scholarly journals Clay Minerals and Detrital Material in Paleocene–Eocene Biogenic Siliceous Rocks (Sw Western Siberia): Implications for Volcanic and Depositional Environment Record

Geosciences ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 162
Author(s):  
Pavel Smirnov ◽  
Oksana Deryagina ◽  
Nadezhda Afanasieva ◽  
Maxim Rudmin ◽  
Hans-Jürgen Gursky
Keyword(s):  
Clay Minerals ◽  
Depositional Environment ◽  
Western Siberia ◽  
Ultramafic Rocks ◽  
Burial Diagenesis ◽  
Detrital Material ◽  
Siliceous Rocks ◽  
Low Degree ◽  
Provenance Areas ◽  
High Degree

The paper presents the results of a study on clay minerals and detrital material of biosiliceous rocks (Paleocene–Eocene) from three sections in the Transuralian region. The authigenic processes in sediments resulted in the formation of dioctahedral clay minerals (illite, smectite) and insignificant amounts of sulfide phases (pyrite, hydrotroillite). Detrital minerals from the studied diatomites and diatomaceous clays often have a subangular and semi-rounded habit that is evidence of a low degree alteration of the sedimentary material in the provenance areas. The high degree of preservation of the bioclastic debris and the transformation of the limited volcanogenic substratum in clay minerals apparently was possible by initial burial diagenesis. The morphology of kaolinite and illite suggests that these mineral formations were caused by diagenesis with feldspars and smectites as a substrate for their formation. The smectite zone of weathering crust that developed on the adjacent land could have also served as a significant source of smectites entering the sea basin. The association with smectite in aggregates of mixed clayey composition indicates a sequential smectite-to-illite reaction via mixed-layered minerals. Such minerals as amphiboles, pyroxenes, and olivines, semi-stable to transportation and genetically associated with ultramafic rocks, form a significant part of the clastic fraction of the rock, indicating the proximity of provenance areas. This is the evident reason that the provenance areas made of mafic and ultramafic rocks played an essential role.

scholarly journals Actuopaleoichnology of a modern Bay of Fundy macro-tidal flat: analogy with a Mississippian tidal flat deposit (Hartselle Sandstone) from Alabama

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6975
Author(s):  
Louis G. Zachos ◽  
Brian F. Platt
Keyword(s):  
Tidal Flat ◽  
Depositional Environment ◽  
Exposure Period ◽  
Hydrodynamic Characteristics ◽  
Bay Of Fundy ◽  
Grain Texture ◽  
Tidal Regime ◽  
Low Degree ◽  
High Degree ◽  
High Diversity

Trace fossil zonation in the Hartselle Sandstone of Mississippian age (Chesterian: Visean-Serpukhovian) exposed on Fielder Ridge, Alabama is compared with modern macro-tidal flat ichnocoenoses on the Bay of Fundy at Lubec, Maine, and demonstrated to be analogous by sedimentologic and ichnotaxonomic criteria. The modern flat has minimal influence from either waves or freshwater influx, and can be divided into five distinct ichnocoenoses, characterized by surface traces (epichnia) and four sedimentologic facies defined by gross grain texture or hydrodynamic characteristics, but lacking significant surface traces. Several characteristics of tidal flat deposits in a fetch-limited, marine (i.e., non-estuarine), meso- to macro-tidal regime can be used to recognize similar environments as old as the late Paleozoic. These criteria include (1) limited influence of wind and waves on the depositional environment, (2) lack of significant freshwater influence and therefore any persistent brackish environments, (3) a distinct spatial distribution of microenvironments defined by substrate and exposure period, (4) high diversity of epichnial traces directly associated with microenvironments across the tidal flat, (5) generally low degree of reworking of traces by bioturbation but high degree of reworking by tidal currents, and (6) preservation of traces of predation and scavenging behavior on an exposed surface. These features, together with the regional depositional pattern of the Hartselle Sandstone interpreted as tide-influenced bars and shoals, support a meso- to macro-tidal interpretation of the depositional environment.

