Dakota Sandstone Research Articles

Abstract: Intravalley Cut-and-Fill Structures in Lower Cretaceous fluvial Strata of Colorado and Kansas: A Cause for Compartmentalization in Fluvial Reservoirs 

The upper Muddy Sandstone in southeastern Colorado and the Terra Cotta Member of the Dakota Sandstone in central Kansas both represent mid-Cretaceous (AIbianKenomanian) fluvial deposition in the U.S. Western Interior between marine deposition of the Kiowa-Skull Creek and Greenhorn cycles. amalgamated channel-fill, lateral accretion, and overbank-fine elements; and are channel shaped with width/ depth ratios near 14:1, and thicknesses near 7-12 m. At least in the situation of the Muddy Sandstone examples, these structures are bound by larger scale channel-shaped surfaces that represent cut-and-fill of large-scale valleys. These intravalley cut-and-fills thus exist on a scale larger than channel scours and smaller than fluvial valley scours, and seem to result froin primarily tectonic and climatic stimuli that result in temporary episodes of incision of channels into their own alluvium and subsequent filling. Because these cut-and-fill structures may be filled with a wide variety of lithofacies, the potential to generate permeability contrasts across structure boundaries is high (as is exemplified in the Terra Cotta Member). Because of their linear nature, such structures may serve as narrow conduits for petroleum migration as well. As the processes that fonn these structures are widespread in most modern fluvial systems, these structures should be universal to fluvial deposits. They, however, are rarely reported from ancient strata. These units also are characterized by intravalley cut-and-fill structures. These structures are composed of

Abstract: Dakota Sandstone Reservoirs of the San Juan Basin, New Mexico and Colorado: Deciphering Complex Facies Architecture to Develop Hidden Reserves 

Abstract: Dakota Sandstone Reservoirs of the San Juan Basin, New Mexico and Colorado: Deciphering Complex Facies Architecture to Develop Hidden Reserves 

Stratabound Geothermal Resources in North Dakota and South Dakota

Geothermal energy resources in North Dakota and South Dakota occur as low (T 130 mW m−2) in the discharge area in south-central South Dakota and anomalously low (≍30 mW m2) in the recharge area near the Black Hills and along the western limb of the Kennedy Basin in western South Dakota. Heat-flow disturbances are the result of vertical groundwater flow through fractures in the discharge area of the regional flow system in South Dakota are minor and may be significant only in deeply incised stream valleys. An important factor that controls the temperature of the resource in both North Dakota and South Dakota is the insulating effect of a thick (500–2000 m) layer of low thermal-conductivity shales that overlie the region. The effective thermal conductivity of the shale layer is approximately 1.2 W m−1 K−1 in contrast to sandstones and carbonates, which have conductivities of 2.5 to 3.5 W m−1 K−1. This low conductivity leads to high geothermal gradients (dT/dz > 50°C km−1), even where heat flow has normal continental values, that is 40–60 mW m−2. Engineering studies show that geothermal space heating using even the lowest temperature geothermal aquifers (T ≍ 40 °C) in North Dakota and South Dakota is cost effective at present economic conditions. The Inyan Kara Formation of the Dakota Group (Cretaceous) is the preferred geothermal aquifer in terms of water quality and productivity. Total dissolved solids in the Inyan Kara Formation ranges from 3,000 to more than 20,000 mg L−1. Porosities normally are higher than 20%, and the optimum producing zones generally are thicker than 30 m. The estimated water productivity index of a productive well in the Inyan Kara Formation is 0.254179 l s−1 Mpa−1. Deeper formations have warmer waters, but, in general, are less permeable and have poorer water quality than the Inyan Kara.

Evidence for social behavior in ornithopod dinosaurs from the Dakota group of northeastern New Mexico, U.S.A.

Studying the trackways of extinct animals is one of the few ways to determine social behaviors, especially herding. We present an analysis of footprint data following the method of Alexander (1989) from the Caririchnium tracksite at Mosquero Creek, New Mexico described by Lockley and Hunt (1995a). This analysis indicates that the distribution of the directions and speeds of the trackmakers is consistent with movement as a group. In addition, there is an anticorrelation (correlation coefficient=‐0.36) between footprint size and relative stride in the sense that the larger animals, were exerting less effort than the smaller animals but moving at approximately the same physical speed. As a test of the technique, a Late Triassic tracksite which was not expected to show organized movement was analyzed. This tracksite, Apache Canyon, New Mexico, had tracks of ichnogenera Pseudotetrasauropus and Grallator which show a large scatter in speed and direction.

