Compressional folds and faults of the Sierra de Perija are strongly aligned in a trend bearing about N. 35° E. Combined in the range with this longitudinal pattern are several local or less prominent trends of faulting and disturbance. South-trending faults branch from the longitudinal faults in the northern part of the range, and emerge into the Maracaibo Basin. Crossing through the southern and south-central part of the range is a system of transverse faults related to the Arena Blanca trend defined in the César Valley. The east-trending transverse Oca fault system crosses and terminates the north end of the range.
In the longitudinal system are the Perija and Tigre faults, and numerous features of the central and western parts of the range. The Cuiba fault, broadly defined to include faulting southward along the range front to the Río Ariguaisa, also mainly conforms to the longitudinal pattern. A junction of four major faults occurs at the Río Palmar, where the arcuate Socuy-Cuiba alignment is crossed by the Tigre-Perijá alignment. The Socuy, Cuiba, and Arena Blanca faults form a single continuous arcuate trend suggesting a lobate thrust-block.
The Perijá fault system crosses diagonally through the Perijá range from the Río Palmar southwestward into the César Valley. It marks a synclinal trough and structural depression that segments the range. West of the fault lies the bulk of the northern Perijá range, including the Serrania de Valledupar, and structural blocks of the Palmar-Guasare area. East of it lie the entire southern segment of the range, the Río Negro anticlinal feature, and the structural eminence known as the Totumo-Inciarte arch. The Perijá fault terminates or is sharply offset where it meets the Arena Blanca displacement in the Río Tocuy drainage of the César Valley.
A discussion of the geological history reviews the pattern of sedimentation. Development of the Cretaceous Perijá trough, and early Eocene movements on the borders of this trough, are defined. The Totumo-Inciarte arch and Manuelote syncline are strongly evident in this historic pattern. Events also can be related to the Oca fault. Several geomorphic stages of Quaternary beaches formed across the Oca fault zone near Sinamaica show evidence of Pleistocene or Recent movement on the Oca fault.