The banding in serpentinites and its influence on character of talc-magnesite and magnesite mineralization (natural and experimental data)
Resumo
The geological setting of some banded talc-magnesite ores and magnesites was studied in the
field (Urals, Russia; Finland, East Iran). Talc-magnesite and magnesite ores occur in ultramafic
rocks. Experimental methods were used in order to determine the influence of physico-mechanical
parameters on the formation of banded structures in talc-magnesite rocks and magnesites.
Experiments were carried out with axial compression up to 10 kbar and confining pressure 2, 4, 6
and 8 kbars at room temperature.
The samples were chemically analyzed using a Philips Analytical PW 2400 authomatic XRF
Spectrometer and a scanning electron microscope (SEM).
Some analyses were made with a "Camebax SX-50" electron microprobe, using an accelerating
voltage of 20 kilovolts for all elements with a sample current of 20 nanoamps. X-ray method for
phase identification was used. Structure peculiarities of rocks prior to the experiment and after
were studied by optical methods in polished sections and thin sections.
It was shown, that banding in talc-magnesite stone and magnesites are inherited from banded
serpentinites and can affect on distribution and composition rock-forming minerals.
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Texto completo:
PDFDOI: http://dx.doi.org/10.5380/geo.v50i0.4154