GEOCHEMICAL ANALYSIS OF THE PACAYA VOLCANIC COMPLEX IN GUATEMALA

The Pacaya Volcanic Complex in Guatemala sits atop an active subduction zone. With the Cocos plate (sitting below the Pacific Plate) moving to the east and subducting under the Caribbean plate, active volcanism presents itself about 40 miles inland into Guatemala and surrounding Central American countries. Yet, this volcanism has a geochemical signature of back-arc basin volcanism rather than arc magmatism, as would be expected of this tectonic boundary as seen in other subduction zones around the world. From 17 samples of Pacaya lava flows dating from 2006-2021, 10 major oxides and 18 trace elements have been accounted for and analyzed. This data gives the necessary geochemical information to interpret the type of volcanism occurring within the complex. Additionally, the data gives vital information as to the state of the magma chamber and melt composition or the Pacaya complex over this 2006- 2021 time.