ABSTRACT: Seismic and Structural Expression of Rocky Mountain Foreland Uplift Overhangs Incorporating New Data from 1980's Drilling Activity.
M. Williams, E. Lafehr, R. Mueller, J. Dolson, C. Murray, J. Garing, L. Eggers
During the 1980s numerous Precambrian subthrust penetrations were completed throughout the Rocky Mountain foreland. This drilling has more than doubled our pre-existing data regarding footwall and mountain front structural geology. These data provide new insights into geologic models and seismic interpretations.
Variable hanging wall velocities, rock types, fracture patterns, and fault sliver thicknesses and lithologies impact seismic predictability. Recently processed seismic data and offset seismic models help refine subsurface interpretations. Polyphase deformational history, synorogenic conglomerates, and variable structural styles are also important.
Despite the general lack of success of subthrust exploration, drilling has confirmed the existence of some subthrust structures. New seismic methods and better data integration will be necessary for successful commercial discoveries. Data and lessons gleaned from the Rocky Mountain foreland may one day prove useful in this and geologically similar provinces.
AAPG Search and Discovery Article #91002©1990 AAPG Rocky Mountain Section Meeting, Denver, Colorado, September 16-19, 1990