Rafidain Journal of Science

ان صعوبة تقدير بعض المعاملات المستخدمة في التقدير شبه الكمي للمعادن في تحاليل الأشعة السينية الحائدة لنماذج أطيان الكاؤولين عند استخدام الأشعة من نوع Cukα في التحاليل بسبب احتواء النماذج على تراكيز عالية نسبياً من اطوار الحديد، والذي يعطي شدة عالية لخط المرجع مما يشوه تقدير وحساب المساحة تحت منحني الأنعكاس أو الشدة لأي طور معدني موجود في النموذج، كما ان بعض منحنيات الأنعكاس للأطوار السائدة بتراكيز عالية تعمل على حجب منحنيات الأنعكاس الصغيرة العائدة لأطوار متواجدة بتراكيز قليلة مما يصعب قياسها إلا بعد اجراء معاملة للشرائح. ولذلك يمكن الأستفادة من التشخيص الوصفي للأطوار المعدنية في التعرف إلى انواعها ، ومن الممكن توظيف معطيات الأشعة السينية مع التحاليل الكيميائية في تقدير المحتوى المعدني، لاسيما وان اغلب اطيان الكاؤولين تمتاز بنفس الصحبة المعدنية بسبب تشابه السلوك الجيوكيميائي لنواتج عمليات الغسل والتجوية على الصخور والتي تؤدي الى تكون الكاؤولينايت والأطوار المعدنية المرافقة له مثل الإلايت والمرو والأناتيس والروتايل والجوثايت والهيماتايت. أما تباين نسبها فيعزى الى طبيعة الظروف والعمليات التحويرية التي تعمل على أعادة توزيعها ضمن البيئة التي ترسبت فيها، وهذه الظروف تتباين تبعا لكل منطقة في البيئة الترسيبية لها.

The present investigation deals with the litho- and biostratigraphy of the Tayarat Formation (Upper Cretaceous) from five subsurface sections in Western Iraq. The studied formation composed lithologically of limestone, sometimes dolomitized. The benthonic foraminifera recorded from the Tayarat Formation permit the recognition of the following zones from base to top:



1-Orbitoides tissoti-Orbitoides medius Zone.
2-Orbitoides apiculatus Zone
3-Lepidorbitoides socialis – Lepidorbitoides minor Zone.
4-Pseudochrysalidina conica – Pseudolituonella reicheli Zone

The present investigation indicates that the Tayarat Formation is Late Campanian-Late Maastrichtian in age.

Textural grain-size analysis of Injana Formation in borehole (KH8/9) indicate the dominance of sandstones and siltstones. Cumulative frequency curves imply transporta-tion in different modes: suspension, saltation and rolling with the last of minor importance.
Textural attributes of the clastics showed them to be composed of fine sand, medium sorting with very positive skewed and being leptokurtic. The data point to the deposition by weak current and rapid accumulation. Bivariant plots of statistical parameters and applying of (C-M) diagram elucidated deposition in meandering river system.

Field and facies analyses have revealed the possibility of dividing the reefal Sinjar Formation (Paleocene–Early Eocene) within Sinjar anticline into three diagnostic stratigraphic units. These are: lagoonal semi Massive lower unit, lagoonal stratified middle unit and massive upper unit, which is lagoonal, reefal and forereefal in its lower, middle and upper parts respectively. The units are characterized by the quick identification and ease lateral correlation across most lithological sections exposed in the area. It has also been revealed that the lower and upper contact surfaces are unconformable.

In this study, a new method was introduced to conduct Bouguer correction, taking in the consideration the geological structures existing in the Bouguer slab. The method is based on modeling the shape and density contrast of the geological structures.

The present study describes and tries to identify the possible origin of some circular features that observed during field work at the southern limb of Seno Mountain Northwest of Mosul / Iraq. From structural Geology point of view this mountain considered a symmetrical anticline and one of many anticlines that satellite the giant Sinjar Mountain. The circular features identified at the lower member of Al-Fatha Formation (Middle Miocene), this member generally consist of complete and incomplete cycles of Gypsum and Limestone while the Upper member consists besides that of Claystone and Marl. The lower member consists the core of the mountain while the upper member rimmed of it also the upper member represent low relief compare with core.
Many circular features identified at the Southern Limb of Seno.
Anticline but the largest one has a diameter of about fifteen meters. These circular features can be divided into two distinct parts, the inner which represents most of the features and consists of friable Gypsum and Salt and outer part which represents the frame of these features and consists of hard well bedded Limestone which is dipped radially from the center. The amount of dips of these Limestone is about ten degree and vertically jointed. The amount and direction of the Limestone are not coincide with the general dips of the beds of the southern Limb generally to the south and reach about twenty five degree.
The present study also discussed the reasons that causes not delineated the circular features by remote sensing methods during the preparation of photogeological map of the study area and show also that depend only on these methods can guide to incorrect interpretation.

