bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shublik Formation Lithofacies, Environments, and Sequence Stratigraphy, Arctic Alaska, U.S.A.
Authors: Parrish Judith Totman , Whalen Michael T. , Hulm Erik J. 
Published: November 2010

Abstract
The Shublik Formation (Triassic, North Slope, Alaska) is an organic-, phosphate-, and glauconite-rich unit with abundant fossils of marine vertebrates and mollusks. Five lithofacies, generalized around significant chemical constituents or lack thereof, are identified in the Shublik Formation:nonglauconitic sandstone - thin- to medium-bedded, fine, quartzose, calcareous to noncalcareous sandstone or silty to muddy sandstone, fossiliferous in places;glauconitic - thin- to medium-bedded, fine, quartzose sandstone, muddy sandstone, or siltstone containing 10% to &gt; 50% glauconite grainsphosphatic - thin- to medium-bedded siltstone or sandstone or laminated, black silty limestone or limestone containing phosphate nodules; andorganic-rich - laminated, black limestone, marl, and mudstonenonphosphatic, nonorganic-rich limestone - bioclastic wackestone, or argillaceous grainstone and packstone or graded grainstone and packstone.
Ichnofabrics provide evidence of fluctuating oxygen levels within the facies, especially the nonglauconitic sandstone and glauconitic facies. The organic-rich facies and, to a lesser extent, the phosphatic facies contain abundant, pristine, disarticulated shells of the clam Halobia. The lithofacies, ichnofabrics, and taphonomy are interpreted to be related to onshore-offshore gradients in biologic productivity and redox conditions. The Shublik Formation is interpreted as an upwelling-zone deposit formed on a shallow shelf.
The Shublik Formation in the Prudhoe Bay region is interpreted to comprise three sequences; these have been extended to outcrop but not to cores in the National Petroleum Reserve. Facies stacking patterns indicate that siliclastic facies are most common during lowstand and transgression, organic-rich facies are characteristic of transgression, and carbonate-rich facies are more prevalent during highstand. Phosphatic facies occur along transgressive and maximum flooding surfaces and are thus integral to subdividing sequences into systems tracts.
Lithofacies, Organic Geochemistry, Petrology, and Sequence Stratigraphy of the Ellesmerian Sequence
Authors: Robison Vaughn D. , Dawson William C. 
Published: November 2010

Abstract
The Tenneco Phoenix #1 well (OCS-Y-0338) cored a nearly complete section through the Pebble Shale (Cretaceous), Sag River and Shublik Formations (Triassic), and the Eileen and Ivishak Formations (Permo-Triassic). Cores of the Shublik Formation and the underlying Eileen and Ivishak Formations. (7, 800 to 8, 200 ft) were subjected to detailed geochemical and sedimentological analyses. These cores allowed comprehensive study of source rock and reservoir lithofacies from a known petroleum system within a sequence stratigraphic context. The basal (reservoir) section of the studied interval (Ivishak Sandstone) records nonmarine (fluvial) deposition during highstand. The overlying Eileen and lower Shublik Formations are marine lithofacies that developed during a major transgression (source rock and seal lithofacies). A distinctive glauconitic, pyritic and phosphatic unit (condensed interval) occurs near the top of this transgressive interval. Overlying upper Shublik strata record deposition during highstand conditions. The distribution of oil-prone facies within the Shublik Formation is related to stratigraphic position and is predictable within a sequence stratigraphic framework. The lower (transgressive) part of the Shublik Formation is dominated by oil-prone facies, whereas upper (regressive) Shublik strata are predominantly gas-prone to nonsource.
Ivishak sandstones in the Phoenix #1 well are equivalent to the main reservoir interval in the Prudhoe Bay field. These sandstones have average porosity ranging from 18 to 22 percent. Cross-stratified medium-grained Ivishak sandstones have average horizontal permeability that exceeds 2 Darcies. Other cored Ivishak lithofacies have average permeability values that range from 138 to 353 md. Compaction and the precipitation of quartz and siderite cements reduced the effectiveness of pore systems in Ivishak sandstones. Overlying Eileen sandstones are cemented pervasively with calcite. Marine shales (Shublik and Pebble Formations) provide potential seals for the North Slope Alaskan petroleum system.
Lithofacies and Depositional Environments of the Permo-Triassic Sadlerochit Group in the National Petroleum Reserve-Alaska (NPRA)
Authors: Wilson Gregory C. , Burns Beverly A. , McGowen Joseph H. , Tye Robert S. , Veldhuis Jerry H. 
Published: November 2010

