bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagenesis of the Capitan Limestone, Upper Permian, Mckittrick Canyon, West Texas
Authors: Mruk Denise H. 
Published: November 2010

Abstract
This paper is a summary of a diagenetic study of calcite cements in the Capitan Limestone, McKittrick Canyon, West Texas (Mruk, 1985). This study deciphers the diagenetic history of the Capitan Limestone using basic field observations, detailed cathodoluminescence petrography, and carbon and oxygen isotopes.
Dolomitization Model for the Forereef Facies of the Permian Capitan Formation, Guadalupe Mountains, Texas-New Mexico
Authors: Melim Leslie A. , Scholle Peter A. 
Published: November 2010

Abstract
The Capitan Formation includes the massive "reef" and the bedded forereef slope facies of the Permian Reef Complex (Fig. 1). The ongoing controversy over the nature of the reef has not substantially affected interpretation of the bedded forereef slope portion of the Capitan. Whether the "reef" was a major wave-resistant barrier or not, it shed massive volumes of debris into the 600 m deep Delaware Basin allowing as much as 7 km of lateral progradation during Late Guadalupian time. The forereef talus facies contains allochthonous fragments of both reef and near-back-reef material; much of this detritus dips steeply into the basin (with primary dips of up to 35°) and interfingers at the base of the slope with siltstones of the Bell Canyon Formation. Material was transported downslope by rockfall, debris flow, turbidity current, and other processes, yielding complex large- and small-scale fabrics. In general, sorting is poor and individual beds thin rapidly and get finer-grained in a basinward direction. Locally, small channels filled with sand- to silt-sized siliciclastic material cut through the carbonate strata. These slope channels (carbonate and noncarbonate) and variably sorted sediment packages exerted a strong influence on the early hydrology of the forereef zone.
Carbonate Sedimentology of the Manzanita Member of the Cherry Canyon Formation
Authors: Hampton Bret D. 
Published: November 2010

Abstract
The Manzanita, the uppermost member of the Cherry Canyon Formation, is one of three carbonate units that extend from the toe of the Goat Seep Dolomite far out across the Delaware Basin. It is one of eight named carbonate units that serve to subdivide the 1000 m-thick siliciclastics of the Delaware Mountain Group. The Manzanita Member is unique among these Delaware Basin carbonates (Table 1). Instead of thickening into the toe-of-slope reef carbonates, the Manzanita appears to pinchout at the top of slope (King, 1948; Newell et al., 1953). The Manzanita has uniform thickness (approximately 15 to 20 m) far into the basin and contains no channels or coarse shelf debris; it is dolomitized much farther into the basin than the other tongues and has numerous evaporite molds. The continuity across the basin and paucity of coarse fossil grains also distinguish the Manzanita from most other tongues.
The Manzanita crops out in three major areas. Two of these, approximately perpendicular to depositional strike, are along the Western Escarpment of the Guadalupe Mountains and the top of a cuesta extending some 25 km into the Delaware Basin (see Fig. 1). More isolated outcrops occur in the third area, which extends about parallel to depositional strike for some 12 km eastward along the base of the Capitan Reef Escarpment from the southwestern tip of the Guadalupe Mountains. A representative section (Fig. 1) in this vicinity, 3 km east of the type section at Nipple Hill, is shown graphically on Figure 2.
Shallow-Water Gypsum in the Castile Formation - Significance and Implications
Authors: Kendall Alan C. , Harwood Gill M. 
Published: November 2010

