Iraqi National Journal of Earth Science

The sequences of the Bajawan Formation (late Oligocene) has been studied in three subsurfaces sections from the Kirkuk oil field. These wells (K-183, K-218, and K-246) are located on the Baba dome of the Kirkuk anticline. The study includes an analysis of 60 cutting-thin sections at different depths of the Formation in the three wells. The successions of the formation in these wells, which has a thickness of about 35, 20 and 60 mrespectively, consist of limestone and dolomitic limestone. Petrographically, the formation consists of skeletal grains, which includes shells and bioclastes of benthic foraminifera represented by the genera Miliolid (Quinquiloculina sp., Triloculina sp.) and the rotalids represented by the genus (Rotalia sp.), as well as red and green algae, echinoderms, bryoza, sponges and It also contains non-skeletal grains such as peloids and rock fragment. The formation sequences have shown the effects of digenesis processes represented by dissolution, dolomitization, cementation, micritization, and neomorphism. Microfacies analysis studies have shown that the sequences of the Bajawan Formation consist of two mains successive microfacies: lime wackstone facies, and lime packstone facies. In turn, these three microfacies are subdivided into thirteen sub-microfacies, indicating that the formation was deposited in the environment of the inner and the middle ramps, which reflect a relative shallowing in the depositional environment of the formation.

Biostratigraphy of the Shiranish Formation is investigated in Zozik anticline located whithin high folded zone. Depending on lithology of the Shiranish Formation in the studied section is divided to three rock units, lower unit consisting of marly limestone, middle units consisting of limestone, marly limestone, and shale and the upper units consisting of limestone and marly limestone. Shiranish formation in the Diana area is bounded from below by the Bekhme Formation with an unconformity relationship, and from above by the clastic Tanjero Formation with a conformity and gradual relationship. The purpose of this paper is to record the planktic foraminiferal and determining the biostratigraphy zones, and correlation them locally and regional to determine the age of formation. In this paper has been determined 50 species of planktic foraminifera are described in 48 samples. The formation divided into four biozones (Radotrucana calcarata Interval biozone,Globotruncanella havanensis Interval Biozone, Globotruncana aegyptiaca Interval Biozone, Gansserina gansseri Total Biozone) Based on this, the age of formation was determined by the Late Campanian to Early Maastrichtian.

A number of logs have been studied, represented by the Gamma Ray Log, the Density Log, the Neutron Log and the Sonic Log for a number of wells in the Jambur and Kirkuk oil fields in northeastern Iraq, namely the Ja-40 well, the K-243 well and the K-411 well for the Aaliji Formation and the Jaddala Formation, through which the total size of the shale was determined based on the Gamma ray log reading by special equations and then the total porosity was determined based on the reading of the density and neutron logs. After being corrected from the influence of gas using approved mathematical equations. The primary porosity was calculated using acoustic sensor reading after being corrected from shale and hydrocarbons effect and then calculating the secondary porosity from subtracting the primary porosity from the total porosity. After that, the study compositions in each well were divided into five reservoir units for both formations from top to bottom (A, B, C, D, E) and determine which is the best porosity and which is the least porous, as it was found that unit A in the upper Jaddala Formation of the best porous units while unit E below Aaliji Formation of the lowest porous units.

The new methodology in the study is concerned with finding the optimal and safest operating level of the reservoir that corresponds to the number of discharges coming out of the Haditha Dam and determining the optimal and safest operational level and in return produces less submerged areas and less contact with the rock exposure of the formations in the study area. A flowchart has been developed for the follow-up methodology and this new and innovative methodology for flood tracking can be applied to all types of reservoirs in the world. The process of follow-up in this study represents a new and modern innovative method that has not been used previously, several hypotheses were adopted as a basis for the follow-up process, and three mathematical models are used for the follow-up process, namely, the equation for determining the amount of demand in the downstream to find out the amount of water that is wasted, and the equation of the level-storage in a modern dam reservoir to know the amount of storage achieved against each level, and the ratio relationship - the size of the storage of the (assumed) Baghdadi Dam, whose results are derived from the geometric analysis, and the calculation of the storage difference for the process of follow-up in several ways and finding the relationship between them and the level difference and finding sources of fluctuation and variation in these readings and suggesting several causes for them.

