scholarly journals Sedimentology and stratigraphic architecture of a fluvial to shallow-marine succession: The Jurassic Dhruma Formation, Saudi Arabia

2021 ◽  
Vol 91 (7) ◽  
pp. 773-794
Author(s):  
Bassam Alshammari ◽  
Nigel P. Mountney ◽  
Luca Colombera ◽  
Mohammed A. Al-Masrahy
Keyword(s):  
Saudi Arabia ◽  
Gamma Ray ◽  
Quantitative Information ◽  
Delta Front ◽  
Thin Sections ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Wide Range ◽  
Facies Associations ◽  
Depositional Models

ABSTRACT The interaction of fluvial, tidal, and wave processes in coastal and paralic environments gives rise to sedimentary successions with highly varied styles of facies architecture; these are determined by the morphology and evolutionary behavior of the range of coastal sub-environments, which may be difficult to diagnose in subsurface sedimentary successions with limited well control. This study presents depositional models to account for stratigraphic complexity in a subsurface fluvial to shallow-marine succession, the Middle Jurassic Dhruma Formation, Saudi Arabia. The study achieves the following: i) it examines and demonstrates sedimentary relationships between various fluvial, nearshore, and shallow-marine deposits, ii) it develops depositional models to account for the stratigraphic complexity inherent in fluvial to shallow-marine successions, and iii) it documents the sedimentology and the stratigraphic evolutionary patterns of the lower Dhruma Formation in the studied area of Saudi Arabia. The dataset comprises facies descriptions of 570 m of core from 14 wells, 77 representative core thin sections, 14 gamma-ray logs, and FMI image logs from 4 wells. These data are integrated with quantitative information from > 50 analogous systems from a wide range of modern and ancient settings, stored in a relational database. Stratigraphic correlations reveal the internal anatomy of the succession. Facies associations are representative of fluvial channels, intertidal flats, pedogenically modified supratidal flats or floodplains, river-influenced tidal bars, weakly storm-affected shoreface and offshore-transition zones, storm-dominated delta-front and prodelta settings, and an open-marine carbonate-dominated shelf. These sub-environments interacted in a complex way through space and time. The vertical succession of the studied interval records an overall transition from coastal-plain deposits at the base to marine deposits at the top. As such, the succession records a long-term transgressive, deepening-upward trend. However, this general trend is punctuated by repeated progradational events whereby coastal sand bodies of fluvial, wave, and tidal origin prograded basinward during stillstands to fill bays along a coastline. The nature of juxtaposition of neighboring sub-environments has resulted in a sedimentary record that is highly complex compared to that generated by morphologically simple shoreface systems that accumulate more regularly ordered stratal packages.

scholarly journals Three dimensional reconstructions of Nummulites tests reveal complex chamber shapes

2015 ◽  
Author(s):  
Willem Renema ◽  
Laura Cotton
Keyword(s):  
Benthic Foraminifera ◽  
Three Dimensional ◽  
3D Reconstructions ◽  
Thin Sections ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Regular Shape ◽  
Computed Microtomography

Larger benthic foraminifera (LBF) are an important tool for the biostratigraphy of (sub)tropical shallow marine deposits. In Paleogene the genus Nummulites is an important genus for biostratigraphical zonation schemes. However, classification is Europe centered and based on external characters and equatorial thin sections. New results from regions outside the northern Tethys shows that a more rigid framework for the classification of nummulites is needed. Here we present a new tool for achieving this goal. We visualise 3D chamber shape of Nummulites djodjokartae and compare these to traditional morphometrical characters. To achieve this goal we use computed microtomography of well preserved Nummulites tests. We find that despite the regular shape in equatorial and axial thin section 3D chamber shape is not predicted by these sections. We argue that 3D reconstructions of Nummulites tests will be a great aid in improving our understanding lineages within the genus Nummulites, and to elucidate its evolutionary and biogeographical history.

scholarly journals VÝSLEDKY VRTNÉHO PRŮZKUMU NA LOKALITĚ HOLUBICE (SPODNOBADENSKÉ SEDIMENTY KARPATSKÉ PŘEDHLUBNĚ)

2014 ◽  
Vol 21 (1-2) ◽  
Author(s):  
Slavomír Nehyba ◽  
Václav Zborník ◽  
Vladimíra Jašková
Keyword(s):  
Grain Size ◽  
Gamma Ray ◽  
Facies Analysis ◽  
Primary Source ◽  
Heavy Minerals ◽  
Shallow Marine ◽  
Facies Associations ◽  
Mineral Compositions ◽  
Drill Holes ◽  
Depositional Setting

