Fracture history of the Divide Creek and Wolf Creek anticlines and its relation to Laramide basin-margin tectonism, southern Piceance Basin, northwestern Colorado

Abstract

Zl Introduction Zl General geology Z2 Lithology Z5 Structural setting Z6 Economic significance of fractures Z6 Previous studies of joints in the Piceance basin Z7 Procedure and techniques Z7 Joint sets of the Piceance basin and Grand Hogback monocline Z8 Piceance system Z8 Hogback system Z10 Joint sets of the Divide Creek and Wolf Creek anticlines Z10 Discussion Z14 Distribution of MV2 set Z15 Presence and prominence of local fold-parallel fractures Z16 Distribution of fractures of the Piceance system Z18 Fracture history and fluid movement Z20 Timing of fracture formation Z20 Fluid movement through upper Mesaverde and lower Wasatch strata Z22 Comments on coal Z22 Concluding remarks Z22 References cited Z23 Appendix Summary of characteristics of fracture sets Z28 FIGURES 1-2. Maps showing: 1. Location of study area, late Paleozoic uplifts, and Tertiary basins and uplifts, northeastern part of Colorado Plateau and adjacent Rocky Mountain foreland Z3 2. Geology of area of Divide Creek and Wolf Creek anticlines and part of Grand Hogback monocline Z4 3. Vertical section through study area showing combined interpretation of seismic, gravity, and drill-hole data Z5 4 6. Maps showing: 4. Regional distribution and orientation of joints of Fj F4 sets in Piceance basin Z9 5. Average orientation of joints of MV2 fracture set in study area, southern Piceance basin Z12 6. Average orientation of joints of fold-parallel fracture sets in study area, southern Piceance basin Z13 7. Photographs showing fold-parallel fractures in sandstone bed of Wasatch Formation on Divide Creek anticline Z14 8. Map showing average orientation of joints of F: fracture set in study area, southern Piceance basin Z15 Contents III IV Contents

Insights into the growth of basement uplifts deduced from a study of fracture systems in the San Rafael monocline, east central Utah

“…The approach follows that of previous workers who have examined fracture system architecture or regional stresses in basement uplifts in the Colorado Plateau and elsewhere [e.g., Hodgson, 1961;Wise, 1963;Reches, 1978;Paylor et al, 1989;Ameen, 1990;Grout and Verbeek, 1992;Wise and Obi, 1992;Evans et al, 1993;Engelder et al, 1997;Gregson and Erslev, 1997;Mollema and Aydin, 1997;Davis, 1999;Tindall and Davis, 1999].…”

Tectonic trends of the northern part of the Paradox Basin, southeastern Utah and southwestern Colorado, as derived from Landsat multispectral scanner imaging and geophysical and geologic mapping: Uncontrolled X-band radar mosaic of the western part of the Moab 1° x 2° quadrangle, southeastern Utah and southwestern Colorado

“…lOC) relative to the north-northeast-and northeast-trending joints (M.A. Grout, U.S. Geological Survey, written cornmun., 1991) also suggests a significant counterclockwise rotation of the stress field through time since the main phase of the Laramide orogeny, as documented for the adjacent Piceance Basin (Grout and Verbeek, 1991 figure 12 and listed with stratigraphic information in table 1.…”

“…7A) is clearly coincident with one of the youngest joint sets in the Piceance Basin; the joints formed during final uplift of the basin and are 10 million years old or younger (Grout and Verbeek, 1991). In the Marble plateau area of northern Arizona joint sets at N. 10°-15° E. are of post-Laramide age (Sutphin and Wenrich, 1988).…”

Use of diverse geochemical data sets to determine sources and sinks of nitrate and methane in groundwater, Garfield County, Colorado, 2009

“…The thickness of the Wasatch Formation ranges from about 365 m near the southern end of the Divide Creek anticline to more than 1,710 m along the west side of the study area (URS Corporation, 2006). The Divide Creek anticline, located in the southeastern part of the study area, plunges into the central part of the study area (Hoak and Klawitter, 1977;Grout and Verbeek, 1992;URS Corporation, 2006). Structural features (for example, faults and fractures) associated with the anticline may be important pathways for water or gas movement, or both, from deeper to shallower zones in the area (URS Corporation, 2006).…”