OF-99-01 Evaluation of Mineral and Mineral Fuel Potential of Phillips County State Mineral Lands Administered by the Colorado State Land Board


Includes a general summary of the geology and mineral and mineral fuel potential of Phillips County along with topographic and geologic maps of tract locations. The main body of the report is an evaluation of the resource potential for oil and gas, coal, metallic minerals, and industrial minerals for individual tracts. Digital PDF download. OF-99-01D

Four general categories of resources are included in this inventory:

  • oil and gas
  • coal
  • metallic minerals
  • industrial minerals and construction materials

Each individual tract evaluation includes:

  • A bar graph which ranks each tract’s resource potential for each of the four mineral categories. An explanation of the categories may be found at the end of this introduction
  • Tract identifier number, county name, and county location map
  • Tract location on a 7-1/2-minute United States Geologic Survey topographic map
  • Tract location on a United States Geologic Survey surface outcrop map
  • Location as to section, township, and range and approximate acreage
  • Overview of tract geology
  • Specific assessment of the resource potential for the four resource categories
  • References used in assessing tract potential

From the Introduction:

Phillips County is situated high on the gently dipping east flank of the sedimentary Denver Basin of northeast Colorado, southeast Wyoming, and the southern panhandle of Nebraska. Mineral resources are limited to sand and gravel, sourced primarily from Pleistocene and Holocene age river and stream alluviums and associated terrace deposits in the South Platte River valley. There were no metallic minerals or coal. Oil and gas production in Phillips County has been established from two horizons; Upper Cretaceous Niobrara Formation chalks and Lower Cretaceous Dakota Formation sandstones.