Abstract
The predominantly anhydritic Castile Formation (Lower Ochoan, Permian) of the Delaware Basin (Fig. 1) is commonly used to illustrate the necessity for surface-reflux in marine evaporite basins and as a textbook example of deep-water evaporite sedimentation in a barred basin. The occurrence of basin-wide, mm-calcite/anhydrite laminae and of salinity cycles (laminar anhydrite at the base, passing upward gradationally into 'nodular' anhydrite and laminar halite) have generated depositional models involving a brine-filled basin (up to 600 m deep) that exhibited periodic fluctuations in salinity. Such models have been widely applied to other evaporite-filled basins.
Pseudomorphs of bottom-grown gypsum crystals have been found in 'nodular' anhydrite intervals within the lower parts of the Castile Formation in the Union University "37" No. 4 well (Anhydrite I Member) and the much visited New Mexico roadside outcrop (the "State Line Outcrop") along U.S. 62, 1.2 km north of the Texas-New Mexico boundary (which Anderson and Kirkland, 1987, attribute to the uppermost Anhydrite II Member) (Figs. 2 and 3). Complete gradation between well-preserved pseudomorphs and nodular anhydrite layers in the Union core suggest that nodular anhydrite intervals throughout the Castile Formation were also originally composed of bottom-grown gypsum crystals. This would better explain their lateral persistence and their stratigraphic restriction to certain horizons than their being a recrystallization of anhydrite laminae, as has previously been suggested.
Inside Auk—the Anatomy of an Eolian Oil Reservoir
Authors: Heward Alan P. 
Published: November 2010

Abstract
Auk field is located in the central North Sea and produces oil from Permian Zechstein carbonates and the underlying Rotliegend sandstones. The Rotliegend is 150 to 500 m thick and can be divided into five discrete episodes of desert sedimentation. Deposits of the upper three episodes are oil bearing, with eolian slipface sands forming the main producing intervals. The earliest deposits (unit 5) are localized waterlain conglomerates, which possibly infill topography on the unconformity with the Devonian. They are overlain by a large wedge-shaped mass of eolian slipface sands (unit 4) that onlaps the Devonian. Unit 3 represents a change in eolian deposition with a marked increase in wind-ripple laminated strata. Their abundance probably indicates more variable winds, and thin conglomerates of interdunal dolomite clasts suggest periodically wet conditions. This depositional unit varies in thickness by about 100%, with thick areas corresponding to the stacked deposits of slipfaceless draa and thin areas to stacked interdunes. Dune slipface sands within the draa accumulations are orientated toward the east and cannot be correlated over hundreds of meters between wells in a cross-wind direction. Unit 2 contains a still greater proportion of wind-ripple laminated sands and waterlain deposits. Its geometry is dominated by a large depositional mound -7 km across wind, 87 m thick, and thinning to 10 m in its adjacent interdunes. The mound is located above an interdunal thin of unit 3. Several intervals of dune and probably draa slipface sands occur where the mound is thickest, and a distinctive body of fine-grained eolian sands mantles its northern flank. The uppermost unit (1; Weissliegend) comprises waterlain mass-flow sands that partially infill interdunal lows and appear to represent reworking of a largely abandoned erg by rain water. Intercalated organic-rich shales and dolomites contain indications of evaporitic conditions, desiccation, and deflation and yield no evidence of marine faunas. The succeeding marine Zechstein gently inundated remaining topography.
Subsurface Characterization of Mesaverde Reservoirs in Colorado
Authors: Lorenz John C. , Warpinski Norman R. , Branagan Paul T. 
Published: November 2010

Abstract
The geometries of nonmarine-sandstone reservoirs of the subsurface Mesaverde Group in northwestern Colorado were estimated on the basis of sedimentologic studies. The accuracy of the estimates was subsequently assessed by geophysical tests and reservoir-engineering studies, such as vertical seismic profiles, hydraulic-fracture diagnostics, pressure tests (drawdown/buildup, production, and interference tests), and tracer tests. After the effects of natural fractures on these subsurface tests are accounted for, the tests provide indications of reservoir boundaries, internal heterogeneity, and continuity that are compatible with sedimentologic predictions.
Variations in Fluvial Style as Revealed by Architectural Elements, Kayenta Formation, Mesa Creek, Coloralk), USA
Authors: Bromley Michael H. 
Published: November 2010

