Correlation of the formation of iron-silicate and carbon matter of carbonaceous chondrites

Abstract

Chondrites consist of an ironrich matrix and silicate chondrules, the complimentary compositions ofwhich exclude the concepts of their separate formation, which is proved in [1]. The evolution of chondritemagmatism controls the formation of the most primitive iron–stony planets; their explosive destructionformed the asteroid belt that is the source of chondrites. The formation of chondrites with forsterite andenstatite chondrules and the metallic tanite–kamacitematrix is related to the very beginning of this evolution. For example, magnesium chondrules and theirfragments of the Hammadah al Hamra chondrite [2]are included into the metallic matrix with the finegranular kamacite mass containing larger metalliczoned grains (5–10 wt % Ni). This chondrite containslarge (of centimeter size) metallic drops; this leads tothe concept of its formation as a result of core separation during the formation of the corresponding chondritic planet. All chondritic planets were conceivedand started their evolution as iron–silicate cores oftheir parental giant planets under the huge pressure offluid envelopes of these giant planets. The evolution ofchondritic planets was finished by rapid cooling at lowpressure after the loss of fluid envelopes by their parental giant planets under the influence of the Sun on thestage preceding the explosive destruction of chondriticplanets into asteroids [3].The chronology of the evolution of chondriticplanets is clearly printed in the mineral composition ofchondrites. The primary metallic matrix of all types ofchondrites contains small grains of diamond enrichedin fluid inclusions. Diamond was formed in chondriticmelts under the huge pressure of envelopes of theirparental giant planets similar to Jupiter. Direct confirmation of this was obtained in 1996, when the spaceship