Early Badenian deposits of the Carpathian Foredeep were newly studied in the sedimentary successions from drill holes Holubice 1 and Holubice 2. Facies analysis together with study of grain size, the shape and roundness of the coarsest grains, the mineral compositions of selected heavy minerals (garnet, rutile) and the gamma-ray spectra, were all used for better understanding the depositional setting and provenance. Studied sediments were deposited in coastal and shallow marine environments. Six lithofacies was recognised in the sedimentary succession in the drill holes. They have been combined into two facies associations – lower clastic one and upper carbonate one, refl ecting deposition in shallow marine settings, upward shallowing trend and reduction of siliciclastic input. The primary source of the material is located mainly in the metamorphic rocks (gneisses, amphibolites and granulites). The spectral gamma-ray logs show vertical organization, which is consistent with the facies analysis and partly also grain-size. A significant reduction of terrigenous input is connected with deposition of carbonates (sandy limestones) in the upper part of the succession.

scholarly journals Three dimensional reconstructions of Nummulites tests reveal complex chamber shapes

2015 ◽  
Author(s):  
Willem Renema ◽  
Laura Cotton
Keyword(s):  
Benthic Foraminifera ◽  
Three Dimensional ◽  
3D Reconstructions ◽  
Thin Sections ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Regular Shape ◽  
Computed Microtomography

Larger benthic foraminifera (LBF) are an important tool for the biostratigraphy of (sub)tropical shallow marine deposits. In Paleogene the genus Nummulites is an important genus for biostratigraphical zonation schemes. However, classification is Europe centered and based on external characters and equatorial thin sections. New results from regions outside the northern Tethys shows that a more rigid framework for the classification of nummulites is needed. Here we present a new tool for achieving this goal. We visualise 3D chamber shape of Nummulites djodjokartae and compare these to traditional morphometrical characters. To achieve this goal we use computed microtomography of well preserved Nummulites tests. We find that despite the regular shape in equatorial and axial thin section 3D chamber shape is not predicted by these sections. We argue that 3D reconstructions of Nummulites tests will be a great aid in improving our understanding lineages within the genus Nummulites, and to elucidate its evolutionary and biogeographical history.

scholarly journals Basin Analysis of Tertiary Strata in Golden Bay, Nelson

2021 ◽  
Author(s):  
◽  
William Leslie Leask
Keyword(s):  
Iron Ore ◽  
Tectonic Activity ◽  
New Members ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Facies Associations ◽  
Iron Ore Deposit ◽  
Sand And Gravel ◽  
Coal Measures ◽  
River Catchments

<p>Eocene to Miocene strata comprise the Brunner Coal Measures (Ak-Ld), Takaka Limestone (Ld-Po), Tarakohe Mudstone (P1-S1) and Waitui Sandstone (Sc-Sl), and form a transgressive-regressive sequence on an essentially stable structural platform. Brunner Coal Measures in the Takaka valley (up to 350m thick) consist of cross-bedded sand and gravel, interlaminated sand and silt, bioturbated muddy sandstone, carbonaceous mudstone and coal. Five facies associations are recognized and interpreted as river/floodbasin, estuarine and shallow marine deposits. In the Aorere and Parapara River catchments, two new members are recognized: the Quartz Wash Member, comprising quartzose sand and conglomerate, and the Washbourn Limonite Member, a sedimentary iron-ore deposit. The Takaka Limestone (up to 100m thick), consists of bryozoan, bivalve or sandy grainstone or packstone, deposited on a tidal current-swept shallow-middle shelf with minimal terrigenous influx. Diagenesis was controlled by pressure-solution during deep burial, and resulted in a rightly cemented rock with dolomite and neomorphic features. The Tarakohe Mudstone (up to 900m thick) is dominated in its lower half by massive mudstone of hemipelagic and turbiditic origin, and in its upper half by shallow shelf-estuarine sandstones and mudstones. The Waitui Sandstone (160m thick) comprises shallow marine sandstone. Deposition of the Brunner Coal Measures took place in localized fault-angle depressions. The Takaka Limestone was deposited during a period of regional subsidence and minimal tectonic activity. The Tarakohe Mudstone and Waitui Sandstone were deposited in synclinal basins which were later modified by rising monoclinal boundaries.</p>

scholarly journals Basin Analysis of Tertiary Strata in Golden Bay, Nelson

2021 ◽  
Author(s):  
◽  
William Leslie Leask
Keyword(s):  
Iron Ore ◽  
Tectonic Activity ◽  
New Members ◽  
Shallow Marine ◽  
Marine Deposits ◽  
Facies Associations ◽  
Iron Ore Deposit ◽  
Sand And Gravel ◽  
Coal Measures ◽  
River Catchments

