Lithofacies analysis and Depositional Environment of Eocene – Paleocene Sediments of Ewekoro Quarry SW, Nigeria

In the northern section of the Western Desert, there are many extremely profitable petroleum and natural gas deposits in the Abu EL-Gharadig Basin. This study aims to highlight the hydrocarbon potential of Abu Roash F Formation, which stands for high organic content unconventional tight reservoirs, and Abu Roash G Formation which stands for conventional sand reservoirs, in Sitra field located in the central-western part of the Abu EL-Gharadig Basin. The research employed well-log data from four wells to ascertain petrophysical properties combined with core samples of two wells for a comprehensive examination and description of lithology. Initially, we commenced the execution of petrophysical analysis, encompassing log quality control procedures. Subsequently, we identified and revealed zones of interest and hydrocarbon indicators in both formations. Additionally, we ascertained the three most influential parameters, shale Volume, effective Porosity, and water saturation, which serve as defining factors for reservoir quality. Subsequently, an examination of the core samples, which encompassed lithologic description, lithofacies analysis, paleoenvironmental interpretation, petrographic analysis, and porosity assessment is conducted. For the sake of a more accurate interpretation, we conclude our research with cartographic maps created to evaluate the geographical distribution of hydrocarbon potential based on petrophysical characteristics, Distribution of the net-to-gross ratio among wells by correlating the litho-saturation models (rock models) for the four wells. The foregoing results declare that The Abu Roash F carbonate-rich rocks are a contender for unconventional tight oil reservoir potential with thin secondary porosity and high organic content, which normally requires a kind of hydraulic fracturing for prospective oil extraction, Furthermore, the upper section of Abu Roash G formation, particularly in well sitra8-03, has highly favorable conventional reservoir characteristics.

Rock petrophysical properties, including porosity and permeability, are fundamental factors in regulating fluid ingress, flow and fluid-rock interaction across various length scales and tectonic settings. The composition of fluids, and their modes of ingress into- and reaction with host rocks, in turn influence bulk rock properties. Therefore, fluids can significantly alter rock rheology, potentially modifying their density, long-term viscosity, porosity and permeability. Mineralizing fluids may also change the rock composition, heal fractures, and promote strain hardening within active fault systems, potentially impacting the seismic cycle.To better understand these processes and the governing background conditions, it is particularly useful to investigate the pathways for fluid flow, especially in rocks with low primary porosity and permeability, which would normally hinder significant fluid circulation. In micritic, horizontally-bedded carbonates, for example, vertical fluid flow is generally limited far away from tectonic fractures, whereas lateral, bed-parallel circulation is favoured exploiting laterally continuous planar anisotropies (e.g., bed-bed interfaces), to progressively permeate the succession. Secondary anisotropies, such as pressure-solution seams (e.g., stylolites), may represent other interesting features for fluid flow, being at times very abundant in limestone. However, they are typically considered to reduce the permeability and porosity of host rocks due to (i) the cementation and precipitation of dissolved materials in pores within the immediately surrounding rock and (ii) the accumulation of insoluble, fine-grained and low-permeability material on their surfaces. Recent studies in carbonates challenged this assumption, demonstrating that burial stylolites can be preferential pathways for karst dissolution.We present here new data on the petrophysical properties of Cretaceous micritic limestone from the Lessini Mountains, Veneto, Italian Southern Alps, where much of the exposed, generally sub-horizontal Mesozoic carbonate succession underwent pervasive dolomitization during Eocene extensional tectonics and the onset of the Venetian Volcanic Province magmatism. Petrographic analyses, Hg-porosimetry, and He-pycnometry were applied to assess the effects of Mg-rich fluids, probably connected with the volcanic environment, on micritic limestone. Preliminary results indicate that burial stylolites developed in low porosity limestone are selectively dolomitized, with dolomitization seams 1-10 mm thick, suggesting pervasive bedding-parallel fluid flow. Dolomitization occurred also along vertical fractures and in fracture meshes of mosaic breccias, suggesting across-bedding Mg-rich fluid circulation associated with normal faults accommodating.Dolomitization significantly increased rock density from ~2.65 g/cm³ in the pristine micritic limestone to ~2.9 g/cm³ in the fully dolomitized rock. Additionally, pore size, porosity, and the capillary threshold pressure of Hg injection change gradually but substantially from the limestone to the dolomite, with median pore sizes increasing from ~0.012 μm to ~0.33 μm, porosity from ~3.2% to 21.8%, and capillary threshold values decreasing from ~5140 to ~35 PSI.These results demonstrate that, under specific conditions, stylolites can actually serve as effective pathways for fluid ingress/migration and thus promote fluid-rock interaction in rocks characterized by overall low porosity and permeability (e.g., micritic limestone). Furthermore, we show that dolomitization significantly modified the petrophysical rock properties, further enhancing fluid ingress and likely promoting fracturing and brecciation by changing rheology, with consequences for deformation localization and partitioning during later tectonic activity.

