Paradox Formation Research Articles

Oil and Gas Developments in Utah and Nevada in 1955

Exploratory tests in Utah and Nevada averaged 4,488 feet in depth, or a total footage of 359,045 feet in 1955, a decrease of 8.7% from the preceding year. Greatly decreased drilling in Nevada was responsible for the decrease in total footage. Discovery of the second commercial productive oil reservoir in the Paradox formation at North Boundary Buttes in the Paradox basin of Utah, and the discovery of commercial quantities of gas at San Arroyo in east-central Utah, high-lighted 1955 activities. New Uinta basin gas fields were discovered at Bluebell, Chapita Wells, Southman Canyon, and Walker Hollow. In east-central Utah new gas fields were found at Westwater Creek and East Seiber Nose. A new oil field was found in the same general area at Seiber Nose. Another Utah gas discovery was made at Joe's Valley on the Wasatch Plateau, and a gas-distillate field, producing from the Paradox formation in the Paradox basin, was found at Coalbed Canyon in 1955. There were no new discoveries in Nevada. An important extension to the oil and gas field at Red Wash was made in Utah in 1955. Dry exploratory tests on the Wasatch Plateau, in the Paradox and Uinta basins, in southern and east-central Utah, and in eastern Nevada furnished valuable geological information. Exploratory methods in Utah are largely unchanged from previous years. The majority of locations were based on surface, seismic, or a combination of the two, methods. Gravity methods increased 1.7 times over 1954, due to preliminary evaluation of parts of the Utah portion of the Paradox basin and the Great Basin area of western Utah. Somewhat greater emphasis was placed upon subsurface studies and stratigraphic relationships in Utah. Nevada exploration was largely conducted by seismic, gravity, and surface methods. Stratigraphic developments and changes in nomenclature during 1955 are summarized. The principal trends expected in 1956 are: the same or decreased activity in eastern Nevada, very minor activity in the Utah part of the Basin-and-Range Province, and approximately the same amount of work in the Utah part of the Paradox basin, the Uinta basin, and the Wasatch Plateau

Tectonics of Paradox Basin and Its Relation to Oil Occurrence: ABSTRACT

The Paradox basin is defined as the areal extent of the Pennsylvanian evaporitic Paradox formation in the Four Corners area. Two areas of uplift, the Fort Defiance and San Luis, influenced sedimentation throughout the entire Paleozoic. The Uncompahgre uplift developed during early Pennsylvanian time and remained active through the Permian. Possible stratigraphic traps are postulated for the Devonian and Mississippian sediments in the proximity of the Fort Defiance and San Luis uplifts. Tectonism during the Pennsylvanian has given rise to potential reef production in beds bordering the evaporite basin. Stratigraphic porosity trends within the Paradox evaporite basin have yielded oil and gas. The major duty of the stratigrapher will be to determined the porosity belts. Sand pinch-outs may be expected in proximity to the uplifted areas in both Pennsylvanian and Permian sediments. End_of_Article - Last_Page 789------------

Oil and Gas Developments in Utah and Nevada in 1954

Exploratory tests in Utah and Nevada averaged 4,230 feet in depth, or a total footage of 393,399 feet in 1954, an increase of 12.9 per cent over the preceding year. Greatly increased drilling in Nevada was responsible for the increase in total footage. Discovery of the first commercially productive oil reservoir in the Paradox formation at Desert Creek in the Paradox basin of Utah and the first discovery of commercial quantities of oil in Nevada high-lighted 1954 activities. New Utah oil fields were also discovered at Brennan Bottoms and Jacks Canyon in the Uinta basin, and the Cisco Townsite and Crescent Junction areas in the east-central part of the state. Entrada formation gas was discovered in the West Bar X area of eastern Utah. Important extensions to the gas fields at Clear Creek and Peters Point were made in Utah in 1954. Dry exploratory tests on the Wasatch Plateau, in the Paradox and Uinta basins, in central and east-central Utah, and in Nevada furnished valuable geologic information. Exploratory methods in Utah are unchanged from previous years. Surface, seismic, or a combination of surface and seismic methods accounted for eight of the nine discoveries. In Nevada, gravity and seismic activity increased sharply over previous years. The discovery well was located by seismic methods. Stratigraphic developments during 1954 are summarized. The principal trends expected in 1955 are: greatly increased activity in eastern Nevada, increased activity in the Utah part of the Basin and Range Province, and an accelerated program in the Utah part of the Paradox basin. It is expected that exploration in the Uinta basin and Wasatch Plateau areas of the Utah will be approximately the same as in 1954.

