مجلد 20 عدد 1 (2020)
Articles
Abstract: The aim of the current study is to determine the geotechnical properties of the investigated claystones /clayey soils in Koya area, Iraqi Kurdistan Region. This paper deals with the evaluating of the physical, mechanical and index properties of claystones. The study based on the field reconnaissance for twenty-five claystones samples were collected from five outcrops location within Fat'ha Formation. The results obtained from the laboratory tests revealed that the averages of specific gravity, porosity, void ratio, water absorption, natural water content and uniaxial compressive strength values of claystones are (1.5, 4.45%,4.5, 0.3, 3%, 65 MPa) respectively. Whereas the results of the index geotechnical characterization of clayey soils revealed that the averages values of liquid limit, plastic limit, plastic index, flow index, toughness index, liquidity index, consistency index, swelling potential, activity index, and expansive potential are (25.2, 15.0, 10.2, 0.2, 0.5, -1.2, 2.2, 0.62, 0.31, low or non-expansive) respectively. Among the index properties, the clayey soils are suitable for foundation and building materials industry. Furthermore, the regression coefficients of their correlation (R²) obtained from the analysis show that there are strong relationships between the physical and mechanical properties of claystones. Concluding remark is that geotechnical properties of examined natural claystones satisfy the relevant regulation to be used for construction purposes.
Abstract: Hard ground at the uppermost part of Bekhme Formation is studied at three outcrop sections located in the Dohuk area, northern Iraq, and it is found that it consists of two distinct facies associations. The first includes limestone beds that comprise the hard ground and its omission surfaces. The second consists of limestone, marly limestone, and marl, which is interbedded with successive hard ground. The overall characters of these two facies associations indicate that deposition took place in a carbonate ramp setting. Vertical variations of sedimentary components suggest that the hard ground was developed by three successive stages. These are the end of shallow carbonate sedimentation and the drowning of the platform, the formation and modification of hard grounds, and finally the deposition of pelagic carbonate sediments of the Shiranish Formation. The second stage is characterized by intercalations of continuous depositional and biological processes. These include bioturbation, bioencrustation, and secondary mineralization in addition to other early and late diagenetic processes. The depositional area had been affected by tectonic drowning of carbonate ramp with a wide gradual marine transgression associated with a period of local marine regression that is, in turn, responsible for deposition, transportation, redeposition, submarine erosion and formation of hard grounds. Thus, the hard ground zone represents drowning unconformity surfaces between Bekhme and Shiranish formations through the Campanian- Maastrichtian boundary.
Abstract: Sedimentary rock beds and drainage pattern offset took place predominantly at the southeastern plunge of Bashiqa anticline which indicates shear zone in this area represented by apparent left-lateral fault separation of reverse fault dipping to the southeast. This study will discuss and update the geological information of the impressions of the fault on the surface topography based on the morphotectonic evidences including visual interpretation of the satellite image for the landforms and regional stress analysis of the study area. The variations of landform features are regarded as an efficient geological indicator for tectonic activity in the area.
Abstract: The work deals with the study of hydromorphology of the regulating lake which located at (50Km) north of Mosul city. The survey started in November, 2012 using the EchoSounder, and carried out by dividing the lake into (30) sections starting from the lower surface of the main dam and ending at the regulating dam. Data are recorded and represented using GIS technology (Arc GIs v10.4) and Microsoft program (Excel). The survey shows that the shallowest depth in the lake is found at left bank of section (5) which reached (7.65 m) and the deepest point is Found in the left bank of the section (9) which reached (18.22m) directly on the Thalwage line. The hydraulic gradient of the lake is (1m/Km ), and the overall shape of the sections is (U) shape. The variation in depth in each section is mostly due to difference in the sedimentation and erosion. There was deposition on the convex sides and erosion in the concave sides of the banks, the erosion and sedimentation processes vary with the variation of water velocity, slope and rock components of the river along the regulating lake.