Twenty-three samples are collected from different springs in Nineveh Governorate to determine the quality and type of the prevailing water during two seasons. The samples are analyzed to determine the dominant cations (Ca2+, Mg2+, Na+, K+) and anions (HCO3-, SO42-, Cl-, NO3-) as well as the physicochemical properties, hydrogen number (pH), electrical conductivity (EC) and total dissolved solids (TDS). The results of the Piper and Stiff classification show that the water quality in all the samples for the two seasons is normal earth alkaline water type with the prevailing sulfates and chlorides by (83%) of the total samples except the samples: (Sw5) is earth alkaline water with increased alkali with prevailing bicarbonate, (Sw17) is normal earth alkaline water with prevailing bicarbonate, (Ss13) is normal earth alkaline water with prevailing bicarbonate and sulfates or chlorides and the sample (Ss4) is earth alkaline water with an increase in alkalinity with prevailing sulfates and chloride, These samples constitute (17%) of the total samples. The results of the analysis show that the dominance of calcium ion over the rest of the cations, followed by Mg2+, Na+, K+, and predominance SO42- over the rest of the anions, followed by HCO3-, Cl-, NO3-. The Water Quality Index (WQI) indicates that all samples are unsuitable for drinking for the two seasons except the samples: (Sw4) is very poor, (Sw5) is poor and (Sw17) is good for drinking. The results of several classifications used for irrigation purposes show that the spring waters of the study area are classified as excellent water for irrigation with Na%<20, SAR<10 and RSC=1.25 except sample (Sw5), which is good for irrigation.

This study deals with a comparative experimental investigation of industrial waste clays as recyclable materials in blended cement production. Even though waste of fired clay bricks (WFCBs), ground or broken bricks, waste of ceramic tiles (WCTs), and waste of vitrified clay pipes (WVCPs) are silicate solid waste, their recycling management has the best environmental, social, and economic aspects. The implementation of these wastes as recyclable materials in wall materials, mortar, and concrete are used as raw materials or cement additives as pozzolanic materials for rapid urbanization and improvement of construction and high pollution rates in developing countries such as Egypt. A large amount of these wastes has been produced by factories for producing clay bricks, ceramic tiles, and vitrified clay pipes, as well as construction operations, building improvement, and the demolition of old buildings. The mortar's microscopic structures are observed by scanning an electronic microscope (SEM), while hydrous minerals are studied using X-ray diffraction (XRD) as well as differential thermal analysis (DTA). These wastes, as artificial pozzolanic materials, raise the setting time of cement products. The average strength of compressive and flexural accelerates at an early age slower than later age. The study aims to reduce construction solid waste and conserve raw material resources. These wastes are widespread in the Egyptian provinces, and there is very little available information on their chemical composition and mineral components.

Vertical stress evaluation is pivotal in the domains of well construction and sand production assessment. This research focuses on estimating vertical stress within the Nahr Umr, Shuaiba, and Zubair layers at depths of 2737.5, 2990.83, and 3083m, respectively, within the Rumaila oil field. Various methodologies, including extrapolation, Miller, Amoco, Wendt non-acoustic, Traugott, and averaging density methods using Techlog 2021, are employed to predict vertical stress.Significantly, the extrapolation method excels in shallow depth calculations, while the Miller method accurately represents actual density values at greater depths, particularly within the Nahr Umr, Shuaiba, and Zubair layers. Remarkably close alignment is observed between the vertical stress values obtained from the Miller and extrapolation methods. For example, at the specified depths, the Miller method yields stress values of 8980, 9373, and 9981 psi, closely resembling the extrapolation method's results of 8987, 9373, and 9987 psi. Alternative techniques, including the Amoco, Wendt non-acoustic, Traugott, and average density methods, yield comparable outcomes. These approaches rely solely on density records as inputs and provide consistent apparent density values from the surface to the intended depth.Incorporating these findings into geomechanical modeling enhances comprehension of rock behavior under varying loads, offering valuable insights for optimized well construction and sand production management strategies. This research underscores the critical importance of understanding vertical stress as a cornerstone in achieving these objectives.

