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Christopher R Fielding - One of the best experts on this subject based on the ideXlab platform.
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DEPOSITIONAL ARCHITECTURE OF THE TURONIAN FERRON SANDSTONE IN THE WESTERN HENRY
2016Co-Authors: Christopher R FieldingAbstract:central Utah, U.S.A., indicates sediment accumulation in a series of flood-dominated, marine current- and wave-influenced, deltas. Twelve lithofacies are recognized: 1. erosionally based, thick cross-bedded sandstone bodies (Distributary Channels), 2. similar though thinner bodies containing common bioturbation (Marine-Influenced Distributary Channels), 3. root-penetrated, plant fossil bearing Siltstone with minor sandstone (Coastal Floodplain and Floodbasin), 4. coal and carbonaceous shale (Coastal Mire), 5. thin-bedded, carbonaceous and bioturbated sandstone–Siltstone (Coastal Lagoon), 6. erosionally based sandstone with large- and small-scale cross-bedding and bioturbation (Mouth-Bar Complex), 7. sharply based sandstone bodies internally dominated by hummocky cross-stratification, soft-sediment deformation, or lacking structure (Proximal Delta Front), 8. sharply bounded, calcareous, fossiliferous and bioturbated sandstone sheets (Abandoned Delta Lobe), 9. thickly interbedded sandstone, coarse- and fine-grained Siltstone (Medial Delta Front), 10. thinly interbedded sandstone, coarse- and fine-grained Siltstone (Distal Delta Front), 11. mainly Siltstone with minor thin-bedded sandstone (Prodelta) and 12. fine-grained Siltstone with bentonite beds (Offshore). Deltas prograded into shallow water, forming sharp-based mouth-bar sand bodies. The upper delta front was evidently fluidal and prone to failure, leading to the development of rotational slope failures, debris–flow filled gullies, and, in places, growth faults. Paleocurrent data indicate that the regional sediment dispersal direction was eastward. Data from delta-front facies, however, suggest that outflow plumes and associated bottom currents were deflected towards the southeast, giving rise to a
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planform and facies variability in asymmetric deltas facies analysis and depositional architecture of the turonian ferron sandstone in the western henry mountains south central utah u s a
Journal of Sedimentary Research, 2010Co-Authors: Christopher R FieldingAbstract:Abstract Facies analysis of the Upper Cretaceous (Turonian) Ferron Sandstone in the western Henry Mountains of south-central Utah, U.S.A., indicates sediment accumulation in a series of flood-dominated, marine current- and wave-influenced, deltas. Twelve lithofacies are recognized: 1. erosionally based, thick cross-bedded sandstone bodies (Distributary Channels), 2. similar though thinner bodies containing common bioturbation (Marine-Influenced Distributary Channels), 3. root-penetrated, plant fossil bearing Siltstone with minor sandstone (Coastal Floodplain and Floodbasin), 4. coal and carbonaceous shale (Coastal Mire), 5. thin-bedded, carbonaceous and bioturbated sandstone–Siltstone (Coastal Lagoon), 6. erosionally based sandstone with large- and small-scale cross-bedding and bioturbation (Mouth-Bar Complex), 7. sharply based sandstone bodies internally dominated by hummocky cross-stratification, soft-sediment deformation, or lacking structure (Proximal Delta Front), 8. sharply bounded, calcareous, fossiliferous and bioturbated sandstone sheets (Abandoned Delta Lobe), 9. thickly interbedded sandstone, coarse- and fine-grained Siltstone (Medial Delta Front), 10. thinly interbedded sandstone, coarse- and fine-grained Siltstone (Distal Delta Front), 11. mainly Siltstone with minor thin-bedded sandstone (Prodelta) and 12. fine-grained Siltstone with bentonite beds (Offshore). Deltas prograded into shallow water, forming sharp-based mouth-bar sand bodies. The upper delta front was evidently fluidal and prone to failure, leading to the development of rotational slope failures, debris–flow filled gullies, and, in places, growth faults. Paleocurrent data indicate that the regional sediment dispersal direction was eastward. Data from delta-front facies, however, suggest that outflow plumes and associated bottom currents were deflected towards the southeast, giving rise to an asymmetric delta planform. The Holocene and modern Burdekin River Delta of NE Australia is considered a close planform, process, and facies analog for the Ferron Notom deltas. The Burdekin Delta facies assemblage is vertically and laterally heterogeneous, despite being the product of a consistent array of environmental controls. Adopting a model that incorporates such a degree of heterogeneity negates the need for multiple depositional models for complex stratigraphic intervals such as the Ferron Sandstone. The facies model also suggests that asymmetric deltas may be produced by directional growth of delta lobes, rather than by deflection of beach ridges. Stratigraphic stacking patterns strongly suggest that sediment accumulation in the Ferron Sandstone of the western Henry Mountains was forced by a regime of progressively more limited accommodation through time.
