scholarly journals BIOSTRATIGRAPHIC CHARACTERIZATION OF THE CRETACEOUS DEPOSITS OF THE SAN-PEDRO MARGIN OF DRILL HOLES K1 AND K2 OF BLOCK KL: PALEOENVIRONMENT IMPLICATION

2021 ◽  
Vol 9 (11) ◽  
pp. 289-301
Author(s):  
Koffi Chiaye Larissa ◽  
◽  
Djeya Kouame Leger ◽  
Douzo Jolie Wanesse Danielle ◽  
Monde Sylvain ◽  
...  
Keyword(s):  
Water Depth ◽  
Depositional Environment ◽  
Point Of View ◽  
Coarse Grained ◽  
Fine Grained ◽  
San Pedro ◽  
Drill Holes ◽  
Coarse Grained Sand ◽  
Cretaceous Deposits

The KL block studies was carried out the eastern part of the San Pedro margin, it has an area of 2034 km2 with a water depth varying from 500 to 2750 m with two probings (K1 and K2).The objective of this work is to carry out a biostratigraphic and paleoenvironmental study based on the associations of planktonic and palynomorphicmicrofauna in the formations of the KL block boreholes. From a lithological point of view, the base of the boreholes generally comprises alternating limestone and argillite, very fine to fine grained quartz sandstone. Its upper part is overlain by claystoneinterbedded with limestone, silstone and siliceous cemented sandstone and alternating claystone, medium to coarse grained sand and siliceous cemented quartz sandstone. The Albian is determined by the presence of the species Ticinellamadecassiana. The Cenomanian is identified by the micropalaeontological assemblages composed of Globigerinelloides spp., Guembelitria spp., Hedbergella spp., Hedbergelladelrioensis, Globigerinelloides bentonensisandLoeblichella cf. hessi. The Turonian is based mainly on the species Hedbergellaplanispira, Heterohelixmoremani and Whiteinella archaeocretacea. The Early Senonian is characterized by associations of species (Hedbergellasp, Hedbergella cf. delrioensis, Buliminacrassa and Whiteinella baltica) and palynomorphs (Proteaciditestienabaensis, Odontochitinacostata, Odontochitinaporiferaand Tricolpites sp). The roof of the Campanian is known by the association of the palynomorph (Trichodinium castanae) and the microfossil (Gaudryina cretacea) The Maastrichtian is highlighted by the associations composed of species Rzehakina epigona fissistomata, Rzehakina minima, Plectina lenis, Reophax duplex, Reophax pilulifera, Reophax globosus, Gaudryina pyramidata and Afrobolivina afra) and palynomorphic species (Andalusiella gabonensis, Cerodinium granulostriatum and Palaeocystodinium australinium). All the micropalaeontological data coupled with those of the microfaunas make it possible to envisage a depositional environment of the internal platform type with continental influence on an external platform.

Rheology of hydrocarbon gels

1950 ◽  
Vol 200 (1061) ◽  
pp. 183-188 ◽  
Keyword(s):  
Mechanical Properties ◽  
Experimental Measurement ◽  
Theoretical Basis ◽  
Continuous Media ◽  
Point Of View ◽  
Coarse Grained ◽  
Testing Instrument ◽  
Fine Grained ◽  
Mineral Oils ◽  
Space And Time

Hydrocarbon gels contain a number of materials, such as rubber, greases, saponified mineral oils, etc., of great interest for various engineering purposes. Specific requirements in mechanical properties have been met by producing gels in appropriately chosen patterns of constituent components of visible, colloidal, molecular and atomic sizes, ranging from coarse-grained aggregates, represented by sponges, foams, emulsions, etc.; to fine-grained and apparently homogeneous ones, represented by optically clear compounds. The engineer who has to deal with the whole range of such materials will adopt a macroscopic point of view, based on an apparent continuity of all the material structures and of the distributions in space and time of the displacements and forces occurring under mechanical actions. It has been possible to determine these distributions in the framework of a comprehensive scheme in which the fundamental principles of the mechanics of continuous media provide the theoretical basis, and a testing instrument of new design, termed Rheogoniometer, the means of experimental measurement (Weissenberg 1931, 1934, 1946, 1947, 1948).

scholarly journals Microstructural and Mechanical Characterization of Multilayered Iron Electrodeposits

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb
Keyword(s):  
Mechanical Properties ◽  
Columnar Structure ◽  
Multilayered Structure ◽  
Structure Design ◽  
Coarse Grained ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure ◽  
Iron Coatings

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.

scholarly journals Lithology of the Upper Jurassic-Lower Cretaceous deposits of the eastern part of the Myrgovaam and Rauchua depressions, Western Chukotka