The Sinjar Formation in the Duhok area, Kurdistan region, Iraq, is characterized by lateral and vertical mixed carbonates and siliciclastic facies. Therefore, the main target of this work is to identify the diagnostic lithofacies and microfacies of the carbonate successions of the Sinjar Formation. The carbonate-predominant Sinjar Formation was deposited as patchy reefs that show interfingering, along with the siliciclastic-dominated turbidites facies of the Kolosh Formation (Lower to Upper Paleocene). The depositional environments of the Sinjar Formation have been recorded as inner to middle shelf deposition settings based on the micro and macrofossil associations and facies indications. The inner shelf successions included three microfacies, dolomitized mudstone and wackestone, which show alternations with proximal Turbidites facies (sandy conglomerates). In comparison, the middle shelf represents five microfacies: framestone, coral-algal wackestone, microbial bioclastic wackestone, packstone, and grainstone microfacies, and shows alterations with the middle to distal turbidite facies. The recorded shallow larger benthic foraminiferal biozones are: 1) Orbitolites complanata –Saudia labrynthica – Opetorbitolites Assemblage Zone; 2) Idalina sinjraica- Alveolina globosa- Rotalia trochidiformis Assemblage’s zone. They are indicating Ypresian age. The mixed carbonates and siliciclastic parasequences evolutions have been used to identify the stacking patterns response to the eustatic sea level changes. The studied successions represent one complete third-order depositional system, started with sequence boundary type two at its base and capped by sequence boundary type one, manifested as an incised valley between the patchy reef-marine Sinjar deposits and the non-marine molasses of the Gercus Formation.

In many countries, some buildings are constructed on compacted soil brought from another site. Therefore, the soil examination of the physical and engineering properties one of the important procedures in civil engineering to determine the characteristics and amount of buildings volume that this soil can bear. There are several methods to test the physical and engineering properties of the compacted soil as well as to identify its suitability for construction; some of them are laboratory methods, while others are field methods by conducting various geophysical surveys, which is considered one of the most important field methods as it provides wide coverage of the test site. The current study aimed to show the variation in the effect of the soil compaction process on the distribution of its resistivity, determine the subsurface distribution of soil components, and attempt to determine the effect of the compaction process on the same soil type. A 2D resistivity imaging was conducted an area of land inside the University of Mosul estimated to be about 11,000 m2, which was filled with soil transferred from another site and then compacted.The study included a 2D resistivity imaging of 10 profiles with a length of 40 m. for each profile and a distance of 30 m. between one profile and another.The results of the study showed that there is the difference in the soil resistivity distribution after the compaction as a result of the variation in size gradient and the variation in compaction degree on the burial soil.

Industrial district as well as human and natural activity are the main sources of pollution in Al-Qayarah City area. These sources release pollutants into nearby areas. Twenty-six soil samples were collected at a depth range of (0-30) centimeters. The heavy metals (As, Cd, Co, Cr, Ni, Pb) are analyzed using ICP-MS technique; in addition to measuring some physicochemical properties of the soil such as pH, EC, OM. Contamination factor, enrichment factor, pollution loading index, and long-term carcinogenic risk estimation are calculated based on exposure through ingestion, dermal contact, and inhalation. The average values of pH, EC, and OM% are 7.7, 3.37 dS/m, and 2.35% respectively. The average concentrations of As, Cd, Co, Cr, Ni, and Pb are (6.40, 0.205, 18.68, 101.46, 159.06, and 9.93) ppm respectively.The significance of the contamination and enrichment factors, as well as the pollution loading index, for heavy elements range from low to medium values. The pollution loading index for the contaminated samples follows the following order:
AB6>QR1>AB5>AB4>QF8>AB3>AB2>GS4>QF7>QR2>QF9. Whereas, the enrichment and pollution factors for heavy elements follow the following order: As>Ni>Cd>Cr>Pb>Co. The values of the total carcinogenicity factor through ingestion, dermal contact, and inhalation are (1.2x10-4), (6.91x10-4), and (7.85x10-3) respectively. All exposure pathways to studied pollutants are in the following order: Carcinogenic inhalation hazard > Carcinogenic skin hazard > Carcinogenic oral hazard. Site AB6 is considered the most polluted due to the impact of most influential factors and a high probability of cancer risk.