Paradox Formation: ABSTRACT

The principal occurrence of the Paradox formation is in a northwest-southeast trending basin west of the Uncompahgre uplift, chiefly in southwest Colorado and adjacent portions of southeast Utah. It extends, roughly, from Barker Dome on the Colorado-New Mexico line, northwestward to the vicinity of Green River, Utah. It is approximately 200 miles long and 115 miles wide. The town of Monticello, Utah, is near the geographical center. It is a structural basin lying between the Uncompahgre-San Juan Mountains on the east and the San Rafael-Circle Cliffs upwarps on the west. It is separated from the San Juan basin on the south by a relatively low saddle, and perhaps from the Uinta basin to the north by a similar saddle. The Paradox is a depositional wedge, within the Hermosa formation. It is lower Pennsylvanian in age. Similar sediments of black shale, gypsum, and anhydrite of Pennsylvanian age occur in the Eagle-Glenwood Springs area, east of the Uncompahgre and on the east flank of the White River uplift. While these sediments probably are equivalent to the Paradox formation, there is no evidence to indicate that the basins were ever connected, and the term Paradox formation has not been applied, officially, to the sediments in the Eagle basin. The chief exposures of the Paradox occur in Gypsum Valley, Paradox Valley, Sinbad Valley, in Colorado, and in Moab-Spanish Valley, Onion Creek, and Cache Creek-Salt Valley in Utah; all of which are commonly referred to as breached salt anticlines. In these exposures the Paradox consists of irregular beds of gypsum, limestone, dark shales and some find sands. In many places these beds are highly contorted and brecciated, indicating flowage from a deeper source, and contain blocks of foreign material dragged up from below. The maximum thickness of the Paradox is unknown, but in one occurrence it exceeds 10,800 feet, although this undoubtedly represents flowage rather than depositional thickness. Several wells which have drilled a normal section have had in excess of 2,000 feet. The section is so irregular that no correlation horizons which can be used for more than local work have been established. In the salt anticlines the section is so garbled and twisted that little bedding remains, and thickness cannot be established. No exposure out in the basin exhibits the base, but in Salt Valley blocks of conglomerate, believed to have been dragged up with the salt, may represent the underlying formation. End_of_Article - Last_Page 962------------

Geologic Structure of Southeastern Utah

Southeastern Utah, lying within the Colorado Plateau, is characterized by several types of structural features, including (a) huge asymmetrical upwarps, (b) domes associated with laccolithic intrusions, (c) the southern edge of the Uinta Basin structural depression, (d) a north-trending zone of normal faults at the west edge of the plateau, and (e) a group of numerous folds, faults, and faulted folds that are found in a limited area near Moab. Folding has occurred in the region several times since the end of the Mississippian, but the principal deformation that is reflected in the structure of the surface rocks took place at the end of the Cretaceous or early in the Tertiary and was therefore related to the Laramide orogeny. The large domical uplifts have a northerly tren and are strongly asymmetric, with the steep limb toward the east; they were formed at the end of the Cretaceous, possibly as a reflection in the surface rocks of more or less vertical uplifting along deep-seated reverse faults. The group of numerous smaller folds, faults, and faulted anticlines in the part of the region near Moab also is believed to have been formed near the end of the Cretaceous; the deformation is obviously related to the presence of the plastic salt-bearing beds of the Pennsylvanian Paradox formation beneath the surface rocks, because the structural features of this type near Moab are typically developed only within the area underlain by the Paradox formation and because the salt-bearing beds have been intruded into the overlying rocks at the crests of some of the fo ds. Events in the Tertiary structural history of the region include the intrusion of igneous rocks in four isolated mountain groups, the downwarping of the Uinta Basin, and the development of the zone of normal faults at the west edge of the plateau; it is not possible to determine the order of these events, or to determine whether they represent different modes of expression of one period of crustal disturbance.

Paradox Formation of Eastern Utah and Western Colorado

The Paradox formation consists of gypsum, anhydrite, and salt, interbedded with shale, sandstone, and limestone. It is the oldest rock exposed in several anticlines in eastern Utah and western Colorado and has been found in a number of wells in the same region. The occurrences indicate much movement of materials, apparently due to the relatively plastic character of salt deposits, and the relationships and true thickness are difficult to determine. Actual thickness in wells exceeds 6,000 feet, but the maximum original thickness may not have been more than about 2,000 feet. The Paradox formation is believed to be conformable with the overlying Hermosa formation and unconformable on the underlying Mississippian beds, though normal contacts have not been observed. The format on contains a few fossil plants, invertebrates, and conodonts which agree in indicating a lower Pennsylvanian age, though the writers infer that the Paradox is wholly older than the Hermosa formation. It is suggested that the Paradox formation occupies an elongated basin southwest of the Uncompahgre uplift and that it thins out southward at Elk Ridge, Utah; westward at San Rafael Swell, Utah; eastward at the Uncompahgre uplift. It is also suggested that the saliferous beds constituting the Weber shales northeast of the Uncompahgre uplift occupy another basin essentially contemporaneous with that occupied by the Paradox formation, though perhaps not connected with it.