Kaiparowits Basin Research Articles

Basin‐axial progradation of a sediment supply driven distributive fluvial system in the Late Cretaceous southern Utah foreland

AbstractThe Turonian‐Coniacian Smoky Hollow Member of the Straight Cliffs Formation in the Kaiparowits basin of southern Utah records a stratigraphic transition from isolated fluvial channel bodies to increasingly amalgamated channel belts capped by the Calico bed, a sheet‐like sand‐gravel unit. Characteristics of the Smoky Hollow Member are consistent with a prograding distributive fluvial system including: up‐section increases in average grain size, bed thickness, channel‐body amalgamation, a fan‐shaped planform morphology and a downstream increase in channel sinuosity. The system prograded to the northeast based on thickness and facies patterns, and palaeocurrent indicators. This basin‐axial sediment‐dispersal trend, which was approximately parallel to the fold‐thrust belt at this latitude, is supported by provenance data including detrital zircons and modal sandstone compositions indicating sediment derivation mainly from the Mogollon Highlands and Cordilleran magmatic arc to the southwest, with episodic input from the more proximal Sevier fold‐thrust belt to the west. Progradation occurred during a eustatic still‐stand, relatively stable climatic conditions, and continuous tectonic subsidence, thus suggesting increased extrabasinal sediment supply as a primary control on basin‐fill. Progradation of the Smoky Hollow Member fluvial system culminated in a ~2–3 My hiatus at the top of the lower Calico bed. Correlation with the Notom delta of the Ferron Sandstone, 80 km northeast in the Henry basin, is proposed on the basis of facies relationships and geochronology. The Calico bed unconformity is linked to regional tectonically driven tilting and erosion observed in both basins.

Development of large‐scale seismites in Upper Cretaceous fluvial sandstones in a fault‐proximal setting

AbstractLarge‐scale soft‐sediment deformation structures occur within fluvial sandstone bodies of the Upper Cretaceous Wahweap Formation in the Kaiparowits basin, southern Utah, USA. These structures represent an exceptional example of metre‐scale fault‐proximal, seismogenic load structures in nearly homogenous sandstones. The load structures consist of two types: large‐scale load casts and wedge‐shaped load structures. Large‐scale load casts penetrate up to 4·5 m into the underlying sandstone bed. Wedge‐shaped load structures include metre‐scale, parallel, sub‐vertical features and decimetre‐scale features along the periphery of the large‐scale load casts or other wedge‐shaped load structures. Wedge‐shaped load structures contain well‐developed, medial cataclastic shear deformation bands. All load structures contain pervasive well‐defined millimetre‐thick to centimetre‐thick internal laminae, oriented parallel to the outside form of the load structures and asymptotic to deformation bands. Both types of load structures formed because of an inverted density profile, earthquake‐triggered liquefaction and growth of irregularities (a Rayleigh–Taylor instability) on the sandstone–sandstone erosional contact. The internal laminae and deformation bands formed during deformation and clearly demonstrate polyphase deformation, recording a transition from liquefied to hydroplastic to brittle modes of deformation. Decimetre‐scale wedge‐shaped load structures on the edge of the large‐scale load casts probably formed towards the end of a seismic event after the sediment dewatered and increased the frictional contact of grains enough to impart strength to the sands. Metre‐scale wedge‐shaped load structures were created as the tips of downward foundering sediments were driven into fractures, which widened incrementally with seismic pulsation. With each widening of the fracture, gravity and a suction effect would draw additional sediment into the fracture. Superimposed laminae indicate a secondary syndeformational origin for internal laminae, probably by flow‐generated shearing and vibrofluidization mechanisms. Large‐scale and wedge‐shaped load structures, polyphase deformation and secondary laminae may characterize soft‐sediment deformation in certain fault‐proximal settings.

Magnetostratigraphy of Upper Cretaceous strata in Grand Staircase-Escalante National Monument, southern Utah: The Santonian–Campanian Stage boundary, reassessment of the C33N/C33R magnetochron boundary, and implications for regional sedimentation patterns within the Sevier Foreland Basin

