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Abstract

Carbonate mass failures are widespread, particularly along steep tropical shorelines, however, the age, frequency, and cause of these failures are often poorly constrained. As shorelines undergo intensive human development, understanding when carbonate slopes failure occur is becoming increasingly important. Using both land and marine-based observations,we present methods for making valuable first-order age estimates of near-shore slope failures. As a case study, we analyze the partially submerged lower carbonate terrace along the southern shoreline of Curacao, Netherlands Antilles.This terrace sits adjacent to a well-documented carbonate slope failure. Our combined land-sea study constrains the slide contact, the amount of post-slide coral reef growth, and the location of erosional shoreline notches. From these observations,we place limits on the timing of slope failure, and conclude that the Caracas Bay slide did not occur recently (within the last ~3000 years) but more likely at least ~116,000 years ago, near the end of the last interglacial sea level high stand. Slope failure likely occurred along the unconformable contact separating the base of the coastal limestone with underlying Cretaceous basalt, and may have been triggered by a large earthquake along the Caribbean-South American plate boundary.