IRAQI BULLETIN OF GEOLOGY AND MINING
مجلة الجيولوجيا والتعدين العراقية
ISSN 1811 - 4539
اهداف ومجال النشر تعليمات النشر للمؤلفات البحوث المنشورة هيئة التحرير
MICROFOSSIL ASSEMBLAGES AND DIAGENESIS OF BALAMBO FORMATION FROM AZMER MOUNTAIN IN NORTHEAST SULAIMANIYAH, KURDISTAN REGION, IRAQ
Hyam S. Daoud, Ramona Balc and Ghafor H. Sur
Received: 15/ 6/ 2009, Accepted: 1/ 4/ 2010
Key words: Calcareous nannofossils, Diagenesis, Balambo Formation, Upper Barremian, Azmer Mountain, Kurdistan Region, Iraq.
(p. 1 – 16)
ABSTRACT
A detailed Lower Cretaceous section of Balambo Formation, which is exposed in the Azmer Mountain, northeast of Sulaimaniyah city (Kurdistan, Iraq) has been investigated. Eighty four limestone samples have been studied for microfacies analyses and 52 clay and marl samples were investigated for calcareous nannofossils determinations.
Most of the rocks consist of two main types of facies: Wackestone and packstone with radiolaria. The main diagenetic processes are represented by dissolution, calcitization, dolomitization, stylolitization, silicification and cementation.
The calcareous nannofossils from Balambo Formation were studied for the first time from the study area. Based on the identified calcareous nannofossil assemblages, the studied rocks were assigned to the Upper Barremian. The calcareous nannofossil assemblages are dominated by Micrantolithus, Nannoconus and Rhagodiscus spp.
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CHANGE DETECTIONS IN MARSH AREAS, SOUTH IRAQ, USING REMOTE SENSING AND GIS APPLICATIONS
Mawahib F. Abdul Jabbar, Ahmed F. Al-Ma'amar and Ahmed T. Shehab
Received: 27/ 9/ 2009, Accepted: 1/ 4/ 2010
Key words: Marshes, Change detections, Land cover classification, Soil salinity
(p. 17 – 39)
ABSTRACT
The marshes of the southern part of Iraq are considered the most outstanding feature in the area. They are developed within the Mesopotamian Plain forming natural balance between the Tigris and Euphrates Rivers and Shat Al-Arab that leads to the Arabian Gulf.
The marshes that are locally called "Ahwar" have suffered from drying processes, since early eighties of the last century. During the late nineties, large parts were dried leaving barren salty (Sabkha) lands devoid of all types of life, especially those related to the large water bodies, beside human activities. Moreover, hydrological and climatic changes that clearly could be observed in the areas involved.
To detect the considerable changes, in land use and land cover, remote sensing techniques and GIS applications were used; among these are Landsat images in three different intervals: MSS in 1973, TM in 1990 and ETM in 2000. These were used in the changes detection method. Moreover, different digital image processing techniques that are available in ERDAS program were applied. Normalized Difference Vegetation Index (NDVI) was also used to recognize the vegetation cover. The classified images were converted to vector shape in GIS media in each class; the area of each class is determined as percentage from the total coverage area of the marshes.
The current study revealed that large changes took place between 1973 and 2000 in land cover and land use. The barren land is increased; while the water bodies are decreased drastically, consequently desertification is increased causing large environmental and hydrological changes that affected on the physical and chemical properties of the soil. The soil became unfertile and not suitable for agricultural purposes. The marsh areas were also abandoned by the local people due to the mentioned changes.
Since 2004, great efforts are carried on in the marsh areas to rehabilitate and reactivate the marshes. Therefore, considerable parts of the marshes have grown again; local people started to reconstruct their communities. Some types of birds, fishes and vegetation reappeared again. The coverage area of the marshes is about 50% of the original marsh areas, hitherto.
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TECTONIC AND STRUCTURAL EVOLUTION OF THE MESOPOTAMIA FOREDEEP, IRAQ
Saffa F. A. Fouad
Received: 28/ 6/ 2010, Accepted: 30/ 09/ 2010
Key words: Mesopotamia Foredeep, Tectonics, Basinal analysis and Structures
(p. 41 – 53)
ABSTRACT
The geological setting of the Mesopotamia Foredeep within the tectonic framework of Iraq, has been reviewed and redefined according to the modern concepts of foreland basins, and new structural boundaries are introduced. The Mesopotamia Foredeep, which is the present day expression of the terrestrial part of the Zagros Foreland Basin, is an integral part of the Zagros Fold – Thrust Belt that lies between the deformational front of the Zagros orogenic belt and the stable interior of the Arabian Platform.