<p>Eocene to Miocene strata comprise the Brunner Coal Measures (Ak-Ld), Takaka Limestone (Ld-Po), Tarakohe Mudstone (P1-S1) and Waitui Sandstone (Sc-Sl), and form a transgressive-regressive sequence on an essentially stable structural platform. Brunner Coal Measures in the Takaka valley (up to 350m thick) consist of cross-bedded sand and gravel, interlaminated sand and silt, bioturbated muddy sandstone, carbonaceous mudstone and coal. Five facies associations are recognized and interpreted as river/floodbasin, estuarine and shallow marine deposits. In the Aorere and Parapara River catchments, two new members are recognized: the Quartz Wash Member, comprising quartzose sand and conglomerate, and the Washbourn Limonite Member, a sedimentary iron-ore deposit. The Takaka Limestone (up to 100m thick), consists of bryozoan, bivalve or sandy grainstone or packstone, deposited on a tidal current-swept shallow-middle shelf with minimal terrigenous influx. Diagenesis was controlled by pressure-solution during deep burial, and resulted in a rightly cemented rock with dolomite and neomorphic features. The Tarakohe Mudstone (up to 900m thick) is dominated in its lower half by massive mudstone of hemipelagic and turbiditic origin, and in its upper half by shallow shelf-estuarine sandstones and mudstones. The Waitui Sandstone (160m thick) comprises shallow marine sandstone. Deposition of the Brunner Coal Measures took place in localized fault-angle depressions. The Takaka Limestone was deposited during a period of regional subsidence and minimal tectonic activity. The Tarakohe Mudstone and Waitui Sandstone were deposited in synclinal basins which were later modified by rising monoclinal boundaries.</p>

Portable XRF analyzer: a powerful tool for multiscale assessment of soil contamination

2021 ◽  
Author(s):  
Florindo Antonio Mileti ◽  
Antonietta Agrillo ◽  
Piero Manna ◽  
Langella Giuliano ◽  
Fabio Terribile ◽  
...  
Keyword(s):  
Soil Contamination ◽  
Gamma Ray ◽  
Industrial Wastes ◽  
Hazardous Substances ◽  
Thin Sections ◽  
Distribution Maps ◽  
Gamma Ray Spectrometer ◽  
Natural Gamma ◽  
Wide Range ◽  
Site Characterisation

&lt;p&gt;All around the world, a wide range of rural and industrial areas contaminated by PTE (potentially toxic elements) is affected by general lack of ex-ante information on type, quantity and location of potentially hazardous substances, hence the increasing request of proper investigation tools enabling preliminary screening of soil environment. Besides, spatial understanding of soil contamination is a prerequisite for the achievement of both proper site characterisation and reclamation.&lt;/p&gt;&lt;p&gt;Continuous aquisition in field of physical soil properties (such as apparent electrical conductivity by means of EMI equipments or natural gamma-ray dose rate by gamma-ray spectrometer) is of great importance to follow soil short range spatial variability. However, when the key parameter to be monitored is the soil PTE concentration (to assess, for example, exceeding of the established screening values - CSCs), a different tool is required. &amp;#160;&lt;/p&gt;&lt;p&gt;In a farmland of South of Italy, confiscated by the Italian Judiciary due to past illegal burial of industrial wastes, a portable handheld XRF analyzer (pXRF) was used at field scale to measure PTE (As, Cd, Cr, Ni, Pb) content on soil samples collected on a regular sampling grid of 20x20 m, at three depths (0-20, 30-60, 70-90 cm). On the basis of the contaminant content, distribution maps were outlined and &amp;#8220;spatial pollution hot spots&amp;#8221; revealed.&lt;/p&gt;&lt;p&gt;In correspondence of the most contaminated areas, 8 soil trenches and 5 profiles were dug. In one of the most representative soil trenches, a large (depth/height = 200 cm and width = 500 cm) wall was in situ analysed with high detail by using the pXRF at pedon scale (measurement distance of 10 cm vertically and between 20-35 cm horizontally). The use of the software Surfer 12 enabled the spatialization and mapping of the in depth contamination. Results showed a moderate but diffuse and homogeneous Cr contamination in the topsoil (400 mg/kg), a higher but point-source (2-3%) contamination in the subsoil and uncontaminated soil (40 mg/kg) below 2 m of depth. Most contaminated soil/wastes were then morphologically described and collected, bulk samples for chemical analyses and undisturbed samples for micromorphological thin sections.&lt;/p&gt;&lt;p&gt;pXRF analyzer was also used at microscopical scale on soil thin sections, using a small spot collimator (analysis area of 0.07 cm2), to preliminary detect and select contaminated micro &amp;#8211; pedofeatures, to be further sub-microscopically (SEM-EDS) analysed.&lt;/p&gt;

