Complex sentence: Eclogitization is the tectonic process in which the high-pressure, metamorphic rock, eclogite is formed and consequently effects a change in densities, kinematics and plate motion of subduction zones.
Split into simpler sentences: Eclogitization is the tectonic process in which the high-pressure, metamorphic facies, eclogite is observed. This appearance of the eclogite facies leads to a change in densities, kinematics, and plate motion of subduction zones.