Bee burrows in the late cretaceous (Late Cenomanian) Dakota formation, northeastern Arizona

Cretaceous burrows attributable to bees are the earliest known record of activity by those insects and are equivalent in age to, or possibly older than, the oldest known bee body fossil. The burrows consist of vertical shafts from which short lateral corridors and numerous brood cells open. They occur in a lenticular fluvial sandstone in the middle carbonaceous member of the Late Cretaceous (Late Cenomanian) Dakota Formation. A new ichnospecies, Celliforma dakotensis, is proposed for this trace fossil, which is distinguished from other members of the ichnogenus by the size of the brood cells and the nest architecture. The presence of these burrows is consistent with the environmental interpretation of this part of the Dakota Formation as representing an aggrading coastal plain.

Abstract: Clays and Cements - Their Effect on Dakota Sandstone Pores, Sand Wash Basin, Colorado

Abstract: Clays and Cements - Their Effect on Dakota Sandstone Pores, Sand Wash Basin, Colorado

Prevalence of psychotropic and anticonvulsant drug use among North Dakota group home residents.

In a previous study, the present authors reported on the prevalence of psychoactive (psychotropic and anticonvulsant) medication use among people with intellectual disability residing in community settings in the state of North Dakota, USA. The present study replicates the earlier survey. A questionnaire was sent to all group homes serving people with developmental disabilities. Questionnaires were obtained for 100% of North Dakota group home residents. Psychoactive medications (anticonvulsants included) were used by 38% of the 1384 residents represented. The results are discussed in relation to the previous study from North Dakota.

Heat Flow in the Cretaceous of Northwestern Kansas and Implications for Regional Hydrology

Temperature logs are interpreted to investigate the thermal structure of the units overlying the Kansas portion of the Cretaceous Dakota aquifer. The aim of this study is to determine if additional heat input by fluids exists and thus clarify whether the overall conductive heat flow from the basement through the sequence might be overprinted by heat advection. Although interval thermal gradients are determined for different lithologic (stratigraphic) units, the shale thermal gradients are preferred for heat-flow estimation. Shale thermal conductivity as measured in Mesozoic shales in Nebraska and South Dakota is extrapolated to the area because of the similar lithology. A few thermal-conductivity values are determined in sandstone samples of the Dakota Formation and also used in heat-flow estimation. In general, the noncalcareous, marine Cretaceous shales (Pierre, Carlile, Graneros, and Kiowa) show different thermal gradients. Gradients in the Pierre (average value 58.5°C/km) and Carlile (55.5°C/km) are slightly higher than the average gradient in the Graneros Shale (45.1°C/km) and Kiowa Formation (46.5°C/km). The higher thermal gradients are limited to the extreme northwestern corner of the study area where the Pierre and Carlile are present. The heat-flow density of 69-74 mW/m2 observed there is slightly higher than the average of 60 mW/m2 typical for central and eastern Kansas. The higher heat flow observed is in the range of data reported and mapped for northeastern Colorado and the Nebraska Panhandle on the western flank of the Chadron Arch, an area with geothermal overprint by warm fluids. Regional differences in heat flow in western Kansas seemingly are caused by the different composition, porosity, and permeability of the aquifer and the nearness to recharge areas.

Abstract: Depositional Environments and Sandstone Diagenesis in the Tyler Formation (Pennsylvanian), Western North Dakota 

