IRAQI BULLETIN OF GEOLOGY AND MINING
مجلة الجيولوجيا والتعدين العراقية
ISSN 1811 - 4539
اهداف ومجال النشر تعليمات النشر للمؤلفات البحوث المنشورة هيئة التحرير
THE DEMISE STAGE OF RUDIST BEARING MISHRIF FORMATION (LATE CENOMANIAN – EARLY TURONIAN), SOUTHERN IRAQ
Salam I. Al-Dulaimi, Ayad A. Al-Zaidy and Sa'ad S. Al-Jumaily
Received: 12/ 08/ 2012, Accepted: 27/ 01/ 2013
Keywords: Rudist, Cretaceous, Mishrif Formation, Demise, Iraq
(p. 1 – 20)
ABSTRACT
The Cretaceous carbonates are of unique significance in the stratigraphic succession of the Middle East, because much of the discovered prolific carbonate reservoir facies are in the rudist bearing formations. The Late Cretaceous carbonates of the Mishrif Formation are one of these prolific reservoir facies, which extends along the southern parts of Iraq and the Arabian Gulf.
Five subsurface sections were selected from wells of three fields in south and southeastern parts of Iraq, including West Qurna 21, 57 and 215, Tuba 4 and Nasiriyah 2, to determine the radiation and the demise of the rudists in the Mishrif Formation.
This study showed that the rudists of the Mishrif Formation were affected in two stages of demise. The first (Fd) took place during the early Late Cenomanian, recorded by a drastic decline in the abundant occurrence of the recumbent rudists (Caprinidae and Ichthysarcolitidae), which together represent Cenomanian species of the Mishrif Formation. Consequently, the followed Cenomanian – Turonian transition was not only a significant crisis in the abundance of the rudists, but also the benthic foraminifera were affected. The second demise of the rudists was recorded by the disappearance of elevator Hippuritidae and Radiolitidae; represented by these species: Durania araudi, Sauvagesia sharpie, Praeradiolites echennesis, Praeradiolites sarladensis and benthic foraminifera, specially Miliolids, with abundance of planktonic foraminifera of the Khasib Formation, this demise took place during the late Early Turonian.
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GEOMORPHOLOGY AND MORPHOMETRY OF THE GREATER ZAB RIVER BASIN, NORTH OF IRAQ
Varoujan K. Sissakian
Received: 05/ 12/ 2012, Accepted: 25/ 02/ 2013
Key words: Morphometric parameters, Geomorphological units, Greater Zab River, Drainage basin, Iraq
(p. 21 – 49)
ABSTRACT
The Greater Zab River is one of the main tributaries of the Tigris River. The river runs in the central northern part of Iraq, and then joins the Tigris River south of Mosul city, in the northern central part of Iraq. It has four main tributaries, called; Shamdinan, Haji Beg, Rawandooz and Khazir – Gomal rivers, beside tens of small tributaries and ephemeral streams, which drain directly in the main river. The studied catchment area of the Greater Zab River; in Iraq attains about 13708 Km2, and extends in the northern and northeastern parts of Iraq, and farther more in Turkey and Iran. The basin of the river is divided into four sub-basins of the aforementioned tributaries and a fifth one, which includes the catchment area that drain directly in the Greater Zab River. The widths of the five sub-basins range from (1.54 – 6.19) Km, whereas their lengths range from (41.4 – 108.3) Km.
The catchment's areas of the Greater Zab River and its four tributaries are covered mainly by carbonate rocks of many formations, which range in age from Triassic to Pliocene – Pleistocene, beside igneous and metamorphic rocks, especially in the northeastern parts. Moreover, fine clastics of Injana and Mukdadiya formations, coarse clastics of Bai Hassan Formation, and marl, limestone and gypsum of the Fatha Formation cover considerable area. Through the courses of the Greater Zab River and its four tributaries, they cross tens of anticlines, almost perpendicularly; some of them have gorge forms, forming 34 water gaps and 15 air gaps, in the studied area. The geomorphology and morphotectonics of the Greater Zab River basin are studied. Six Morphometric indices have determined in this study, using ArcGIS technique, which indicated High, Moderate, Very High, Very High and High relative tectonic activity for the five sub-basins, respectively. Geomorphological and basin drainage maps of the studied area are prepared, too.
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SLOPE STABILITY ASSESSMENT WITHIN AND AROUND THE RESERVOIR OF THE PROPOSED BASARA DAM, SULAIMANIYAH, NE IRAQ
Ghafor A. Hamasur
Received: 08/ 12/ 2011, Accepted: 28/ 04/ 2013
Keywords: Slope stability, Landslide Possibility Index, Failure, Degree of Hazard, Iraq
(p. 51 – 66)
ABSTRACT
The study of the slope stability within and around the reservoir of the proposed Basara dam near Delaizha village, Sulaimaniyah District, Kurdistan Region, NE Iraq is carried out. To evaluate the stability of slopes in the studied area, sixteen stations were selected within and in the vicinity of the reservoir area, fourteen stations in the rock slopes, and two stations in the soil and talus sediments.
