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This article, titled "\"woman\".", is published in the journal Alocasia: A Journal of Queer Plant-Based Writing. The author, Mukethe Kawinzi, reflects on their experience of observing nature and wanting to share it with someone. They mention the blooming of ceanothus blueblossom, the slow pace of life, and the beauty of poppies and trefoil. The author expresses a desire to communicate these observations to someone, but it is unclear if they were able to do so. Mukethe Kawinzi is a ranch worker in California who enjoys being around both animals and humans. [Extracted from the article]

REGULARSTaken in Zhangye National Geopark, Gansu, China, this colourful mountain range spans an area of around 197 square miles. Millions of years of tectonic uplift and compression in sedimentary sandstone and siltstone has led to the formation of a rainbow mountain range. Each layer in the rocky rainbow is packed with different minerals, such as iron and sulphur, which give them striking colours. [Extracted from the article]

The ecological significance of ice-rafted dropstones in present-day glacial marine benthic environments has received considerable attention from ecologists, but similar studies based on the geological records of dropstones and associated fossils are rare. In this study, we report statistically significant co-occurrences of ice-rafted dropstones with brachiopod shells in multiple stratigraphic horizons at multiple sites from the Middle Permian Wandrawandian Siltstone of the southern Sydney Basin in southeastern Australia. We analysed the distribution patterns of both dropstones and brachiopod-dominated fossil assemblages by using a quadrat-based sampling method and spatial point pattern analysis. It was revealed that the co-occurrences of ice-rafted dropstones and brachiopod shells are not random; rather, they demonstrate statistically significant and stratigraphically recurring associations that are here interpreted to represent dropstone-associated, brachiopod-dominated palaeoecological communities. In these recurring palaeocommunities, the presence of ice-rafted dropstones is considered to have added habitat complexity and heterogeneity to the benthic environment, especially suited to the settlement of brachiopods. In addition, the sinking of dropstones, from floating ice masses through the water column to the silty seafloor, is interpreted to have enriched the nutrient and oxygen supply to the benthic environment, further aiding the flourishing and maintenance of a diverse and stable marine benthic fauna. [ABSTRACT FROM AUTHOR]

The article focuses on several plant species that are growing in the Petrified Forest National Park in Arizona including cutleaf daisy, wild potato, gray globe mallow, painted desert milk vetch, gladiator milk vetch, brandegee's milk vetch and northern fringepod. It mentions that Painted Desert in the Petrified Forest National Park is an expanse of badlands with stratified layers of siltstone, mudstone, and claystone of the Chinle Formation.

The Upper Devonian-Lower Carboniferous Bakken Formation is a widespread siliciclastic unit in the subsurface of the Williston Basin that is subdivided into three members: lower and upper organic-rich shale members and a dolomitic, silty, and sandy middle member. Although the unit has become one of the most active oil plays in North America and numerous sedimentologic studies have been made, no consensus about the depositional environments of the middle member has been achieved. Previous studies suggested several depositional and sequence-stratigraphic scenarios, including lowstand offshore-shoreface, normal-regressive offshore-shoreface, incised estuary, and falling-stage shoreface complexes for the middle member. We propose a new depositional and sequence-stratigraphic model and compare it with some previous interpretations. This new model includes a basal transgressive systems tract (TST) embracing shelf deposits, a highstand systems tract comprising shelf to lower shoreface environments, and an upper TST encompassing a brackish-water embayment complex and offshore to shelf settings. Petrophysical characterization of the sedimentary facies reveals that bay-mouth cross-stratified fine-grained sandstone, flaser-bedded very fine grained sandstone formed in wave-dominated tidal flats, offshore-transition highly bioturbated interbedded very fine grained sandstone and siltstone, and tidal-flat very fine grained sandstone with common mud drapes possess the best reservoir qualities. Recognition of a restricted embayment within the Bakken middle member has major implications for both exploration and production. Embayment facies with good reservoir quality constitute good oil prospects in localized areas, whereas fully marine facies may represent good oil prospects of more regional extent. [ABSTRACT FROM AUTHOR]

