Abstract

The Gulf of Venezuela lies at the contact of the overriding Caribbean and stable South American plates, an area characterized by a unique geologic setting. A recent three-dimensional (3-D) survey (ca 700 km²) in the eastern part of the Gulf of Venezuela reveals a previously unknown Paleogene to Recent complex structural history. An important strike-slip fault was recognized on the basis of en-echelon fault patterns in the younger Neogene sedimentary sequences in the northern part of the survey. The fault has an en-echelon fault pattern striking NW–SE, showing an impressive similarity to experimental physical models. The strike-slip fault is rooted in the basement with an E–W-trending linear segment. Along the basement, transpressional or transtensional fault segments can be recognized depending on the small variations of the fault direction. The fault was active after the Paleogene and cuts up to the surface indicating recent tectonic activity along the strike-slip fault. The movement along the fault is dextral and because it does not connect the individual en-echelon faults in the sedimentary cover, we suggest that strike-slip movement was minor in the Quaternary. To the east, the fault connects to the northern part of the Paraguana Peninsula, where it was recognized initially during previous geologic mapping as the Punta Macolla fault with an E–W strike. Onshore, the fault displaces Neogene sediments, showing a similar strike-slip pattern. Based on new seismic data, the Punta Macolla strike-slip fault can be traced offshore, at least 40 km (24.8 mi) to the west, with a total length of 100 km (62.1 mi).