scholarly journals Types of Void Space in the Bazhenov Reservoir Rocks

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 269
Author(s):  
Olga V. Postnikova ◽  
Alexander V. Postnikov ◽  
Olga A. Zueva ◽  
Artem E. Kozionov ◽  
Ekaterina V. Milovanova ◽  
...  
Keyword(s):  
Western Siberia ◽  
Distribution Patterns ◽  
Void Space ◽  
X Ray Diffraction ◽  
Bazhenov Formation ◽  
Reservoir Rocks ◽  
Oil Reserves ◽  
Light Oil ◽  
Clay Rocks ◽  
High Degree

The deposits of the Bazhenov formation are a unique reservoir of unconventional oil reserves in Western Siberia. They contain both solid organic matter (kerogen) and liquid light oil. The successful development of these hydrocarbons is largely determined by the adequacy of the void space models. The aim of the study is to identify the types of void space in the sediments of the Bazhenov formation and to identify the distribution patterns across the section of the researched wells. The void space was studied by electron and optical microscopy, and the mineral composition of the rocks was determined by X-ray diffraction analysis. The deposits of the Bazhenov productive formation in the territory of Western Siberia are represented by a wide complex of lithotypes, including various kinds of silicites, carbonate, clay rocks, and mixtites. The reservoir space in the reservoir rocks of the Bazhenov formation is a complex and hierarchically subordinated system, which includes voids and fractures of various sizes, configurations, and genesis. The void space of the Bazhenov formation is characterized by a fairly high degree of spatial heterogeneity, which is controlled by lithological, facies, and tectonic factors, as well as the direction of catagenetic processes.

Stimulation of β-(l → 6)-glucanase production by oxidized pustulan

1972 ◽  
Vol 18 (10) ◽  
pp. 1543-1550 ◽  
Author(s):  
Robert G. Brown
Keyword(s):  
Enzyme Activity ◽  
Isoelectric Focusing ◽  
Gel Filtration ◽  
Tween 80 ◽  
Sole Source ◽  
Cellulase Production ◽  
Low Degree ◽  
Degree Of Oxidation ◽  
High Degree ◽  
Stimulation Of

A strain of Penicillium lilacinum, isolated from soil, produced pustulanase, β-(1 → 3)-glucanase, (EC. 3.2.1.6) and cellulase (EC.3.2.1.4) when cultivated on a medium containing pustulan as the sole source of carbon. If pustulan was replaced by ketopustulan, the production of pustulanase was stimulated about 10-fold although the amount of stimulation was dependent on the degree of oxidation of pustulan. β-(1 → 3)-Glucanase production was stimulated slightly by ketopustulan; however, the degree of oxidation did not affect significantly the yield of this enzyme. Cellulase production was either unaffected by the oxidized polymer, or at higher degrees of oxidation, decreased. Tween 80 stimulated the production of the three enzymes in media containing ketopustulan with a low degree of oxidation but was inhibitory to pustulanase and cellulase production in media containing ketopustulan with a high degree of oxidation. A combination of gel filtration and isoelectric focusing revealed that each enzyme activity was attributable to at least two proteins.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

Leadership Styles of Public Schools Principals in the City of Hail in the Kingdom of Saudi Arabia: أنماط القيادة لدى مدراء مدارس التعليم العام في مدينة حائل في المملكة العربية السعودية

2021 ◽  
Vol 5 (41) ◽  
pp. 161-138
Author(s):  
Fahad Husain Alshammari Fahad Husain Alshammari
Keyword(s):  
Public Schools ◽  
Leadership Style ◽  
School Principals ◽  
Statistical Significance ◽  
Point Of View ◽  
Years Of Experience ◽  
Public School Principals ◽  
Low Degree ◽  
Study Population ◽  
High Degree

    This study aimed to: Identify the leadership style prevailing among public school principals in Hail from the teachers ’point of view, and to reveal the statistical significance of the differences in the estimates of the study sample individuals of the leadership style prevailing among school principals, which may due to variables of (educational stage, number of years of experience, and specialization). The researcher used the descriptive method, and prepared a questionnaire consisting of (24) statements distributed to (3) dimensions, which are: Democratic style, authoritarian style and chaotic style. The current study population included all the teachers of public education schools in Hail, who numbered (9390) teachers. The questionnaire was applied to a random sample of (296) teachers. The study found a set of results, the most important of which are: The prevailing leadership style among school principals is the democratic style, followed by the authoritarian style, and then the chaotic style. Where the democratic style obtained a mean (4.18) and a high degree of approval from the study sample, while the domineering style obtained a mean (1.83) and a low degree of approval from the study sample, and the chaotic style obtained an average (1.73) and a low degree of approval. Very members of the study sample. The results also showed that there are statistically significant differences in the degree of the study sample’s estimates of the leadership style prevailing among school principals due to the variable of years of experience, while there are no statistically significant differences in the degree of the study sample’s estimates of the leadership style prevailing among school principals due to the variables of the educational stage or specialization. In light of these results, the researcher recommended organizing training courses for school principals to enlighten them about the modern trends in educational leadership, and urged school principals to follow the democratic style of administration.

