Search
Results:
Vol. 12 (2009 year), No. 3
Serov P.A., Yekimova N.A.
Potential of the Sm-Nd dating of ore processes using sulphides
Researches of greenstone belt associations of late Archaean have allowed to divide all ancient continental formations into three basic groups – protoequatorial, protonorthern and protosouthern extended in the sublatitudinal direction. Greenstone belts of that time naturally varied in space on structure and relative prevalence of volcanic rock according to parameters of the Earth mantle temperature mode. Geochemistry data of the basic metavulcanite ancient convergent zones have confirmed geodynamic states that southern rock associations of late Archaean age were formed in conditions of higher temperatures of the mantle. Komatiite magmas generated in conditions of greater overheat of the Earth mantle were enriched by a number of siderophilic and halkophilic elements, that determined a great number and genetic variety of deposits of gold, nickel and elements of platinum group.
(in Russian, стр.5, fig. 2, tables. 2, ref 14, Adobe PDF, Adobe PDF 0 Kb)
Vol. 12 (2009 year), No. 3
Nerovich L.I., Bajanova T.B., Savchenko E.E., Serov P.A., Yekimova N.A.
New data on geology, petrography, isotope geochemistry and PGE mineralization of the Monchetundra intrusion
The paper presents new Sm-Nd isotope-geochronological and geochemical data for the ore-bearing rock of the Fedorovo-Pansky Palaeoproterozoic layered complex (Kola Peninsula) and Nottrask layered intrusion (Sweden). For the first time, Sm-Nd dating procedure has applied sulphides as new minerals-geochronometers that allow direct dating of ore-forming events. The resultant ages of 2475В±37 Ma for the gabbronorite of the Fedorovo-Pansky complex and of 1740В±27 Ma for the gabbro of the Nottrask intrusion have been interpreted as the time of ore-forming processes in the two intrusions. Thus, it has been demonstrated that sulphides may be used as minerals-geochronometers for Sm-Nd isotope-geochronological investigations.
(in Russian, стр.17, fig. 8, tables. 3, ref 14, Adobe PDF, Adobe PDF 0 Kb)