My work lies in the area of sedimentation and tectonics, particularly the response of depositional systems and stratigraphy to crustal deformation. Some current research topics are listed here.

1. The Late Jurassic-Early Cretaceous extensional Border rift system in southern Arizona, southern New Mexico, northern Sonora and Chihuahua. The Late Jurassic rift system includes strata of the Bisbee Basin and Chihuahua trough, as well as strata of uncertain affinity in northern Sonora. These sedimentary rocks were deposited in extensional basins during a major reorganization of the Cordilleran continental margin. The main objectives of this work are to establish the basins' histories and tectonic setting through improved lithostratigraphy and biostratigraphy and to understand the stratigraphic context of volcanic rocks in the basins. Collaborators on this project include: Jeffrey Amato and Nancy McMillan, NMSU; Carlos Gonzalez-Leon, Instituto de Geologia, Hermosillo, Sonora; Alexander Iriondo, U.S.G.S., Denver; Spencer Lucas, New Mexico Museum of Natural History, Albuquerque.

2. History of the Sevier orogenic belt and adjacent foreland basin in Utah. This on-going work currently consists of two projects. One in central Utah emphasizes origin and correlation of coarse-grained Cretaceous strata in the thrust belt and proximal foreland basin. The relationship of thrust structures and conglomerates is important to deciphering thrust timing and basin geometry. The second project seeks to integrate sandstone petrology, sediment dispersal and fluvial sequence stratigraphy in the Cretaceous of the High Plateaus region of southern Utah. Collaborators include: Peter DeCelles, University of Arizona: Jeffrey Eaton, Weber State University ; Ruth Robinson, St. Andrews University, Scotland; Douglas Sprinkel, Utah Geological Survey.

3. Structural and stratigraphic effects of diapirism in the foreland of the Sierra Madre Oriental foldbelt and the interplay of diapirism and crustal deformation. In the La Popa basin of northeastern Mexico, salt diapirism affected basin stratigraphy in a number of important ways. Stratigraphic units thin onto diapirs and form growth strata that record changes in the balance between salt rise and sediment accumulation. In addition, diapirism strongly affected the distribution of adjacent sedimentary facies by localizing shallow-marine carbonate facies upon the diapirs and by influencing positions of sandstone bodies in adjacent, asymmetrically subsiding minibasins. Primary objectives of the work include documentation of stratigraphic geometries and sedimentary facies, both near diapirs and basinwide, restoration of folded growth strata to understand diapiric mechanisms, and compilation of a basin-wide geologic map. Collaborators include: Kate Giles, NMSU; Brenda Buck and Andrew Hanson, UNLV; Mark Rowan, Rowan Structural Consultants, Boulder, Colorado; Francisco Vega, UNAM, Coyoacan, Mexico; This work is currently funded by a consortium of industrial affiliates.

4. Laramide inversion of Bisbee basin rift structures. The Late Jurassic extensional faults of the Bisbee basin determined the locations of Laramide reverse faults during Late Cretaceous-early Cenozoic time. Continuing mapping and stratigraphic studies in southwestern New Mexico and southeastern Arizona are designed to understand the characteristics and origin of inverted structures.

Last modified Monday, March 4, 2002