Abstract
Architectural studies in the Kayenta Formation (Lower Jurassic) of the Colorado Plateau reveal the characteristics of two types of sandstone body, that reflect both ephemeral and perennial fluvial processes. The first type is composed of high-regime horizontally-laminated sandstone, forming multiple-event Storys up to 8 m thick, deposited by flash floods. The second type is composed of planar cross-beds, deformed parabolic cross-beds and massive sandstone formed under low-regime flow from a perennial river during high stage.
The style of deposition is dependent upon the degree of confinement within the boundaries of the channel system in question. Where confinement was dominant, sedimentary fill often reflects the geometry of the containing channel. Paleocurrent distribution reflects the depositing flow conditions in confined bodies. Horizontally-laminated units show strongly unimodal currents, whereas the heterolithic confined units show a wider scatter.
Where flow was unconfined (during high stage, when thalwegs were inundated), the resulting deposits are broad sheets interfingering with underlying confined sandbodies. A zone of interdigitation displays sharp changes in paleoflow direction within the same stratigraphic horizon, resulting from the simultaneous action of confined and unconfined depositional processes. The interdigitation records the incremental abandonment of channels, as large unconfined barforms encroached on them during high stage.
Discharge variability is inferred from lithofacies composition; variable but perennial discharge shows a wide range of lithofacies, including clay drapes resulting from minimum, sluggish flow. Flashy discharge shows only two lithofacies types, those representing low-regime waxing and waning flow and those representing high-regime peak flow. Clay drapes are absent
Facies Architecture of a Devonian Soft-Sediment-Deformed Alluvial Sequence, Broken River Province, Northeastern Australia
Authors: Lang Simon C. , Fielding Christopher R. 
Published: November 2010

Abstract
The Late Devonian Rockfields Member of the Bulgeri Formation in northeast Queensland, Australia, was deposited in a tectonically active alluvial basin. The source area was an uplifted igneous and metamorphic terrain to the south of a major oblique-slip fault zone, forming the basin margin. The member is characterized by relatively uniform, very fine- to medium-grained, soft-sediment-deformed sandstones, interbedded predominantly with slightly reddened siltstones. Detailed mapping of sediment body geometries and internal structures has resulted in the recognition of eight architectural elements. Channel-fill elements include laminated sand sheets, dune complexes, scour fills, laterally-and downstream-accreting macroforms, and linguoid barforms. Floodplain elements include levees, crevasse splays, and overbank fines.
The abundant soft-sediment deformation structures (mainly convolute lamination) were produced by liquefaction of sandy bedforms, during or immediately after rapid deposition. Larger scale structures, however, deform multiple erosion surfaces. These may be due to liquefaction of saturated unconsolidated sands during earthquakes of magnitude &gt;5, with inferred epicenters along the fault zone 20 km to the south.
The proposed depositional model comprises a broad, sandy braidplain with marked discharge variation, resulting in widespread seasonal flooding. Channel-avulsion events, combined with a relatively high subsidence rate associated with tectonic activity, resulted in the accumulation of laterally extensive, sheet-like, channel sandbodies and fine-grained floodplain deposits. A modem analog is the seasonally inundated low-sinuosity channel system of the alluvial plains and fans surrounding the Gulf of Carpentaria, north Queensland. This model bears some resemblance to published models for low-sinuosity streams, but sufficient differences warrant recognition as a distinct fluvial style.
The unit represents an example of a strongly layered sequence with laterally extensive (&gt;1,500 m) channel sandstone bodies 3-10 m thick, separated by floodplain deposits 0.3-2 m thick of comparable lateral extent (1,500 to &gt;4,000 m). Hydrocarbon reservoirs with similar architecture, uniform grain size, and a general lack of internal fine partings could be considered to behave isotropically with respect to fluid flow within individual bodies.
Cenozoic Fluvial-Facies Architecture and Aquifer Heterogeneity, Oroville, California, Superfund Site and Vicinity
Authors: Blair Terence C. , Baker Fred G. , Turner Joseph B. 
Published: November 2010

