastern Syria, from the west; this is 32 meters (105 feet) high, and its base covers 37 hectares (91 acres) Tel Be'er Sheva, Beersheva, Israel. In archaeology, a tell (from Arabic: تَلّ, tall, 'mound' or 'small hill') [1] is an artificial topographical feature, a mound [a] consisting of the accumulated and stratified debris of a succession of consecutive settlements at the ...
Archaeologists have uncovered the remains of two more victims of the notoriously deadly Mount Vesuvius eruption that buried Pompeii in 79 A.D.
The water was unleashed to scour the hillside below, both soil in the case of prospecting for metal veins, and then rock debris after a vein had been found. Fire-setting was used to break up the hard rocks of the vein and the surrounding barren rock, and was much safer to use in above ground workings since the smoke and fumes could dissipate ...
Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. [1] [2] The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to discover the ore veins.