Lowermost Sandstone Research Articles

Ornithopod tracks and bones: Paleoecology and an unusual evidence of quadrupedal locomotion in the Lower Cretaceous of eastern Iberia (Teruel, Spain)

Dinosaur tracks and osteological remains in the El Castellar Formation (upper Hauterivian–lower Barremian) in the Peñagolosa subbasin, southwest sector of the Maestrazgo Basin (Teruel Province, Spain), are scarce and fragmentary, respectively. Here, we report several unexpected, well-defined natural casts of large ornithopods from several sites of the El Castellar Formation. Moreover, an unusual manus-pes track set preserved as convex hyporelief has been found in the lowermost sandstone level of the Camarillas Formation, the first evidence of dinosaur for the base of this unit at the Peñagolosa subbasin. The ichnological comparison allows us to ascribe the studied tracks to Caririchnium. Their trackmakers were large styracosternans related to Iguanodon, and the presence of a manus-pes track set verifies that some of them may have a quadrupedal locomotion. This associated manus-pes track set constitutes one of the oldest ichnological pieces of evidence of quadrupedalism in large ornithopods from the Lower Cretaceous of Iberia and increases the limited record of this kind of track in the Lower Cretaceous of Europe. In addition, we describe some osteological fossils of these dinosaurs from the El Castellar Formation. These skeletal remains are related to medium to large-sized styracosternans, some of which closely resemble those of other European styracosternans such as Iguanodon. The evidence provided here verifies that these dinosaurs were frequent components in the coastal wetland, and fluvial to deltaic systems developed, during the late Hauterivian–early Barremian, in the Peñagolosa subbasin, possibly because these may have had a source of fresh vegetation and may have provided protection.

Comments: Water Pressures

Drought conditions rated as “moderate or worse” affected 31 US states as of 8 June, as reported by the US National Integrated Drought Information System. Particularly dry are the West and Upper Midwest regions, relevant to the Permian and Bakken, respectively. While not a record-level drought, attention is turning to the Missouri River in North Dakota where streamflow levels are at low levels for this time of year—about 48% below the seasonal average. About 96% of the water in North Dakota’s rivers and streams flows through it, making it one of the main sources of fresh water for oil and gas production in the Bakken. In the extreme drought, water restrictions could come into play. Throughout the industry, recycling and reuse of frac and produced water have been studied, and where the chemical makeup of the frac or produced water is suitable for optimal and economical treatment, it has been implemented. However, Bakken production is typically associated with 1.0 to 1.5 bbl of produced water per barrel of oil (a water cut of approximately 50%). It is highly saline with total dissolved solids (TDS) ranging up to 350,000 mg/L (seawater is about 35,000, or 10 times less salty than Bakken brine). Treatment options for such high TDS levels are limited and often cost-prohibitive. The Bakken’s produced water volumes increased fourfold since 2008 to about 740 million bbl per year due to increasing volumes per well and increasing water cut. Produced water disposal volumes in the same period increased fivefold to about 680 million bbl per year. More than 95% of saltwater disposal (SWD) targets the Inyan Kara Formation, the lowermost sandstone interval of the Dakota Group. The increase in SWD volumes has resulted in localized areas of high pressure in the formation in geographic regions associated with high levels of oil and gas activity. This increased pressure affects the economics and risk associated with the drilling of new wells that now require additional intermediate casing strings (“Dakota Strings”), adding a cost of $300,000 to $700,000 per well. About 200 wells to date have been identified with additional casing strings, according to the Energy & Environmental Research Center (EERC). Faced with the challenges of high salinity in recycling/reuse of produced water, constraints on SWD injection, freshwater limitations, pressure regulation, and inflated drilling costs, a 2-year project was begun in January 2020 which may hold promise for greater use of the produced water. Participants in the $1.3-million project are EERC, Nuverra Environmental Solutions, and the US Department of Energy.

