What is the process of ore forming?

All the common ore-forming elements are present in magmas and ordinary

rocks, in amounts ranging from a few parts per billion to several thousands of

parts per million. Selective concentration of one or more ore constituents to

form a mineral deposit is achieved by some combination of the following:

1. extraction of the constituents from magmas, rocks, and oceans;
2. transport of the constituents in a fluid medium from the source region to the site of deposition.
3. localization of the constituents at certain favorable sites.

The ore-forming processes may be grouped into the following four broad

categories:

1. Orthomagmatic processes
2. Sedimentary processes
3. Metamorphic processes
4. Hydrothermal processes