Dur Al-Najaf is considered one of the most distinguished semi-precious stones in Iraq, especially in the province of Najaf. A field survey is conducted in the areas within the Bahr Al-Najaf region and among the recent sediments and the Dibdibba Formation. The study aims to analyze the mineral and chemical makeup of this semi-precious stone, to categorize its type, to provide an overview of its typical attributes, and to ascertain the origin and geographical distribution of these semi-precious stones. The samples underwent examination from a sedimentological, mineralogical, and geochemical perspectives. Four distinct samples of stones, each representing a different color variant, underwent examination to explore their petrology through polarized light microscopy and mineralogy via XRD analysis. Additionally, three more stones were subjected to SEM analysis. The results reveal three types of these stones which are pure type, oily type (gray), and Al-Husseini type (reddish brown). Results of XRD, XRF, and EDX analysis show that these stones are various forms of pure sedimentary quartz mineral. Some of these stones contain impurities that give them varying colors, such as gray, which may have resulted from a high concentration of CaO, or red to reddish color, resulting from high FeO concentrations. These stones represent pieces of quartz minerals included in the components of the Dibdibba Formation, which resulted from the erosion and crushing of igneous rocks from the Arabian Shield that spread to wide extents in the Najaf Plateau.

The lithology of the Dammam Formation is limestone, dolomitic limestone, and dolomite rocks, which are also used as raw materials in the manufacture of cement. It is characterized by shallow marine environment. The Eocene succession is described and illustrated in two complete sections in the Samawah and Nasiriyah regions. Determining the age of the formation accurately is in the form of multiple biozones. Biostrtigraphically, the Dammam Formation is divided into six main biozones including: 1. Nummulites deserti- Nummulites fraasi range zone: Early Eocene (E. Ypresian age), 2. Nummulites lucasanus range zone: Early Eocene (L. Ypresian age), 3. Nummulites globulus- Nummulites Zettie: Middle Eocene (E. Lutetian age), 4.Nummulites gizehensis- Nummu-lites discorbinus- Nummulites planulatus Assemblage Zone: Middle Eocene (L. Lutetian) age; this zone is divided into three subbiozones: a) Lockhartia alveolata Interval subzone: Middle Eocene (early Late Lutetian age); b) Nummulites milacaput range subzone: Middle Eocene (middle Late Lutetian age); c) Nummulites elevate range subzone: Middle Eocene (late Late Lutetian) age, 5. Nummulites striatus range Zone Middle Eocene (Bartonian), and finally 6. Nummulites incressatus range Zone: L. Eocene age (Priabonian). The study emphasizes the different sedimentation times of the Dammam Formation during the Eocene epoch across various sections in Iraq. It identifies in details the biozones in E. Eocene (Ypresian) and M. Eocene (Lutetian) ages, along with the lack of precise age determination for the Bartonian and Priabonian ages. The study suggests that the Bartonian age may start with the appearance of N. striatus and transition to the Priabonian age with the presence of N. incressatus.

Received: 27- Aug -2023
Revised: 02- Oct -2023
Accepted: 30- Oct -2023
Available online: 01- Jul– 2024 The Paleocene-Eocene (P-E) Sinjar Formation from Kalka Smaq section, Dokan area, Sulaimaniya, northeastern Iraq has been studied in terms of mineralogy and geochemistry using X-Ray Diffraction (XRD) supported by Scanning Electron Microscopy (SEM) and elemental X-Ray Fluorescence (XRF) geochemical analyses in addition to stable isotopic C and O analysis. The study revealed indications for mineralogical and elemental variation across the P-E transition which may refer to the regionally recognized depositional and paleoclimate changes of the Paleocene Eocene Thermal Maximum (PETM) in the region. The dominance of shallow marine water deposition is interrupted by fresh-water deposition accompanied by increase in temperature suggesting the warming conditions in the Eocene. This result is supported by mineralogical variation in calcite, Mg-calcite and dolomite accompanied with anomalies in δ18O and δ13C data and variation in CaO, MgO, SiO2, TiO2, Fe2O3, and Al2O3 in addition to Co, Ni, Sr and Ba elemental data, which in general may suggest the increase in precipitation and low effect of weathering across the P-E transition boundary in the region.

