Iraqi Bulletin of Geology and Mining

A mineralogical and geochemical study has been done on (20) Hussainiyat Formation (Early Jurassic) samples in western Iraq. Mineralogical analysis of clays by X-ray diffraction (XRD) shows that the predominant clay mineral is kaolinite and traces of montmorillonite-illite mixed layer with palygorskite. The non-clay minerals are mostly quartz, goethite, hematite, and anatase. Heavy minerals were separated from (sandstone) clastic samples and studied by both polarized and reflected microscopes. These heavy minerals are detected in fewer than 1% quantities and consist of silicates and oxides. The most common of these mineral grains are stable heavy minerals ZTR (zircon, tourmaline, rutile) and apatite, staurolite, and garnet, which indicate that the acidic granite rocks with almost metamorphic rocks were a source of kaolinite. In a geochemical study by XRF, claystone samples were analyzed for SiO2, Al2O3, TiO2, Fe2O3, MgO, CaO, Na2O, K2O, MnO, P2O5, and L.O.I. kaolinite (claystone) of the Hussainiyat Formation contains a high concentration of iron, which is interbedded with kaolinite as hematite, goethite, and limonite. Kaolinite occurs as kaolinitic pellets and as nuclei of the majority of ironstone ooids and pisoids, together with the alternating concentric laminae of their cortices. Manganese is associated with the kaolinite of the Hussainiyat due to its high iron content.
The present study showed that the kaolinite deposits within the Hussainiyat Formation are less mature than other clays (montmorillonite-illite mixed layer and palygorskite), because the Hussainiyat Formation suffered from less intense chemical weathering, leading to the dissolution of only alkalis and earth alkali metals but not iron. However, the alumina is still stable with li, due to their high resistance, the alumina is still stable with little silica to form kaoliniteintensive chemical weathering, and kaolinite builds by Si and Al. This is because these two oxides are, typically, stable within different physical and chemical weathering. After kaolinite, the rest only gibbsite and boehmite bauxite mineral at the end of the intensive chemical weathering.

Clay sediments were evaluated in playa lake called (Fedhat) in the south of Al-Samawa city within Al-Muthanna Governorate as a raw material for the bricks industry. These sediments are distributed in the specific area belonging to the Al-Salman district. Six samples were carefully selected from these sediments. These deposits are considered as a layer of fine-grained dark brown silt, interspersed with sandy lenses of various sizes. The chemical analysis showed that the major oxides are within the acceptable limits of the brick industry. The X-ray diffraction results of the samples showed two types of minerals; the clay minerals included (montmorillonite, palygorskite, kaolinite, chlorite, and illite), while the non-clay minerals are quartz, calcite, dolomite, and feldspar and gypsum.
The clay samples were ground to obtain fine sizes for each sample. Then, the sample was divided, squared, and sieved by a dry sieve device. The materials were mixed well by the continuous stirring of the sample and an amount of 600 grams was taken from each of the studied samples, and fermentation by adding an appropriate amount of water estimated at 18% to the sample for 72 hours for the bricks formed by extrusion method. As for the bricks manufactured by the semi-dry pressing method, water is an addition at a rate of 8% to the sample, which is equivalent to 48 milliliters, and then the samples were kept in sealed plastic bags for fermentation for 24 hours. Sixty samples were formed by extrusion method with a laboratory size (2.5 x 3.85 x 7.5) cm, and 60 samples by semi-dry pressing method with dimensions 5.12 cm2 in diameter and height, the samples were squeezed under a pressure of 250 kg/cm2. The drying process of the samples was carried out in two stages at room temperature for 48 hours, and in a binder oven, at a temperature of 100 °C (±5)° for 24 hours. These samples were burned according to a specific firing program at different temperatures (750, 950, and 1100 °C). When the prepared brick samples were fired under temperatures of 1100 °C, the fired samples have good results in terms of compressive strength, water absorption, gradual increase in bulk density, and the absence of cracks, in general, the external appearance of the bricks remained unbroken. It is important that a very large reduction of calcite was observed when temperatures rose to 1100 °C, as the mineral calcite does not decrease with increasing temperatures, calcite can react with other compounds and form new phases accompanied by glass phases resulting from the presence of molten materials. The reactions that occur during burning at a temperature of (1100 °C) lead to the formation of the mineral mullite in a crystalline form.

The current work is carried out to classify the carbonate rock masses around the Al-Salman Depression, using the Rock Mass Index (RMi) system. The RMi system uses the uniaxial compressive strength (UCS) of the intact rock and the jointing parameters, which is a combined measure of the block size (or intensity of jointing) and joint characteristics. This method measures the reduction of intact rock strength caused by discontinuities and can be applied in various types of rock engineering works and design, using field observation and measurements, and from empirical relationships. The RMi system was applied to the carbonate rock masses of the Middle Unit of the Dammam Formation (Middle Eocene age), which forms the rock slopes around Al-Salman Depression, Southwest Iraq. The current work. The results of this work denoted that all the rock masses of the studied sites are rated as; “Very High RMi” for sites; 3 and 5, and “High RMi” for the other studied sites. These are due to the “Very Strong” and “Strong” strength, “Massive” and “Blocky” rock masses.