Proveniência de arenitos da Formação Cerro da Angélica (Grupo Bom Jardim, Ediacarano do RS) na porção sul da sub-bacia Camaquã central e suas implicações tectônicas

This paper presents provenance data from the lowermost sandstone deposits of the Cerro da Angelica Formation (~605 Ma) of the Bom Jardim Group (Camaqua Basin), which crops out in the Casa de Pedra region, Bage, Rio do Sul State, southern Brazil, integrated with sedimentary facies analysis, based on detailed description of columnar sections. This approach aims to determine the tectonic context and the sense of displacement of the basin-border faults during the deposition of the unit. Four facies associations were identified: (i) distal alluvial fan deposits, (ii) ephemeral stream deposits, (iii) proximal alluvial fan deposits and (iv) eolian dune field deposits. Microscopic provenance analysis revealed stratigraphic changes in the proportion of granitic and basic volcanic sources. In the case of the alluvial fan deposits, there is a progressive increase of the granitic contribution, which is interpreted as the result of a progressive denudation of the volcanic cover and ensuing exposure of the plutonic basement. In the distal alluvial deposits, there is an alternation between the two main sources, which is interpreted as a consequence of change in the contribution from proximal, border-fault derived detritus related to transversal alluvial systems and from distal sources fed by axial alluvial systems. The presence of basic or intermediate volcanic rocks as detritus in the basin reveals volcanic activity before the deposition of the Cerro da Angelica Formation. This interpretation corroborates the model of active rifting for the evolution of the Camaqua Basin, as the main extensional phase (Bom Jardim Group) begins with volcanic activity. The absence of provenance variations in the alluvial fan successions suggests that there was no sin-depositional strike-slip displacement between the source and the deposits, thus confirming previous models of normal faulting during the deposition of the Bom Jardim Group.

Stratigraphic Evolution of Fine-Grained Submarine Fan Systems, Tanqua Depocenter, Karoo Basin, South Africa

Abstract The integration of correlated outcrop and newly acquired core and wireline logs, extensive paleocurrent data, and accurately mapped surfaces has enabled a common model of the stratigraphic evolution to be developed of four Permian fine-grained submarine fan systems (Fans 1–4) from the Tanqua depocenter, SW Karoo Basin, South Africa. Additionally, this data has revealed the influence of subtle seabed topography on the fan systems' boundaries, internal facies architecture, and paleocurrent directions. Furthermore, the internal stratigraphy of individual fan systems are now known to be more complex than first believed. Mapping high-frequency intrafan units reveals a progradational–aggradational–retrogradational stacking pattern common to each submarine fan, which allows the geographic and stratigraphic distribution of lithofacies and architectural elements to be predicted. Basinward of the main feeder system, fan axes are dominated architecturally by sheet turbidites with discrete zones of high amalgamation during progradational and aggradational phases, whereas isolated channel forms that cut thin-bedded turbidites are more common in the retrogradational phase. This change is interpreted to be due to local increase in the lower slope gradient through sediment aggradation increasing the potential for channel avulsion and the development of splay lobes during decreasing sediment supply. The progradational, aggradational, and retrogradational phases are assigned to the early, middle, and late lowstand systems tract of a fifth-order sequence respectively. Each phase is built of higher-frequency (sixth-order) sequences so that each fan is a composite sequence. The overall basinward-to-landward stepping of the individual fans means that moving down dip in any basin-floor fan system, the lowermost sandstone preserved is progressively younger, whilst the uppermost sandstone is progressively older. This stacking pattern imparts an important predictable control on reservoir and seal geometries. This study aids the development of predictive models for fine-grained submarine fan initiation, growth, and abandonment, and lithofacies and architectural element distributions in space and time.

Three-dimensional imaging of a deep marine channel-levee/overbank sandstone behind outcrop with EMI and GPR

Deepwater channel-levee/overbank sandstones are important sources of oil and gas, but their internal stratigraphy is complex and not well understood. One means to better characterize this complex stratigraphy is through the study of outcrops, such as the Dad Sandstone member of the Lewis shale (Figure 1) in Carbon County, Wyoming, U.S. (Pyles and Slatt, 2000). Figure 1. (top) The outcrop of the Dad Sandstone member of the Lewis Shale. A series of channel-fill sandstones dip toward the lower right (west). The lowermost sandstone is the subject of this study. This sandstone trends along the outcrop face toward the lower right, but is juxtaposed against shale toward the west, at the same stratigraphic level. The GPR line on the lower left of the figure (modified from Young et al., 2003) shows the base of the channel-fill sandstone (red line) where it intersects the ground surface. Northwest of the base of the sandstone, at equivalent radar times, the lithology is shale. The lower right figure shows the EMI volume in plan view, with sandstone in yellow and shale in gray; note the bend in the sandstone at the location where the channel base intersects the ground surface. Channel-levee/overbank systems are a result of multiple sediment gravity flows. The channel itself is formed from aggradation of levees over long periods of time. As sediment flows within the channel, fine particles are expelled over the channel edges, thus forming the levees. Coarser particles not deposited on the levee are transported beyond the channel to form frontal splays or lobes. Sediment may slump off the levee walls onto the channel floor during this time interval. Channels are later backfilled with sand and/or mud as transport energy diminishes, probably during an early rise in sea level. The materials that fill the channel can be configured in different arrangements …