Abstract
The Permo-Triassic Sadlerochit Group is divided, in ascending order, into the Echooka Formation, Kavik Shale, Ivishak Sandstone, and Fire Creek Formation in the National Pertroleum Reserve-Alaska (NPRA). It pinches out near the Barrow area in the north and thickens to at least 2250 ft (685 m) in the Tunalik 1 well 100 miles to the southwest. The base is defined by the pre-Echooka unconformity, a transgressive surface of erosion developed on the Carboniferous Lisburne Group (Jamison et al., 1980). During a regional north-to-south regression, the Kavik Shale and Ivishak Sandstone were deposited. In general, they are characterized as an upward-shoaling succession of prodelta/shelfal mudstones to proximal deltaic, intertidal, and fluvial deposits. The Fire Creek Sandstone records an abandonment or transgression of the proximal, non-marine facies of the Ivishak Sandstone and return to fully marine depositional conditions. This work subdivides the Sadlerochit Group into lithofacies that characterize the wide range of depositional environments. The primary focus is on the Ivishak Sandstone cored in the JW Dalton, Drew Point, and East Simpson 1 wells.
Facies Associations and Depositional Environments of the Mississippian Endicott Group in the National Petroleum Reserve – Alaska (NPRA)
Authors: Wilson Gregory C. , McGowen Joseph H. , Veldhuis Jerry H. 
Published: November 2010

Abstract
The base of the Middle Ellesmerian Megasequence of Hubbard et al. (1987) in the National Petroleum Reserve - Alaska (NPRA) is the non-marine to marginal marine Mississippian Endicott Group. It overlies a highly irregular erosional surface on pre-Mississippian basement complex and is mostly overlain by and transitional with the Mississippian-Pennsylvanian Lisburne Group shallow water carbonates. A late Devonian to early Mississippian breakup of the Basement Complex created the Meade, Ikpikpuk, and Umiat basins in the NPRA. Owing to accommodation within these basins and erosional relief at the top of Basement Complex outside the basins, the distribution of the Endicott Group across the NPRA is highly variable. Seismic correlation and limited well data suggests the basins were filled with as much as 5,400 m (17,700 ft) of clastics and carbonates of the Endicott and Lisburne groups. These same rocks are locally absent between basins and are thin to absent along the coast of NPRA. Core of the Endicott Group in NPRA is limited to four wells, but is only plentiful in the East Simpson 2 well. This core is interpreted to represent the Kekiktuk Formation of the Endicott Group and is comprised of coal and what appear to be crevasse splay sandstone and flood basin mudstone associated with a fan delta system and shallow lacustrine swamp. Limited Endicott core from the Inigok 1 well is tightly quartz-cemented pebbly sandstone and granule conglomerate that appears to be of fluvial origin. Reservoir potential of the Endicott Group within the deep basins is low, but there may be limited potential in the thin, shallower accumulations along the NPRA coast.
Lithologies of the Basement Complex (Devonian And Older)in the National Petroleum Reserve – Alaska
Authors: Dumoulin Julie A. 
Published: November 2010

Abstract
Rocks of the basement complex (Devonian and older) were encountered in at least 30 exploratory wells in the northern part of the NPRA. Fine-grained, variably deformed sedimentary rocks deposited in a slope or basinal setting predominate and include varicolored (mainly red and green) argillite in the Simpson area, dark argillite and chert near Barrow, and widespread gray argillite. Chitinozoans of Middle-Late Ordovician and Silurian age occur in the dark argillite and chert unit. Sponge spicules and radiolarians establish a Phanerozoic age for the varicolored and gray argillite units, both of which contain local interbeds of chert-rich sandstone and silt-stone. Conglomerate and sandstone, also chert-rich but interbedded with mudstone and coal and of Early-Middle Devonian age, occur in the Topagoruk area; these strata formed in a fluvial environment. At East Teshekpuk, granite of probable Devonian age was penetrated. Brecciated, quartz-veined rock of uncertain protolith that may be part of the basement complex was encountered in the Ikpikpuk well. Seismic data indicate that angular unconformities truncate all sedimentary units of the basement complex in NPRA. Rocks correlative in age and lithofacies with the dark argillite and chert unit occur in the subsurface near Prudhoe Bay. Other argillite units in NPRA have similarities to basement rocks in the subsurface adjacent to ANWR and the Ordovician-Silurian Iviagik Group at Cape Lisburne, but lack the interbedded limestones found in the ANWR strata, and are less metamorphosed than, and compositionally distinct from, the Iviagik. The Topagoruk conglomerate and the East Teshekpuk granite resemble the Ulungarat formation and the Okpilak batholith, respectively, in the northeastern Brooks Range.
Petroleum Plays and Systems in the National Petroleum Reserve - Alaska
Authors: Houseknecht David W. 
Published: November 2010