Groundwater has been considered one of the most important sources of water for agricultural, household, and industrial operations in the Kirkuk City. The current study intends to investigate groundwater storage and estimating the hydraulic characteristics of the primary aquifers within the study area. Pumping tests are carried out in (5) water wells using the main observation wells dug in the Bai-Hassan Formation and Quaternary deposits. The aquifer types are confined to semi-confined and unconfined based on the diagrams of the drilling wells and the results of the hydraulic characteristics. The saturation thickness of the studied aquifers ranges from 22 to 66 m. The hydraulic conductivity values vary from (19.29 to 70.79 m/d), while the highest transitivity value is 1758.58 m2/day. The storage coefficient values range between (0.0002059 - 0.074). The flow net map is generated by monitoring groundwater depths from 22 wells drilled within the region of interest. The water table depths range from (1.5 m) to (31 m) below the ground surface. According to the groundwater flow map, groundwater in the region flows mostly from the north and northeast to the southwest and moves parallel to the Kassa River.

Received: 16- Aug -2023
Revised: 21- Oct -2023
Accepted: 12- Nov -2023
Available online: 01- Jul– 2024
Groundwater quality and quantity are important factors for controlling the management of water. The significance of the hadrochemical analysis underlies the fact that the chemistry of the ground water can conventional be rated with the source of water, climate, and geology of the region. The study includes the hadrochemical characterization of groundwater in Eastern and Western catchments in Erbil city, Kurdistan Region, to achieve their chemistry, quality, suitability for drinking, irrigation, and industry purposes. Water well samples were collected from different wells during two periods, the first period is considered a minimum recharge period (dry) in November 2021 and the second period is considered a maximum recharge period (wet) in May 2022; 36 samples (18 from the eastern part, 18 from the western part) for each period. The physicochemical parameters, namely (ph), electrical conductivity (EC), total dissolved solids (TDS), Temperature, Salinity, major cations and anions) were analyzed to evaluate the present groundwater quality as well as the possible source of ions in the groundwater. The chemical composition of water is based primarily on the minerals which have dissolved in it and modified by ion-exchange equilibrium. Aquifer sediments and abundant soils are considered to be the major sources of cations and anions, whereas the fertilizers, municipal wastewater and irrigation-return flows are additional contributors of Mg2+, Na+, K+, Cl-, SO42- ions. The concentration of major ions decreases slightly in the wet season due to excess rainfall which normally dilutes dissolved elements. Generally, the concentration of physiochemical parameters, cations, and anions in the eastern part is lower than in the western part because the eastern part is considered a recharge zone of the Erbil basin it depends on the soil formation and depth of wells. The results reveal that the dominant types of groundwater in the eastern and western parts based on piper and schoellar diagrams are calcium bicarbonate water in both seasons. Gibb’s ratio indicates that the groundwater in both parts is affected by the weathering of rock-forming minerals for the groundwater samples.

Evaluating the land cover changes is a critical issue for the process of environmental sustainability strategies. This study evaluates the land cover changes in Karbala Governorate during the last two decades (2001-2021) using Landsat Images based on the supervised maximum likelihood classification (MLC) method. Land cover is classified into four categories using supervised classification and two satellite imageries; Landsat 7 for the date 2001, and Landsat 8 for the date 2021. The results show a noticeable increase in the urban category associated with a decrease in the water cover. Additionally, a significant expansion occurred in the urban category at the expense of agricultural lands and the groves category. This expansion has resulted in the unplanned growth of settlements and the difficulties that go with it. The escalating urbanization in this particular region is associated with several prominent adverse outcomes.

In the last decade, the repercussions of global warming in Iraq have become more severe. Scientists recommended storing carbon dioxide as it is the most greenhouse gas resulting from fossil fuel burning. As a result of the repercussions of injection operations, problems emerged related to the failure of the reservoir’s seal. This study creates a model and applies a simulation of the process of injecting carbon dioxide gas into the reservoir for a specific period. The computer modeling Software (CMG) is applied to study the distortions occurring as a result of increasing hydrostatic pressure of the pore fluids on the seal. The study results reveal that the secondary porosity is due to the fracture of the rock structure after two years of the CO2 injection process at a rate of 200 thousand cubic meters per day into the selected reservoir. The Barton Bandel model is used to diagnose permeability variation, as it is proven that the geometric deformation in the rock structure of the seal is proportional to the permeability resulting from the failure of the seal.