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lithostratigraphy of the late early permian kungurian wandrawandian Siltstone new south wales record of glaciation
Australian Journal of Earth Sciences, 2007Co-Authors: S G Thomas, Christopher R Fielding, Tracy D FrankAbstract:The late Early Permian (273–271 Ma) Wandrawandian Siltstone in the southern Sydney Basin of New South Wales represents a marine highstand that can be correlated over 2000 km. A mainly fine-grained terrigenous clastic succession, the Wandrawa ndian Siltstone contains evidence for cold, possibly glacial conditions based on the presence of outsized clasts and glendonites, mineral pseudomorphs after ikaite, a mineral that forms in cold (0–7°C) marine sediments. A lithostratigraphic and facies analysis of the unit was conducted, based on extensive coastal outcrops and continuous drill-cores. Eight facies associations were identified: (i) Siltstone; (ii) Siltstone with minor interbedded sandstone; (iii) interbedded tabular sandstone and Siltstone; (iv) ad mixed sandstone and Siltstone to medium-grained sandstone; (v) discrete, discontinuous sandstone intervals; (vi) chaotic conglomerate and sandstone in large channel forms; (vii) chaotically bedded and pervasively soft-sediment-deformed intervals; and (viii) tuffaceous Siltstone and claystone. Using lithology and ichnology, relative water depths were ascribed to each facies association. Based on these associations, the unit was divided into five informal members that reveal a history of significant rel ative sea-level fluctuations throughout the formation: member I, interbedded/admixed sandstone and Siltstone; member II, silt stone; member III, slumped masses of members I and II; member IV, Siltstone and erosionally based lensoid sandstone beds and channel bodies; and member V, interbedded/admixed sandstone and Siltstone with abundant tuffs. Member I marks an initial marine transgression from shoreface to offshore depths. Member II records the maximum water depth of the shelf. Member III is interpreted to be a slump sheet; plausible mechanisms for its emplacement include seismicity produced by tectonism or glacio-isostatic rebound, changes in pore-water pressures due to sea-level fluctuations, or an increase in sedimentation rates. Members IV and V record minor fluctuations in depositional environments from offshore to shoreface water depths. Member IV includes regionally extensive, large channel bodies, with composite fills that are interpreted as storm-influenced mass-flow deposits. Member V includes a greater abundance of volcanic ash. Glacial controls (isostasy, eustasy) and tectonic affects may have worked in concert to produce the changes in depositional environments observed in the Wandrawandian Siltstone.
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submarine mass wasting deposits as an indicator of the onset of foreland thrust loading late permian bowen basin queensland australia
Terra Nova, 1997Co-Authors: Christopher R Fielding, Christopher J Stephens, R J HolcombeAbstract:In the eastern part of the Permo-Triassic Bowen Basin of Queensland, Australia, a transition from passive, thermal subsidence to flexural (foreland basin) subsidence is recorded within the Upper Permian stratigraphy. Two coarse-grained intervals containing deposits of mass-wasting processes occur within an otherwise Siltstone-dominated succession over 1500 m thick (the Moah Creek Beds and equivalents). These intervals can be traced over at least 350 km north-south, along the structural eastern margin of the basin. The lower of the coarse-grained intervals is spectacularly exposed in the banks of the Fitzroy River, west of Rockhampton. Here, interbedded sandstones and Siltstones of marine shelf origin are abruptly truncated by a mudrock succession containing evidence of slumping and contemporaneous magmatic activity. This unit passes up-section into packages of mass-flow conglomerates and diamictites, interpreted to have formed on an unstable submarine slope. The character of the mass-flow deposits, their stratigraphic position and lateral extent are interpreted in terms of destabilization of a sloping marine surface by pulsed, subsurface thrust propagation.
Luis A Buatois - One of the best experts on this subject based on the ideXlab platform.