In this study, the stability of the rock slopes have evaluated by a new system, known as Landslide Possibility Index (LPI), as well as the approach of Hoek and Bray for those stations that are near the proposed dam site and need a detailed study. Moreover, the soil and talus slopes have evaluated by conventional methods.
The application of the LPI system leads to the conclusion that the possibility of failures and the degree of hazard in the eight rock slopes, Stations No. 2, 5, 8, 9, 11, 12, 13 and 15 is Moderate, while in the six remained rock slopes, Stations No. 1, 3, 4, 6, 7 and 10; the possibility of failures and the degree of hazard is High.
Detailed study of rock slopes in the vicinity of the proposed Basara dam (Stations No. 1 and 2) revealed that they are unstable, where toppling, rock fall, rock rolling have occurred. Further failures will occur in the future, which might affect the stability of the dam, because during toppling and/ or rock fall; some of the blocks may roll down into the reservoir of the dam, when it is filled by water, where the consequences will be very hazardous.
The study of the soil and talus slopes revealed that soil slump had occurred in Station No. 14, which is recognized by leaning of the trees down slope and the moved soil left a scar due to movement. While in the talus slope (Station No. 16) rock rolling and falling have occurred, because the slope has a direct contact with the valley floor and being continuously under-cut by water currents during floods, thus the water currents have removed, the fine materials between large blocks.
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PROVENANCE OF SEDIMENTS OF SAND DUNES IN THE WESTERN PARTS OF THE EUPHRATES RIVER, IRAQ
Luma E. Al-Mukhtar
Received: 04/ 08/ 2012, Accepted: 25/ 02/ 2013
Key words: Heavy minerals, Grain size, Sediments, Sand Dunes, Iraq
(p. 67 – 82)
ABSTRACT
This study is concerned with the heavy minerals (HM) of the + 63 micron fraction of the sand dune sediments, which cover 608.686 Km2 of an area from Najaf to Samawa, and the southern borders of Al-Qadissiya Governorate. Moreover, grain size analysis, chemical and XRD analysis are carried out. HM analysis indicates that the proportion of the unstable minerals makes about 12.7% for Najaf dunes and 44.83% for Samawa – Qadissiya dunes, whereas the metastable minerals make about 15.81% and 21.03% and the ultra stable minerals make about 16.83% and 3.01% for Najaf and Samawa – Qadissiya dunes, respectively. Opaques are present in high proportions reaching about 34.04% for Najaf dunes and 28.54% for Samawa – Qadissiya dunes.
Grain size analysis indicates that the sediments of Najaf dunes are coarser than the sediments of Samawa – Qadissiya dunes and the sorting of sediments of Najaf dunes are medium, while sediments of Samawa – Qadissiya dunes are fine. Moreover, the sediment of Najaf dunes are more mature than the sediment of Samawa – Qadissiya dunes due to the ZTR index.
Chemical and XRD analysis revealed that the sediments of the studied dune fields are composed essentially of quartz, feldspar; as the dominant minerals with a paucity of carbonate and sulphate minerals, in addition to heavy minerals. Clay minerals occur in Najaf dune fields represented by montmorillonite, palygorskite and kaolinite and the same clay minerals except montmorillonite occur in Samawa – Qadissiya dune fields.
All results indicate that Najaf sand dunes are derived from felsic igneous rocks (granitoid rock), metamorphic rocks (schist and gneiss) and older sedimentary rocks, while Samawa – Qadissiya dunes are essentially derived from metamorphic rocks (schist and gneiss), basic igneous rocks (Basalt and Gabbro) and older sedimentary rocks.
The Dibdibba Formation (Pliocene – Pleistocene) in Tar Al-Najaf, where the sediments are transported from the Arabian Shield, is the most important source for supplying sand forming the dune fields of Najaf, while the source area that supplies the sediments of Samawa dunes is mixed, the essential one is the surrounding formations, where the sediments are transported from Arabian Shield and the second source is the Euphrates River, where sediments are transported from the north (Syria and south of Turkey).
