Variations in Structural Styles Across the Burgos Basin, Mexico

Abstract The Burgos Basin in northeastern Mexico as shown in Fig. 1 produces from the clastic Paleocene in the western portion of the basin to the Miocene in the east. Fig. 2 is a stratigraphic chart of the Tertiary. As different Tertiary formations exhibit different structural styles, the primary structural style of each major formation will be discussed and compared. Structural features across the Burgos Basin are not uniform, but complex. Interpretation on 2D and 3D seismic data, on both regional and field development scales, has revealed faults and structures that result not only from extensional forces, but also from compressional or transverse forces. The purpose of this paper is to give a general synopsis of many of the structural styles that have been observed in the Burgos Basin. A common perception that structuring in Burgos is similar to South Texas may limit a more complete understanding of the basin's true potential. A majority of the faults are normal faults. Fault displacements range from a few meters to greater than 2000m (along the major growth fault systems). The extensional normal faults found in the basin have listric and high angle fault planes, syndepositional and post-depositional movement. Generally, synthetic faults are down-to-the-east and antithetic faults are down-to-the-west. Extensional structures include anticlines, synclines and graben systems. While most of the structuring is consistent with traditional Gulf of Mexico basin extensional tectonics, faults with reverse throw, normal faults along which there has been subsequent reverse movement, and anticlinal folds have been observed. These features may be related to deformation occurring in the mountains to the west of the Burgos Basin and result from transverse movement that extends as far to the east as the border with the United States. These anomalous structures are strikingly visible on 3D seismic data. A northeast-southwest or northwest-southeast trend is observed in non-extensional faults and may influence producing trends through the formation of natural fracture systems.