Matrix nature is an indicator of temperature conditions of suevite formation (on the example of clastic impactites of the Kara meteorite crater)

The paper proposes a new approach for the study of suevites formation features — the analysis of temperature conditions of clastic impactites formation based on the analysis of local matrix sintering using materials science methods. Structural and textural features and substance composition of the suevite matrix of the bottom and ejecta facies of the Kara astrobleme are studied. The petrochemical composition of the clastic impactite matrix reflects the composition of the target rocks, it can be complicated with the suevites post-impact altering. Quartz and albite clusters in the matrix have signs of different sintering stages, indicating a strong variety in local temperature conditions of the suevites formation. In this regard, it makes no sense to conclude about a certain temperature of rock formation as a whole. During lithification the suevites of aerodynamic facies the local temperature could reach 1200 °C. The bottom facies had relatively higher temperature formation where the maximum temperatures locally reached 1700 °C. The sintering nature of the suevite matrix is an indicator of the specifics of the formation conditions and can be used to diagnose facies of detrital impactites and to clarify the parameters and scenario of impact events.