Volume 21, Issue 2, Autumn 2021


Research Paper

Mineralogy and Geochemistry of Qulqula Limestone in Shenrui, Halabja Governorate, Northeastern Iraq

Nian Samin

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 1-14
DOI: 10.33899/earth.2021.170382

      This study focuses on the mineralogy and geochemistry of the limestone unit of the Qulqula Formation (Early Cretaceous). The age and stratigraphic position of this formation are controversial because of insufficient studies and the complex structure of the occurrence area. Twenty samples were selected and analyzed which represent six sections: Sarkan, Awera, Griana1, Griana2, Hawar, and Hawara Kon at the Mount of Shenrui in Halabja area located in Kurdistan Region, northeastern Iraq near the Iraqi-Iranian borders. The mineralogical study by the X-ray diffraction technique shows that the samples are composed of 70.14 % calcite, and 28.07% quartz. The geochemical analysis shows that CaO is abundant in most of the studied samples, the increases of (SiO2, Al2O3, Fe2O3, TiO2, and K2O), and the decrease in (CaO and MgO) leads to the change of limestone to siliceous type. The limited dolomitization can be confirmed by the low concentration. The component Sr has a negative correlation for both major and trace elements. On the other hand, (Cr, Co, Ni, V, and Zr) have a positive correlation with (MgO, Fe2O3, SiO2, Al2O3, K2O, and TiO2), thismay indicate the effect of the basic rocks in surrounding areas enriching limestone with these elements.

The Influence of Shell Permeability on Stability of Upstream Slope during Rapid Drawdown – Khassa Chai Earth Dam as a Case Study

Krikar Noori; Sirwan Salim

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 15-28
DOI: 10.33899/earth.2021.170383

Several factors affect the stability of earth dam during sudden drawdowns such as permeability and mechanical properties of soil, upstream side slope, drawdown ratio, and drawdown rate. This paper investigates the influence of shell permeability on earth dam upstream slope stability and its role in the change of pore water pressure at different locations of the embankment during the sudden drawdown, using different limit equilibrium methods. To accomplish the objective of this study, (Geo Studio 2012 Software) as one of the powerful geotechnical programs was used for the modeling and numerical analysis. The study shows that decreasing in the shell permeability resulted in the reduction of pore water pressure dissipation and variation of shell hydraulic conductivity plays a vital role in the overall stability of the upstream slope under rapid drawdown conditions.

Assessment of Avroman Limestone Formation for Portland Cement Industry, Halabja Area, Kurdistan Region, NE-Iraq

Chro Fatah; Tola Mirza

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 29-48
DOI: 10.33899/earth.2021.170384

Limestone is the main constituent of the raw materials used in manufacturing cement. In this study, the limestone deposits from the Avroman Formation are evaluated by using chemically and mineralogical techniques for their suitability to be used as a raw material for the cement industry.
Twenty-one samples of limestone are collected from different beds of the Avroman Formation for petrographic study which shows that the limestone samples consist mainly of crystalline calcite. Physical and mechanical tests are performed in addition to the mineralogical and geochemical analysis using x-ray diffraction (XRD), x-ray fluorescence (XRF). Geological review and obtained results show that there is a good potential for industrial-grade limestone. The major clay minerals in the clay samples are chlorite, illite, montmorillonite, were as kaolinite appears as minor clay minerals. The geochemical analysis indicates that the limestone of Avroman formation has a wide range of CaO (46.13-56.00), Al2O3 (0.01-0.86), SiO2 (0.00-1.51), Fe2O3 (0.00-1.25), MgO (0.24-0.71), K2O, Na2O, TiO2, and MnO are traces. The physical properties (water absorption and moisture content) and chemical-mineralogical composition of the formation reflect that the dry process is preferable for the production of Portland cement. Mechanical analyses, especially compressive strength show that the quarrying and crushing will be competitive economically during manufacturing. From the results of the analyses, we conclude that the limestone of the formation and clay material of the study area are of good quality and fulfill the international standards of Portland cement.

Planktic Foraminiferal Biostratigraphy of the Upper Part of the Damlouk Member, Ratga Formation, Western Desert, Iraq

Imad Ghafor; Basim Al-Qayim

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 49-62
DOI: 10.33899/earth.2021.170385

The basinal part of the Damlouk Member upper sedimentary cycle of the Ratga Formation exposed in the Qaim area of the Iraqi western desert is examined. The studied section consists of marlstone, marly and phosphatic limestone, and planktic foraminifera-rich limestone beds. Detailed study of the planktic foraminiferal assemblages of these rocks revealed the occurrences of (30) species belonging to (11) genera. The stratigraphic distribution of these species permits the recognition of three biozones. These are from the lower to upper part of the section: - Acarinina bullbrooki Zone, (Middle Lutetian), Morozovelloides lehneri Zone, (Late Lutetian), Globigerinatheca semiinvolutaHantkenina alabamensis Zone, (Early Bartonian). These zones indicate that the studied section of the Ratga Formation (Damlouk Member) is of Middle-Late Lutetian to Early Bartonian age. These biozones are correlated with different local and regional studies.