2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Elena V. Vatrushkina ◽  
◽  
Marianna I. Tuchkova ◽  
Keyword(s):  
Lower Cretaceous ◽  
Upper Jurassic ◽  
Coarse Grained ◽  
Fine Grained ◽  
Tectonic Environment ◽  
The Matrix ◽  
Siliciclastic Rocks ◽  
Facies Variation ◽  
Felsic Volcanic ◽  
Cretaceous Deposits

Upper Jurassic-Lower Cretaceous deposits were formed on the South-Western margin of the Chukotka terrane in active tectonic environment. Their stratigraphic units characterized by sedimentary structures and lithology similarities, facies variation and scarcity of reliable fauna findings. Detailed lithological studies are necessary due to the absence of a unified approach to the stratigraphic division of deposits. The paper presents petrographic, geochemical, and isotope-geochemical characteristics of Upper Jurassic-Lower Cretaceous rocks. The stages of changing the sedimentation conditions and sources, which determined the differences in sedimentological features and the composition of the studied strata, are reconstructed. The Oxford-Kimmeridgian section is composed of sandy debris flow deposits with an arcosic composition of psammitic differences. Among their sources, ancient granitoids dominated, while siliciclastic rocks, volcanites and metamorphic complexes were secondary. Volgian-valanginian interval is characterized by the accumulation of sediments in various parts of the submarine fan. In Volgian sequences fine -, medium - and coarse-grained turbidites with lenses of small-pebble conglomerates are identified. A large number of simultaneous pyroclastic material in the Volgian deposits indicates the synchronous volcanic activity. In the Volgian period, the province was dominated by volcanites, mainly of the basaltic and andesitic composition, siliciclastic rocks were present in smaller amount. The Berriasin section is composed of fine-grained turbidites with single horizons of medium-grained turbidites and gravelitic lenses, as well as slope deposits in the form of rhythmically interbedded sandstones and mudstones with slump structures. Sandstones have greywacke composition and contain an admixture of ash material in the matrix. The main sources for Berriasian deposits were siliciclastic rocks and felsic volcanic complexes. The Valanginian section is represented by fine and medium-grained turbidites with horizons of amalgamated sandstones. Sandstones are classified as arkoses by the ratio of rock-forming components. The dominant source in the Valanginian time was ancient granitoids, while siliciclastic rocks and volcanites were secondary.

Inference of lithologic distributions in an alluvial aquifer using airborne transient electromagnetic surveys

Geophysics ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. WA149-WA161 ◽  
Author(s):  
Jesse E. Dickinson ◽  
D. R. Pool ◽  
R. W. Groom ◽  
L. J. Davis
Keyword(s):  
Alluvial Aquifer ◽  
Coarse Grained ◽  
Resistivity Structure ◽  
One Dimensional ◽  
Fine Grained ◽  
Transient Electromagnetic ◽  
San Pedro ◽  
Resistivity Logs ◽  
Sand And Gravel ◽  
San Pedro Basin

An airborne transient electromagnetic (TEM) survey was completed in the Upper San Pedro Basin in southeastern Arizona to map resistivity distributions within the alluvial aquifer. This investigation evaluated the utility of 1D vertical resistivity models of the TEM data to infer lithologic distributions in an alluvial aquifer. Comparisons of the resistivity values and layers in the 1D resistivity models of airborne TEM data to 1D resistivity models of ground TEM data, borehole resistivity logs, and lithologic descriptions in drill logs indicated that the airborne TEM identified thick conductive fine-grained sediments that result in semiconfined groundwater conditions. One-dimensional models of ground-based TEM surveys and subsurface lithology at three sites were used to determine starting models and constraints to invert airborne TEM data using a constrained Marquardt-styleunderparameterized method. A maximum structural resolution of six layers underlain by a half-space was determined from the resistivity structure of the 1D models of the ground TEM data. The 1D resistivity models of the airborne TEM data compared well with the control data to depths of approximately [Formula: see text] in areas of thick conductive silt and clay and to depths of [Formula: see text] in areas of resistive sand and gravel. Comparison of a 3D interpolation of the 1D resistivity models to drill logs indicated resistive (mean of [Formula: see text]) coarse-grained sediments along basin margins and conductive (mean of [Formula: see text]) fine-grained sediments at the basin center. Extents of hydrologically significant thick silt and clay were well mapped by the 1D resistivity models of airborne TEM data. Areas of uncertain lithology remain below conductive fine-grained sediments where the 1D resistivity structure is not resolved: in areas where multiple lithologies have similar resistivity values and in areas of high salinity.

