Seamounts and ridges are often invoked to explain subduction-related phenomena, but the extent of their involvement remains controversial. An analysis of seismicity in the region of the Pampean flat slab through an application of an automated catalogue generation algorithm resulted in 143,716 local earthquake hypocenters, 35,924 of which are associated with at least 12 arrival time estimates, at least 3 of which are from S waves, along with a total of 12,172 focal mechanisms. Several new features related to the subduction of the Juan Fernandez Ridge were discovered, including: (1) a series of parallel lineaments of seismicity in the subducted Nazca plate separated by about 50 km and striking about 20, and (2) a strong spatial correlation between these deeper (> 80 km depth) regions of intense seismicity and concentrations of activity in the crust almost directly above it. Focal mechanisms of the deeper events are almost exclusively normal, while those in the crust are predominantly reverse. The deeper lineaments mirror the origination and spacing of several seamount chains seen on the Nazca plate, suggesting that these patterns are caused by these same types of features at depth. This would imply that relatively minor features persist as slab anomalies long after they are subducted. The correlation of these deeper features with seismicity in the mid to lower crust suggests a genetic relation between the two. We postulate that volatiles from the subducted ridges percolate into the South American crust and induce seismicity essentially by fracking it.