AUTHORS Marı ´a Vero ´ nica Castillo  Department of Geological Sciences and Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759; present address: Enersis S. A. (ENI), Caracas, Venezuela; veronic_00@hotmail.com Marı ´a Vero ´ nica Castillo is an exploration geosci- entist at ENI Venezuela in Caracas and a lecturer on three-dimensional seismic interpretation at the Universidad Central de Venezuela in Caracas. She obtained her Ph.D. in geology at the University of Texas at Austin in 2001, where she focused on the structural evolution of the Maracaibo Basin, Venezuela. Her current interest is using merged 3-D seismic data sets for regional basin analysis. Paul Mann  Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, 4412 Spicewood Springs Road, Building 600, Austin, Texas 78759; paulm@utig.ig.utexas.edu Paul Mann is a senior research scientist at the Institute for Geophysics, University of Texas at Austin. He received his Ph.D. in geology at the State University of New York in 1983 and has published widely on the tectonics of strike-slip, rift, and collision-related sedimentary basins. A current focus area of research is the interplay of tectonics, sedimentation, and hydrocarbon occurrence in Venezuela and Trinidad. ACKNOWLEDGEMENTS We thank Petro ´ leos de Venezuela, S. A. for pro- viding seismic and well data used in this study and for supporting the first author as a Ph.D. student in geology for 4 yr at the University of Texas at Austin. We thank J. Lugo, F. Audemard, A. Bally, A. Escalona, D. Goddard, and M. Nun ˜ ez for valuable discussions and reviews. The authors acknowledge financial support for this pub- lication provided by the University of Texas at Austin’s Geology Foundation and the Jackson School of Geosciences. University of Texas, Institute for Geophysics contribution 1772. Editor’s Note Color versions of Figures 1–15, 18, 21, and 22 may be seen in the online version of this article. Cretaceous to Holocene structural and stratigraphic development in south Lake Maracaibo, Venezuela, inferred from well and three-dimensional seismic data Marı ´a Vero ´ nica Castillo and Paul Mann ABSTRACT The subsurface of the southern part of the Maracaibo Basin has been studied in much less detail than the central and northern basin be- cause hydrocarbon-rich rocks of Cretaceous and Paleogene age are deeply buried to a depth of 4.5 km (2.7 mi) by a thick Neogene clastic section eroded off of surrounding mountain ranges. In this article, we describe the results of the interpretation of 1600-km 2 (617-mi 2 ) three-dimensional (3-D) seismic reflection data centered on this horizontal to monoclinally southwestward-dipping middle Cretaceous to Holocene section adjacent to a zone of northwestward overthrusting along the mountain front of the Me ´rida Andes. To establish the structural and stratigraphic history of the 3-D seismic study area, a series of time slices were constructed at key horizons through the 3-D seismic volume. The ages of units in these time slices were correlated to stratigraphic formations known from outcrops at the basin edges, well data from the 3-D seismic study area, and sub- surface correlation with better studied areas in the northern basin. The type and orientations of structures along each time horizon were mapped to constrain the successive structural and stratigraphic events that affected the different tectonosequences in the southern Maracaibo Basin. The main tectonic events recorded both by structures and unconformity-bound tectonosequences include the following events from youngest to oldest: (1) Pliocene –Holocene shortening pro- duced by the uplift of the Me ´rida Andes and overthrusting at the mountain front has produced an approximately 6-km (3.7-mi)-deep localized foredeep basin; the axial traces of these folds trend AAPG Bulletin, v. 90, no. 4 (April 2006), pp. 529–565 529 Copyright #2006. The American Association of Petroleum Geologists. All rights reserved. Manuscript received February 19, 2005; provisional acceptance August 4, 2005; revised manuscript received September 28, 2005; final acceptance October 13, 2005. DOI:10.1306/10130505036