What was I working on so diligently in the photo of me studying?
- July 15, 2005
My subduction zone term paper and presentation, of course! The following is the abstract from that paper.
Volcanics along the modern-day Central American Volcanic Arc (CAVA) are due to the subduction of the Cocos Plate beneath the Caribbean Plate. CAVA spans ~1100 km and contains 40 major active volcanic centers. There is an along-arc symmetrical variation of geochemical and physical properties centered on Nicaragua. Crustal thickness and volcanic flux rates reach a minimum in Nicaragua and progressively increase toward Guatemala and Costa Rica. Slab dip angles display the inverse pattern. Incompatible elements and slab fluid components also vary symmetrically along the arc. Nicaragua has low concentrations of incompatible elements, suggesting high degrees of melting, and has high concentrations of sediment-derived trace elements, suggesting a high slab influence. These along arc variations can be explained through two separate melting models. Plank and Langmuir (1988) suggested that crustal thickness controls the degree of melting and Carr et al. (1990) suggested that the angle of dip controls the amount of slab influence and further controls the degree of melting. When viewed together, these two models accurately explain the Central American along arc variations.
Volcanics along the modern-day Central American Volcanic Arc (CAVA) are due to the subduction of the Cocos Plate beneath the Caribbean Plate. CAVA spans ~1100 km and contains 40 major active volcanic centers. There is an along-arc symmetrical variation of geochemical and physical properties centered on Nicaragua. Crustal thickness and volcanic flux rates reach a minimum in Nicaragua and progressively increase toward Guatemala and Costa Rica. Slab dip angles display the inverse pattern. Incompatible elements and slab fluid components also vary symmetrically along the arc. Nicaragua has low concentrations of incompatible elements, suggesting high degrees of melting, and has high concentrations of sediment-derived trace elements, suggesting a high slab influence. These along arc variations can be explained through two separate melting models. Plank and Langmuir (1988) suggested that crustal thickness controls the degree of melting and Carr et al. (1990) suggested that the angle of dip controls the amount of slab influence and further controls the degree of melting. When viewed together, these two models accurately explain the Central American along arc variations.