Tight gas reservoirs are notoriously difficult to characterize; routine methods developed for conventional reservoirs are not appropriate for tight gas reservoirs. In this article, we investigate the use of nonroutine methods to characterize permeability heterogeneity and pore structure of a tight gas reservoir for use in flow-unit identification. Profile permeability is used to characterize fine-scale (<1 in. [<2.5 cm]) vertical heterogeneity in a tight gas core; more than 500 measurements were made. Profile permeability, although useful for characterizing heterogeneity, will not provide in-situ estimates of permeability; furthermore, the scale of measurement is much smaller than log scale. Pulse-decay permeability measurements collected on core plugs under confining pressure were used to correct the profile permeability measurements to in-situ stress conditions, and 13-point averages of profile permeability were used to relate to log-derived porosity measurements. Finally, N2 adsorption, a new method for tight gas was used to estimate the pore-size distribution of several tight gas samples. A unimodal or bimodal distribution was observed for the samples, with the larger peak corresponding to the dominant pore-throat size, as confirmed by independent methods. Furthermore, the adsorption-desorption hysteresis loop shape was used to interpret the dominant pore shape as slot-shaped pores, which is typical of many tight gas reservoirs. The N2 adsorption method provides rapid analysis and does not suffer from some of the same limitations of Hg injection. In the future, we hope that the N2 adsorption method may prove useful for flow-unit characterization (based on dominant pore size) of fine-grained (siltstone-shale) tight gas reservoirs. [ABSTRACT FROM AUTHOR]

Wave-dominated, shoreface-shelf parasequences are commonly modeled as simple layer-cake reservoirs, yet analysis of modern and ancient analogs demonstrates that these intervals contain a more complex physical stratigraphy. We investigate the impact of depositional and diagenetic heterogeneity associated with gently dipping clinoform surfaces on fluid flow and recovery during water flooding, using a three-dimensional model reconstructed from a well-exposed outcrop analog. We demonstrate that the volume of oil in place is affected by variations in facies thickness associated with interfingering along clinoforms, whereas waterflood sweep efficiency is affected by barriers to flow along clinoform surfaces, such as calcite-cemented layers, mudstones, and siltstones. Sweep efficiency is low when water flooding is down depositional dip because oil is bypassed at the toe of each clinothem as water flows preferentially through high-quality sandston facies in the upper part of the parasequence. Sweep efficiency is higher when water flooding is up depositional dip because the gravity-driven, downward flow of water sweeps poorer-quality sandstone facies in the lower part of the parasequence. In both cases, injectors may offer limited pressure support to producers. Water flooding along depositional strike yields good pressure support but poor sweep because the gravity-driven flow of water into the lower part of the parasequence is significantly reduced. This yields highly variable fluid saturations but a uniform pressure gradient, which is consistent with pressure and fluid saturation data from the mature Rannoch Formation reservoir, Brent field, United Kingdom North Sea. Simple layer-cake models fail to capture the range of flow behaviors described above and overpredict recovery by up to 20% as a result. [ABSTRACT FROM AUTHOR]