scholarly journals Genetic linkage map of Phaseolus vulgaris and identification of QTLs responsible for resistance to Xanthomonas axonopodis pv. phaseoli

2003 ◽  
Vol 28 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Amaury S. Santos ◽  
Ricardo E. Bressan-Smith ◽  
Messias G. Pereira ◽  
Rosana Rodrigues ◽  
Claudia F. Ferreira
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Linkage Map ◽  
Linkage Groups ◽  
Resistant Genotype ◽  
Xanthomonas Axonopodis ◽  
Low Degree ◽  
Phenotypic Variations ◽  
Genomic Regions ◽  
High Degree

Common bean (Phaseolus vulgaris) cultivars with a high degree of resistance to Xanthomonas axonopodis pv. phaseoli (Xap) are not available in Brazil. Despite many studies, a low degree of resistance to Xap continues to exist due to its complex genetic inheritance, which is not well known. The objectives of this research were to complement a common bean genetic map based on the cross between a susceptible genotype 'HAB-52' and a resistant genotype 'BAC-6', and to map and analyze genomic regions (quantitative trait loci – QTLs) related to Xap resistance. Eleven linkage groups were determined using 143 RAPD markers, covering 1,234.5 cM of the genome. This map was used to detect QTLs associated with Xap resistance on leaves and pods. The averages of disease severity on leaves (represented by the transformed disease index – TDI) and pods (represented by the diameter of lesion on pods – DLP) were added to the data of the linkage map. Five TDI QTLs and only one LDP QTL were detected. The TDI QTLs were placed in the A, B, G and J linkage groups, with phenotypic variations ranging from 12.7 to 71.6%. The DLP QTL explained 12.9% of the phenotypic variation and was mapped in a distinct linkage group. These results indicate that there are different genes involved in the control of resistance on leaves and pods.

Depositional facies, diagenetic clay minerals and reservoir quality of Rotliegend sediments in the Southern Permian Basin (North Sea): a review

Clay Minerals ◽  
1982 ◽  
Vol 17 (1) ◽  
pp. 55-67 ◽  
Author(s):  
U. Seemann
Keyword(s):  
Clay Minerals ◽  
North Sea ◽  
Effective Porosity ◽  
Hydrocarbon Exploration ◽  
Reservoir Quality ◽  
Burial Diagenesis ◽  
Permian Basin ◽  
Northern Margin ◽  
The North

AbstractThe Southern Permian Basin of the North Sea represents an elongate E-W oriented depo-centre along the northern margin of the Variscan Mountains. During Rotliegend times, three roughly parallel facies belts of a Permian desert developed, these following the outline of the Variscan Mountains. These belts were, from south to north, the wadi facies, the dune and interdune facies, and the sabkha and desert lake facies. The bulk of the gas reservoirs of the Rotliegend occur in the aeolian dune sands. Their recognition, and the study of their geometry, is therefore important in hydrocarbon exploration. Equally important is the understanding of diagenesis, particularly of the diageneticaily-formed clay minerals, because they have an important influence on the reservoir quality of these sands. Clay minerals were introduced to the aeolian sands during or shortly after their deposition in the form of air-borne dust, which later formed thin clay films around the grains. During burial diagenesis, these clay films may have acted as crystallization nuclei for new clay minerals or for the transformation of existing ones. Depending on their crystallographic habit, the clay minerals can seriously affect the effective porosity and permeability of the sands.

scholarly journals Palynological profile and depositional environment of the Ishim formation (upper Miocene) in Tobol-Ishim interfluve, Western Siberia

