Petrogénesis of a Las Lajas Caldera lava and tectonic processes in Nicaragua

Abstract

The Las Lajas Caldera, western Nicaragua, is one of three known early Quaternary volcanic centers on the eastern side of the Niearaguan Depression. A porphyritic basaltic andesite from Las Lajas was chosen for prelimináry examination as part of an extensive study to determine the relationships be:tween earIy Quaternary volcanism in Nicaragua, the belt of Recent volcanism approximately 50 km to the west, and the tectonic activity associated with the Middle America Trench.