Morphometric Characteristics of Erosion Activity in the Komel River Basin

Mahmoud Hamrawi; Ibrahim Ibrahim

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 1-16
DOI: 10.33899/earth.2021.170386

The study area is represented by the Komel River basin, which is located in Duhok Governorate, northern Iraq. Several secondary basins are selected in the northeast of Sheikhan district within the main Komel River basin. This basin is located between longitudes (43º 29´ 00= – 43º 10´ 30=) east, and latitudes (36º 57´ 30= – 36º 46´ 30=) north. The study aims to determine the erosion activity of the main Komel River basin and the secondary basins that make up the basin, by finding the morphometric characteristics and the shape of the hypsometric curve for these basins using the WMS7.1 Watershed Modeling System program. The results of the morphometric analysis are represented by the value of (Hi) and the shape of the hypsometric curve of the Great Komel River basin and its secondary basins showing a discrepancy in erosion activity from one basin to another. The topographical variation of the basins such as the rocky discoveries and the vegetation cover of each basin has been seen. The morphometric characteristics of the basins in general and the main basin, in particular, show the possibility of exploiting the main Komel basin in the water harvesting, as it is a basin in the maturity stage presented by the (Hi) value of (0.40) and is compatible with its hypsometric curve shape. The validity of the Komel River basin in the field of water harvesting is an encouraging conclusion for the development of planting this area with forest trees, pastoral plants, and crops. In a manner that suits the climatic environment of the region, especially if we take into account the basin area of (536,253) square kilometers, which will make the area a facility Tourist.

Specifying the Vegetation Cover Changes in Komel River River Using Remote Sensing Techniques

Mahmoud Hamrawi; Ibrahim Ibrahim

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 17-26
DOI: 10.33899/earth.2021.170387

This study aims to specify the changes that occurred in the vegetation cover of the Komel River basin located in the northeastern Shikan distract in the Duhok –Kurdistan region in Iraq with a total area equal 536.000 km2. Two images from LANDSAT 8 represent the study area for two different periods: the first one on 7/4/2018 during the spring period and the second one on 2/10/2020 during the autumn period. In this study, the vegetation cover is analyzed for the two periods taking into account the differences in annual temperature and rainfall. The final result of this study shows that there is an agreement between the distribution of the vegetation cover and the annual temperature and rainfall, this compatibility is evident by the study of the area topography and its slopes in addition to rocks and soil types where the correlation coefficient, r =0.61.

Reservoir Characterization of the Middle Cretaceous Mishrif Formation in the Buzurgan Oilfield, Southern Iraq

Muneef Mohammed; Hameed Salih; Kadhim Mnaty

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 63-77
DOI: 10.33899/earth.2021.170388

The Mishrif Formation is considered the main oil reservoir in the Buzurgan oilfield, southern Iraq. This study aims to characterize and evaluate the reservoir properties of the Mishrif Formation based on the interpretation of well logs data. The logs data for six wells have been analyzed and interpreted by using Techlog 2015.3 software. The lithology of the Mishrif Formation was determined by using the M-N cross plot method based on the interpretation of density, neutron, and sonic logs. The results showed that the Mishrif Formation is mainly composed of limestone. The shale volume in the Mishrif Formation has been estimated from the gamma-ray log. The results illustrated that the shale volume is about 20% of the bulk volume, and may increase to reach the highest value at the upper part of the MA unit of the formation. The porosity of the Mishrif Formation was calculated based on the interpretation of neutron, density, and sonic logs. To achieve accurate values of porosity, the log-derived porosity has been correlated with the core-derived porosity, and the comparison showed a good correlation between the two types of porosity. The results showed that the Mishrif Formation is characterized by low to medium porosity (about 5% to 18%). The secondary porosity of the formation is most dominant in the MB21 unit compared with the other stratigraphic units of the Mishrif Formations. This indicates that the MB21 unit was affected by the diagenesis processes. The MB21 unit of the Mishrif Formation represents the most dominant reservoir because it was delineated by high effective porosity and high oil saturation.

