GRAVITY, MAGNETIC AND GEOLOGIC CONSTRAINTS ON THE RATON BASIN OF SOUTHERN COLORADO

The overall goal of this project is to better understand the tectonic and magmatic influences on hydrocarbon development in the Raton Basin of Colorado. The Raton Basin is a Rocky Mountain foreland basin that contains Pennsylvanian through modern sedimentary rocks. The current structure of the basin is thought to have formed during the Late Cretaceous through Tertiary Laramide orogeny. During this event, the basin was folded into a syncline, steep reverse faults formed along the western edge of the basin and the Pre-Cambrian crystalline rocks of the Sangre de Cristo Range were partially thrust over the basin itself. In the Oligocene through present, the tectonic environment of the basin has been dominated by extension and extensional magmatism related to the Rio Grande Rift. A series of small plutonic bodies and more spatially extensive magmatic dikes intruded into the basin over this time interval. Hydrocarbons in the Raton Basin are thought to be primarily coal-bed methane and tight shale oil. One potential influence on the formation of the coal bed methane is heating of coal beds via the magmatic dikes and sills. This project seeks to investigate this possibility by better determining the structural and thermal characteristics of the dikes with respect to hydrocarbon bearing strata. In the field, this will be accomplished by a combination of structural and magnetic mapping. Quantitative models, using field collected magnetic and existing gravity data, will be constructed to constrain the 3-dimensional geometry of the dikes and other intrusions with respect to the sedimentary basin.