Sandstone-Body Variability in the Medial–Distal Part of an Ancient Distributive Fluvial System, Salt Wash Member of the Morrison Formation, Utah, U.S.A.

2018 ◽  
Vol 88 (5) ◽  
pp. 568-582 ◽  
Author(s):  
John T. Chesley ◽  
Andrew L. Leier
Keyword(s):  
Distal Part ◽  
Morrison Formation ◽  
Fluvial System ◽  
Sandstone Body

scholarly journals Quantification of a Distributive Fluvial System: The Salt Wash DFS of the Morrison Formation, SW U.S.A.

2015 ◽  
Vol 85 (5) ◽  
pp. 544-561 ◽  
Author(s):  
A. Owen ◽  
G. J. Nichols ◽  
A. J. Hartley ◽  
G. S. Weissmann ◽  
L. A. Scuderi
Keyword(s):  
Morrison Formation ◽  
Fluvial System

Translating Outcrop Data to Flow Models, With Applications to the Ferron Sandstone

1999 ◽  
Vol 2 (04) ◽  
pp. 341-350 ◽  
Author(s):  
C.D. White ◽  
M.D. Barton
Keyword(s):  
Flow Behavior ◽  
Rock Properties ◽  
Data Sets ◽  
Recovery Efficiency ◽  
Fluvial System ◽  
Delta Front ◽  
Shallow Marine ◽  
Valley Fill ◽  
Channel Form ◽  
Sandstone Body

Summary Quantitative models are needed to predict interactions between rock properties and drive mechanisms in geologically complex reservoirs. Analog studies using outcrop data provide insights for modeling, understanding, and predicting the behavior of oil and gas reservoirs. Stratigraphic cornerpoint grids preserve the geometries and facies distributions of outcrop data sets. Flow simulations of two outcrop exposures of sandstone-rich fluvial-deltaic tongues within the Cretaceous Age Ferron sandstone (Utah) revealed differences in fractional flow, recovery efficiency, and deliverability that can be related to stratigraphic setting. Compared with homogeneous models, models based on the landward-stepping tongue exposed at the Picture Flats locality had more tortuous flow paths and lower gas recovery efficiency. In the seaward-stepping tongue exposed at the Interstate 70 location, the displacement was layer like. Gas deliverability at the Interstate 70 locality varied with the well location; it was highest when the well penetrated high-permeability shallow-marine sediments and lowest when flow was restricted by a shale-lined valley-fill succession. Introduction Emerging technologies continue to improve reservoir modeling methods. Measurements such as borehole imaging and three dimensional (3D) seismic provide data at high density and resolution, and geostatistical methods enable construction of large, heterogeneous models.1 Cornerpoint grids with non-neighbor connections can represent complex geometries for reservoir simulation.2,3 However, we often lack the data and methods necessary to build detailed reservoir models at scales of interest. Outcrop studies provide data and insights to build models. The Ferron sandstone outcrop study combines regional stratigraphic relationships with a detailed reservoir-to interwell-scale view of layering, facies distribution, permeability, and flow behavior.4–8 The data sets discussed in this article contain hundreds of sandstone and shale layers and thousands of sedimentologic and petrophysical measurements. Layers are laterally discontinuous, nonrectangular, and nonhorizontal. Thin shales intermittently separate sandstone layers. Rock properties depend on facies, and sandstone layers may comprise more than one facies. These layer and lithofacies geometries are difficult to model using a Cartesian grid. Reservoir simulation models were built from layer, shale, and facies diagrams. Vertical measured sections recorded grain size, permeability, sedimentary structures, and facies. The diagrams were edited, sorted, and discretized to create stratigraphic cornerpoint grids that conform to observed layer geometry. These non-Cartesian grids used void blocks and non-neighbor connections extensively. Hierarchical layer ordering preserved stratigraphic grouping throughout the modeling process. The flow behavior of these models was predicted using a reservoir simulator.3 Geologic Setting. The Ferron sandstone is a lithostratigraphically defined member of the Mancos Shale Formation exposed in east-central Utah.9 The Ferron fluvial-deltaic system was deposited during a widespread regression of the Western Interior Seaway as thrust-belt sediments were shed eastward and accumulated along the margin of a rapidly evolving foreland basin during Late Cretaceous (Turonian) time.10,11 The Ferron sandstone is composed of two distinct clastic wedges:11,12 an early wedge derived from the northwest (the Clawson and Washboard sandstones) and a later wedge derived from the southwest (the Ferron clastic wedge). Marine shales divide the Ferron clastic wedge into five sandstone-rich tongues, each comprising a delta-front sandstone body overlaid by a coal (Fig. 1).13 The tongues are as much as 100 ft thick and extend basinward 3 to 30 mi. Early tongues (numbers 1 to 3) step seaward, whereas later tongues (numbers 4 and 5) stack vertically or step landward. Each tongue contains many upward-coarsening and upward-shoaling shallow-marine successions4,5 or parasequences.14 Individual parasequences are 15 to 45 ft thick and extend basinward 1/2 to 5 mi. Within each tongue a nonconformity, which is marked by an incised fluvial system and an abrupt basinward shift in facies, separates underlying progradational-to-aggradational parasequences from overlying aggradational-to-backstepping parasequences.6 Patterns of Stratal Architecture. The spatial arrangement of facies within tongues is related to the stratigraphic position within the Ferron clastic wedge (Fig. 1).4,5 In seaward-stepping tongues, sandstone is preserved mainly within the shallow-marine facies tract. The shallow-marine deposits are broadly lenticular parasequences separated by thin marine mudstones. Individual parasequences (as much as 30 ft thick and 3 mi long) stack progradationally to aggradationally, forming composite delta-front bodies (as much as 100 ft thick and 30 mi long in the dip direction). These delta-front sandstone bodies are locally incised and replaced by homogeneous ribbon-like sandstone bodies that are as much as 80 ft thick and 1/2 mi wide. The crosscutting sandstone body comprises many channel-form sandstone bodies that are as much as 25 ft thick and approximately 30 to 700 ft wide. The channel-form bodies are similar in scale and structure to channel stories defined by Allen;15 they are interpreted to be deposits of fluvial channels and bars. The channel-form bodies are thin relative to the crosscutting body, and they do not interfinger with adjacent shallow-marine strata. Thus, the channel-form bodies are interpreted to be deposits of a fluvial system that aggraded within an incised valley.7 Although the volume of valley-fill sandstone is small compared with the volume of the shallow-marine sandstone, valley fills may connect or segregate reservoir units. This is the setting of the Interstate 70 locality (Ferron sandstone cycle 2, Fig. 1).