Abstract: The Naokelekan Formation (Late Oxfordian - Early Kimmeridgian) was studied at three surface sections (Rowanduz, Ranya and Sargelu), in northeastern Iraq. The Formation is composed mainly of alternating sequence of thin- bedded limestone, dolomitic limestone and bituminous black shales. Streaks of calcite veins, chert nodules and bituminous stylolite are present. Traces of Ammonite molds, flat, wavy to domal stromatolites are also present. The Petrographic study showed that the formation contains various petrographic components represented by Ammonites, pelecypods, gastropods, calcispheres, planktonic and benthonic foraminifera, ostracods, stromatolite, radiolaria and bryozoans, pellets and intraclasts, in addition to the groundmass of micrite and microspars. The rock successions were extensively affected by many diagenetic processes and their effect is most pronounced pronounced on textural properties of these rocks. The dolomitization seems to be one of the most important diagenetic processes recognized. The other processes are; compaction, micritization, bioturbation, authigenic minerals, cementation, neomorphism, dissolution, fractures and veins, silicifaction, replacement and dedolomitization. The detailed facies analysis reveals that the rock succession consists mainly of three microfacies and two lithofacies type. The main microfacies include lime mudstone,wackestone and packstone. Where the lithofacies comprise limestones and shales which are represented by four sub lithofacies. The overall characters of these facies indicate that the formation was deposited in two different environments; (1) shallow marine sub tidal environment at the lower part and upper part respectively. (2) Outer shelf in a euxinic environment at its middle part.
Abstract: The purpose of this study is to evaluate the impact of weathering on rocks used in construction during a defined period of these rocks. The field study involves weathering and rock strength measurements using a geological hammer. Laboratory testing for both wall limestone and fresh quarry limestone was performed to determine the bulk density, the porosity and absorption of water, and the durability test was performed for fresh quarry limestone. A polarized microscope and scan electron microscope, petrographic analysis has been conducted for various weathering rates. Field notes explain the moderate and high degree of weathering and low strength in the bottom of the wall, whilst the top is slightly weathered and high strength. Laboratory notes through stone crushing show a change from white to beige for slightly weathered samples to moderately and highly weathered samples in powder color. Increasing weathering reduces bulk density and insoluble residues, from 13% in non-weathered rocks to 25% in high-weathered rocks the level of insoluble residue increases. Water absorption in non-weathered rocks and high weathering rocks rises from 6% to 14% and porosity from 14% to 27% respectively. Durability tests show that calcarenite exceeds very high durability, high durability calcirudite and calcilutite, and moderately durable calcisiltite. Four types of porosity, intergranular, intragranular, mold and microfracture appear in the petrographic study using a polarized microscope. Clay minerals and iron oxides surrounding the pores appear in weathered specimens, not in fresh, calcite crystal oxidation and secondary calcite growth on the inner surface of voids have also been shown in the scanning of electron microscopes.
Abstract: The results of the analysis and interpretation of multi-date satelliteimages for the period between (1987-2007) in the Nineveh’s province to the presence of local spectral anomalies in some areas, reflect a clear change in the pattern of spectral using reflectivity. Analyses of spectral reflectivity using Analytical Spectral Devise (ASD) field Spectro Radiometer for selected samples of soils that have been taken by field work from some sites in the province. They gave spectral anomaly in their profile patterns, compared with other unaffected sites, which have been useful in determining and locating the pollution sites and its classification. Classification of the above pollution sites has been accomplished depending on the comparison of spectral signature of these samples with the field informations. These classes are shown on Geoenvironmental thematic map prepared at scale of 1:50000. This map includes areas of radioactive contamination and environmental, indusial and other of military activity.