The Elm Coulee field of the Williston Basin is a giant oil discovery in the middle Bakken Formation (Devonian-Mississippia) discovered in 2000. Horizontal drilling began in the field 2000, and to date, more than 600 wells have been drilled. The estimated ultimate recovery for the field is more than 200 million bbl of oil (31.8 million m³). The Bakken Formation in the field area consists of three members: (1) upper shale, (2) middle silty dolostone, and (3) lower siltstone. The total Bakken interval ranges in thickness from 10 to 50 ft (3.1 to 15.3 m) over the field area. The upper shale is dark-gray to black, hard, siliceous, slightly calcareous, pyritic, and fissile. The shale consists of dark organi kerogen, minor clay, silt-size quartz, and some calcite and dolomite. The kerogen consists mainly of amorphous materia and the organic material is distributed evenly throughout the shale interval (not concentrated in laminations or lenses). The upper shale ranges in thickness from 6 to 10 ft (1.8 to 3.1 m) over the field area. The middle member consists of a silty dolostone and ranges in thickness from 10 to 40 ft (3.1 to 12.2 m). The lower member in the Elm Coulee field consists of brownish-gray, argillaceous, organic-rich siltstone. Burrowing and brachiopod fragments are common in the lower member. This facies is equivalent to the lower Bakken black shale facies on the northern side of the field and is interpreted to be an updiplandward equivalent to the deeper-water, black shale facies. The lower member ranges in thickness from 2 to 6 ft (0.61 to 1.8 m). Based on the abundance of fossil content and amount of burrowing, the members of the Bakken Formation are interpreted to have been deposited under aerobic (middle member, common burrows, and rare fossils), dsyaerobic (lower member, common fossils, and lesser amount of burrows), and anaerobic conditions (upper member, rare fossils, and burrows). The main reservoir in Elm Coulee field is the middle member, which has low matrix porosity and permeability and is found at depths of 8500 to 10,500 ft (2593 to 3203 m). The current field limits cover approximately 450 mi² (1165 km²). The middle Bakken porosities range from 3 to 9%, and permeabilities average 0.04 md. Overall, the reservoir quality in the middle Bakken improves upward as the amount of clay matrix decreases. The middle Bakken is interpreted to be a dolomitized carbonate-shoal deposit based on subsurface mapping and dolomite lithology. The main productio is interpreted to come from matrix permeability in the field area. Occasional vertical and horizontal fractures are noted in cores. The vertical pay ranges in thickness from 8 to 14 ft (2.4 to 4.3 m). The Bakken is slightly overpressured with a pressure gradient of 0.53 psi/ft (0.02 kPa/m). Horizontal wells are drilled on 640- to 1280-ac (259- to 518.4-ha) spacing units. Long single laterals, dual laterals, and trilaterals have all been drilled in the field. The horizontal interval are sand-, gel-, and water-fracture stimulated. Initial production ranges from 200 to 1900 BOPD (31.8 to 302.1 m³/day). Initial potential rates for vertical wells are generally less than 100 BOPD (15.9 m³/day). The upper Bakken shale probably also contributes to the overall production in the field. The exact contribution is unknown but estimated to be less than 20% of the total production. The Elm Coulee field illustrates that the Bakken petroleum system has enormous potential for future oil discoveries in the Williston Basin. [ABSTRACT FROM AUTHOR]

An analysis of 31 whole cores (~ 1600 ft, ~490 m) and closely spaced wireline logs (,~500 wells) penetrating the Lower Cretaceous (Cenomanian) lower Woodbine Group in the mature East Texas field and adjacent areas indicates that depositional origins and complexity of the sandstone-body architecture in the field vary from those inferred from previous studies. Heterogeneity in the lower Woodbine Group is controlled by highstand, fluvial-dominated deltaic depositional architecture, with dip-elongate distributary-channel sandstones pinching out over short distances (typically < 500 ft [ < 150 m]) into delta-plain and interdistributary-bay siltstones and mudstones. This highstand section is truncated in the north and west parts of the field by a thick (maximum of 140 ft [43 m]) lowstand, incised-valley-fill succession composed of multistoried, coarse-gravel conglomerate and coarse sandstone beds of bed-load fluvial systems. In some areas of the field, this valley fill directly overlies distal-delta-front deposits, recording a fall in relative sea level of at least 215 ft (65 m). Correlation with the Woodbine succession in the East Texas Basin indicates that these highstand and lowstand deposits occur in the basal three fourth-order sequences of the unit, which comprises a maximum of 14 such cycles. Previous studies of the Woodbine Group have inferred meanderbelt sandstones flanked by coeval flood-plain mudstones and well-connected, laterally continuous sheet sandstones of wave-dominated deltaic and barrier-strand-plain settings. This model is inappropriate, and a full assessment of reservoir compartmentalization, fluid flow, and unswept mobile oil in East Texas field should include the highstand, fluvial-dominated deltaic and lowstand valley-fill sandstone-body architecture. [ABSTRACT FROM AUTHOR]