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the upper devonian lower mississippian bakken formation of west central saskatchewan stratigraphic architecture and sequence stratigraphy of a conventional heavy oil reservoir
Bulletin of Canadian Petroleum Geology, 2017Co-Authors: Luc E Chabanole, Luis A BuatoisAbstract:Abstract The Bakken Formation (Upper Devonian-Lower Mississippian) of western Saskatchewan has lower and upper members dominated by black shales and a heterolithic middle member, similar to southeastern Saskatchewan and North Dakota. However, the middle member in western Saskatchewan contains fine-grained sandstone where porosity and permeability values commonly exceed 25% and 1 Darcy respectively that are absent in southeastern Saskatchewan and North Dakota. Although focus has been in southeastern Saskatchewan and North Dakota, the Bakken Formation of west-central Saskatchewan has conventionally produced heavy gravity oil (API approximately 12 degrees) since the 1950s using vertical wells. The sequence-stratigraphic framework of the Bakken Formation of west-central Saskatchewan includes deposition under open-marine and marginal-marine conditions. Open-marine black shales were deposited during late-stage transgression (TST1) and progradation of offshore Siltstones during the subsequent highstand systems tract (HST). Fine-grained sandstone, Siltstone, and mudstone showing evidence of tidal influence was deposited during a falling-stage systems tract (FSST), initiated under forced-regressive conditions. Increased fluvial influence and dilution of normal marine salinity established marginal-marine conditions, evidenced by the low bioturbation index (BI: 0−2). Subsequent transgression (TST2) led to increased marine influence, reflected in a sudden increase in biogenic activity (BI: 4−5). Offshore Siltstone and black shale were deposited through continued transgression (TST2) resulting in the re-establishment of open-marine conditions. Preserved thickness of the Bakken Formation in west-central Saskatchewan has been affected by post-Mississippian erosion during the creation of the sub-Cantuar drainage network, which was later filled by Lower Cretaceous clastics. The Bakken middle marginal-marine interval in west-central Saskatchewan differs from that in southeastern Saskatchewan. Fine-grained sandstones associated with tidal channels in west-central Saskatchewan comprise a reservoir characterized by porosity and permeability values that commonly exceed 25% and 1 Darcy, respectively. In contrast, in southeastern Saskatchewan, the Bakken Formation produces from a dolomitized silty sandstone where low porosity and permeability values have led to the widespread use of unconventional exploitation techniques to produce economically.
Robert L Cullers - One of the best experts on this subject based on the ideXlab platform.
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the controls on the major and trace element evolution of shales Siltstones and sandstones of ordovician to tertiary age in the wet mountains region colorado u s a
Chemical Geology, 1995Co-Authors: Robert L CullersAbstract:A vertical section of shales, Siltstones and sandstones from Ordovician to Eocene age in a limited geographic area east of the Wet Mountains and Sangre de Cristo Mountains in Colorado have been analyzed for major elements and a variety of trace-element concentrations, including the REE. In addition, the petrography of the sandstones has been determined. The quartz-rich arenites contain considerably lower concentrations of most elements relative to coexisting shales or Siltstones at the same outcrop. The arkosic sandstones contain similar to lower concentrations of most elements compared to coexisting shales or Siltstones in the same area. Accordingly, the average concentrations of Al2O3, Fe2O3, MgO, TiO2, LOI, Rb, Th, Co, Sc, Cr, Cs, Nb, Y and REE are significantly lower in all sandstones relative to all shales and Siltstones. The exceptions are SiO2, Na2O and Ba concentrations, and the Eu/Eu★, LaSc and ThSc ratios as they are higher in the sandstones than the shales and Siltstones. There is no significant difference in the MnO, CaO, K2O and Sr concentrations or the solLaCo, ThCo, LaNi, CrTh and (LaLucn ratios of the average sandstones relative to the shales and Siltstones. Many of these differences may be related to the higher quartz and feldspar and lower clay mineral amounts in the sandstones than in the shales and Siltstones. For example, average LaSc, ThSc, EuEu★ and (LaLucn ratios of th arkosic sandstones tend to be higher than the coexisting shales and Siltstones due to enrichment of the arkoses in feldspar relative to the other minerals (e.g., EuEu★ = 0.82 ± 0.19 in average arkoses in the Trinidad, Vermejo, Raton, Poison Canyon and Cuchara Formations; EuEu★ = 0.63 ± 0.19 in average shales and Siltstones in the same formations). In addition, the elemental concentrations and ratios are more variable for most elements in the sandstones than the shales and Siltstones. This suggests that the shales are rapidly homogenized near the source. The elemental fractionation in the arkosic sandstones due to enrichment of feldspar relative to other minerals suggests that they are poorer indicators of provenance that the associated shales, whereas, the more homogeneous elemental distributions in the shales and Siltstones suggest that they may be better indicators of provenance than the sandstones. Nevertheless, the elemental ratios that are most similar in the sandstones and in the shales and Siltstones are consistent with their derivation from similar average intermediate to silicic source rocks.