The thermal and physical properties of rock units from Ikogosi Warm Spring (IKGWS) in the Southwestern part of Nigeria were examined in order to characterize and explore its geothermal prospect and to provide an insight into the different thermal properties of rocks of the study area. A total of 40 rock samples made up of granite, quartzite and gneiss series were collected from the outcrops of the study area and analyzed for Thermal conductivity (TC), Radiogenic heat production (RHP), Heat flow (HF), Porosity, Density and surface spring temperature measurements. The RHP values for all samples varied from 1.8 to 3.5μWm-3 with an average value of 2.5μWm-3 and standard deviation (SD) of 0.4 while the heat flow values varied from 14 to 27mWm-2 with an average of 19mWm-2 and SD of 3.4. The TC values varied from 2.95 to 4.11 with a mean of 3.49mWK-1 with a SD of 0.4 while the porosity values varied from 0.21-1.15 % with a mean of 0.62% with SD of 0.39. The density values varied from 2.68 to 2.85gcm-3 with a mean of 2.76gcm-3 and SD of 0.067. The surface temperature of the spring varied from 32 to 45°C with a mean of 38.9°C. From these results the average RHP and HF values estimated from all samples was below the 4μWm-3 and 100mWm-2 recommended value of heat to be considered for economic importance. Thus, the IKGWS geothermal field cannot be explored for power generation but for other geothermal activities and may be classified as a low enthalpy geothermal system (

Coal-bed folios are currently being prepared for major coal beds in the Eastern Kentucky coalfield. These comprehensive folios contain information on geologic setting, coal setting, coal quality, coal resources, and environments of deposition for each of the selected coal beds. Additionally, each folio contains a series of maps (at a scale of 1:500,000) and geologic cross sections. Individual structure, isopach, coal-quality (sulfur, ash, and Btu), and overburden maps are prepared in conjunction with longitudinal and transverse geologic cross sections. The folios are compiled using field-measurement and chemical-analysis data maintained by the Kentucky Geological Survey in its Kentucky Coal Resources Information System (KCRIS). KCRIS is a computer-based, fully integrated data storage and retrieval system that contains coal-thickness measurements, coal-quality analyses, core descriptions, petrographic analyses, and lithologic descriptions. Maps and cross sections for the coal-bed folios are computer generated using coal-thickness and coal-quality information from the KCRIS data set. Grid matrices are prepared for the appropriate coal-thickness measurements or coal-quality parameters. These grids are then modeled or contoured on the Survey's computer system using MINEX software, and the resulting plot files are then plotted on a multi-pen or ink-jet plotter.