The Mesopotamia Foredeep is an elongated epicontinental basin formed above an earlier plat formal and marginal basin. Accordingly, the Phanerozoic stratigraphic sequence of the basin can be broadly categorized into three major tectono-stratigraphic assemblages; Cambrian – Early Permian intraplate assemblage, Late Permian – Middle Cretaceous Neo-Tethys passive margin assemblage, and Late Cretaceous – present foreland basin assemblage.
The Mesopotamia Foredeep is a mobile tectonic zone and contains several buried structures including folds, fault and diapiric structures. Recent activity of some of these structures is recorded through their effects on the Quaternary stratigraphy and present geomorphological landforms.
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NEOTECTONIC MOVEMENTS IN DARBANDI BAZIAN AREA, SOUTHWEST OF SULAIMANIYAH CITY, NE IRAQ
Varoujan K. Sissakian
Received: 07/ 09/ 2009, Accepted: 28/ 12/ 2009
Key words: Neotectonics, Alluvia fans, Pila Spi Formation, NE Iraq
(p. 57 – 69)
ABSTRACT
The northeastern part of Iraq is known to be tectonically an active area due to its position in the northeastern marginal part of the Arabian Plate, which is in collision with the Eurasian (Iranian) Plate. Therefore, the whole area referred to the High Folded Zone is consequently active. The activity, however, is not uniform; locally more active areas do exist causing Neotectonic movements.
Darbandi Bazian Gorge that is located southwest of Sulaimaniyah city, NE Iraq suffers from Neotectonic movement, being more active from near surroundings. The gorge is located within the Pila Spi Formation that consists of well bedded, hard limestone and dolostone with very rare marl intercalations; its thickness is about 120 m. The Pila Spi Formation forms a continuous ridge, few hundred kilometers in length that represents the boundary between the High Folded and Low Folded Zones, the former being in the north.
The area had suffered from Neotectonic movement, which is indicated by the existence of large alluvial fans, southwards of Darbandi Bazian Gorge, the fans are formed by a single perennial stream that was previously flowing out of the gorge towards south. The older alluvial fan is now inactive, because the stream is divided into two parts; the divide point being on the top of the Pila Spi Formation that forms a high ridge, about 200 m and dips southwestwards. Part of the stream; called Chamai Bawa Fany flows southwards across the alluvial fan, whereas the other part; Tainal Stream flows northeastwards then turns southeastwards; parallel to the ridge of the Pila Spi Formation and continues its direction for about 20 Km, then turns southwestwards and crosses the same ridge in another gorge; called Basara, which is parallel to Darbandi Bazian Gorge.
The abandoned alluvial fan, the presence of old fan near Cham Chamal town, the division of the stream into two opposite parts, the abnormal trend and course of Tainal Stream, and the abnormal shape of the Darbandi Bazian Gorge are good indications for uplifting Neotectonic movement in Darbandi Bazian area, which is estimated to be during the late Holocene.
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PETROLOGY, GEOCHEMISTRY AND DEPOSITIONAL ENVIRONMENT OF THE KHABOUR FORMATION IN ORA AND KHABOUR LOCALITIES, NORTHERN IRAQ
Khaldoun S. Al-Bassam
Received: 24/ 11/ 2009, Accepted: 2/ 6/ 2010
Key words: Khabour Formation, Depositional environment, Iraq
(p. 71 – 94)
ABSTRACT
The Khabour Formation, the oldest exposed rock unit in Iraq (Ordovician), was sampled in two exposed sections at Ora and Khabour localities. It is comprised of about 800 m thick sandstone-shale cyclic alternations. Petrographic study showed that quartz arenite and phyllarenite are the main textural varieties of the sandstone with mica and silt-size quartz dominating the shale. The sandstones are texturally mature and mineralogically mature to submature. The mineralogy includes: quartz (dominant), muscovite, illite, glauconite, chlorite/serpentine (mixed layer), francolite (conodont) and heavy minerals (opaques and ZTR). Silica cementation is the main diagenetic process, resulted from pressure solution of silica and lead to an interlocking quartz mosaic texture. Alteration is of minor intensity.
The chemical composition is characterized by high SiO2/Al2O3 and K2O/Na2O ratios. The geochemical associations are controlled by the mineralogy and three groups were recognized by factor analysis, namely the sheet alumino-silicates, phosphate and heavy minerals (ZTR). All of which are diluents to the major mineral constituent: quartz.