2019 ◽  
Vol 27 (6) ◽  
pp. 103-123
Author(s):  
O. B. Kuzmina ◽  
I. V. Khazina ◽  
P. V. Smirnov ◽  
A. O. Konstantinov ◽  
A. R. Agatova
Keyword(s):  
Late Pleistocene ◽  
Organic Substance ◽  
Late Miocene ◽  
Depositional Environment ◽  
Western Siberia ◽  
Ice Age ◽  
Quaternary Sediments ◽  
Upper Miocene ◽  
Neogene Sediments ◽  
First Time

For the first time some outcrops of the Upper Miocene Ishim Formation on the south of Tyumen Area near Pyatkovo, Masali and Bigila villages are studied by palynological method in detail. A series of mineralogical analyzes of these sediments and radiocarbon analysis of the Quaternary sediments overlying the Ishim Formation are done. Four palynocomplexes (PC) are established in the Ishim Formation: PC1 with Botryococcus; PC2 with Botryococcus, Sigmopollis; PC3 with Alnus, Polypodiaceae, Botryococcus, Sigmopollis; PC4 with Betula, Alnus, Corylus. The layers with PC1, PC2 и PC3 are traced in two outcrops near Masali and Bigila Villages. PC4 is revealed from the sands and aleuropelits of the outcrop near Pyatkovo Village, it is characterized by a significant content of diverse pollen of temperate termophylic broad-leafed taxa and by the presence of rare typical Miocene elements (Таxodiaceae, Nyssa, Tsuga). The PC3 and PC4 are compared with the complexes well known from the Neogene sediments of Western Siberia. PC5 with Betula, Herbae, Fungi is revealed from the bedded silts overlying the Ishim Formation in Masali outcrop. Previously, these sediments were attributed to the Late Miocene Pavlodar Formation. The composition and the structure of PC5 allowed making an assumption about Quaternary age of the enclosing sediments. Radiocarbon analysis of the organic substance from the silts showed, that these sediments were accumulated in the Late Pleistocene (Sartan Ice Age). For the first time the information about microphytoplankton (Botryococcus, Pediastrum, Zygnemataceae, Sigmopollis) and other nonpollen palynomorphs, contained in Ishim Formation (Upper Miocene) and in Pleistocene sediments, is given. On palynological data, some stages of development of the Late Miocene Ishim Basin and the type of vegetation surrounding this basin are considered. The depositional environment of Pleistocene sediments (Masali outcrop) is reconstructed.

scholarly journals TOLAK UKUR FUNGSI HATI BERDASARKAN DERAJAT FIBROSIS PENYAKIT HATI KRONIS (Liver Function Parameters based on Degree of Liver Fibrosis in Chronic Liver Disease)

2018 ◽  
Vol 21 (1) ◽  
pp. 57
Author(s):  
Rahmafitria Rahmafitria ◽  
Mutmainnah Mutmainnah ◽  
Ibrahim Abdul Samad
Keyword(s):  
Liver Disease ◽  
Liver Fibrosis ◽  
Liver Function ◽  
Chronic Liver Disease ◽  
Total Bilirubin ◽  
Chronic Liver ◽  
Low Degree ◽  
Significant Difference ◽  
The Mean ◽  
High Degree

Evaluating the degree of liver fibrosis degree is invasive as well as uncomfortable, therefore, non invasive examinations such as liverfunction tests and elastography (Fibro Scan) as a predictor‘s device of liver fibrosis degree are necessary. The aim of this study was toknow the differences of liver function parameters based on the fibrosis degree in patients with chronic liver disease. This study was a crosssectional design using data from chronic liver disease patients treated at the Dr. Wahidin Sudirohusodo Hospital. The elasticity of the liverwas measured using a fibro scan device during June 2010–July 2011. The analysis was carried out by ANOVA test on various parametersof liver function particularly on the fibrosis degree in chronic liver disease. In this study PT, albumin, total bilirubin and platelet countshowed a significant difference of 0.019, 0.009, 0.017 and 0.000 respectively. The mean values of PT and total bilirubin were significantlyhigher in the high degree of fibrosis compared to those with medium and low degree of fibrosis in the chronic liver disease patients. Basedon this study, the mean albumin levels and platelet count were significantly lower in the high degree of fibrosis compared with the mediumand low degree of fibrosis, however, no significant differences in AST, ALT, APTT and GGT were found.

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