Possibly the most extensive and best-preserved Archaean halite casts yet discovered occur in the c. 2.58 Ga upper Black Reef and basal Oaktree formations, Transvaal Supergroup, in Mpumalanga Province, South Africa. Halite casts are isolated on bedding planes, range in size from c. 1 mm to 20 mm, and have cubic, dumbbell and triangular shapes, as well as hopper-like pyramidal hollows on cube faces. Some of the casts display distinct hopper shapes characteristic of halite crystals. The halite cast-bearing pavements are developed within silicified mudstone interbedded with siltstone or stromatolitic dolomite. Associated sedimentary structures pointing to subaerial exposure include adhesion ripples and warts, desiccation and prism cracks, rill marks and tepee structures. Halite cast-bearing beds are interpreted as supratidal flat or sabkha deposits. The presence of isolated casts and hopper-shaped crystals suggests that halite resulted from displacive growth within the sediment from supersaturated residual brines after mudstone deposition. Absence of any indication of the former presence of gypsum or anhydrite supports previous contentions that the Neoarchaean ocean was deficient in sulphate or contained a high bicarbonate to calcium ratio such that with progressive evaporation, most calcium was consumed before the gypsum stability field was reached. The association of halite and carbonate in the upper Black Reef and basal Oaktree formations constrains the palaeolatitude of the Transvaal Basin at 2.58 Ga to subequatorial (10-30°). [ABSTRACT FROM AUTHOR]

The Potrerillos minibasin of the La Popa basin, Mexico, is defined by the Carroza syncline and bounded by the El Gordo anticline and the La Popa salt weld. Stratigraphic geometries and facies distribution of the upper sandstone member of the Potrerillos Formation within the minibasin indicate that diapirism, shortening, and deposition were simultaneous and complexly interrelated during the Paleocene. The upper sandstone member is a regressive succession of marginal marine, siliciclastic deposits. Wave-dominated shoreface deposits consist of mudstone, siltstone, and sandstone and are interpreted to represent offshore to upper shoreface environments. Tide-dominated environments are heterogeneous and grouped into four broad classes based on the energy of the depositional environment. Lower delta-plain deposits range from mudstone to sandstone and are interpreted to represent channel, flood-plain, and lagoonal environments. Sedimentary structure orientations indicate asymmetrical, bidirectional paleocurrents with a dominant southeast trend parallel to regional structural trends. Unconformity-bounded strata onlap the El Gordo anticline, indicating syndepositional folding and control of the depositional system by detachment fold trends in the basin. The strata of the upper sandstone member are interpreted to contain six systems tracts that record three successive fourth-order eustatic cycles. These strata represent the deposits of a prograding, ebb-dominated deltaic system confined to the Carroza syncline. Maximum stratal accumulation in the syndinal hinge caused the migration of underlying salt into flanking structures. A balance between salt withdrawal and subsidence stabilized the position of both the synclinal hinge and the shoreline, leading to a positive deposition-subsidence feedback loop. During regional regression, the structural basin defined by the syncline formed a paleogeographic embayment and controlled shoreline evolution. [ABSTRACT FROM AUTHOR]

The coalbed methane resource is very abundant in Qinshui basin (3.28 x 1012 m³ 114 tcf). The investigation on the upper Paleozoic coalbed methane system is a guide to the exploration and development of coalbed methane. The upper Paleozoic coalbed methane system in the Qinshui basin is sealed by a low-permeability roof and floor strata comprising mudstone, siltstone, and bauxite of the Carboniferous Benxi Formation and the Permian Shanxi and Xiashihezi formations. The overburden is the Lower Permian Xiashihezi Formation and the Upper Permian, Triassic, and Middle Jurassic clastic deposits. The source and reservoir rocks are the Carboniferous--Permian coal seams. The hydrocarbon generation of the source rocks reached its first peak in the Late Triassic. The highest maturity was about Ro = 1.2% under a normal paleogeothermal gradient (2-3°C/ 100 m; 1.1-1.7°F/100 ft). A tectonic thermal event during the Jurassic and Cretaceous Yanshanian orogeny enhanced the coal maturity and caused a second peak of hydrocarbon generation. Varying igneous intrusions caused the coal maturity to be higher in the southern, northern, and eastern parts of the Qinshui basin instead of the central and western parts. The highest maturity was greater than Ro = 4% in the Jincheng area. The migrated thermogenetic coalbed methane accumulated in the reservoirs in which abnormally high reservoir pressure exists locally under the hydrodynamic drive. Because of the different hydrodynamic background and sealing condition, the distribution of coalbed methane content is inhomogeneous. The reservoir is undersaturated with gas in most areas. Based on the coalbed methane system investigation, we assessed the coalbed methane producibility in different parts of the Qinshui basin, and the major producibility area is in the southern part of the basin. [ABSTRACT FROM AUTHOR]

