Comment on “Relict basin closure and crustal shortening budgets during continental collision: An example from Caucasus sediment provenance” by Cowgill et al. (2016)

The southern slope of the Greater Caucasus mountains is the site of a former rift basin. In order to explain shortening deficits, plate deceleration, and the ~5 Ma reorganization of the Arabia-Eurasia collision zone Cowgill et al. (2016) proposed that this basin closed ~5 Myrs ago. Within the western Greater Caucasus, at least, careful examination of sedimentological, provenance, and seismic data, however, supports an earlier ~35 Ma basin closure age. Basin closure cannot therefore be the driving mechanism for the ~5 Ma deceleration of the Arabian plate and reorganization of the Arabia-Eurasia collision zone.