Simulation of phase transformations in clay-containing limestone under impact treatment

Transformation of carbonate matter of a target during impact process remains poorly studied. Phase changes in silicate sedimentary rocks with a high proportion of carbonate matter, as well as limestones with clay and carbonaceous components, are largely unexplored. For the first time an experimental work to simulate an impact process with a short-pulse laser action to bituminous clay limestone to determine the nature of phase transformations was performed. During the action of the laser pulse on the target material we reached temperatures (2200 K) and pressures (24 GPa) which were close to the calculated formation conditions data of large impact structures. Melting and recrystallization of the carbonate melt with formation of intermediate phases and calcite were experimentally established. Formation of impact glass from the clay constituent of the protolith were revealed, and transformation of the carbonaceous substance were produced.