Thirty-three oil well cores were examined and approximately 3,100 oil well logs were used to determine the depositional environments of the Tyler Formation (Pennsylvanian) in northwestern North Dakota. Ninety sandstone thin-sections were described and twenty-nine sandstone samples were analyzed by scanning electron microscope/X-ray microanalysis techniques to characterize sandstone diagenesis. The Tyler Formation in northwestern North Dakota is correlative with the lower unit of the Tyler Formation in southwestern North Dakota. The upper unit of the Tyler Formation in southwestern North Dakota is not present in northwestern North Dakota, contrary to previous workers suggestions. The Tyler Formation in northwestern North Dakota consists of varicolored mudstone, medium-gray claystone, thin bituminous coal beds, dark-gray shale and limestone, and gray sandstone. The upper unit of the Tyler Formation in southwestern North Dakota consists of gray sandstone, dark-gray limestone and shale, and varicolored mudstone. Lenticular sandstones present in the middle and rarely at the base of the formation, which occur in northeast-southwest linear trends, indicate that the Tyler Formation in northwestern North Dakota was deposited as a river channel system on a low-lying, prograding coastal plain. Depositional environments associated with the coastal plain include river channels, flood plains, lakes, estuaries, caliche paleosols, and backswamps. Throughout deposition of the Tyler Formation, several major river channels flowed in a predominantly southwest direction across a low-lying coastal plain and transported quartz sand toward a delta or shoreline, not identified in this study, at the margin of a shallow epeiric sea. Initially, the presence of detrital clay and infiltration clay and early hematite and chlorite coatings on quartz grains was the most important factor influencing porosity reduction in Tyler sandstones. The first major diagenetic event responsible for porosity reduction was the development of authigenic quartz overgrowths. Other cements that have contributed to porosity reduction in Tyler sandstones include amorphous silica (opal), calcite, ankerite, siderite, anhydrite, barite, hematite, and pyrite, In addition, authigenic kaolinite, illite, and chlorite have reduced porosity in Tyler sandstones. Dissolution of carbonate cement resulted in the formation of secondary porosity. Sandstone diagenesis took place shortly after sand was deposited in a marine environment, while sediments were being flushed with meteoric ground water, and while sands were being flushed with chemically evolved pore water released after diagenesis and compaction of interbedded mud-rich sequences. River-channel sandstones in northwestern and southwestern North Dakota and barrier-island sandstones present only in southwestern North Dakota contain considerable amounts of intergranular porosity. Petroliferous sandstones in southwestern North Dakota are fine- to medium-grained, well-sorted, texturally mature…

Abstract: Sequence Stratigraphic Correlation and Reservoir Analysis of the Dakota Formation, San Juan Basin, New Mexico 

Abstract: Sequence Stratigraphic Correlation and Reservoir Analysis of the Dakota Formation, San Juan Basin, New Mexico 

Abstract :Sequence Stratigraphic Correlation and Reservoir Analysis of the Dakota Formation, San Juan Basin, Northwestern New Mexico

Abstract :Sequence Stratigraphic Correlation and Reservoir Analysis of the Dakota Formation, San Juan Basin, Northwestern New Mexico

Abstract: The Dakota Group of South-Central Colorado: Controls on Sedimentation and Stratigraphy 

Abstract: The Dakota Group of South-Central Colorado: Controls on Sedimentation and Stratigraphy 

Preserving Native American Petroglyphs On Porous Sandstone

A new method of chemical treatment is proposed to improve the durability of soft, porous sandstones onto which Native American petroglyphs have been carved Cores of Dakota Sandstone from the Faris Cave site, located along the Smoky Hiil River in Ellsworth County, Kansas, were treated with ethyl silicate dissolved in a lightweight ketone carrier, and some cores were subsequently treated with a combination of ethyl silicate and silane using the same solvent. Measurement of the resulting physical properties, when compared to untreated cores, indicate the treatments substantially increased the compressive strength and freeze-thaw resistance of the stone without discoloring the stone or completely sealing the pore system. The treatment increases the durability of the stone and provides a method for preserving the petroglyphs at the site. After treating test panels at the site, the petroglyphs were treated in like manner.

Stochastic Modeling of Dakota Sandstone (Rocktown Channel Member) in Central Kansas Using Architectural-Element Analysis: ABSTRACT

Stochastic Modeling of Dakota Sandstone (Rocktown Channel Member) in Central Kansas Using Architectural-Element Analysis: ABSTRACT

Cenomanian and Turonian (Early Late Cretaceous) multituberculate mammals from southwestern Utah

Multituberculate faunas from the Dakota Formation (upper Cenomanian) and the Smoky Hollow Member of the Straight Cliffs Formation (middle or upper Turonian) are described. The presence of Cimolodon is established in the Cenomanian; a new genus, possibly cimolodontid, is present as well. A new genus (Dakotamys) is described from the Dakota Formation, and another (Bryceomys) from the Smoky Hollow Member. Neither of the new genera are assigned to suborder or family, and both are morphologically closer to Paracimexomys than to other described taxa. Paracimexomys and, possibly, cimolomyids are present in both faunas. The difference in composition of mammalian faunas from the Cenomanian to Turonian may reflect ecologic changes causing geographic shifts in mammalian faunas rather than an episode of catastrophic extinction.