Improved Reservoir Characterization of the Rose Run Sandstone on the East Randolph Field, Portage County, Ohio: ABSTRACT

ABSTRACT The East Randolph Rose Run field is located in Randolph Township, Portage County, Ohio. The field was discovered in 1992 as a down dip extension of the Randolph Gas field discovered by Belden & Blake Corporation a year earlier. Since its discovery, over 40 wells have been drilled in the East Randolph field that have produced an estimated 600,000 barrels of oil and 1.5 billion cubic feet of gas. Characterization of the productive upper Rose Run sandstone members is underway to determine the technical and economic feasibility of water flooding, gas pressure maintenance, or the possibility of infill drilling for oil in the East Randolph field. Core data and log data for each sandstone member was analyzed and mapped to determine their relationship with estimated ultimate recovery of oil and gas. The upper Rose Run sandstone can be divided into four distinct sandstone units characterized by bedding, mineralogy and log character. Each of the four sandstone units usually represents a fining-upward cycle of sandstone, sandy dolomite and dolomite. The uppermost unit (#1) consists of tightly cemented sandstone with quartz overgrowths, low permeability and low porosity, while the lowermost sandstone unit (#3B) is usually the most permeable (1.5 - 12.9 md) and porous (2.6 - 11.2 percent). This variation in porosity and permeability is predominantly controlled by grain size, amount and type of intergranular cement, and extent of secondary dissolution porosity. Most of the East Randolph field's oil production can be attributed to the reservoir development of the Rose Run #3A and #3B units. Gas production appears to be present in all four units, but seems to be best when good reservoir development is found in the #1 and #2 sandstone intervals. Volumetric calculations using new geologic models increase estimates of the amount of original oil-in-place at over 10 million stock tank barrels, more than double the initial estimates. The new geologic model will be used as input for reservoir simulation to optimize future locations of infill wells, and determine waterflood and/or pressure maintenance feasibility.

Evidence for Local Tectonism Related to a Mid-Turonian Unconformity Beneath Upper Cretaceous Turner Sandy Member of Carlile Formation, Northeastern Powder River Basin, Wyoming: ABSTRACT

In the northeastern Powder River basin the Upper Cretaceous (upper Turonian) Turner Sandy Member consists of marine sandstone, siltstone, shale, and bentonites. These lithologies comprise several laterally continuous, primarily upward-coarsening sequences. Turner petroleum production (> 11 million bbl of oil) has been largely from the lowermost sandstone. In this part of the basin, the Turner is conformably overlain by the Sage Breaks shale, but the base of the Turner is, in most areas, unconformable with the underlying Greenhorn Formation. This unconformity records a mid-Turonian sea level lowstand accompanied by widespread erosion. Turner sediments were deposited during the subsequent sea level rise and onlap the erosional surface. Detailed correlations of several shaly or bentonitic marker horizons within the Turner and Greenhorn indicate the unconformity typically occurs at the base of an upward-coarsening sequence. In the far northeast the older Turner sequence may be conformable with the underlying Pool Creek shale. However, to the southwest progressively younger basal Turner sequences onlap progressively older Greenhorn strata at the unconformity. Cross sections and isopach maps document several dominantly north-south-oriented Turner and Greenhorn thins, which they interpret to represent areas of structurally controlled paleohighs. As much as 150 ft of pre-Turner erosion occurs over thesemore » paleohighs. Thickness patterns suggest that the greatest uplift immediately preceded the mid-Turonian erosional event. Decreased uplift continued throughout upper Turonian (Turner) time but became much less evident in post-Turner time.« less