Mineralogical analysis of the studied samples suggests recycled granitic plutonic rocks and more proximal low-grade metamorphic rocks as source of the clastics. The whole sequence of the Khabour Formation seems to have deposited in marine environment extending from shallow intertidal to deep outer shelf, under variable conditions of sea-level fluctuation, subsidence rate, and detritus supply. The whole sequence may have resulted from deposition from turbidity currents; the proximal part is rich in coarse clastics and the distal part is rich in micaceous shale. Complete Bouma sequence was not recognized, but the sedimentary facies of the Khabour Formation may be considered as an example of a passive plate margin turbidities.
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LITHOFACIES ASSOCIATION, DOLOMITIZATION, AND POTENTIALITY OF THE PILA SPI FORMATION, TAQ TAQ OIL FIELD, KURDISTAN REGION, NE IRAQ
Divan H. Othman and Basim A. Al-Qayim
Received: 18/ 11/ 2009, Accepted: 29/ 07/ 2010
Key wards: Pila Spi Formation, Taq Taq, Eocene, Reservoir, Petrophysics
(p. 95 – 114)
ABSTRACT
Subsurface data of four oil wells from the Taq Taq oil field of Northeast Iraq, in addition to one surface section from the near by Haibat Sultan Mountain were selected to study the lithofacies associations of the Pila Spi Formation. Detailed investigation of rock samples, cuttings, cores and wire-line logs is attempted to identify lithologic units and association, and to evaluate dolomitization effect on these rocks and its contribution to the reservoir quality.
The formation, in this area is subdivided into four distinctive lithologic units, from bottom to top are: Lower Brecciated and Silicified Unit (P1), Dolomitized Tidal Flat Limestone (P2), Lagoonal Limestone and Dolostone (P3), and Upper Brecciated Dolomitic Limestone (P4). These rocks were variably affected by diagenesis and intensively modified by dolomitization, which is drastically overprinted the original fabrics and components. Several types of dolomite were recognized including: Fenestral Fine Crystalline Dolomite (D1), Fine Crystalline Planar-e to Planar-s Dolomite (D2), Fine Crystalline Non-planar Dolomite (D3), Medium Crystalline Non-planar Dolomite (D4), and Coarse Crystalline Dolomite (D5).
Dolomitization had positively influenced the reservoir characteristics by enhancing inter-crystalline porosity, and developing intra-skeletal and moldic porosity, which evolve into the common micro-vug porosity, especially, in the middle lithologic units (P2 and P3). Reservoir flow potentiality, however, is greatly enhanced by the secondary fracture porosity.
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COMPARISON OF Gypsiferous SoilS IN SAMARRA AND KARBALA AREAS, IRAQ
Mou'taz A. Al-Dabbas, Tom Schanz and Mohammed J. Yassen
Received: 26/ 11/ 2008, Accepted: 1/ 4/ 2010
Key words: Gypsiferous soil, Clay minerals, Shear strength, Swelling index, Collapse potential
(p. 115 – 126)
ABSTRACT
A proposed engineering gypsiferous soil classification is given using: soil texture, mineralogy, geochemistry, engineering properties, and chemical analyses of soils water-extract. The results reflect that these soils consist of different percentages of sand, silt, clay, and some gravel. Analyses also detected secondary gypsum, quartz, calcite, feldspar and different types of rock fragments and different types of heavy minerals in trace amounts. Clay minerals are dominated by palygorskite. Hydrochemical analyses results of soils water-extract show that the calcium and sulphate ions are most common, followed by sodium, bicarbonate, chloride, magnesium and potassium. Bicarbonate and chloride show high values in Karbala area. Gypsum content ranges from (0.9 – 67.5) % in Samarra area, while in Karbala it ranges from (0.4 – 28.9) %. The physical and engineering properties of the studied soils were determined, such as specific gravity, density, shear strength parameters, unconfined compressive strength, and compression and shear wave velocities, compression index, swelling index, initial void ratio, and collapse potential. Samples, which were allowed to soak water show a sudden drop in unconfined compressive strength and compression and shear values immediately after soaking, then were decreased gradually.
The proposed engineering classification of gypsiferous soils includes two classes: “Gypsiferous Soil” and “Highly Gypsiferous Soil”; according to the gypsum content (< 25% and > 25%, respectively), initial void ratio, coefficient of curvature, coefficient of uniformity, collapse potential, compressive strength, cohesion, plasticity index, content of fines, and the T.D.S of the soils water-extract. It is believed that this proposed classification for Iraqi soils can be applied to other locations, therefore, will be useful for other soil scientists and engineers as well, worldwide.