Coal and Coalbed Methane Resources of Cretaceous Rocks of the Black Mesa Basin, Northeastern Arizona: ABSTRACT

Cretaceous rocks of the Black Mesa basin of northeastern Arizona were deposited from Late Cenomanian to Santonian time near the western depositional limit of the transgressive-regressive Greenhorn and Niobrara cyclothems. Coal-bearing rocks of the sequence (including the Dakota Formation, Toreva Formation and Wepo Formation) are preserved in the Black Mesa structural basin of Laramide age. These rocks of the Black Mesa basin are the object of an NSF-sponsored research project to evaluate their coal resources and potential for coalbed methane occurrence. Forty-five measured sections and descriptions of Cretaceous rocks around the eastern margin of the basin have been incorporated into a data base in the software program LOGGER, and have been used to construct a series of stratigraphic cross-sections across the basin using the software program MacSection. These include coal beds and carbonaceous shales that are potential sources of methane as well as reservoirs, and sandstone bodies that are potential secondary reservoirs of methane (and possibly petroleum hydrocarbons from the Mancos Shale). In order to trace the facies changes between measured sections, aerial videography and 35 mm slides have been taken along the entire eastern margin of Black Mesa, a distance of 70 miles. These were digitized to provide detailedmore » lithofacies analyses of the stratigraphic sections along the north-trending cliff line. Trends of thickness variations within these facies are interpreted from isopach maps and known shoreline trends, in order to predict the areas of greatest probability of coalbed methane generation and accumulation. These predictions are also based on the locations of anticlinal and monoclinal fold axes where they cross the thickest coal trends, due to likely enhancement of permeability by cleat and butt fractures in the coal and shale reservoir rocks.« less

Climatic Implications of the Late Quaternary Alluvial Record of a Small Drainage Basin in the Central Great Plains

Four late-Quaternary alluvial fills and terraces are recognized in Wolf Creek basin, a small (163 km2) drainage in the Kansas River system of the central Great Plains. Two terraces were created during the late Pleistocene: the T-4 is a fill-top terrace underlain by sand and gravel fill (Fill I), and the T-3 is a strath terrace cut on the Cretaceous Dakota Sandstone. Both Fill II (early Holocene) and Fill III (late Holocene) are exposed beneath the T-2, a Holocene fill-top terrace. The T-1 complex, consisting of one cut and three fill-top terraces, is underlain by Fills III and IV. A poorly developed floodplain (T-0) has formed within the past 1000 yr. As valleys in Wolf Creek basin filled during the early Holocene, an interval of soil formation occurred about 6800 yr B.P. Early Holocene fill has been found only in the basin's upper reaches, indicating that extensive erosion during the middle Holocene removed most early-Holocene fill from the middle and lower reaches of the basin. Valley filling between 5000 and 1000 yr B.P. was interrupted by soil formation about 1800, 1500, and 1200 yr B.P. As much as 6 m of entrenchment has occurred in the past 1000 yr. Holocene events in Wolf Creek basin correlate well with those in other localities in the central Great Plains, indicating that widespread changes in climate, along with adjustments driven by complex response, influenced fluvial activity.

Aquifer/aquitard Units of the Dakota Aquifer System in Kansas: Methods of Delineation and Sedimentary Architecture Effects on Ground-water Flow and Flow Properties

ABSTRACT In the near future, the demand for water in many parts of central and western Kansas will exceed the supply available from near-surface aquifers, forcing exploitation of the underlying Dakota aquifer. The Dakota aquifer framework consists of discontinuous sandstone aquifers confined by mudstone aquitards belonging to the Cretaceous Cheyenne Sandstone and the Kiowa and Dakota Formations. These strata were deposited in a variety of nonmarine through marine settings associated with several cycles of sea-level rise and fall. The aquifer comprises two entire and one partial unconformity-bounded sequences recognized in the Western Interior: Cheyenne-Kiowa, lower Dakota J sequence, and upper Dakota D sequence. Scale-dependent heterogeneity characterizes the Dakota aquifer, because of the inf uence of sedimentary processes on the arrangement and geometry of sandstone bodies and on the fabric of the sandstones. A multidisciplinary approach is being employed in the Dakota Aquifer Program of the Kansas Geological Survey to delineate aquifer/aquitard units and characterize scale-dependent heterogeneity using a variety of techniques. Colorized images of the subsurface from gamma-ray logs in cross sections reveal the complex arrangement of sandstone bodies within the Dakota due to deposition in fluvial and deltaic/estuarine to marine settings. At the more local scale, borehole geophysical logs are being used both to delineate local aquifer zones and to estimate overall ground-water quality. Pumping test results indicate that the contrast of hydraulic properties between a sandstone aquifer and its surrounding mudstone aquitard significantly channels the flow of ground water through the aquifer. he geometric mean hydraulic conductivity of fluvial sandstones is generally higher than in deltaic/estuarine sandstones in either the Dakota or Kiowa Formations. Overlapping ranges of hydraulic conductivity values in fluvial and deltaic/estuarine sandstones may be due to the uniformity of the sediment supplied from source areas combined with variations in the energy of transport and winnowing within each of these depositional systems. Permeameter tests of coreplugs and gamma-ray response on logs indicate that the better sorted, coarser, and less radioactive sandstones make the most permeable aquifer units in two cores of fluvial and deltaic/estuarine sandstones. Experimental variograms using coreplug data indicate that bedding is a significant control on the partitioning of hydraulic con uctivity within sandstone bodies. Succeeding efforts will focus on using the results presented in this paper combined with techniques, such as indicator kriging and geologic process modeling, to map the distribution of sandstone aquifers and their properties in the subsurface within small geographic areas of manageable size where detailed information is needed.