Permian Upper Yates Formation Carbonate/Siliciclastic Depositional Patterns, Northwestern Shelf, Guadalupe Mountains, New Mexico: ABSTRACT

Sedimentological field study of the upper three sandstones of the upper Yates Formation (Permian, Guadalupian), Guadalupe Mountains, New Mexico, has shed considerable light on the shelf depositional environment, morphologic profile, and temporal relationships of alternating carbonate and siliciclastic deposition. Outcrops were examined in detail, and 31 stratigraphic sections were measured, described, and correlated within the region 5 km (3 mi) shelfward of the Capitan reef and encompassing an area of 180 km2 (69 mi2). The three sandstones in the upper 15 to 30 m (49 to 98 ft) of the Yates are continuously traceable across the study area as thin, nonchanneled sheet sandstones 0.5 to 8 m (1.6 to 26 ft) thick. They exhibit no deepening or sequences; no beach or tidal sedimentation features; and no vertical repetitive sedimentation patterns. Primary sedimentary structures are rare, obscure, small scale ( Evidence for a marginal mound shelf profile during sandstone deposition is inconclusive. A localized area of fenestral porosity in the lowermost sandstone unit, and a narrow region of probable fossil caliche along the Yates/Tansill formational contact of the upper sandstone, both suggest local emergence of a paleotopographic high located 1.5 to 3.0 km (.9 to 1.8 mi) and 1.5 to 3.25 km (.9 to 2 mi) respectively, shelfward of the Capitan. All three sandstones continuously overlie the area of the marginal mound as inferred from the underlying carbonate facies, hence a marginal mound was not present or had no affect on transport of siliciclastics across the outer 5 km (3 mi) of the shelf. Each sandstone is characterized by a sharp, subplanar erosional base, and typically grades upward into peritidal carbonates, which exhibit along the shelf crest of the marginal mound one or more 1 to 2 m (3 to 6 ft) shoaling-upward hemicycles which commonly built up to depositional fill-level in response to episodic shelf subsidence of 1 to 2 m (3 to 6 ft). The eroded fill-level carbonates of the shelf crest underlying two of the three sandstone intervals were diagenetically micritized analogous to incipient pedogenesis prior to subsidence and burial by subaqueously deposited siliciclastics. Local emergence of 1 to 2 m (3 to 6 ft) relief could explain the inferred pedogenesis, with siliciclastic deposition being favored by subsidence and greater depth which governed siliciclasti transport processes. The following depositional sequence is repeated twice in the study interval: subaqueous deposition of siliciclastics across the eroded surface of the underlying carbonate unit; upward siliciclastic gradation into peritidal carbonates characterized by one or more 1 to 2 m (3 to 6 ft) shoaling-upward hemicyclic deposits which proceeded to fill-level; local emergence with concomitant subaerial erosion and micritization; subsidence and renewed subaqueous siliciclastic deposition. Reconnaissance observations from the middle Yates and lower Tansill reveal numerous analogous sandstone/carbonate relationships. The sandstone intervals interbedded with shelf crest carbonate facies comprise sandstone/carbonate shoaling-upward hemicycles; contrary to current interpretation the sandstone represents the basal deeper deposition, the carbonates represent the shoal water deposition. End_of_Article - Last_Page 435------------

Upper Cretaceous Stratigraphy and Paleontology, Lower Tres Hermanos Sandstone, Sevilleta Grant near La Joya, Socorro County, New Mexico: ABSTRACT

More than 1,300 ft (396 m) of Upper Cretaceous rocks overlie shales of the Upper Triassic Dockum Formation and are exposed on the Sevilleta Grant, near La Joya, Socorro County, New Mexico. The Upper Cretaceous sequence extends from the Dakota Sandstone to the Dilco Member of the Crevasse Canyon Formation and consists largely of shales and sandstones. The included Tres Hermanos Sandstone Member of the Mancos Shale includes sandstones, shales, and two coal beds. The lowermost sandstone unit is a moderately sorted, calcareous sandstone which coarsens upward and with small- and medium-scale tangential, wedge and trough-shaped sets of cross-beds. The sandstone is about 11 ft (3.4 m) thick and contains fossil-rich lenses of poorly sorted, dark yellow-brown-weathering sands that are friable to moderately indurated and calcite cemented. Shale galls are present in the fossil-rich lenses and, together with wood fragments, abundant turtle bone fragments, some crocodile tooth and scute fragments, amid vertebrae and teeth, indicate a nearshore environment with a nearby source of freshwater. Selachian teeth and probable coprolites are richly varied and abundant. The following genera have been recognized: Hybodus, Lonchidion, Squalicorax, Squatina, Bracha lurus, Scapanorhynchus, Odontaspis, Cretoxyrhina, Cretolamna, Plicatolamna, Paranomotodon, Ischyrhiza, Ptychotrygon, Rhombodus as well as several as yet indeterminate genera. The dominant invertebrate genus is the oyster Crassostrea soleniscus although at least two genera of gastropods are present. End_of_Article - Last_Page 554------------

