Tectonics and sedimentation: an example from the Mérida Andes (Venezuela)

Abstract

Two fluvio-glacial terrace levels (20-25 and 6-10 m) crop out in the Los Zerpa morainic valley (Sierra de Santo Domingo). The upper and older tenace contains alluvial sediments deposited within a morainic dam after post-Pleistocene glacier retreat from the valley. Right-lateral movement along the Boconó fault, underlying the terminal moraine, intempted sedimentation and caused erosion. The lower and younger terrace contains three sedimentary  facies (from the lower to the upper part of the valley): a lacustrine, a deltaic, and a.fluvial facies, which represent the second sedimentation event. Latet renewed movement along the fault intempted this phase and caused incision and terrace formation, a process which continues today.