Autopsy of a reservoir: Facies architecture in a multidam system, Elwha River, Washington, USA

2019 ◽  
Vol 131 (11-12) ◽  
pp. 1794-1822 ◽  
Author(s):  
Laurel E. Stratton ◽  
Gordon E. Grant
Keyword(s):  
Sediment Supply ◽  
Aerial Photographs ◽  
Coarse Grained ◽  
Elwha River ◽  
Facies Architecture ◽  
Fine Grained ◽  
Delta Plain ◽  
Digital Elevation ◽  
Upstream Reservoir

AbstractThe 2011–2014 removal of two large dams on the Elwha River, Washington State, the largest dam removal yet completed globally, created extensive cutbank exposures of reservoir sediments, allowing the first characterization of the facies architecture of sediments through direct observation in reservoirs worldwide and providing an unparalleled opportunity to assess the relationship between environmental influences, such as changes in sediment supply, and their expression in the stratigraphic record. Using a combination of facies description from observation of 49 measured sections and >100 exposures and analysis of digital elevation models and historic aerial photographs, we delineated the characteristic depositional zones of each reservoir and mapped the evolution of the subaerial delta over the life span of the reservoir. Former Lake Mills, the younger, upstream reservoir, was characterized by a tripartite, subaerial Gilbert-style delta that prograded >1 km into the main reservoir from 1927 to 2011. Sediments were composed of coarse-grained topset beds, steeply dipping foreset beds, and a fine-grained, gently dipping prodelta. While individual event horizons were discernible in fine-grained sediments of former Lake Mills, their number and spacing did not correspond to known drawdown or flood events. Former Lake Aldwell, impounded from 1913 to 2011, was initially defined by the rapid progradation of a Gilbert-style, subaerial delta prior to the upstream completion of Glines Canyon Dam. However, the 1927 closure of Glines Canyon Dam upstream caused the delta to evolve to a fine-grained, mouth-bar–type delta indicative of low, finer-grained sediment. This evolution, combined with a previously unrecognized landslide deposit into the upper delta plain, suggests that understanding the exogenic influences on reservoir sedimentation is critical to interpretation and prediction of the sedimentation within individual systems.

scholarly journals DELTAIC AND SHELF DEPOSITIONAL PACKAGES OF THE GULANI MEMBER OF PINDIGA FORMATION, GONGOLA SUB-BASIN, NORTHERN BENUE TROUGH, N.E. NIGERIA

2018 ◽  
Vol 6 (4) ◽  
pp. 188-197
Author(s):  
B. Shettima ◽  
A.I. Goro ◽  
M. Bukar ◽  
Y.B. Mohammed
Keyword(s):  
Depositional Environment ◽  
Facies Analysis ◽  
Coarse Grained ◽  
Delta Front ◽  
Benue Trough ◽  
Fine Grained

Stratigraphic and facies analysis of the Gulani Member of the Pindiga Formation in the Gongola Sub-basin of the Northern Benue Trough indicated that the lithostratigraphic architecture of the formation are characterized by three bioturbated lithologic units. These includes the lower succession of heterolithic units with fine grained sandstones and mudstone interbeds, passing into succession of medium-coarse grained sandstone with dominantly trough crossbeds and a upper succession of medium grained trough crossbedded sandstone and mudstone interbeds. Facies evaluation of these distinct succession indicated development of a corresponding pro-delta sands and clays, moving into delta front sands and then shelf sandstone and claystone respectively. Thus suggesting that the Gulani Member was generally formed in a coastal setting defined by river dominated deltaic setting and shelf depositional environment.

Truth and Truthlikeness

2018 ◽  
Author(s):  
Graham Oddie
Keyword(s):  
Point Of View ◽  
Coarse Grained ◽  
Cognitive Value ◽  
Fine Grained

Truth is widely held to be a cognitive value—perhaps because, other things being equal, it is better to believe a proposition if it is true than if it is false. But even if this is a genuine aspect of the value of truth, it is rather coarse-grained. Not all truths are equally valuable, from a cognitive point of view, and neither are all falsehoods equally disvaluable. The concept of truthlikeness, or of closeness to the truth, holds out the promise of a richer, more fine-grained classification of propositions, suitable not just for the up or down evaluation of isolated beliefs, but for the calibrated evaluation of cognitive progress in an inquiry. This chapter reviews approaches to truthlikeness, and some of the problems they face.

scholarly journals Intensions as Computable Functions

2014 ◽  
Vol 9 ◽  
Author(s):  
Shalom Lappin
Keyword(s):  
Programming Languages ◽  
Formal Solution ◽  
Intensional Logic ◽  
Coarse Grained ◽  
Fine Grained ◽  
Semantics Of Programming Languages ◽  
Logical Equivalence ◽  
Intensional Semantic ◽  
Computable Functions

Classical intensional semantic frameworks, like Montague’s Intensional Logic (IL), identify intensional identity with logical equivalence. This criterion of co-intensionality is excessively coarse-grained, and it gives rise to several well-known difficulties. Theories of fine-grained intensionality have been been proposed to avoid this problem. Several of these provide a formal solution to the problem, but they do not ground this solution in a substantive account of intensional difference. Applying the distinction between operational and denotational meaning, developed for the semantics of programming languages, to the interpretation of natural language expressions, offers the basis for such an account. It permits us to escape some of the complications generated by the traditional modal characterization of intensions.

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