Sedimentary succession and evolution of the Mediterranean Ridge western sector as derived from lithology of mud breccia clasts

Interpretation of magnetic anomalies from the southwest Arunta, and Cloncurry, Precambrian basement complexes has been possible only with information on the geochemistry and magnetic properties of the outcropping rocks. The lithological descriptions provided by regional geological maps are not adequate for the purpose of interpretation, owing to the paucity of Precambrian outcrop and also because the magnetic properties of rocks generally are not related to the factors used to classify rock types. Analyses of rock samples from the southwest Arunta Block indicate that the magnetic properties depend in part on rock composition, but also on the degree of metamorphism and other geological processes which are not always reflected in lithological descriptions. Modelling of aeromagnetic data using the measured magnetic properties as a primary control has yielded a new solid geology interpretation of the region.Magnetic susceptibilities and densities measured on samples from the eastern edge of the Cloncurry Complex have been used to interpret aeromagnetic and gravity data over a part of the complex where geological mapping of the basement is precluded by a thin veneer of younger rocks and alluvium. Both lithology and structure of the buried rocks have been interpreted in this way.

Four discrete phases of dolomite are present within rocks which compose the south margin of the small, isolated Miette buildup. Detailed mapping, petrographic analysis, and chemical studies facilitate distinction of the following dolomite types: (1) an early phase of microcrystalline dolomite occurring as a diffuse matrix component of micrite limestones; (2) a pervasive phase of saccharoidal dolomite exhibiting a variety of features inherited from precursor limestones; the degree of dolomitization associated with this phase ranges from partial recrystallization of limestones from all depositional facies to complete dolomite mosaics which modify most primary textures and depositional features in the buildup margin; (3) a relatively minor phase of subhedral to anhedral icrocrystalline to microcrystalline dolomite confined to the buildup interior and associated with bitumen, clay, and iron residues along stylolites, and with characteristic green microcrystalline carbonate accumulations along solution surfaces; (4) a late phase of coarse, white dolomite associated with coarse calcite spar, which is related to brecciation of phase 2 dolomites of the buildup margin. Paragenetic relations between the first three phases are best observed in partially dolomitized micritic limestones from the interior of the buildup. Vuggy porosity is associated with the pervasive dolomites of the buildup margin. Petrographic observations, supported by geochemical and isotopic data, suggest different origins for these different phases of dolomite. Pervasive dolomitization postdates cementation and lithification of back-reef deposits; furthermore, there is little evidence of subaerial exposure, and evaporite-related solution features are absent. Alkaline, magnesium-rich fluids derived from adjacent and underlying basinal strata may have been responsible for the major phase of pervasive dolomitization. Before dolomitization models can be applied to specific localities and to rocks displaying specific facies relations, careful petrographic, geochemical, and stratigraphic analyses are essential. End_of_Article - Last_Page 492------------

The control of mineral constituents and textural characteristics on the petrophysical & mechanical (PM) properties of different rocks of the Himalaya

The upper Miocene, late Mohnian age, Williams Sand crops out in the southeastern Temblor Range along the southwest margin of the southern San Joaquin Valley, California. The Williams is composed of lenses of generally coarse material within the siliceous Antelope Shale Member of the Monterey Formation and is stratigraphically equivalent to the Stevens Sand. The sands and shales were deposited in paleontologically defined waters as much as 4,000 ft (1,219 m) deep. Based on field and laboratory studies, the Williams is interpreted as a End_Page 1689------------------------------ submarine fan deposit. Continuous grain-size plots of the outcropping sands were drafted and distinct turbidite facies were identified using Mutti and Ricci-Lucchi's classification. At the surface, the Williams dips northeast into the valley and contains many rather thin-bedded, usually graded, sandstones and conglomerates, with high porosity and permeability, which are interbedded with siltstone and shale. Thick deposits of shale, commonly cherty, separate large bundles of turbidites that pinch out along strike. The sandstone bundles often form coarsening- and thickening- upward sequences typical of deposition on the smooth suprafan lobes of the midfan. Other sandstones form fining- and thinning-upward sequences diagnostic of deposition on the channelized suprafan, although lack coarse pebbly material. App rently, the Williams fan continued to prograde until at least midway through its depositional history, when significant lateral shifting of coarse-grained sandstone bodies occurred. According to petrographic modal analyses, the sands are arkosic, having a clay matrix and occasional carbonate and opal cements. Lithologic descriptions plus petrographic and paleocurrent data suggest the source terrane was only a few miles west-southwest, and most likely was the northern Gabilan Range. The northern Gabilan Range is composed of granitic and metamorphic rock, and is now located 150 mi (240 km) northwest of the outcropping Williams owing to Miocene and post-Miocene strike-slip displacement along the San Andreas fault. In the subsurface, the Williams is composed primarily of fine to medium-grained sands, which are rather thinly bedded, poorly sorted, and interbedded with thick shales and siltstones characteristic of a lower fan facies. Oil is produced from Williams sands less than 2 mi (3.2 km) north of the study area from the Spellacy and Midway anticlines of the Midway Sunset field. Shales, and occasionally bentonites, separate the producing Williams into different reservoirs. End_of_Article - Last_Page 1690------------

