May 24 2014
An oreshoot may be described as a mass of ore deposit, residing in a vein, that might resemble a pipe, a ribbon or a chimney in structure. The ore shoot consists of the most valuable part of the ore deposit.
An oreshoot is the area of concentration of the primary ore along the veins present on the rocks. Along the oreshoot there is a rich aggregation of the mineral in a vein in a vertical direction.
An oreshoot may also appear in the form of a chimney that extends from wall to wall, having a definite lateral width.
'Oreshoot' is a colloquial term used in mining and geology. This usage originated in the 17th or 18th centuries to describe the origin of various ore deposits.
An oreshoot may also be referred to as a pay streak, since it is an area of payable lode that is surrounded by low values. Mineral extraction done along the oreshoot is the most profitable.
The metal content in oreshoots is distributed in such a way that some areas contain larger deposits compared to others. A structure may consist of multiple oreshoots; some veins or lodes may be as thick as 5 to 20ft, and extending to thousands of feet horizontally and vertically.
Such large veins may contain valuable mineral content, extending to 100ft horizontally and 500ft vertically. An oreshoot may be spotted in a tunnel or a drift during excavations, or by assaying rock samples along the walls and roof of a tunnel.
References
- Definition of Oreshoot - Mindat
- Mineral paragenesis, structure, and "ore sh00t" geometry at the U.S. Treasury mine, Chloride mining district, New Mexico – New Mexico Bureau of Mines and Mineral Resources