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

18F-Deoxyglucose PET for the staging of oesophageal cancer

2003 ◽  
Vol 42 (03) ◽  
pp. 90-93 ◽  
Author(s):  
N. Döbert ◽  
O. Rieker ◽  
W. Kneist ◽  
St. Mose ◽  
A. Teising ◽  
...  
Keyword(s):  
Oesophageal Cancer ◽  
Squamous Cell ◽  
Distal Part ◽  
Standard Uptake Value ◽  
Squamous Cell Carcinomas ◽  
Tumour Grading ◽  
Positron Emission ◽  
Group A ◽  
The Mean ◽  
Drop Outs

SummaryAim: Evaluation of the influence of histopathologic sub-types and grading of primaries of oesophageal cancer, relative to their size and location, on the uptake of 18F-deoxyglucose (FDG) as measured by positron emission tomography (PET). Methods: 50 consecutive patients were evaluated. There were four drop-outs due to previous surgical and/or chemotherapeutical treatments and thus in 46 patients (28 squamous cell carcinomas and 18 adenocarcinomas) a pretherapeutic PET evalution of the primary including a standard uptake value (SUV) was obtained. In 42 cases data on tumour grading were available also. Results: Squamous cell carcinomas (SCC) were in 7/13/8 cases located in the proximal, medial and distal part of the oesophagus, respectively the grading was Gx in 3, G 2 in 12, G2-3 in 7, and G3 in 6 cases. The SUVmax showed a mean of 6.5 ± 2.8 (range 1.7-13.5). Adenocarcinomas (ACA) were located in the medial oesophagus in two cases and otherwise in its distal parts. Grading was Gx in one, G2 in 4, G2-3 in 3, G3 in 3, G3-4 in 3, and G4 in one case. The mean SUVmax was 5.2 ± 3.2 (range 1-13.6) and this was not significantly different from the SCC. Concerning the tumour grading there was a slight, statistically not relevant trend towards higher SUVmax in more dedifferentiated cancer. Discussion: SCC and ACA of the oesophagus show no relevant differences in the FDG-uptake. While there was a significant variability of tumour uptake in the overall study group, a correlation of SUV and tumour grading was not found.

