Karbonatyty i związane z nimi złoża kopalin użytecznych
Abstract
CARBONATITES AND RELATED USEFUL DEPOSITS
Summary
At present, there are known over 200 alkaline-ultramafic and carbonatite rock massifs occuring in 25 provinces. The massifs are the subject of marked interest on account of the occurrence of related complex deposits of columbium, tantalum, cerium group of rare earth elements, apatite, phlogopite, vermiculite, etc.
The massifs are characterized by location at cutting of deep crustal fractures and other structural elements. The structure of these massifs is complex, polygenic and it is possible to differentiate metasomatic-hydrothermal and igneous stages in their development. The metasomatic-hydrothermal stage comprises several phases, including carbonatite phase connected with complex rich mineralization.
Deposits of useful raw materials, related to alka lilfle-ultlfamafic and carbonatite massifs, may be subdivided into pre-carbonatite, carbonatite, post-carbonatite and exogenic. The deposits belong to 3 complexes of ore formations: perovskite-titanomagnetite, apatite-magnetite-phlogopite and polymineral ones. Distribution of mineralization and deposits within a massif is determined mostly by geochemical and tectonic factors.
The question of origin of carbonatites is still not unequivocally solved. Their igneous-injectional origin is supposed by large size of carbonatite bodies, morphological form of massifs, and the presence of fluidal structiures and xenolithes within them. On the other hand, gradual increase in content of Ca and CO2 during evolution of these massifs, metasomatic zonality and some other features seem to support the hypothesis of metasomatic-hydrothermal origin of these rocks.
Geophysical, geochemical and geochemical methods involving the use of mathematical techniques in interpretation of the obtained data are the principal methods in search for deposits related to alkaline-ultramafic and carbonatite rock massifs.
Summary
At present, there are known over 200 alkaline-ultramafic and carbonatite rock massifs occuring in 25 provinces. The massifs are the subject of marked interest on account of the occurrence of related complex deposits of columbium, tantalum, cerium group of rare earth elements, apatite, phlogopite, vermiculite, etc.
The massifs are characterized by location at cutting of deep crustal fractures and other structural elements. The structure of these massifs is complex, polygenic and it is possible to differentiate metasomatic-hydrothermal and igneous stages in their development. The metasomatic-hydrothermal stage comprises several phases, including carbonatite phase connected with complex rich mineralization.
Deposits of useful raw materials, related to alka lilfle-ultlfamafic and carbonatite massifs, may be subdivided into pre-carbonatite, carbonatite, post-carbonatite and exogenic. The deposits belong to 3 complexes of ore formations: perovskite-titanomagnetite, apatite-magnetite-phlogopite and polymineral ones. Distribution of mineralization and deposits within a massif is determined mostly by geochemical and tectonic factors.
The question of origin of carbonatites is still not unequivocally solved. Their igneous-injectional origin is supposed by large size of carbonatite bodies, morphological form of massifs, and the presence of fluidal structiures and xenolithes within them. On the other hand, gradual increase in content of Ca and CO2 during evolution of these massifs, metasomatic zonality and some other features seem to support the hypothesis of metasomatic-hydrothermal origin of these rocks.
Geophysical, geochemical and geochemical methods involving the use of mathematical techniques in interpretation of the obtained data are the principal methods in search for deposits related to alkaline-ultramafic and carbonatite rock massifs.