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GRAVITY AND GROUND MAGNETIC FOLLOW-UP OF AEROMAGNETIC ANOMALY WEST Al-GHAR'RAF RIVER, SOUTH IRAQ
Hayder A. Al-Bahadily and Ahmed S. Musa
Received: 08/ 26/ 2012, Accepted: 30/ 04/ 2013
Keywords: Gravity and Magnetic surveys, Aeromagnetic anomaly, Integrated geophysical studies, Iraq
(p. 83 – 101)
ABSTRACT
A more detailed gravity and ground magnetic surveys have been executed in a mostly agricultural area, which covers (28 × 40) Km and lies between Al-Nasiriya and Al-Kut Governorates, close to Al-Gharraf River and towards west. The surveys aim to determine deep structures within the sedimentary cover, by following-up a deep source anomaly, which appears in aeromagnetic and Unified Bouguer gravity maps. A net of polygons, including 868 gravity and magnetic stations with spacing interval of 0.5 Km, has been measured. Bouguer anomaly and total magnetic intensity (TMI) maps are constructed. Filters for enhancing shallow and deep source anomalies and high gradient areas were applied to Bouguer anomaly and TMI maps. The Bouguer anomaly map shows a prominent gravity high in ENE – WSW direction. In addition, residual anomalies that may reflect antiforms and synforms or faults are pointed out on this map. Gravity profiles across the gravity high and some residual positive anomalies are plotted. On the other hand, the TMI map shows a magnetic high, which has the same direction, extension, length and location of the gravity high. The magnetic high is, essentially, related to a basement intrusion, and it may be a causative source for the gravity high. Two magnetic profiles across and along this high are displayed. The study of depth maps of four seismic reflectors showed no anomalous structures down to the Permian surface (~ 6000 m deep), while it shows considerable paleostructures on this surface. Moreover, the magnetic high (the intrusion) is older than the Permian, which is (6000 – 9000) m deep. However, local magnetic anomalies (LMA) related to Quaternary gray sand sediments, can easily be recognized throughout the area. The LMA tend to disturb the earth’s magnetic field. However, upward continuation filter is applied to remove the effect of these anomalies.
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MINERAL RESOURCES OF KURDISTAN REGION, IRAQ
Khaldoun S. Al-Bassam
Received: 28/ 06/ 2006, Accepted: 24/ 07/ 2008
Keywords: Minerals, Kurdistan, Iraq
(p. 103 – 127)
ABSTRACT
Kurdistan Region is characterized among the rest of Iraqi territory, by the presence of metallic mineral deposits such as Zn, Pb, Cu, Cr-Ni and Mn, together with some unique non-metallic minerals and industrial rocks such as barite, asbestos and marble. The formation of these mineral deposits is associated with the geological and tectonic development of northern Iraq including the major tectonic events associated with the Tethys development and movement of the Arabian Plate. Most of the metallic mineralizations were developed during the Cretaceous Period. Some Zn-Pb deposits are older and may be related to the Triassic and Jurassic Periods.
The actual mineral wealth of the region is not really known, in view of the lack of detailed geological mapping, geochemical survey and air-born geophysical survey. However, based on the available information it is expected that the province is promising for Zn, Pb, Cu, Cr, marble and barite deposits. Building raw materials are available to maintain cement industry and other construction materials. It is essential to start a comprehensive exploration program in Kurdistan Region in order to have a better view of its mineral potential.
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PREPARATION OF HIGH PURITY MAGNESIUM OXIDE FROM SEA BITTERN RESIDUAL FROM NaCl PRODUCTION IN Al-BASRAH SALTERN, SOUTH IRAQ
Alaa M. Kh. Mustafa and Waleed R. Abdullah
Received: 31/ 07/ 2012, Accepted: 25/ 02/ 2013
Keywords: Magnesium Oxide, Magnesium Hydroxide, Calcium Sulfate, Sea bittern, Iraq
(p. 129 – 146)
ABSTRACT
In this study, light and dead-burned magnesia (MgO) were prepared from the sea-bittern residual from the production of NaCl; extracted from sea water (Arabian Gulf) in Al-Basrah saltern in the south of Iraq. Dead burned magnesia of pure and dense form assaying 96.8% MgO, with a bulk density of 3.7 gm/cm3 was prepared at optimum conditions, including pre-treatment of the sea bittern of 26 Baume with calcium chloride at a ratio of 1.05:1.00 (CaCl2:MgSO4) to remove calcium sulfate, addition of precipitant (dolime) at a molar ratio of 1:1 (CaO.MgO:MgCl2), and precipitation temperature of about 70 °C for 60 minutes. The precipitated Mg(OH)2 was subjected to calcination at 1000 °C for 60 minutes, whereby a milky soft powder of light-burned (active) magnesia was produced. Dead-burned (inactive) magnesia was then obtained by burning the light-burned magnesia at 1650 °C for 60 minutes. This study provides further benefit, of producing a high purity calcium sulfate (≥ 98%) as a byproduct of the MgO production.
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