Abstract: Iraq is one of the countries with water abundance because it contains water sources distributed between permanent and seasonal flow. The Tigris River is considered as one of these the most important sources, which requires the necessity to monitor the changes that had been taken place in the course of this river and to study the environmental, climatic and erosional changes that were responsible to change the morphodynamic properties of this resource, especially in the rainy years that cause floods and human disasters, such as what happened in the accident of the sinking of the ferry in the city of Mosul. Consequently, the main objective of the current study is based on observing a selected section of the Tigris River basin at the beginning of its entry into Mosul city and studying the effects of changing the water level during different seasons on the banks of the river and its effects on random housing construction near the river. A new European satellite (Sentinel) is used which has high spatial resolution of up to 10 m per pixel, which was the last launch of its series in April 2018. The new QGIS program is also used to process the satellite data, using digital processing methods for interpretation, and to monitor changes in the studied section of the river. Two satellite images are adopted for two consecutive periods (2018 and 2019), corrected and geographically referenced. The conclusion is that there is an increase of 1.105 km2 in the area of the studied river section between the rainy year and the less rainy year, i.e. an approximate increase in excess of 50%. Therefore, the researchers recommend preventing the construction of any residential or touristic projects on the both Tigris River banks within at city of Mosul, and add to the forbidden areas a distance of not less than 50% of the surface area of at any section of the river inside the city.
Abstract: The present study focuses on the assessment of groundwater for domestic and agricultural usages in two areas northeastern Mosul city: the first is located between Mosul city and Bashiqa Mountain, and the second is located between the road of Mosul-Alqosh and Shikhan – Dahqan – Alqosh Mountains which represents the Alqosh plain. These two locations were classified as agricultural areas. And their villagers use the groundwater for domestic and irrigation. The present study evaluates the groundwater for drinking using the water quality index (WQI). The assessment is achieved by calculating the (WQI) index from the physical and chemical parameters (pH, E.C., T.D.S., T.H., Ca2+, Mg2+, Na+, K+, HCO3-, SO42-, Cl- and NO3- ). The results confirm that the groundwater of the first area is classified as a poor class (WQI=56-73) for drinking due to its reservoir present within the sandstone layers of Injana Formation, which is affected by the infiltration of surface water through soil zone that contains the weathering fragments of carbonates and gypsum. The other wells of this area located along the road between Mosul city and Bashiqa Mountain are classified as very poor to unsuitable class for drinking (WQI=76-135) due to the presence of these wells within Fat'ha Formation rocks, except the Al-benit farm and Al-Fadelya1 groundwater that is classified as a good class for drinking (WQI<50). The Alqosh plain groundwater is classified as excellent to good class for drinking (WQI=15-36) because of their reservoir is present within sandstone layers of Injana Formation, except the wells of Kir-Ishaq, Batnaya, and Alqosh, and Alzayton village which is classified as poor (WQI=61) and unsuitable class (WQI=111-115) for drinking respectively because of their reservoirs are present within gypsum layers of Fat'ha Formation.
Abstract: The present study involves applying a new system by picking the apparent resistivity values from the pseudo-tomography at seven depth's levels and nine orientations with an angle of 20 ° around the mid central point of a 200 m array lengths. The system, which is called the Azimuth Mutib and Al-Fadhel System (AMAS), consists of three types of the electrode arrangement patterns, the first is the Azimuthal Radial Resistance Technique (ARRT) for measurements of resistivity (ρD1 & ρD2), the second is the Azimuthal Forward Resistance Technique (AFRT) for measurements of resistivity (ρD0 & ρD2), and the third is the Backward Resistance Technique (ABRT) for measurements of resistivity (ρD0 & ρD1). A new mechanism is used in this study that includes a series of calibration steps of the electrode spacing intervals with the apparent depth’s levels and median of the depth of investigation, due to the inability of picking the resistivity values of the true depth's levels from electrical resistivity imaging because there is a wide spectral gradient range of colors. As well, the absence of correlating the values of the depth's levels with the electrode spacing in the RES2DINV software. Accordingly, three values were determined for the missing apparent depth's levels with confirmation of the accordant values of the eight levels of the tomography. The data of the ART are represented using radial, forward and backward techniques at four sites using polar graphs and Cartesian curves. According to the mechanisms used in global and local studies and researches, the results are analyzed and for determining the values and trends of the electrical anisotropy for Quaternary deposits and the upperlayers of Fatha Formation in the present study area. The study displays a notable success in applying AMAS by matching between its three mechanisms and deduced the presence of six directions for the strikes of tension and shear fractures (primary and secondary) at two sites near the Mosul Dam penetrating fluvial and alluvial deposits of the Quaternary age.