ABSTRACT
In Central America, knowledge of crustal structure is still limited despite some wideangle seismic experiments during the past decades in southern Central America. The great variability of Central American geology requires detailed mapping of its surface geology and its subsurface crustal structure to better understand its geologic history, its resource potential, and to asses risks from natural hazards. Crustal structure was largely inferred prior to 1990 from geologic maps, gravity studies, potential field data, and sparse seismic and seismological observations. Fundamental questions still debated by geoscientists are the location of boundaries between the continental Paleozoic basement of North America and the oceanic igneous crust or “island arc” crust of Costa Rica and Panama. Another question is the amount of island arc crust preserved and the amount eroded along the Central American convergent margin. In contrast to the lack of crustal data on land is the more complete understanding of offshore structure along Panama, Costa Rica and Nicaragua. During the past 20 years the consensus regarding tectonic processes has changed from accretion to subduction erosion. From the first tests of the constant accretionary hypothesis off Guatemala [1, 2] to the recent tests off the Nicoya peninsula of Costa Rica [3], it is clear that model driven geophysical interpretations of convergent margin tectonic processes must be applied with care.
