From introduction: The goal of this basin analysis study is to reconstruct the fluvial depositional system of the upper part of the Pennsylvanian and Permian Maroon Formation in the Eagle basin, northwest Colorado.

From abstract: The Piceance basin of western Colorado contains large reserves of natural gas in low-permeability reservoirs of the Late Cretaceous-age Mesaverde Formation or Mesaverde Group. The gas accumulation can be divided into three general zones: a zone of surface-water invasion that extends inward a few miles from present outcrops, a gas-and-waterbearing zone that extends 10-20 miles inward from the water-bearing zone, and a central, predominantly gasbearing zone.

From abstract: This report concerns a comparison of detailed measured sections and geophysical well-log profiles through the Sego allows subsurface identification of both depositional cycles and lateral facies changes.

From abstract: The Frontier Formation of the Mancos Group in northeastern Utah and northwesternmost Colorado (proposed new rank designations; formerly known as the Frontier Sandstone Member of the Mancos Shale) consists of several facies of marine and nonmarine rocks of Late Cretaceous (Turonian) age that grade eastward into totally marine rocks in easternmost Utah and northwestern Colorado.

From abstract: This report analyzes the 4-5 million years of depositional history of the Upper Cretaceous Lower Tertiary Rocks along the Green River.

From abstract: Middle Cretaceous rocks (Aptian to Coniacian) on the south side of the Uinta Basin include the nonmarine Cedar Mountain Formation and Dakota Sandstone and the lower part of the overlying marine Mancos Shale. This report examines the rocks contained within this area of the basin.

From abstract: Three closely spaced wells drilled through the Upper Cretaceous Mesaverde Group and were extensively cored and logged in order to identify the factors controlling the occurrence and distribution of gas in low-permeability rocks and to improve recovery technology.

From abstract: Analysis of vitrinite reflectance profiles and surfaces of equal vitrinite reflectance in the southeastern part of the Piceance basin, northwestern Colorado, indicates that burial histories for the Divide Creek anticline and the Grand Hogback are different from those for adjacent synclines. These two positive structures probably reached their present-day thermal maturity before late Eocene folding and before the end of the Laramide orogeny. In contrast, adjacent synclines did not reach their present-day thermal maturity until the end of the Laramide orogeny, or possibly later.

From abstract: This is a report on reconnaissance geologic mapping and isotopic dating of tuff beds in the Uinta Basin of Utah that show that Lake Uinta probably persisted into late Eocene time in the area east of Duchesne and Strawberry Reservoir.

From abstract: This report explores the Central Roan Plateau Area of Northwestern Colorado as it includes formations of the Late Cretaceous age, Paleocene age and Eocene age. There are superficial deposits of the Quaternary age and exposed rocks of the Eocene age.

From abstract: Seismic reflection data from the southern part of the Uinta basin near Price, Utah reveal a network of late Paleozoic faults that produced abrupt variations in stratigraphic thicknesses in a structurally complex 30-mi-wide northwest-southeast-trending trough.

From abstract: Siliciclastic and minor carbonate rocks of the lower part of the Middle Pennsylvanian Minturn Formation of north-central Colorado were deposited in alluvial-fan, braidplain, Gilbert-delta, shoreline, and paralic, and offshore-marine environments. These strata can be divided into twelve genetic sequences that are generally bounded by transgressive surfaces of erosion or paralic flooding surfaces, and are characterized by thin and thick transgressive units. This report examines the paleogeography of this area.

From abstract: A study of mean random vitrinite reflectance of surface and near-surface samples was conducted in western Colorado and eastern Utah in order to better understand the subsidence and thermal histories of the Laramide-age Uinta and Piceance basins and to estimate the the thickness of overburden removed from the two basins. The history of uplift on some of the adjacent Laramide uplifts were also studied.

From abstract: In the Sawatch, Mosquito and Front Ranges of central Colorado and the Sangre de Cristo Mountains of south-central Colorado, Tournaisian beds of the Mississippian Leadville Limestone overlie rocks of Early Mississippian and Late Devonian age. In the Sangre de Cristo Mountains in north-central New Mexico, the oldest beds are the Tournaisian (zone 9) Espiritu Santo Formation. In west-central New Mexico, in the Magdalena, Lemitar, and Ladron Mountains, the Kelly Limestone of Tournaisian and Visean age rests unconformably on Proterozoic metamorphic and igneous rocks. This report examines the stratigraphy of this area.

From abstract: Seventeen stratigraphic sections totalling 4,514.3 m were investigated and previous reports studied in order to clarify and illustrate the stratigraphy of most of the Eocene part of the fluvial and lacustrine Green River Formation in the south-central part of the Uinta basin of Utah.

From abstract: This report is an in-depth observation of the structural evolution of gilsonite dikes in the eastern Uinta basin of Utah.

From abstract: This report describes the North Horn Formation in the eastern part of the San Pitch Mountains of Utah was deposited in nonmarine environments that included alluvial fans, varied fluvial and overbank settings, and lacustrine settings.