LAND STATE BOARD MINERAL INVENTORY
Summary of Resources
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Oil & Gas Coal Metallic Industrial Minerals Minerals
Resource Category
TRACT IDENTIFIER: 57-49 COUNTY: Jackson LOCATION: This tract is located in the North Park Basin about two miles east of State Highway 14 and about eight miles south of Hebron. There is an unimproved road and an improved road in the tract. Legal Description: T. 6 N., R. 80 W. Section(s): 16 Approximate total acreage: 640 QUADRANGLE NAME(S): Spicer Peak, Buffalo Peak
OVERVIEW OF GEOLOGY: This tract is located in the North Park Basin and is comprised of the Tertiary Coalmont Formation, middle and upper members, overlain by Quaternary gravels and alluvium. Surficial deposits on the tract consist of the following units: (Qg) Young Gravels (Pleistocene): Stream, terrace, and outwash gravels. The bedrock geology of the property consists of the following units: (Tc) Coalmont Formation (Eocene and Paleocene): Sandstone, conglomerate, and carbonaceous shale; contains coalbeds. Estimated maximum thickness is 11,000 feet. OIL AND GAS RESOURCES: Three dry holes were drilled within to two miles of the tract. Oil is produced from fractures in the Cretaceous Niobrara Formation at the Coalmont, Grizzly Creek, and Grizzly Creek Southeast fields. The Coalmont field is located in section 35 and 36, T. 7 N., R. 81 W. The Grizzly Creek field is located in section 6, T. 6 N., R. 80 W. and has been shut in since 1985. The Grizzly Creek Southeast field is located in section 8, T. 6 N., R. 80 W. The table below contains summary information on these fields. Field Name Coalmont Grizzly Creek Grizzly Creek Southeast Discovery Date 1973 1982 1993 Producing Formation Niobrara Niobrara Shannon Ss. Niobrara Cumulative Oil Production @ 1996 181,921 BO 1,342 BO 1,535 BO Cumulative Gas Production @ 1996 85,337 MCFG 0 MCFG 0 MCFG
Table 1. Production from nearby oil and gas fields (BO= Barrels of oil; MCFG= thousand cubic feet of gas)
In the eastern part of the North Park Basin, there are several important structural traps in Upper Jurassic and Lower Cretaceous rocks (such as Lone Pine, McCallum, and Canadian River fields). There are no known structures in these rocks in the tract area (Maughan, 1988). Undiscovered Resources: The Niobrara Formation lies at an estimated depth of 4,000 to 5,000 feet in this tract. There is fair potential for fractured Niobrara oil production in this tract. COAL RESOURCES: This tract is located in the North Park coal field. Significant subbituminous coal resources were recovered from the coal Riach bed of the lower Coalmont Formation in section 26, T. 7 N., R. 81 W., about eight miles to the north. In the Coalmont quadrangle, north of the Spicer Peak quadrangle, the Riach coal bed ranges from 25 to 80 feet in thickness (AAA Engineering and Drafting, 1979; Erdman, 1944).
Coal bed Riach
BTU 9,570
C, % 54.98
O, % 29.75
H, % 5.99
N, % 1.21
S, % 0.74
Ash, % 7.33
Table 2. Chemical analysis of a Coalmont Formation coal bed (Henkes, 1957).
As of 1941, total production from the Coalmont Mine was 1.5 million tons; remaining reserves were 177 million tons with 53 million being recoverable (Erdman, 1944). Coal was last produced in the district from the Grizzly Creek Strip, section 32, T. 7 N., R. 80 W.; the mine operated for only one year, 1975, and produced 65,000 tons. The Riach coal bed is laterally discontinuous and pinches out rapidly away from the Coalmont Mine. There are no known or measured coal beds within three miles of the tract. METALLIC MINERAL RESOURCES: This tract is not prospective for metallic mineral resources. INDUSTRIAL MINERALS AND CONSTRUCTION MATERIALS RESOURCES: There are about 200 acres of young gravel deposits containing sand and gravel of unknown quality. Identified Aggregate Resource: There are 200 acres of sand and gravel deposits of unknown quality in the tract. Assuming a density of 111-lbs./cubic foot, and a thickness of 15 feet, there is 7.2 million tons of sand and gravel resource on the tract.
REFERENCES: AAA Engineering and Drafting, Inc., 1980, Coal resource and coal de...