RINE, J. M., J. F. KEITH, Jr., C. A. ALFONSO, I. BALLESTEROS, and F. LAVERDE, Earth Sciences and Resources Institute, University of South Carolina, Columbia, SC, V. E. PEREZ, I. BERNAL, F. CORDOBA, and L. E. NUMPAQUE, Ecopetrol, Bogota, Colombia, and P. E. SACKS and D. T. SECOR, Jr., Department of Geological Sciencies, University of South Carolina, Columbia, SC

ABSTRACT: A Tectonically Controlled Basin-Fill Within the Valle del Cauca, West-Central Colombia

Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordill ra Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.