Samples were collected for magnetostratigraphic analysis from the Upper Cretaceous Straight Cliffs and Wahweap formations within Grand Staircase-Escalante National Monument, southern Utah, in an attempt to locate the C34n–C33r and C33r–C33n boundaries; the former approximates the Santonian–Campanian Stage boundary. Locating both of these horizons within the Monument provides for refined temporal resolution of the many new fossil localities discovered in these units, while also adding to our understanding of the overall Straight Cliffs–Wahweap sequence stratigraphic architecture. Results indicate that the John Henry and Drip Tank members of the Straight Cliffs Formation are of normal polarity, and represent the later part of C34n, the Cretaceous Normal Polarity Super-Chron. The C34n–C33r boundary apparently resides in a significant hiatus determined to occur between the Drip Tank Member of the Straight Cliffs Formation and the lower part of the overlying Wahweap Formation. In stratigraphically ascending order, the informally named lower, middle, and most of the upper members of the Wahweap Formation are of reversed polarity. The C33r–C33n polarity change occurs in the upper part of the upper member, and C33n continues stratigraphically upward through the capping sand member of the Wahweap Formation and into the overlying Kaiparowits Formation. The presence of over 200 m of reversely magnetized strata above a level in the lower part of the middle member dated to 79.9 ± 0.3 Ma, which coincides with the GTS2012 date for the C33r–C33n boundary of 79.9 Ma, suggests that the published age of that boundary may be in error. A new date of approximately 78.91 Ma is proposed, in turn allowing for the thick sequence of reversely magnetized strata above the 79.9 Ma level. Age revision of the Kaiparowits Basin's Late Cretaceous record demonstrates that during late Santonian through early middle Campanian time, except in central Utah, a close correlation in time and facies successions with other successions throughout the Western Interior Basin suggests a eustatic influence on the depositional patterns. Starting in the late middle Campanian, the Kaiparowits record, along with those both to the north and south, appear to diverge in style and facies successions. We consider this to have resulted from a fundamental change in depositional controls triggered by the Laramide Orogeny. The anomalous central Utah record appears to have been profoundly influenced by a massive salient (Nebo-Charleston thrust system) in the Sevier Fold and Thrust belt that was active for much of the Late Cretaceous.

Baenid turtles of the Kaiparowits Formation (Upper Cretaceous: Campanian) of southern Utah, USA

I describe the assemblage of baenid turtles found in the Campanian Kaiparowits Formation of southern Utah and compare it with baenids from other basins across Laramidia. Baenids were one of the most diverse and abundant freshwater turtle clades during the Late Cretaceous. They were restricted to North America, with all except the basal-most taxon (Arundelemys) restricted to Laramidia. During the Campanian, baenids were conspicuous parts of the turtle assemblages of Alberta, Montana and New Mexico. The baenids of the Kaiparowits Formation are critical in that they provide an assemblage from southern Laramidia that is correlative with those from northern Laramidia, allowing for more accurate testing of Campanian palaeobiogeographical hypotheses. In this paper, two new baenid species, Neurankylus hutchisoni sp. nov. and Neurankylus utahensis sp. nov., are described. Additionally, the first description of cranial material from Denazinemys nodosa is provided. A comprehensive survey of collected material indicates that at least six baenid taxa are present in the formation, including Neurankylus hutchisoni, Neurankylus utahensis, Thescelus sp., Arvinachelys goldeni, Denazinemys nodosa and Boremys grandis. Arvinachelys, Neurankylus hutchisoni and Neurankylus utahensis have not been identified outside of the Kaiparowits Basin, but Denazinemys nodosa and Boremys grandis both are known from younger sediments of the San Juan Basin of New Mexico. Members of the genus Thescelus are known from the Campanian of New Mexico and the Maastrichtian of Wyoming, Montana and Saskatchewan, but are conspicuously absent in the Campanian of Alberta and Montana. The baenid assemblage in the Kaiparowits Formation provides support for both basin-scale endemism and north–south provincialism across Laramidia during the Campanian. There is also evidence for a latitudinal gradient in diversity, as only three baenid species have been reported from the temporally correlated Dinosaur Park Formation in Alberta.http://zoobank.org/urn:lsid:zoobank.org:pub:75DF6CFF-3E87-4729-9798-975C0157514F

Growth faults in the Kaiparowits Basin, Utah, pinpoint initial Laramide deformation in the western Colorado Plateau

Growth faults and synorogenic sedimentary strata preserved in Upper Cretaceous units on the margin of the Kaiparowits Basin in southern Utah pinpoint the timing of onset of the Laramide orogeny in this region between 80 and 76 Ma. The newly identified listric normal faults, exposed in the steep limb of the East Kaibab monocline, sole into shales and evaporites of the Jurassic Carmel Formation. Faults lose displacement up-section through the Cretaceous Wahweap Formation and are associated with numerous coseismic sedimentary features. Fault orientations and slip vectors yield strain directions consistent with fold-related extension parallel to the axis of the growing East Kaibab monocline, or with development of a pull-apart basin at a bend in the trend of the fold. The association of the faults with the steep limb of a major basement-cored structure links them to initial Laramide movement along the Kaibab Uplift. When combined with recent radiometric ages of rock units bracketing the fault-induced growth strata, these sedimentary and structural features narrowly define the onset of Laramide deformation in the western Colorado Plateau.