Evaluation of antioxidant enzyme content, phenolic content, and antibacterial activity of Commiphora gileadensis grown in Saudi Arabia

2021 ◽  
Vol 19 (4) ◽  
pp. 329-343
Author(s):  
Yaaser Q. Almulaiky ◽  
Ammar AL-Farga
Keyword(s):  
Antibacterial Activity ◽  
Saudi Arabia ◽  
Oral Hygiene ◽  
Leaf Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Reference Drug ◽  
Wide Range ◽  
Peel Extract

Commiphora gileadensis is commonly used in Saudi Arabia for oral hygiene. A lack of data about its biological activity encouraged us to evaluate the antioxidant and antibacterial activities of its leaf and stem extracts. Ethanol, methanol, acetone and deionized water were tested as extraction solvents. 80% methanol gave the highest extracted concentrations of phenolic and flavonoid substances. The leaf and stem extracts were respectively evaluated for their radical scavenging activity with DPPH (EC50 = 3.39, and 1.06), ABTS (EC50 = 0.690, and 0.55), and peroxide scavenging activity (EC50 = 2.43, and 1.28). GC-MS identified a wide range of compounds that may be responsible for these activities of the results observed. The highest levels of chlorophyll, carotenoids, and lycopene were found in the leaf extract while level of proanthocyanidins was found in the stem peels extract. The peroxidase and catalase activities of stem peel extract were higher than those of the leaf extract. The findings showed that the leaf and stem peel extracts of C. gileadensis exhibited significant antibacterial activity against the test organisms. The minimum inhibitory concentrations for the plant extracts were compared with the standard reference drug Augmentin but the time–kill curves for the C. gileadensis extracts showed that they were less effective than Augmentin. Moreover, the stem peel extract exhibited stronger antibacterial activity than the leaf extract. In conclusion, C. gileadensis can be an important source of natural antioxidants, used as a healthy chewing stick for teeth brushing and oral hygiene purposes.

scholarly journals Quantitative linear dichroism imaging of molecular processes in living cells made simple by open software tools

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Alexey Bondar ◽  
Olga Rybakova ◽  
Josef Melcr ◽  
Jan Dohnálek ◽  
Petro Khoroshyy ◽  
...  
Keyword(s):  
Biological Systems ◽  
Linear Dichroism ◽  
Quantitative Information ◽  
Living Cells ◽  
Software Tools ◽  
Model Systems ◽  
Membrane Properties ◽  
Polarization Microscopy ◽  
Molecular Processes ◽  
Wide Range

AbstractFluorescence-detected linear dichroism microscopy allows observing various molecular processes in living cells, as well as obtaining quantitative information on orientation of fluorescent molecules associated with cellular features. Such information can provide insights into protein structure, aid in development of genetically encoded probes, and allow determinations of lipid membrane properties. However, quantitating and interpreting linear dichroism in biological systems has been laborious and unreliable. Here we present a set of open source ImageJ-based software tools that allow fast and easy linear dichroism visualization and quantitation, as well as extraction of quantitative information on molecular orientations, even in living systems. The tools were tested on model synthetic lipid vesicles and applied to a variety of biological systems, including observations of conformational changes during G-protein signaling in living cells, using fluorescent proteins. Our results show that our tools and model systems are applicable to a wide range of molecules and polarization-resolved microscopy techniques, and represent a significant step towards making polarization microscopy a mainstream tool of biological imaging.

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