Benjamin R. Jordan

Ignimbrites in Central America and Associated Caribbean Sea Tephra:: Correlation and Petrogenesis Benjamin R. Jordan

During drilling in the Caribbean Sea on Leg 165 of the Ocean Drilling Program (ODP) a well-preserved record of explosive volcanic eruptions was found as ashfall layers within the deep-sea Cenozoic sediments. The ash layers define two major episodes of volcanism, one in the late Eocene, the other in mid-Miocene. Much of Central America is blanketed in thick ignimbrite sheets, which extend from southern Mexico into Costa Rica. The research presented in this book ties the Caribbean Sea tephra discovered during ODP 165 with the Cenozoic volcanic deposits in Nicaragua and Honduras. Along with this correlation, a detailed petrogenetic model is presented to explain the formation of the Central American ignimbrite province including geochemical variation along and across the paleoarc and evidence for the influence of sediment-derived fluids from the paleosubduction zone.