Figure 1. (A) Processes by which microseeping hydrocarbons migrate from the reservoir to the surface through faults, fractures as well as stratigraphic boundaries (modified from Schumacher, 1999). (B) Generalized model of hydrocarbon-induced geochemical alterations of soils and sediments (modified from Schumacher, 1996).
Figure 2. Landsat thematic mapper showing major structural features of south-central Wyoming. The Patrick Draw study area is on the east flank of the Rock Springs uplift (boundaries modified from Skeeters and Hale, 1972).
Figure 3. (A) Field map of areas of interest and locations of all samples collected in the field with their labeled names. (B) Photo taken within a lineament at Patrick Draw during field work in the summer of 2005 showing anomalous zone.
Figure 4. Classification results for Patrick Draw area. (A) Spectral reflectance of the end members used in Spectral Angle Mapper (SAM) classification; color of spectra corresponds to color of the class. Field and image spectra are added for comparison. (B) SAM classification based on laboratory spectroscopy.
Figure 5. Patrick Draw area, showing previously determined points of microseeping, associated lineaments, anomalous area (in black), and outline of transitional member of Fort Union Formation.