Petrographic and diagenetic analysis of the Middle-Upper Jurassic successions (Sargelu, Naokelekan, and Barsarin) formations and boundaries between them in the Sargelu area, Kurdistan region, N.E. Iraq was conducted based on the lithologic description, thin section analysis, and scanning electron microscopy. The study aims to define the petrographic components and diagenetic processes that affect the carbonate rocks of Jurassic succession in the studied section. Thirty-eight thin sections have been prepared, with five samples selected using the S.E.M. technique to reveal the petrographic components and diagenetic processes. The Jurassic succession is composed mainly of carbonates (limestone and dolostone) interbedded with shale units. Petrographically, the Sargelu, Naokelekan, and Barsarin formations are composed of skeletal grains (pelagic pelecypods, radiolaria, calcispheres, planktonic and benthonic foraminifera such as miliolid, ostracods, bioclasts, and stromatolites) which are the most common, in addition, non-skeletal grains such as poloids, micritic groundmass, and recrystallized micro spars, Many diagenetic processes affected the studied carbonate rocks such as micritization, dolomitization compaction and stylolite formation, authigenic minerals (pyrite), cementation, neomorphism, dissolution and porosity formation as represented by moldic, vuggy, channel and fracture porosity.

A rhyolite boulder collected by R. S. Newall in 1924 from an excavation at Stonehenge has been pivotal to arguments concerning glacial versus human transport of the bluestones to Stonehenge. Initial studies suggested that the boulder came from north Wales, and hence was a probable glacial erratic. New petrographic and geochemical analyses however support it being from Craig Rhos‐y‐Felin in west Wales, the source of much debitage recovered from Stonehenge. Examination of the form and surface features of the boulder provides no evidence for it being erratic. Instead, it is considered to be one more piece of debitage probably derived from a broken‐up monolith.

There are many causes of abnormally low well production rates, and a good engineering approach should identify them. They include low permeability, low reservoir pressure, high bottomhole pressure (BHP), high reservoir fluid viscosity, and high skin. The remainder of this paper considers the elements that can contribute to a successful hydraulic-fracture-treating program. Not all the elements need to be done in every case. However, they should be considered carefully, because they might affect both the success and the interpretation of the fracture-stimulation treatment. Inadequate evaluation could fail to identify changes and improvements to include in subsequent treatments. The following sections cover the pretreatment, execution, and evaluation phases of hydraulic fracturing. As can be appreciated, the key phase in fracture design is the pretreatment analysis.