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INFILTRATION RATES OF SOILS IN SOME LOCATIONS WITHIN ERBIL PLAIN, KURDISTAN REGION, NORTH IRAQ
Galawezh B. Bapeer, Ali M. Surdashy and Kareem M. Hassan
Received: 06/ 12/ 2009, Accepted: 01/ 07/ 2010
Key words: Erbil Plain, Infiltration capacity, Permeability, Porosity
(p. 127 – 137)
ABSTRACT
The present study includes infiltration capacity of Quaternary sediments in some locations at the middle part of Erbil Plain, which covers a total area of about 1670 Km2. Quaternary sediments cover about 85 % of the study area, which consists mainly of alluvial fans, slope, flood plain, and valley fill sediments. Aeolian sediments and some outcrops of Bai Hassan (ex-Upper Bakhtiari) Formation are also present in northeast, northwest and southeastern parts of the study area. Mukdadiya (ex-Lower Bakhtiari) Formation is also exposed in the northwestern part.
For infiltration tests, seventeen localities are selected in different parts of the study area. These localities were selected according to the texture of the soil and kind of sediments. Depth of infiltration with time is determined for all selected locations.
According to f(t) value, the infiltration capacity of the middle part of Erbil Plain is between Slow – Rapid. The study area is classified in to three zones (A, B and C) based on infiltration results:
Zone A: Is located at the northeastern and southeastern parts of the study area, it is characterized by medium rate of infiltration.
Zone B: Is located at the southern part of the study area, it is characterized by slow to medium rate of infiltration.
Zone C: Is located at the northern, northwestern and southwestern parts of the study area, it is characterized by medium to rapid rate of infiltration.
The infiltration capacity results indicated that all parts, except the southern part, of the study area are considered as a good recharge area for Erbil city, so it is recommended not to use these areas for heavy construction projects to remain as a source of recharge for Erbil city. Whereas, the southern part of the study area is characterized by slow to medium rate of infiltration capacity.
The lithology of the deep wells indicated that the southern part mainly consists of clay with few silt intercalations, where the clay is characterized by high porosity, but low permeability, so the rate of infiltration is low. The other parts of the study area consist of alternation of gravel, sand, silt and clay. Where the gravel, sand and silt are characterized by high porosity and permeability, so the rate of infiltration is high.
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MODES OF GOLD OCCURRENCES IN GA'ARA DEPRESSION, WESTERN DESERT, IRAQ
Mazin M. Mustafa and Faraj H. Tobia
Received: 02/ 07/ 2009, Accepted: 29/ 07/2010
Key words: Gold, Ga'ara Depression, Ga'ara Formation, Ironstone,
(p. 139 – 147)
ABSTRACT
This research deals with gold occurrences in the ferruginous sandstones and ironstones (massive and pisolitic) of the Ga'ara Formation (Permo – Carboniferous). The morphological features of the gold particles suggest that the gold occurrences are multisourced. The gold occurs in two modes namely: mechanical transportation of the gold grains associated with ferruginous sandstones, and chemical mobilization associated with the (massive and pisolitic) ironstones. The most significant primary gold source is the Precambrian Shield of Saudi Arabia after deep weathering and erosion under humid tropical conditions. The other possible source is the supergene ore deposits that are not far from the area. The majority of the gold is transported in a suspended form as scales and gold dust (first mode), or is transported in a colloidal form with the ferric hydroxides (second mode).
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UPGRADING OF MONTMORILLONITE CLAYSTONE (DIGMA FORMATION) FROM WADI BASHIRA, WESTERN DESERT, IRAQ
Abdul Wahab A. Al-Ajeel and Sahar N. Abdullah
Received: 8/ 6/ 2009, Accepted: 2/ 6/ 2010
Key words: Montmorillonite, Dispersion, Upgrading, Beneficiation, Phosphate dispersers
(p. 149 – 157)
ABSTRACT
Wet beneficiation processing of Wadi Bashira Ca-montmorillonite claystone, which belongs to the Digma Formation, has been studied using tetrasodium pyrophosphate as dispersant agent. The claystone is located in the Western Desert of Iraq. It is of a low grade, associated with different amount of clay and non-clay mineral impurities. Calcite (CaCO3) constitutes the major proportion of these impurities.
In this study, the effect of different parameters (slurry solid concentration, dispersant amount and dispersant/ slurry mixing times) on the efficiency of the beneficiation process were investigated and followed through the measurement of CaO% values of the upgraded claystone (concentrate). Gravity and centrifugal sedimentation were tested to separate the impurities from the clay suspension. The process variables were optimized and the yielded claystone was evaluated. It was shown that the beneficiation process was very effective in upgrading the montmorillonite claystone and capable of producing a high grade montmorillonite (89% montmorillonite) with CEC of 85 meq/100 gm.
SCIENTIFIC NOTE: AN UPDATE ON THE MINERALOGY AND CHEMISTRY OF THE ALTA'AMEEM METEORITE
Khaldoun S. Al-Bassam
(p. 159 – 165)
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