Cretaceous Stratigraphy and Biostratigraphy, Sierra Blanca Basin, Southeastern New Mexico: ABSTRACT

The Sierra Blanca basin of Otero and Lincoln counties, New Mexico contains a Lower (upper Albian)-Upper (Santonian) Cretaceous section of marine and nonmarine strata as much as 700 m thick which represent the upper part of a regressive cycle followed by two transgressive-regressive deposition cycles. The lower 55 m of the Cretaceous section are the same tripartite Dakota Group units recognized in Guadalupe and San Miguel counties: basal Mesa Rica Sandstone (late Albian), medial Pajarito formation (late Albian) and upper Romeroville sandstone (earliest Cenomanian). The Mesa Rica and Pajarito represent a regression and are overlain disconformably by the transgressive Romeroville sandstone. Overlying transgressive marine clastics and minor carbonates of the Mancos Shale are as much as 73 m thick and include the early Turonian Greenhorn Limestone. The overlying Tres Hermanos formation (up to 91 m thick) consists of the (ascending order) Atarque sandstone and the Carthage and Fite Ranch sandstone members. These strata represent a mid-Turonian regression in response to regional tectonism (Atarque and Carthage), followed by a transgression (Fite Ranch sandstone) that ended in the deposition of the D-Cross Tongue of the Mancos Shale and Fort Hays Member of the Niobrara Formation during the late Turonian. The subsequent regressionmore » began with the Coniacian Gallup Sandstone (55 m) followed by coal-bearing Crevasse Canyon Formation (up to 244 m thick). The Coniacian-Santonian Crevasse Canyon Formation, the youngest Cretaceous unit in the basin, is disconformably overlain by middle Eocene conglomerates and red-bed siliciclastics of the Cub Mountain formation. Dakota Group age determinations in the Sierra Blanca basin are those of well-dated sections to the north, but ammonites and inoceramid bivalves from the Sierra Blanca basin provide precise age control for Cenomanian-Santonian marine and marginal marine strata and palynology and megafossil plants for nonmarine strata.« less

Sequential Development of an Valley Fill: the Twowells Tongue of the Dakota Sandstone, Acoma Basin, New Mexico

ABSTRACT The late Cenomanian Twowells Tongue of the Dakota Sandstone in the Acoma Basin (northwest New Mexico, USA) is a basinwide sandbody, 30 m thick, deposited during a period of relative sea-level fall and subsequent rise. For most of its extent, the Twowells Tongue consists of two markedly different sandstone units: shoreface and estuarine, respectively. The shoreface sediments were deposited during a period of relative sea-level highstand. The shoreface profile is incomplete, having its uppermost part (upper shoreface and foreshore) removed during subaerial valley incision. In places, the lower shoreface deposits are overlain by paleosols. The erosional surface is of regional extent; it depicts a complex valley morphology, in places 30 m deep, and is locally overlain by pebbles and shell lags. The valley, created during a relative sea-level lowstand, was filled by the second sandbody, consisting of a thick package (20-35 m) of transgressive, cross-bedded medium sandstones probably deposited in a middle to outer estuarine setting. The transgressive deposits of the Twowells Tongue are capped by a horizon of Pycnodonte oysters underlying black shales interpreted to represent abrupt marine deepening. The cross-bedded unit, sharply overlying shales or lower shoreface sediments, resembles other sandbodies of the Cretaceous Western Interior Seaway, traditionally interpreted as offshore ridges, or more recently as lowstand shorelines. However, the investigations in the Acoma Basin show that both the shelf-ridge and the lowstand shoreline models are inadequate explanations, because the cross-bedded lithosome of the Twowells Tongue has the internal characteristics of tidally dominated estuarine deposits.