Pantasma: Evidence for a Pleistocene circa 14 km diameter impact crater in Nicaragua

The circa 14 km diameter Pantasma circular structure in Oligocene volcanic rocks in Nicaragua is here studied for the first time to understand its origin. Geomorphology, field mapping, petrographic and geochemical investigations all are consistent with an impact origin for the Pantasma structure. Observations supporting an impact origin include outward-dipping volcanic flows, the presence of former melt-bearing polymict breccia, impact glass (with lechatelierite and low H 2 O, 10 km found in the Americas