Background: Bureau of Labour Statistics (BLS) has identified on-the-job injuries as a major problem facing health care workers. There is little data available on injuries sustained by physical therapists in Nigeria. 
 Objective: This sfudy was carried out to detennine the nature, prevalence, job risk factors and consequences of occupational injuries with particular focus on musculoskeletal injuries experienced by physical therapists in the south western part of Nigeria. 
 Methods: A hundred copies, self administered questionnaire composed of thirty (30) close-ended questions were administered to physical therapists working in hospitals and private clinics. Questions included occupational history of the physical therapists; duration of injury; body parts affected; activities that aggravate symptoms; patients predominantly treated; management and preventive strategies. The data were analysed using descriptive analysis. 
 Results: Seventy-eight percent (78%) of the physical therapists had past histories of occupational injuries. The most prevalent injured body parts were the lower back (45.2%), wrist and hand (26%) mid back (10.6%) and neck (6.7%). The highest job risk factors were manual therapy techniques (20.9%), transferring patients (13.8%) and static position (12.2%). Stroke (31.7%) and low back (28.2%) patients were predominantly treated. Activities that cause re-injury include manual technique and repetitive tasks. Muscle strain was the commonest type of injury (55%), while fracture was the least (1 %). 
 Conclusion: This study concluded that occupational injury was high among selected physical therapists in the South West of Nigeria. It also concluded that the low back and hands were the most common sites susceptible to injury, while muscle strain was the most common type of injury. 
 KEYWORDS: Occupational injury, Musculoskeletal injury, Physical therapists

<p><span><strong>Abstract:</strong> Reservoir assessment of unconventional reservoirs poses numerous exploration challenges. These challenges relate to their fine-grained and heterogeneous nature, which are ultimately controlled by depositional and diagenetic processes. To illustrate such constraints on shale gas reservoirs, this study focuses on lithofacies analysis, paleo-depositional and diagenetic evolution of the Paleocene Patala Formation at Potwar Basin of Pakistan. Integrated sedimentologic, petrographic, X-ray diffraction and TOC (total organic carbon) analyses showed that the formation contained mostly fine-grained carbonaceous, siliceous, calcareous and argilaceous siliciclastic-lithofacies, whereas carbonate microfacies included mudstone, wackestone and packstone. The silicious and carbonaceous lithofacies are considered a potential shale-gas system. The clastic lithofacies are dominated by detrital and calcareous assemblage including quartz, feldspar, calcite, organic matter and clay minerals with auxiliary pyrites and siderites. Fluctuations in depositional and diagenetic conditions caused  lateral and vertical variability in lithofacies. Superimposed on the depositional heterogeneity are spatially variable diagenetic modifications such as dissolution, compaction, cementation and stylolitization. The δ</span><sup>13</sup><span>C and δ</span><sup>15</sup><span>N stable isotopes elucidated that the formation has been deposited under anoxic conditions, which relatively enhanced the preservation of mixed marine and terrigenous organic matter. Overall, the Patala Formation exemplifies deposition in a shallow marine (shelfal) environment with episodic anoxic conditions.</span></p><p><strong>Keywords</strong><strong>:</strong> Lithofacies, Organic Matter, Paleocene, Potwar Basin, Shale Gas, Shallow Marine.</p>

This study investigates the rate of concurrent depletion on the remnant flora growing in the North-eastern part of Lagos, which lies in the South-western part of Nigeria. Tree species growing in this area are not spared from advancing civilization, which has resulted in inevitable loss of genetic resources. Hence, molecular technique is adopted in an effort to conserve the genetic resources of the tree species. Samples were collected at random from various sites in north eastern part of Lagos and identified. A total of 66 tree species was recorded. Genomic DNA was extracted from fresh leaves samples following modified cetyltrimethyl ammonium bromide (CTAB) DNA extraction protocol. The DNA when viewed on 1% agarose revealed bands of high molecular weight. Also, spectrophotometric check on the genomic DNA showed a good quality DNA samples with absorbance ratio of 1.7 to 1.8. The purified DNA was dissolved in buffer and stored at -80°C in the established DNA Bank at the University of Lagos, Akoka, Lagos, Nigeria. This can be used for further investigations including understanding genetic and evolutionary relationships between taxa, functional analysis of genes, comparative genomics, DNA barcoding and plant breeding amongst others. Key words: Bio-conservation, cetyltrimethyl ammonium bromide (CTAB), Lagos, trees, genetic resources.