| Oca–Ancón Fault System | |
| Other Name: | Falla Oca-Ancón |
| Pushpin Map: | Venezuela |
| Pushpin Map Caption: | Location of the fault in Venezuela |
| Pushpin Relief: | 1 |
| Location: | Northern South America |
| Country: | |
| Region: | Caribbean |
| State: | La Guajira Falcón, Zulia |
| Cities: | Maracaibo |
| Coordinates: | 11°N -116°W |
| Range: | Sierra Nevada de Santa Marta, Serranía del Perijá, Venezuelan Coastal Range |
| Part Of: | Andean faults |
| Segments: | Oca, Ancón |
| Length: | 830km (520miles) |
| Strike: | 275 ± 7 (W-E) |
| Dip Angle: | Vertical to subvertical |
| Displacement: | 0.2-/yr |
| Plate: | South American |
| Status: | Active |
| Earthquakes: | 1834 |
| Type: | Strike-slip fault |
| Movement: | Dextral |
| Age: | Late Pleistocene-Holocene |
| Orogeny: | Andean |
The Oca–Ancón Fault System (es|Falla Oca-Ancón) is a complex of geological faults located in northeastern Colombia and northwestern Venezuela near the Caribbean Sea. The fault system is of right-lateral strike-slip type and extends for an approximate length of 830km (520miles).[1] [2] The Oca–Ancón Fault System is part of the diffuse boundary between the Caribbean plate and the South American plate.[3] The movement rate of the Oca–Ancón Fault System is estimated at 2mm each year, more than most Venezuelan faults.[4]
The vertical to subvertical Oca fault segment in the western part of the fault system has a length of 265km (165miles), running west–east through La Guajira, Colombia. It forms the northern boundary of the Sierra Nevada de Santa Marta and cuts through the Serranía del Perijá continuing into Venezuela. The fault segment with a slip rate of 0.2mm0.8mm per year has been active since the Late Pleistocene (~15,000 years ago) and its most recent activity has been registered in 1834.[1]