Stratigraphic Models and General Criteria for Recognition of Alluvial, Barrier-Bar, and Turbidity-Current Sand Deposits

The depositional framework for sandstone bodies is most accurately determined by comparing their geometry and internal features with those of stratigraphic models (sand units of known depositional environments). Alluvial, barrier-bar, and turbidity-current sandstones are each characterized by a combination, or group, of distinguishing features. The Lower Cretaceous Cut Bank Sandstone of Cut Bank field in northwest Montana is an example of alluvial valley deposition south of an arctic sea. Basal and lateral contacts of the sandstone are sharp, erosional boundaries; the sedimentary structural and textural sequences are quite similar to modern point-bar sequences. Massive beds at the base of the Cut Bank Sandstone are overlain by beds having medium-scale cross-bedding. Grain size decreases upward. The lowermost sandstone unit of the Upper Cretaceous Eagle Sandstone at Billings, Montana, was deposited as a barrier-bar feature some distance east of the mainland. Its features are very similar to those of the modern Galveston Island sand. The lower and lateral contacts are gradational whereas the upper contact is sharp. The width-thickness ratio is high. Low-angle inclined bedding overlies mottled bedding, and the grain size increases upward. The lower Pliocene Repetto Formation of the Los Angeles basin is characterized by a great thickness of turbidity-current sandstone, deposited in a deep-marine orogenic basin. The depositional basin was very similar to modern basins offshore from southern California. Gross sandstone thickness trends parallel the length of the basin. Each sandstone unit is composed of several graded sandstone beds with sharp basal contacts. The sandstones are poorly to moderately sorted. The foraminiferal assemblages in interbedded shale indicate bathyal-abyssal depths during deposition.

Trend and Genesis of Lowermost Sandstone Unit of Eagle Sandstone at Billings, Montana

The Upper Cretaceous Eagle Sandstone in the Billings area of south-central Montana contains as many as five sandstone units, the lowermost of which is exposed in excellent outcrops along the northern flank of the Big Horn uplift. These exposures, in addition to subsurface control north of the outcrop area, allow determination of the geometry and internal rock characteristics of the sandstone body. The trend of the lowermost sandstone unit is N. 20-25° W. through Billings. The known length is about 40 miles, the width 20-30 miles, and the maximum thickness 100 feet. The sandstone grades gradually into shale along its lower and lateral boundaries. The contact with the overlying bed is sharp. The dominant structure of the upper part of the lowermost unit is large-scale, low-angle inclined bedding, which dips S. 60° W., approximately normal to the trend of the sandstone. In the lower part the sandstone is mottled and poorly stratified because of burrowing organisms. Grain-size increases in an upward direction. The sandstone is very fine- to fine-grained and well sorted. Chert and rock fragments are common constituents. Glauconite is present throughout the sandstone body, nd muscovite and carbonaceous material are accessories in the lower part. No fossils were observed. Low-angle inclined bedding, mottled structure, an upward increase in grain-size, and gradational lower and lateral boundaries also characterize Galveston Island, a Recent Gulf of Mexico barrier island. The lowermost sandstone unit of the Eagle is also similar to its Recent counterpart in shape and relationship to regional strand line. The Eagle barrier island originated as a bar in about 75 feet of water and more than 50 miles offshore. Because the dominant sand-laden currents and waves were on the western side of the bar, the barrier island built toward the mainland. About 20 feet of subsidence occurred during deposition. The subaerial part of the barrier island was removed by erosion during the minor transgression which terminated growth of the feature.