A summary of the sedimentology of Deep Sea Drilling Project Leg 67 sites: the Middle America Trench and slope off Guatemala - an active margin transect.

Abstract

The transect of drill sites across the Middle America Trench offshore Guatemala contains portions of the sedimentary record from the Early Cretaceous to the Recent. Hemipelagic muds cover both slopes of the Trench; the thick accumulation on the Cocos Plate indicates transport of these sediments hundreds of kilometers seaward of their land-ward-slope source area. Beneath those muds, the sedimentary section of the Cocos Plate is a classic, basalt-chalk-abyssal clay sequence that records the passage of Site 495 from the E Pacific Rise to depths greater than the calcite compensation depth. A horst is buried beneath the turbidites ponded in the Trench axis. Facies changes are absent within the turbidites, and biogenic components indicate transport from upslope.-from Authors