Lithostratigraphy of the Kweekvlei Formation (Witteberg Group), Cape Supergroup

2017 ◽  
Vol 120 (3) ◽  
pp. 421-432 ◽  
Author(s):  
C. Browning ◽  
M. Reid
Keyword(s):  
South Africa ◽  
Transition Zone ◽  
Distal Part ◽  
Vascular Plant ◽  
Trace Fossil ◽  
Plant Debris ◽  
Lower Carboniferous ◽  
Fossil Assemblage ◽  
Low Diversity ◽  
Storm Wave

AbstractThe Lower Carboniferous, probably Tournaisian, Kweekvlei Formation is part of the Witteberg Group (Cape Supergroup) of South Africa. Together with the overlying Floriskraal Formation, it forms an upward-coarsening succession within the Lake Mentz Subgroup. Sedimentary features of the Kweekvlei Formation suggest deposition in a storm-wave dominated marine setting, within the storm-influenced, distal part of an offshore transition zone environment. This predominantly argillaceous formation preserves a low diversity trace fossil assemblage. Reworked vascular plant debris (including the problematic genus Praeramunculus sp.) and a shark spine have been reported for the Kweekvlei Formation. There are no known stratigraphic equivalents in South Africa.

A New Species of Rhacophorus Genus (Amphibia: Anura: Rhacophoridae: Rhacophorinae) from Van Ban District, Lao Cai Province, Northern Vietnam

2019 ◽  
Vol 26 (6) ◽  
pp. 325-334
Author(s):  
Ivan I. Kropachev ◽  
Nikolai L. Orlov ◽  
Hoa Thi Ninh ◽  
Tao Thien Nguyen
Keyword(s):  
New Species ◽  
Distal Part ◽  
Slender Body ◽  
Northern Vietnam ◽  
Lao Cai ◽  
Lower Ratio ◽  
A New Species ◽  
Green Triangle ◽  
Brown Color

We describe a new species of the Rhacophorus genus, which differs from all species known in Asia by the combination of characters. It strongly differs also from small and middle-sized species of Rhacophorus sensu lato: Rhacophorus calcaneus Smith, 1924, Leptomantis cyanopunctatus (Manthey et Steiof, 1998), Rhacophorus hoabinhensis Nguyen, Pham, Nguyen, Ninh et Ziegler, 2017, Rhacophorus hoanglienensis Orlov, Lathrop, Murphy et Ho, 2001, Zhangixalus jarujini (Matsui et Panha, 2006), Rhacophorus laoshan Mo, Jiang, Xie et Ohler, 2008, Rhacophorus pardalis Günther, 1858, Rhacophorus rhodopus Liu et Hu, 1960, Rhacophorus robertingeri Orlov, Poyarkov, Vassilieva, Ananjeva, Nguyen, Sang, and Geissler, 2012, Leptomantis robinsonii (Boulenger, 1903), Rhacophorus spelaeus Orlov, Gnophanxay, Phimminith, and Phomphoumy, 2010, Rhacophorus translineatus Wu, 1977, Rhacophorus turpes Smith, 1940, Rhacophorus vampyrus Rowley, Le, Thi, Stuart et Hoang, 2010, Rhacophorus viridimaculatus Ostroshabov, Orlov et Nguyen, 2013 by having brown color with two green dorsolateral stripes starting at the groin level and connecting through the distal part of eyelid with green triangle on the head, slender body and head, lower ratio HW/HL 0.86, lower HW/SVL 0.28 and lower ratio HL/SVL 0.32.

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