The interaction of aeolian and fluvial processes during deposition of the Upper Cretaceous capping sandstone member, Wahweap Formation, Kaiparowits Basin, Utah, U.S.A.

Detailed examination of the Upper Cretaceous capping sandstone member of the Wahweap Formation in the Kaiparowits Basin, Utah reveals the presence of aeolian stratification. Deposition by aeolian processes is recognized and distinguished from subaqueous deposition by the presence of centimeter-scale, inversely graded wind-ripple stratification. The aeolian stratification in the Wahweap Formation is the first occurrence reported from Upper Cretaceous strata on the Colorado Plateau of the western U.S.A. Aeolian stratification occurs as thin wind-reworked caps of fluvial-bar sandstones deposited within low-sinuosity braided streams and as more extensive deposits of small-scale dunes that developed in geographically restricted dune fields. Aeolian reworking of bars took place during low-stage flow and was possibly controlled by intermittent (seasonal) discharge variations. Prolonged aridity led to increased sand supply entering the aeolian system, dunes nucleated and grew rapidly between the braided stream systems. These small-scale dunes rarely developed extensive or tall slip faces as evidenced by the rare preservation of grain flow strata and the dominance of wind-ripple stratification. The dune field was characterized by sinuous-crested dunes, probably barchans, amid and linked to the extensive braided stream systems. Based on modern analogs, the resulting change in sand storage/supply probably is related to a short-term shift to a more semi-arid/arid climate, possibly seasonally. However, a longer-term climate change to semi-arid/arid may be indicated for the dune complex near the boundary with the overlying Kaiparowits Formation.

Tectonically Controlled Sequences In Fluvial Deposits, Upper Cretaceous Strata Of The Kaiparowits Basin, Utah

Tectonically Controlled Sequences In Fluvial Deposits, Upper Cretaceous Strata Of The Kaiparowits Basin, Utah

Effects of Grazing on the Vegetation of the Blackbrush Association

Four communities or sites dominated by blackbrush (Cokoflne rumosissima Torr.) were studied in the Kaiparowits Basin of southern Utah and northern Arizona. One site has been heavily grazed yearlong for about 100 years; the second has been lightly to moderately grazed in winter for 3 years; the third has had 10 years of recovery from heavy grazing; and the fourth is a relic, ungrazed blackbrush ecosystem. Soils were 87 to 99% sand and gravel with mean pH’s 8.2 to 8.5. The relic site had significantly more herbaceous vegetation cover (composed primarily of perennial grasses) and total cover than all other sites. The relic site also had significantly more shrub and cryptogamic cover than the heavily grazed and recovery sites. The recovering site showed no significant differences than the heavily grazed site for any of the measured parameters.

Kaiparowits Basin: An Old Frontier with New Potential: ABSTRACT

Situated in the western part of the Colorado Plateau in Utah, the Kaiparowits basin is one of the least explored of the major Rocky Mountain geologic provinces. The Kaiparowits is not a topographic but a stratigraphic basin that began as an early to middle Paleozoic oceanic embayment that stretched slightly east of the shallow shelf transitional hinge line. The full depositional history of the Kaiparowits area records the alternation of basinal sedimentation (early to middle Paleozoic, parts of the Permian, middle to late Mesozoic) and plateau uplift (late Paleozoic-early Mesozoic, late Tertiary-Holocene). Its present configuration is the result primarily of Laramide tectonism. In its overall tectonic aspects, the Kaiparowits describes a large triangular region in which, rom west to east, the structural grain rotates about 70° from a northeast to a northwest trend, with the intensity of deformation decreasing considerably. To date, the only commercially productive area in the basin is the Upper Valley field, where hydrocarbons have been recovered primarily from dolomitized carbonates of the Kaibab Formation and Timpoweap Member of the Early Triassic Moenkopi Formation. Entrapment is within the strongly asymmetrical, doubly plunging Upper Valley anticline, where an active water drive has offset the oil pool onto the steeply dipping western limb. Live oil shows have been reported from nearly every pre-Jurassic formation in the region. Despite this, very few (170) exploratory wells have been drilled in this vast territory of nearly 22,000 mi2 (57,000 km2). Recently, however, a discovery of a different type has indicated the basin contains tremendous amounts of CO2 gas reserves that could prove useful for both ongoing and future secondary recovery programs. At the very least, it is probable that most of the true potential of the Kaiparowits has thus far been overlooked, partially due to the rugged and isolated terrain. It is one of the least densely drilled provinces in the Rockies with one of the highest concentrations of probable source and reservoir rocks. End_of_Article - Last_Page 943------------

Pollutant sorption by desert soils.

