Mineral prognosis maps based on the relationships between metal concentration and deep structure of the lithosphere
published: Dec 1, 1999
ArtNo. ESP136000702002, Price: 19.00 €
The studies of structural control of ore deposits which I have performed in different geological environments on five continents show that an important role in major concentration of metals (giant deposits and major ore clusters) belongs to mantle-rooted structural discontinuities. The role of these discontinuities is manifested, in particular, in places where they intersect plate margins, rift structures, orogenic belts, or deep-seated intraplate boundaries of other trends. Some of these discontinuities are poorly expressed in surface geology, but can be detected by geophysical methods. When projected over the surface geology, they extend across boundaries of crustal blocks, modern stress provinces, or across allochthonous terranes. Mutual intersection of such structural discontinuities delineates major lithospheric blocks, rooted in the upper mantle, of a size several hundred kilometers across. Recognition of such a pattern, its projection onto geological maps and comparison with surface or subsurface structures is of a great importance for compilation of mineral prognosis maps to be used in outlining target areas having high potential for the discovery of giant ore deposits. I have prepared, as a contribution to the IGCP Project 354, examples from my studies of deep controls of mineralization in the western and eastern United States, and demonstrate the preparation of this type of mineral prognosis map on two new examples: on Burma and on western Uzbekistan. An example from a discussion of deep-seated structural boundaries in South America is added.