Abstract
The North Slope of Alaska has re-emerged as one of the most active exploration provinces in the United States. Recent exploration successes, economic benefits of applying innovative exploration and production technologies, evolving industry demographics, rising oil and natural gas prices, and the anticipation that North Slope natural gas resources may become economically viable and marketable through a planned pipeline have stimulated a renewed intensity in leasing and exploration activity. The focus of NPRA exploration appears to include both structural and stratigraphic objectives that may include strata spanning much of the stratigraphic column. The purpose of the core workshop is to prove an opportunity to examine a large collection of core from all major stratigraphic units present in NPRA. The chapters in this volume provide a current perspective on the genesis and petroleum potential of each stratigraphic interval.
Geology of the Capitan Shelf Margin - Subsurface Data from the Northern Delaware Basin
Authors: Garber Raymond A. , Grover George A. , Harris Paul M. 
Published: November 2010

Abstract
Facies relations determined from outcrop studies have been used in conjunction with subsurface data to better understand the geologic evolution, depositional facies, and diagenesis of the Capitan shelf margin. These studies have centered on a 2400 ft (731 m) portion of a 4800 ft (1463 m) continuous core from the Gulf PDB-04 research well that is located in Eddy County, New Mexico, at the northern end of the Delaware Basin.
The evolution of the Capitan shelf and margin was examined after (a) the establishment of time lines for shelf-to-basin correlations in the Late Guadalupian and (b) the confirmation of the stratigraphic units penetrated in the PDB-04 well. Subsurface and outcrop data revealed that the evolution of the 2.5 m.y. duration Capitan shelf margin occurred in two major growth phases: a 1.5 m.y. duration phase during Seven Rivers time when over 80% of the total progradation, over half of the total aggradation, deposition of thick carbonate debris units on the slope and basin margin, and influx of over 60% of the total siliciclastics of the Bell Canyon Formation occurred. A subsequent, 1.0 m.y. growth phase during Yates and Tansill time is dominated by aggradation, steepening of the margin, and corresponds with abundant clastic deposition on the shelf. Maximum progradation of up to 12 miles (19 km) occurred along the northern rim of the basin, where progradation rates in excess of 7500 µm/year are measured.
Detailed shelf-to-basin correlations have revealed that three major processes were responsible for the profound progradation and differentiation of Capitan growth into two major phases: (a) fluctuations of sea level, (b) maximum emplacement of allochthonous carbonate debris along the basin margin during Seven Rivers time, and (c) that abundant siliciclastics bypassed the actively prograding shelf margin and were an important foundation for the progradation. Because the Capitan was a deeply submerged reef during most of its growth, progradation occurred during both
Lateral Variability of the Capitan Reef Complex, West Texas and New Mexico
Authors: Pray Lloyd C. 
Published: November 2010

