| Autor: |
Chaykovskiy, V. K., Stepanov, A. A. |
| Zdroj: |
International Geology Review; May 1965, Vol. 7 Issue: 5 p764-776, 13p |
| Abstrakt: |
Geosynclinal areas of the crust are typified by a zonal distribution in space and time of structure and ore types. Constancy in occurrence and association suggests that mineralization and fracturing are two related aspects of a single post-intrusive process. Fracturing, like mineralization, occurs in a series of stages with each stage corresponding to a new stage of mineralization with particular ore associations. Definite zonal distributions of ore types and jointing characterize geosynclines not only in directions transverse to the structural axis, but parallel to it as well. Toward the margins a gradual change in the mean level of mineralization from types characteristic of acid magmas to ones related to basic (sometimes alkalic) magmas may be noted to occur. Solutions of magmatic origin that give rise to deposits remote from their source require extensive fault zones such as are characteristic of these peripheral parts of geosynclines. The fact that natural concentrations of only a few metals show completely genetic relations to magmas suggests that dispersed metals in sediments may be of great significance in the formation of ore bodies, particularly for medium and low temperature deposits. The long paths from source to areas of deposition result in prolonged contact of solutions with country rock. This in turn results in enrichment of metals that were present in a dispersed state. Ore bodies of the northeastern U.S.S.R. are examined to show the relationship between mineralization, fracturing and distribution.—R.D. DeRudder |
| Databáze: |
Supplemental Index |
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