The research aims to prepare cordierite by using sources of alumina, silica, and magnesia from local and available raw materials (kaolin and dunite rocks). Cordierite ceramic was prepared by different mixtures of raw materials, different preparation methods (molding and hydraulic pressing) were used to form the starting materials, also magnetic separation was used to purify dunite from iron. Sintering the prepared samples at different temperatures (1200, 1250, 1300, and 1350 °C) for 2 hours. The prepared sintered samples were characterized by chemical analysis, X-ray diffraction, porosity, and bulk density. The proportions of oxides affect the preparation of cordierite also sintering temperature is a very important factor. For samples prepared by molding at temperatures (1200 – 1250) °C, different minerals appeared with cordierite (mullite, cristobalite, and corundum) by increasing the sintering temperature to 1300 – 1350 °C the cordierite peaks increased. Samples prepared by using dunite 30 wt.% and 40 wt.% cordierite was the only mineral that appeared. The preferred dunite rocks content was 30 wt.% because increasing the percentage of dunite in the mixture at 1350 °C leads to deforming of the sample. The chemical analysis of the sample prepared by 30 wt.% dunite and 70 wt.% kaolin is close to the chemical composition of cordierite. Different mixtures were pressed and sintered at temperatures 1250 °C and 1300 °C. The only mineral that appeared at 1250 °C was cordierite but with lower intensity compared to the sample sintered at 1300 °C. At 1300 °C, cordierite peaks are accompanied by small peaks of clinoenstitate. Samples prepared with 20 wt.% and 30 wt.% dunite sintered at 1300 °C had high peaks intensities of cordierite, the sample prepared with 20% dunite is closer to the chemical composition of cordierite. Magnetic separation was used to reduce iron in dunite to 1.21%, and different quantities of dunite were used (20 wt.%, 30 wt.%, and 40 wt.%) sintered at 1350 °C. In mixtures containing 30 and 40% dunite, cordierite was the only mineral. By using magnesium oxide instead of dunite rock in the mixture and sintered at different temperatures of 1200 – 1350 °C, cordierite appeared with mullite and cristobalite in all samples.

The climate variability severely affects the factors influencing groundwater recharge. The unreliable seasonal and poor quantities of the surface water resources tend to increase the decline in the groundwater levels. Therefore, it is necessary to delineate the groundwater potential availability (GWP), which can be used to augment the groundwater source.
The analytical hierarchy process (AHP) technique, as a popular method, is applied to determine the importance of groundwater influencing factors. To integrate the groundwater influencing spatial dataset, all the geospatial datasets was carried out in the Geographic Information system (GIS) environment.
The Al-Ajeej drainage basin was chosen in this research to delineate the groundwater potential zones, where the groundwater serves as the main source for domestic and agricultural uses more than the seasonal surface water. Seven thematic layers of the influencing factors, such as rainfall, lithology, geomorphology, elevation, lineament density, slope, and drainage density, have been selected to assess groundwater potential zones (GWPZ) for the Al-Ajeej drainage basin.
Three GWPZ have been concluded, comprising “Good”, “Moderate” and “Poor”. The Good GWPZ is developed in the northern and southeastern parts; the Moderate GWPZ is distributed in the north and southwestern parts, while the Poor GWPZ is significant on the southern slopes of Sinjar Mountain and a small area in the most western part.

Marches have a significant impact on the ecosystem of Iraq and provide habitat for several types of organisms. The study area, Al-Hammar Marsh, is situated entirely south of the Euphrates, extending from near Al-Nasiriyah city in the west to the outskirts of Al-Basrah city along the Shatt Al-Arab in the east, while the Central Marshes formed between the Tigris and Euphrates rivers. The goal of the study is to detect changes in Al-Hammar and Central marshes by using Modified Normalized Difference Water Index (MNDWI) via Google Earth Engine (GEE) cloud; considering GEE adds great value to users of remote sensing data, especially, no experts who may not be aware of the intricacies involved with data organization and large-scale computing. Sensors Landsat 5, 7, and 8 were used and 10802 scenes were analyzed and filtered to get MNDWI by special code under the GEE environment. Flood data were used to validate the results, which represent flood years and scarce years. Among flood years are 1946, 1954, 1963, 1968, 1969, 1988, 1993, 1995 and 2019. Whereas the years of scarcity were 1934, 1935, 1961, 1999, 2000, 2001, 2008, and 2009, while the year 2018 was the scariest year for Iraq.
Many factors affect the study area’s inundation, such as related to the amount of rain and snow that falls in the main river basins (Tigris and its tributaries), the operation policy of the dams and reservoirs, which are built at the top of the shared rivers in Turkey, Syria, Iraq, and Iran. In addition to the position of Iraq as a downstream country, the geological setting of marshes because they are depression areas as well as the long path for the Euphrates and Tigris rivers, and the existence of tens of regulators and agricultural lands. By applying the Pearson equation between hydrological years data and inundation years in the study area, the value for Tigris was R2 = 0.5, which is an acceptable relationship, whereas for the Euphrates was R2 = 0.4, which is a poor relationship.