Abstract
The Delaware Basin is a pear-shaped, NNW-SSE elongate, intracratonic basin, about 250 km long and 150 km wide at its bulging northwestern end. The Capitan Reef Complex forms a narrow carbonate belt along the rim of the Delaware Basin for some 600-700 km, but outcrops occur only along about one-sixth of its rim. Most of these are in the Guadalupe Mountains where they fringe the Northwestern Shelf, but some occur in the Apache Mountains and fringe the Diablo Plateau, and also in the Glass Mountains where they fringe the Southern Shelf (index map of Fig. 1).
The most extensive and laterally continuous exposures are in the Guadalupe Mountains, and most subsurface data is from the area east and southeast of the Guadalupes. By far the most sedimentologic research has been of outcrops of the Guadalupe Mountains. Here excellent exposures, tectonic simplicity, and the large scale of the dramatic shelf-to-basin transitions have, justifiably, made the Permian of this area, and especially the Capitan Reef and its associated facies, a world-famous sedimentologic model.
But the extensive research over more than half a century on the Guadalupe outcrops (and on the petroleum-bearing area adjacent to them) has created two dangerous impressions: (1) that the Capitan Reef and its associated facies are well understood, and (2) that the "model" derived from study of the Guadalupe Mountains outcrops can be safely extrapolated along the remainder of the Capitan trend rimming the Delaware Basin. Despite major progress in recent decades as concerns "what is where" and "how did it form," much remains to be learned to arrive at a satisfactory sedimentologic understanding of the Capitan Reef and its associated facies. Moreover, the available surface and subsurface evidence indicates that considerable depositional and diagenetic lateral variability exists along the Capitan trend, and application of sedimentologic principles indicates that considerable lateral variability should be expected.
Characterization of an Upper Guadalupian Barrier-Island Complex from the Middle and Upper Tansill Formation (Permian), East Dark Canyon, Guadalupe Mountains, New Mexico
Authors: Parsley M. J. , Warren J. K. 
Published: November 2010

Abstract
The youngest Guadalupian shelf deposits in the Permian Basin region of West Texas and southeastern New Mexico are exposed in the Tansill Formation in East Dark Canyon, Guadalupe Mountains, New Mexico (Figs. 1 and 2). Previous investigations of the Capitan Limestone have suggested that Ochoan deposition was foreshadowed by Delaware Basin shallowing conditions (Babcock, 1974; Toomey and Babcock, 1983) and increasing restriction of basinal and shelf waters (Given and Lohmann, 1985) at the end of the Guadalupian. The deposits of the middle and uppermost Tansill Formation (Tyrrell et al., 1978) in East Dark Canyon provided the opportunity to describe and interpret the latest pulses of Guadalupian back-reef sedimentation in the barrier-island complex of the shelf.
Peritidal Facies of the Guadalupian Shelf Crest, Walnut Canyon, New Mexico
Authors: Neese Douglas G. 
Published: November 2010

Abstract
The facies succession of shelf carbonates in the upper Yates and lower Tansill formations shows a complex progression of environmental conditions across the shelf through time. An interval approximately 50 m thick centered about the easily recognizable contact between the Yates and Tansill formations was studied in an outcrop belt 3.5 km wide and 11 km long parallel to, and 1 to 8.5 km shelfward of, the Capitan Limestone (Walnut Canyon, New Mexico). The stratigraphic interval includes three major outcrop-defined carbonate units; in ascending order, the Hairpin Dolomite (Yates Formation), Triplet Dolomite (Yates Formation), and Basal Tansill Dolomite (Fig. 1), which have been subdivided into eight fabric-specific facies (Neese and Schwartz, 1977).
The geological literature of the Guadalupian shelf is extensive; King (1948), Newell et al. (1953), and Hayes (1964) concentrated primarily on broad stratigraphic relationships, lithologic features, and biota of shelf sediments and their reef and basinal equivalents. More genetic sedimentologic considerations of the Guadalupian shelf strata and their environments have been presented by Dunham (1972), Smith (1974), Pray and Esteban (1977), Neese (1979), Sarg and Lehmann (1986), and Tye (1986). The focus of this study is on the facies relationships of the grainstone and packstone facies of Dunham (1972) and Smith (1974).
Stratigraphy and Sedimentology of the Back-Reef Upper Queen-Lower Seven Rivers Strata, Goat Seep-Capitan Reef Complexes (Middle-Late Guadalupian, Permian), Southeast New Mexico
Authors: Sarg J. F. (Rick) 
Published: November 2010