Abstract
A three-dimensional facies analysis of Cenozoic fluvial deposits in the vicinity of a federal Superfund site near Oroville, California, was conducted to characterize aquifer heterogeneity and to provide a basis for accurate modeling of the complex groundwater system. A network of 29 boreholes in the 6.5-km2 study area penetrated four distinctive fluvial units, including the Laguna Formation (upper Pliocene-Holocene), Nomlaki Tuff (upper Pliocene), Mehrten Formation (Miocene-upper Pliocene), and lone Formation (Eocene). All four formations consist of pebble-cobble gravel, sand, and clay deposited by the Feather and ancestral Feather River systems at the margin of the Sacramento Basin near the western Sierra Nevada mountain front. Sediment gravity flows and waterlain andesitic and pumice-rich volcaniclastic facies derived from the southernmost Cascade volcanic centers episodically choked the ancestral Feather River system during late Pliocene upper Mehrten and Nomlaki Tuff deposition. Cenozoic fluvial aggradation was interrupted by three periods of valley cutting, which occurred 1) during the Oligocene, between deposition of the lone and Mehrten Formations; 2) during the late Pliocene, between deposition of the Nomlaki Tuff and Laguna Formation; and 3) during the middle Pleistocene, after most Laguna deposition was completed. The Oligocene and late Pliocene paleovalleys, 24 to 61 m deep, are filled with vertically and laterally interconnected channel pebble-cobble gravel of the Mehrten and Laguna sequences.
The principal aquifer zones in the study area are &gt;30-m-thick units of hydraulically continuous channel gravel and sand of the Laguna, Mehrten, and lone Formations. These aquifer zones are continuous across Oligocene and late Pliocene paleovalley margins through channel-fill gravel and sand of the various formations. Floodplain clay and volcaniclastic debris-flow units act as aquitards, which locally limit the interaction between permeable zones. A dissolved pentachlorophenol plume in local ground water originates at the Superfund site (a wood treatment plant) in the northern end of the study area, where it initially moves within the Laguna Formation. The plume has migrated into hydraulically continuous Mehrten and lone gravels that are in contact -425 m south of the plant site. The plume has also passed into juxtaposed Mehrten and Laguna gravels 1,400 m south of the plant site. Pumping-test data demonstrate that no marked changes in hydraulic conductivity occur across the paleo v alley- fu11 boundaries. Local changes in the hydraulic-gradient vector are caused by changes in the permeability of the aquifer material or in the thickness of the aquifer zones, both of which are associated with lateral changes in formations and facies.
Fluvial-Sandstone Reservoirs of The Travis Peak Formation, East Texas Basin
Authors: Tye Robert S. 
Published: November 2010

Abstract
Gas production (7.2 Bcf) from low-permeability sandstones in the Early Cretaceous Travis Peak Formation, North Appleby field, Nacogdoches County, Texas, is enhanced through hydraulic fracturing of stacked, blocky to upward-fining sandstones encased in impermeable mudstone interbeds. Pervasive quartz cement in the sandstones decreases porosity and permeability and contributes to formation of the reservoir seal.
Subsurface data indicate that much of this 615-m-thick section represents aggradation of alluvial-valley deposits. Multiple channel belts form a network of overlapping, broad, tabular sandstones having thickness-to-width ratios of 1:850 (2.4 to 13.2 m thick; widths exceed 6.4 to 8 km). Six to eight channel belts, each containing 80 to 90% medium- to fine-grained sandstone, locally occupy a 61 -m-thick interval. In a vertical sequence through one channelbelt sandstone, basal planar cross-bedding grades upward into thinly interbedded sets of planar cross-beds and ripple cross-lamination. Clay-clast conglomerates line scoured channel bases. Adjacent to the channels, fine-grained sediments accumulated in well-drained swamps and lakes. Poorly sorted sandstones represent overbank deposition. During Travis Peak deposition, alluvial styles evolved from dominantly bed-load deposition near the base of the formation to more mud-rich, mixed-load systems at the top.
Sandstone geometry, continuity, and internal heterogeneity influence reservoir performance and well-to-well communication. Small-scale bedforms, biogenic structures, and scour surfaces create fluid-flow barriers and segment reservoirs. Within the channel belts, best-quality reservoir sandstone (high porosity and low-water saturation) exists in narrow bands that are oriented subparallel to depositional dip. Reservoir quality decreases at channelbelt margins (levees) and tops (abandoned channel) and in fine-grained interchannel areas (shadow zones behind longitudinal bars).
Sand Bank and Dune Facies Architecture of a Wide Intracratonic Seaway
Authors: Surlyk Finn , Noe-Nygaard Nanna 
Published: November 2010

