Structures pirops from kimberlites with the different diamonds contents of the tube Luele (Angola)

Abstract

In work the statistical analysis of the made microanalysis definitions of structures pyrops from kimberlites of a different diamonds contents of a tube to Luele (Angola) is made. Recalculations of structures perops on the main paragenetic groups of structures on N.V. Sobolev's classifications and clusters groups of Dawson are executed. Significant correlation of paragenetic groups and clusters groups of structures pyrops with an diamonds contents of three versions of kimberlites is established. Additional Mn-Mg criterion for an assessment of a potential diamonds contents of kimberlites on the basis of relative calculation of grains pyrops which structures get to area of a diamondiferous window according to the contents in these minerals of oxides of manganese and magnesium is approved. The fact that for assessment of storm content of diamonds in kimberlites on structures of pyropes of the ultramain paragenesis works as well criterion of Mn-Mg of a cloud is result of this work. On this example of researches it is proved that the central region of a projection of this cloud of points for structures of pyropes which on the manganese thermometer it is favorable for a collateral crystallization and safety of diamond gets to the area of 0,4% of weight contents for MnO and 20% of weight percents for MgO. Deviations of a projection of points on binary charts of structures of pyropes from above the specified parameters of maintenance of MnO and MgO decides for such PT grains by parameters not stable for a mass crystallization of diamonds on them in mantle.