Abstract
The uppermost 27 m of the Shattuck Member of the Queen Formation (Middle Guadalupian) and the lower 156 m of the overlying Seven Rivers Formation (Late Guadalupian) represent portions of two depositional sequences (Fig. 1). A subaerial sabkha surface near the top of the Shattuck Member is interpreted to be a sequence boundary and separates the two sequences. This disconformity is widespread over the Permian Basin, correlates with a toplap surface at the Goat Seep platform margin, and suggests a major sea-level drop at the end of Goat Seep deposition. Deposition of the basin-restricted Manzanita Member of the Cherry Canyon Formation is interpreted to have occurred during this lowstand in sea level. The immediately overlying 7 to 11 m of the topmost Shattuck contains fossilized and dolomitized Permian soil caliche (dolocalcrete). The dolocalcrete occurs in a repeated series of soil profiles overlain by evaporite solution residues. These dolocalcrete cycles are interpreted to have been deposited during a time of slowly rising sea level toward the end of the Manzanita lowstand and just prior to deposition of the Capitan Reef Complex (Sarg, 1985).
The dolocalcretes consist of nodular, massive, and mottled textures containing clotted and fractured micrite, microspar, equant spar-filled solution channels, coated fractures, and pisolites similar to modern caliche fabrics. Profiles are thin (approximately 0.5 m) and incomplete, and record short-lived soil-forming conditions with little external addition of CaCO3. The upper surfaces of the dolocalcretes are hard and undulatory, and erosional in part. The overlying evaporite solution residues are composed of interbedded green/red clayey siltstone and thin, discontinuous zones of red calcitic dolomite. The dolomite consists of small angular clasts of microcrystalline dolomite in a coarsely crystalline calcite matrix. Overlying dolomite beds are commonly brecciated (Sarg, 1977, 1985).
The Massive Facies of the Capitan Limestone Guadalupe Mountains, Texas and New Mexico
Authors: Babcock Jack A. , Yurewicz Donald A. 
Published: November 2010

Abstract
The Guadalupe Mountains provide dramatic exposures of the Capitan Limestone along the northwest margin of the Delaware Basin. These exposures provide unparalleled opportunities to examine lateral and vertical variations in the Capitan Limestone along a portion of the basin margin. Our work (Babcock, 1974, 1977; Yurewicz, 1976, 1977a) focused on outcrops of the massive facies of the Capitan Limestone in Slaughter, McKittrick, Walnut, and Dark canyons, and was supplemented by studies in Big, Rattlesnake, Bear, and Pine Springs canyons and Jurnigan Draw. These exposures show distinct, progressive changes in the Capitan as it prograded into the Delaware Basin. This paper summarizes those observations (Table 1). In order to document changes within the Capitan, we have divided it into three informal stratigraphic units: the lower, middle, and upper Capitan equivalent to the Seven Rivers, Yates, and Tansill formations on the shelf (Fig. 1). It is important to emphasize that our observations, although extensive, are not necessarily representative of the entire reef trend or even the entire exposed trend in the Guadalupe Mountains.
Large-Scale Channel Development within the Capitan Reef Complex - Evidence from Carlsbad Caverns
Authors: Harwood Gill M. 
Published: November 2010

Abstract
Carlsbad Caverns have formed within the uppermost Capitan reef and, where the cavern margins have not been coated with cave formations, allow examination of three-dimensional transects through the reef and adjacent facies. This study was made within Left Hand Tunnel, which is developed mostly on one stratigraphic-level within the reef facies (Fig. 1a). Although in situ reef is developed both at the entrance to the tunnel and further along the tunnel, mapping has identified an area, commencing near the western end of the tunnel, where large rotated blocks of reef facies sediments are present (Fig. 1b). A further, smaller area of rotated reef facies blocks is present near the eastern end of the tunnel (Fig. 1b). These areas are interpreted as paleochannels which developed within the reef. The western paleochannel is some 230 m wide by over 25 m deep. The size of the eastern paleochannel cannot be determined as the surrounding areas are covered by cave formations.
An Investigation of the Use of Paleomagnetic Techniques in a Carbonate Terrane - The Capitan Reef Complex, Southwestern U.S.A.
Authors: Darke Gill 
Published: November 2010

Abstract
Paleomagnetic methods have been used to obtain both qualitative and quantitative data concerning the depositional and diagenetic environments of rocks from the Capitan Reef Complex (Guadalupian, Upper Permian) in the Guadalupe Mountains of West Texas and New Mexico, southwestern U.S.A. The natural remanent magnetism (NRM) of rocks can be dated using paleomagnetic methods. This information on absolute ages can place constraints on the timing of depositional and diagenetic events. The study of magnetic minerals in rocks can also yield qualitative data concerning the nature of the system in which those minerals developed.