The sorption experiments reported upon in this paper were undertaken to provide data for an ecosystem model to predict the potential impact of coal-fired power plants on the cool desert ecosystem found in the Kaiparowits Plateau and the Kaiparowits Basin of northern Arizona and southern Utah. Natural conditions were simulated by passing pollutant-containing air streams over the surface of soil samples.

Patterns of Natural Revegetation in Arid Southeastern Utah

adapted species and to the unpredictability of natural precipitation. This study was designed to sift the native flora of the benchlands of the Kaiparowits Basin, a potentially important coal field, for native species capable of naturally recolonizing disturbed sites. We also provide some information concerning ecological situations where such species might best be used.

Kaiparowits and Black Mesa Basins--Stratigraphic Synthesis: ABSTRACT

The Black Mesa and Kaiparowits Basin area is located in the southwest portion of the Colorado Plateau Structural Province. The Black Mesa basin, encompassing approximately 6400 square miles, extends from the Kaibab upwarp on the west to the Defiance uplift on the east; from the Mogollon Rim on the south to the Utah-Arizona line on the north. The Kaiparowits basin covers approximately 8500 square miles and is bounded by the Sevier and Paunsaugunt faults which delineate the east edge of Basin and Range structures and by the Circle Cliffs upward on the east. To the north the Kaiparowits basin passes under the extensive Tertiary flows of the Aquarius Plateau. Throughout most of Paleozoic time, the Black Mesa and Kaiparowits basin area occupied an extensive shelf area between the Ancestral Sierra Grande on the east and the Cordilleran geosyncline on the west. Cambrian, Devonian, Mississippian, Pennsylvanian and Permian sedimentary units are present in the subsurface. No rocks of Ordovician or Silurian age are recognized. Rocks of Permian age and younger are commonly exposed. Paleozoic strata are products of marine sedimentation on the shelf which bordered the Cordilleran geosyncline. Stratigraphic or depositional strike was apparently controlled by adjacent low-lying land masses and embayments into the shelf area from the Cordilleran geosyncline. Orogenic activity, beginning in Late Pennsylvanian and continuing through the Tertiary affected sedimentation during this portion of geologic time as the seas periodically withdrew and encroached upon the shelf area. Large anticlinal features are present in both basins which appear to have had an early history and offer many favorable possibilities for oil and gas production in areas of favorable stratigraphy. End_of_Article - Last_Page 1874------------

Paleozoic Stratigraphy and Oil Possibilities of Kaiparowits Region, Utah

The Kaiparowits region, as defined in this report, covers more than 8,500 square miles in southern Utah. It is essentially a part of a great platform area between the Paradox basin on the east and the Great basin on the west. The Kaibab and Circle Cliffs upwarps, separated by the Kaiparowits basin, are the major structural elements in the region. Cambrian, Devonian, Mississippian, Pennsylvanian, and Permian sedimentary units are present in the subsurface, of which only the Permian is exposed. The lower Paleozoic strata are characteristic products of marine sedimentation on a broad platform bordering the Cordilleran geosyncline. Epeirogenic movements prior to the deposition of the Devonian, and again before Pennsylvanian beds were laid down, were responsible for regional unconformities in pre-Pennsylvanian rocks. Commencing in the early Pennsylvanian, the Kaiparowits region underwent mild orogenic activity related to the ancestral Rockies. The Kaibab and Circle Cliffs uplifts became positive at this time, profoundly affecting sedimentation in the Pennsylvanian strata in a westwardly direction. Continued uplifting caused complet withdrawal of the seas, and in later Wolfcampian time sand dunes swept across most of the region. In Permian Leonardian time the seas again encroached from the west, effecting the deposition of the Toroweap evaporites in a basin in the vicinity of the present Kaiparowits downwarp. The Toroweap passes into a sandstone facies toward the north and east, and is closely related to the Coconino and White Rim sandstones. Equivalents of the Coconino sandstone are found throughout the region, but they occupy only a small interval in the thick sandstone sequences found in the Permian of east-central Utah. The Kaiparowits region has remarkably few major faults except in the western part. A number of anticlinal features exist that have not been drilled for oil or gas, and stratigraphic conditions are favorable for petroleum production at many localities.