In this study upward continuation technique is considered as a clean filter because it produces no side effect like other filter used in processing to acquire residual gravity data in the western and eastern regions of the central part of Iraq. The residual anomalies maps achieved to 2km, 12km, 16km, and 22km upward elevation levels The approximate equivalent depth of detection for the four upward continuation elevation levels generally ranges (0.6-1) in relation to the upward continuation elevation. The Total Horizontal Derivative (THD) technique is applied to the residual anomaly maps to identify the lineaments (faults or source boundaries) of the two studied parts. The THD measures the lateral rate of change of the measured gravity field. It is useful to detect the edges and delineate the boundaries (Faults), where the peak values occur over the edge of block. The most lineament trends in western part area is NW-SE trend, and the less trend is NE-SW. The N55W, N45W, and N35W trends percentage is 51% of all lineaments in the western part. The percentage of the three mentioned trends for the four considered levels range is 48-60%, where the percentage value increase with the deeper lineaments, this may indicate the faults in the sedimentary cover affected by the basement rocks. The group of lineaments N35E, N45E, and N25E trends percentage in western part faults about 24%. Applying the idea of conjugate faults for the western part indicates that According to the idea of conjugate faults to the inferred trends in the western part of the study area, it is concluded that the main stress direction is N-S. This stress direction may be related to the collision of the Arabian plate with the northern plates in certain geological history. The predominant lineaments trends in the eastern bank of the Euphrates River are N45W, N35W and the N55W, respectively. These three trends represent 72% percentage of lineaments in this part for all upward elevation levels. The general trends of lineaments in eastern part are NW-SE. The NW-SE lineament trends are noticed in the both parts of the study region correspond to the Najd fault system, while N-S fault trends are associated with the Nabitah system.

The present study focuses on mineralogy of the middle to upper Jurassic Sargelu, Naokelekan and Barsarin formations form northeastern Iraq to elucidate the implications of mineralogical variation for interpretation of provenance and climatic condition. The results from X-ray diffraction supported by scanning electron microscopy have revealed the presence of calcite and dolomite as dominating minerals, followed by quartz and feldspars in addition to pyrite, anatase and natrolite. The dominated clay minerals are illite-mica, kaolinite and mixed layers of illite/smectite (I/S). Illite and kaolinite are of detrital origin, while I/S is of diagenetic origin. Variation in mineralogical constituents reflects the effect of source area composition, depositional environment and diagenesis and the prevailing climatic conditions. Calcite is commonly formed in restricted evaporative conditions. Felsic igneous rocks from Zagros ophiolites and related igneous rocks, and/or Arabian Shield are suggested for the presence of detrital quartz and feldspars in addition to weathering from older clastic sedimentary rocks. Illite-mica and kaolinite as common clay minerals reflect also the contribution from felsic igneous rocks and the prevailing hot dry and humid climatic conditions which coincides with a global paleoclimatic conditions. Pyrite is formed under reducing environmental conditions. The presence of illite/smectite, natrolite and pyrite suggest the effect of diagenetic events on the studied rocks.

The present study is intended to evaluate one of the oil-bearing horizons in the (WN) oil field within the High Folded zone in the Kurdistan Region of Iraq, which represents a carbonate reservoir of the Tertiary units. Also, the picking and mapping of two other horizons of interest from the top and bottom of the reservoir horizon are done across the area. This work is achieved using 3D seismic data, check shots, and well logs. The methodology involves several processes including data loading, well seismic tying, horizon and fault identification and interpretation, velocity modelling, time-depth conversions, petrophysical analysis, and 3D properties modelling. Isochron and depth maps for three horizons and two isopach maps are constructed. An asymmetrical doubly plunging rollover anticlinal closure with a length of 6.4 km and width of 3.5 km is identified on the reservoir maps that trend in the East-West direction. Faults are identified and extracted manually and automatically. A total eighteen of minor reversal faults striking the northern flank of the anticlinal closure are interpreted. Variance, Chaos, and Ant Tracking attributes are selected and applied successfully that help to better visualize fractures and automatic fault extraction. Petrophysical analysis and cross-plots demonstrates that the reservoir consists of dolomite, lime dolomite, and anhydrite limey dolomite. The petrophysical properties reveal the average of each effective porosity, secondary porosity, permeability, clay volume, and water saturation of the reservoir at 9.98%., 4.39%., 14.1 milli Darcy, 9.13%, and 47.8% respectively. The study shows that the reservoir has moderate hydrocarbon prospects.