Study of the Mineral and Chemical Variation of the Raw Material Mix Used for Production of the Clinker and the Sulfate Resistant Portland Cement of Al-Hadbaa Plant, Hammam Al-Alil, Iraq

Safaa Al-Jubouri; Sahra Al-Maadhidee

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 27-42
DOI: 10.33899/earth.2021.170389

Twenty-four samples (6 samples of raw material mix slurry, 9 samples of cement clinker, 9 samples of sulfate resistant cement) are collected during four months from the production line of Al-Hadbaa Cement Plant, which operates in a wet production method, in Hammam Al-Alil district, south of Mosul city. Some of the studied samples are analyzed for mineral diagnosis by X-ray diffraction device, chemical analysis by X-ray fluorescence device, gravimetric titrimetric chemical methods, and petrographic study for the clinker samples by reflected light microscope and using etching solutions. The research aims to study the variation of the mineral and chemical content in the studied samples.
The mineral and petrographical study show that there is no significant difference in the mineral content between the samples of the same type and that the difference is in the percentage of the presence of minerals. The raw materials mix mainly contains calcite and quartz. As for clinker and cement, it contains a lite phase C3S with a stable growth (pure) type with a monoclinic crystal system and a type of unstable growth (impure and containing inclusions) with a trigonal crystal system. In addition to the belite phase C2S of shapes β, α, and ᾱ, the aluminate phase C3A and C12A7 type and the alkaline type containing Na, the ferrite phase C4AF and C2F and the phase of fine crystalline glass. The chemical study indicates that the content of most of the main components SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Na2O, K2O, TiO2, MnO, P2O5, Cl, and LOI for the raw materials mix, clinker, and cement are close to the samples of the same type of the studied samples. It confirms the proposed specifications by some researchers, except for the deviation in K2O, Fe2O3. It is noticed from comparing the expected clinker content with the actual clinker, as well as calculating some of the qualitative control modules (lime saturation factor, silica, and alumina modulus) to the presence of relative stability in the content of the raw mix and cement produced in the studied cement plant.

Evaluation of Sulphate Resistant Cement and Oil-well Cement Produced in Al-Hadbaa Cement Plant

Safaa Al-Jubouri; Sahra Al-Maadhidee

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 43-59
DOI: 10.33899/earth.2021.170391

Twenty-three samples are collected (9 samples of sulfate-resistant cement, 7 samples for each of the oil-well cement, class B and G) during four months from the production line of Al-Hadbaa cement plant, which operates in the wet production method, in Hammam Al-Alil district south of Mosul city. The research aims to evaluate the chemical and physical properties of sulfate-resistant cement and oil-well cement produced in the studied plant according to the approved standard specifications. Some of the samples are analyzed by X-ray diffraction device, and chemically by X-ray fluorescence and gravimetric titrimetric chemical methods. The results of physical tests are obtained (fineness by Blaine method and sieves, water-cement ratio, setting time (initial and final), soundness by autoclave method, and compressive strength) for cement of three types according to the requirements of the Iraqi Standard Specification (no.5, 1984). As well as the results of physical tests (mixing water percent, fineness, slurry density, thickening time, free fluid content, compressive strength, and dry cement density) for oil-well cement are according to the requirements of the American Petroleum Institute specifications for the samples taken from Al-Hadbaa cement plant, which is carried out within the requirements of quality control overproduction.
The study concludes that the results of chemical analysis, calculating some of the chemical moduli, percent of mineral phases, and results of physical tests for three types of cement are close in their values, ​​and conforming to the limits of chemical and physical requirements of the Iraqi Standard Specification (no.5, 1984). Except that the aluminate phase C3A content, which is more than the required limit. The results of chemical analysis, calculating the percent of mineral phases, and the results of physical tests for the studied oil-well cement are in conformity to the limits of chemical and physical requirements of the American Petroleum Institute Specifications (API 10A, 2010), for the cement type of moderate resistant for sulfate (class B and G). Except for the values ​​​​of alite phase C3S content, and alkalis (sodium) equivalent Na2OEQ for class G, which are not conforming to specifications.

Groundwater Vulnerability Evaluation in the Nineveh Plain, Northern Iraq, using a GIS-based DRASTIC Model

Ali Al-Ozeer علی; Alaa Al-Abadi

Iraqi National Journal of Earth Sciences, 2021, Volume 21, Issue 2, Pages 78-92
DOI: 10.33899/earth.2021.170392

The goal of this study is to determine the vulnerability of groundwater in northern Iraq's Nineveh Plain by utilizing the DRASTIC method and geographic information systems (GIS). In the context of human or environmental systems, vulnerability refers to the potential for harm as a result of stress or disturbance, it may be related to a particular system, hazard, or group of hazards. The vulnerability map includes three vulnerability categories: very low, low, and medium. Following the results of the spatial analysis, it can be concluded that the southern and northeastern portions of the study area have been the most vulnerable to contamination under the medium vulnerability group. According to statistics acquired by removing one DRASTIC element at a time and analyzing the effect on the calculated vulnerability index, the impact of the vadose zone is the most sensitive factor (the mean value is 3.00). The aquifer type, topography, and hydraulic conductivity all have the same mean value of 1.5. The soil factor has a mean value of 0.5, making it the least effective. The research recommends the necessity of using groundwater vulnerability maps in the process of planning future lands and the protection of the Nineveh Plain area from pollution.