Abstract
The 200- to 300-m-thick Raukelv Formation was deposited in an intracratonic seaway between East Greenland and Norway during the Late Jurassic-earliest Cretaceous (Volgian-Valanginian), a period of considerable tectonic unrest in the region. The formation is three-dimensionally exposed over 900 km2. Four basic architectural elements are recognized: 1. The sandbank (SB) element is composed of single, tabular mega-cross-beds 15-50 m thick, which extend over the whole outcrop area (900 km2). 2. the sand-dune (SD) element consists of a large-scale tabular cross-bedded coset, 2-8 m thick, which extends over the whole outcrop area (900 km2). 3. the sandsheet (SS) element comprises a burrowed and glauconitized, mainly trough cross-bedded coset, 2-10 m thick, with sheet geometry, which extends over most or all of the outcrop area; and 4. the siltstone (SI) element is 2-20 m thick, has sheet geometry, and extends over at least 100 km2.
The SB, SD and SS elements are topped by planar, glauconitized commonly pebble-sttewn omission surfaces with U-shaped burrows. Most sand banks of the SB element migrated eastward from the western coastline, whereas the linear dunes of the SD element migrated southward, parallel to the basin axis and to the coast. Sedimentation seems to have been governed mainly by coast-parallel or offshore-directed currents set up by storms and tides. The low-amplitude 3-D dunes of the SS element migrated toward the south or, rarely, toward the north.
Rates of subsidence and sediment influx can be considered as relatively constant for the time interval in question. The succession consists of stacked SB, SD, SS and SI elements. A clear, systematic, sequential stacking order has not been observed, although there is a tendency for development of an SB, SS, SD cycle. A total of four SB, three SD, three SS and two SI elements has been recorded. Deposition is interpreted as controlled mainly by fluctuations in regional sea level during a period of lowstand. The individual elements reflect fairly rapid regional sea-level fluctuations on a background of the overall lowstand. The main transport of sand in the basin took place in extensive fields of linear sand dunes (SD element). Sand banks (SB element) were initiated at times of high rate of sea-level rise, and the main growth by eastward progradation took place during highstands. Some bank tops were eroded during sea-level fall, whereas others were drowned during rise. In both cases the tops became glauconitized and burrowed during the succeeding rise. The omission surface was slowly covered by bioturbated siltstone (SI element) during high rate of sea-level rise. In case of slower rate of rise a reworked, transgressive sheet sand (SS element) was formed. Sea level is estimated to have fluctuated between 30 and 50 m during deposition of the SB elements. These oscillations had a duration of about 1 m.y. and were superimposed on a lowstand following the Kimmeridgian highstand. The lowstand had a duration of about 10 m.y.
Contrasting Styles of Late Neogene Deep-Water Sandstone Deposition, Offshore Texas
Authors: Morton Robert A. 
Published: November 2010

Abstract
Middle Miocene and middle Pliocene deep-water sandstone reservoirs of the western Gulf Coast Basin are associated with failed shelf margins and subregional unconformities referred to as submarine pediments. The submarine pediments formed broad, convex-landward arcs along nondeltaic slopes and on the southwestern flanks of subjacent delta systems. They were created by retrogressive failure and were later enlarged by erosion during periods of lowered sea level. At times of lowered sea level, the deep embayments that carved into the continental platform funneled nearshore sands downslope to basin-floor fans.
The pediments were first backfilled by deep-water mudstones deposited by mass-transport processes. These slump blocks and high-energy turbidites exhibit mounded to chaotic seismic reflections that dip landward. Later, sand-rich channel-levee complexes were deposited above the basal mudstones and near the seismic-facies transition from chaotic reflections to overlying horizontal or wavy reflections. The pre-entrenchment morphology of the shelf margin was finally restored by coalescence of small, prograding deltas that are recorded as clinoform reflections.
Unconfined lower-slope and basin-floor fans associated with the submarine pediments are generally sand poor. The sand-rich lowstand-fan deposits are restricted to highly elongate, dip-oriented leveed channels that mark the principal pathways of sediment transport.
Sandstones confined to leveed channels of the upper-fan and pediment fill are the most prolific hydrocarbon reservoirs within each stratigraphic sequence. These channel sandstones exhibit high vertical continuity but low lateral continuity because interbedded turbidite mudstones increase away from the channel axes. Thin sandstones of the lower fan may exhibit high lateral continuity, but they typically have poor-reservoir properties because of high concentrations of original muddy matrix.