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the controls on the major and trace element variation of shales Siltstones and sandstones of pennsylvanian permian age from uplifted continental blocks in colorado to platform sediment in kansas usa
Geochimica et Cosmochimica Acta, 1994Co-Authors: Robert L CullersAbstract:Shales, Siltstones, and sandstones of Pennsylvanian-Permian age from near the source in Colorado to those in the platform in eastern Colorado and Kansas have been analyzed for major elements and a number of trace elements, including the REEs. The near-source sandstones are significantly more enriched (Student t-test at better than the 99% confidence level) in SiO2 and Na2O concentrations and more depleted in Al2O3, Fe2O3 (total), TiO2, Th, Hf, Sc, Cr, Cs, REEs, Y, and Ni concentrations and LaCo and LaNi ratios than the near-source shales and Siltstones, most likely due to more plagioclase and quartz and less clay minerals in the sandstones than in the shales and Siltstones. There are no significant differences in K2O and Sr concentrations and EuEu∗, LaLu, LaSe, ThSc, ThCo, and CrTh ratios between the near-source sandstones and the near-source shales and Siltstones. Samples of the Molas, Hermosa, and Cutler formations near the source that were formed in different environments in the same area contain no significant difference in EuEu∗, LaLu, LaSc, ThSc, ThCo, and CrTh ratios, so a generally silicic source and not the environment of deposition was most important in producing these elemental ratios. For example, CrTh ratios of near-source shales, Siltstones, and sandstones range from 2.5 to 17.5 and EuEu∗ range from 0.48 to 0.78, which are in the range of sources of sediments derived from mainly silicic and not basic sources. Near-source shales and Siltstones contain significantly higher (Student t-test) and more varied concentrations of most elements (Al2O3, Fe2O3, MnO, TiO2, Ba, Th, Hf, Ta, Co, Sc, REEs, Nb, Y) but significantly lower concentrations of Na2O and EuEu∗ than platform shales and Siltstones in Kansas (e.g., La = 65.7 ± 40 and EuEu∗ = 0.55 ± 0.07 in near-source shales and Siltstones and La = 23.7 ± 8.7 and EuEu∗ = 0.64 ± 0.08 in platform shales and Siltstones). The SiO2 and CaO concentrations are not significantly different in platform shales and Siltstones compared to the near-source shales and Siltstones, so dilution of other minerals by quartz and calcite is not the main reason for the lower concentration of most elements in the platform relative to the near-source shales and Siltstones. Rather the lesser concentrations of most elements in clay minerals of the platform shales and Siltstones can account for the lower concentration of most elements compared to corresponding near-source shales and Siltstones. The lower concentrations of many elements in clay minerals in the platform shales and Siltstones may be a result of having been derived from recycling of clay minerals from older rocks. The greater homogeneity of elemental concentrations of the platform shales and Siltstones compared to those in the source is also consistent with homogeneous mixing of such recycled material. Also there is no significant difference in ThSc, LaCo, ThCo, LaNi, and CrTh ratios of the near-source sedimentary rocks in Colorado to the platform shales and Siltstones in Kansas, and the latter are also consistent with derivation from mostly silicic source rocks.
Craig R Glenn - One of the best experts on this subject based on the ideXlab platform.
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eolian derived Siltstone in the upper permian phosphoria formation implications for marine upwelling
Geology, 1998Co-Authors: Alan R Carroll, Nat P Stephens, Marc S Hendrix, Craig R GlennAbstract:Previously described organic-rich shale facies of the Meade Peak Member of the Phosphoria Formation at Soda Springs, Idaho, consist of well-sorted, laminated Siltstone containing little or no clay. The planar-parallel fabric preserved in many of the Siltstone beds suggests suspension settling onto the outer shelf or upper slope, most likely under low oxygen conditions. Evidence for transport of silt to the depositional site by sediment gravity flows is absent, as are sandstone beds. We propose that Meade Peak Siltstone facies record subaqueous deposition of windborne silt that was transported southward from central Montana. As such, they provide the first direct geologic evidence of a wind regime favorable for marine upwelling, the process commonly postulated to have localized the deposition of Permian phosphatic sediments. They may also provide indirect evidence of upwind eolian sand transport at that time.
R J Holcombe - One of the best experts on this subject based on the ideXlab platform.
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submarine mass wasting deposits as an indicator of the onset of foreland thrust loading late permian bowen basin queensland australia
Terra Nova, 1997Co-Authors: Christopher R Fielding, Christopher J Stephens, R J HolcombeAbstract:In the eastern part of the Permo-Triassic Bowen Basin of Queensland, Australia, a transition from passive, thermal subsidence to flexural (foreland basin) subsidence is recorded within the Upper Permian stratigraphy. Two coarse-grained intervals containing deposits of mass-wasting processes occur within an otherwise Siltstone-dominated succession over 1500 m thick (the Moah Creek Beds and equivalents). These intervals can be traced over at least 350 km north-south, along the structural eastern margin of the basin. The lower of the coarse-grained intervals is spectacularly exposed in the banks of the Fitzroy River, west of Rockhampton. Here, interbedded sandstones and Siltstones of marine shelf origin are abruptly truncated by a mudrock succession containing evidence of slumping and contemporaneous magmatic activity. This unit passes up-section into packages of mass-flow conglomerates and diamictites, interpreted to have formed on an unstable submarine slope. The character of the mass-flow deposits, their stratigraphic position and lateral extent are interpreted in terms of destabilization of a sloping marine surface by pulsed, subsurface thrust propagation.
