Pseudotachylitic breccias are the most prominent impact-induced deformation phenomenon in the Vredefort Dome, the eroded central uplift of the 2.02 Ga, originally 250-km-wide Vredefort impact structure in South Africa. Controversy remains about the origin of these melt breccias, and the most popular hypotheses are genesis by (1) shearing (friction melting), (2) shock compression melting, (3) decompression melting immediately after shock propagation through the target or slightly later during the modification phase of cratering, (4) combinations of these processes, or (5) intrusion of allochthonous impact melt. A resolution to this problem requires detailed multidisciplinary analysis in order to characterize the nature...