Oolitic carbonates and associated rocks in the San Andres Formation produce hydrocarbons at Olson field, west Texas. Mudstones, dolomitized fusulinid-peloid packstones and wackestones, ooidpeloid grainstones and packstones, and minor siliciclastic sediments occur in the field. The reservoir is stratigraphicaUy compartmentalized by lenticular oolite deposits that are overlain by algal-laminated mudstones and siltstones. Pore-filling anhydrite cement, common in all lithologies, adds to porosity heterogeneity. Interwell communication is poor, as indicated by variable bottomhole pressures and erratic waterflood response. A medium-radius lateral hole was drilled to a total depth approximately 50 ft (15 m) from an offset vertical well. At this depth, the horizontal well intersected a previously existing artificial fracture that occurred in the nearby vertical well. The intersection of this fracture by the lateral borehole had a significant economic impact. The production rate in the vertical well jumped from a few barrels per day to an average of 70 BOPD and less than 20 BWPD. The ensuing years maintained relatively high flow rates. Projected incremental oil recovery is 153,000 bbl, roughly equivalent to production from an average well drilled during the early life of the field. Other unsuccessful horizontal wells have been drilled at Olson field, but they have not targeted preexisting hydrofractures in offset vertical wells. Therefore, the concepts presented in this paper have not been retested. This approach, intentionally drilling a drainhole to intersect a preexisting hydrofracture, could add new life to many older, compartmentalized reservoirs. [ABSTRACT FROM AUTHOR]

Describes Blackie's Hollow, Virginia, located in the George Washington National Forest. Geology; Topography; Vegetation; Consideration of the research on shale barren by naturalist Edward Steele; Formation of siltstone and shale; How certain endemic plant species have restricted ranges in the shale barrens.

The article reveals that a new study in 2015 on the siltstone Gaojiashan Lagerstätte in Southern China has provided insights on the formation of soft-bodied fossils. Topics covered include how almost 80 percent of the worm-like fossils known as Conotubus in Gaojiashan are preserved as 3-D tubes made of pyrite and how the pyritization process was probably fueled by sulfate-reducing bacteria that consumed the soft tissue of the worms.

The article discusses research conducted by a team of primatologists led by Elisabetta Visalberghi of the Institute of Cognitive Sciences and Technologies on the behavior of bearded capuchin monkeys in the Brazilian forest. These monkeys use specific tools to crack open nuts. Researchers provided the monkeys with tools made of siltstone, sandstone, and quartzite and then evaluated which were selected for opening the nuts.

Data from faults with core recovery offshore Norway and from outcrops in study areas onshore demonstrate the development and continuity of smear along large (seismic-scale) faults. Smear along these faults is typically associated with thick (tens of metres) shale source layers and fault segments that are slightly offset, where the overlap between the segments creates an extensional dip relay. It is demonstrated that rock types other than shale, such as coal, siltstones and carbonates, may smear and thereby contribute to the low- permeable fault gouge. A critical threshold for the shale smear factor (SSF), given by the fault throw divided by the thickness of the shale source layer, is established to separate continuous and discontinuous smears. An SSF ≤4 is likely to correspond to a continuous smear along large faults and thereby to a sealing membrane on the fault surface. For small (subseismic) faults, a continuous smear can be maintained for both shale and coal source layers for much higher smear factors compared with large faults. The continuity of smear associated with small faults also displays a greater variation (SSF in the range of 1-50), to become less predictable than smear along large faults. [ABSTRACT FROM AUTHOR]

The article presents information on determining the age of two human skulls--Omo I and Omo II--found in 1967 in the Kibish Formation, Ethiopia. Researchers have recently determined that both fossils are almost 196,000 years old. This is more than 35,000 years older than the next oldest known skulls from Herto, Ethiopia. Researchers calculated the maximum age (196,000 years) by measuring the accumulation of radiogenic argon-40 within volcanically derived rocks found below the skulls. Distinct beds of tuff are buried in layers of sandstone, siltstone and claystone, which were originally deposited by the Omo River.