This study aimed to evaluate the water quality for a group of wells in hawi al-kanissa region north west of mosul city, the study revealed that 50% of wells under study is of calcium-sulfate type, 20% of calcium-magnesium-sulfate type, 20% of calcium-magnesium-sodium-sulfate type and 10% of sodium-calcium-bicarbonate-sulfate type Also the wells have a high permanent hardness and most of them classified as a doubtful to unsuitable for irrigation and some of them from the type of good to permissible, also the water of these wells is unsuitable for humane drinking

Existence of small percentages of sand and coarse clay in alluvial rivers bed downstream of dams constructed on these rivers with the degradation processes caused by released discharges from dams clear of sediments as a result of sedimentation processes in the upstream reservoirs will lead to washing, segregation and removal of fine materials from the bed leaving coarse sizes gradually. This will cause an increment in the bed roughness and lowering in the flow velocity which in-turn lead to the equilibrium condition. This state of bed roughness is called (armouring). The present research work focuses the light on the armouring phenomenon in rivers and trying to apply on Tigris river downstream Mosul dam identifying the capability of river bed to this phenomenon after Mosul dam operation for about sixteen year since 1985 using various number of criteria laboratory and field relations predicted by many researchers. The results proved that the armouring conditions was existed in Tigris rivers bed in the present study reach and probably had been reached before number of years as a result of Mosul dam operation . The value of geometric standard deviation of the armour layer was 1.58 and the mean diameter was 33 mm. The results proved lowering in the geometric standard deviation of the surface bed material in Mosul city since Mosul dam operation. The average ratio between the mean diameter of the original layer and the armour layer was 0.82, which confirm the conclusion concerning the arrival of the river bed to the armouring state.

Lithological studies of three surface sections of Jaddala Formation, Sinjar anticline, indicated the presence of Avanah Formation, this manifested by three interfingring beds in Sharafadden village section and two thin beds in Jaddala village section, while non is present in Bara village section. These interfingering beds are comprised of three microfacies : Nummulitic lime grainstone microfacies (A1), Bioclastic lime grainstone-ies (A2) and Alveolina lime wackestone microfacies (A3), their depositional environment extended from inner-middle-outer ramp zones.
The disappearance of interfingering from the western part of Sinjar anticline and it's presence in the eastern part, point to the deepening deepocenter during the Eocene of the Sinjar basin in westward direction of the studied area.

Al-Qaim area has been chosen as typical area for western and southwestern parts of the Euphrates River to investigate their soil physical properties and classification. This is due to great soil and bed rock similarities. Two types of soil samples were performed one of them is surfacial and the other 0.3m deep. Several boreholes and vertical pits were used throughout this study.
The study reveals that there were two types of soils; the residual (Sandy loam) and transported soil (Loamy sand). It is also revealed difference in their field density. These types of soils are loose and are regarded agriculturally has bad physical properties. The results show that the residual soil varied in thickness between (0.0-2.4) m whereas, the transported soil reached 3.5m. particularly in wadi cliffs.

Al-Hamdanyia district is located east of Tigris River, northern Iraq. It is regarded as an important agricultural land. Consequently, it is necessary to give great deal to the water resources particularly the ground water. The present study deals with water level and extension of ground water reservoir through the data gathered from the drilled boreholes and vertical geoelectrical sounding. Additionally, water samples were collected and analyzed to evaluate ground water quality and its uses for different purposes. The study also concentrates on the contents of the cations; Ca2+, Mg2+, Na+ and K+ and anions; CO3=, HCO3-, SO4=, Cl- and NO3- in addition to pH, Ec, T.D.S and T.H.
The study reveals wide differences in water quality and may be related to the type of bedrocks of the ground water reservoir. Aquifers are located within Injana Fn. in the northern and northeastern parts of the study area. The aquifers are characterized by low T.D.S in comparative with aquifer within Fat’ha Fn. Which is located in the middle, western and western south parts.

The present investigation deals with the lithostratigraphy and planktonic foramini-feral biostatigraphy of the Shiranish Formation from a surface section in Sinjar area, northwestern Iraq. Depending on lithological characteristic, the formation is divided into three units: the lower unit consists of friable marl, the middle unit embrace an alternations of marl, marly limestone, limestone, sandy limestone and lenses of breccia, while the upper unit is consist of marl and marly limestone. The stratigraphic distribution of the planktonic foraminifera throughout the section permits the recognition of four zones, these are:
1. Globotruncanita calcarata Zone.
2. Globotruncanella havanensis – Rosita fornicata Zone.
3. Globotruncana aegyptiaca Zone.
4. Gansserina gansseri Zone,
The present work indicates that Shiranish Formation is of Late Campanian-Late Maastrichtian age.

Petrographic description of sandstones of the Injana Formation (Upper Miocene) from several selected sections in Iraq shows similarity in mineralogical composition. This is represented by litharenite and feldspathic litharenite eroded from precursor sedimentary, metamorphic and igneous rocks and transported for short distance to be deposited within the fluvial environment. Generally, the sandstone are mineralogically immature; due to increased rates of erosion and deposition associated with dominant mechanical weathering and subdued chemical action.
Presentation of petrographic results as specific relationships point to the deposition under semiarid–semihumed climatic conditions accompanied by little ineffective chemical weathering induced by high relief of source area . Likewise semiarid conditions promoted sparse plant cover, thus providing large quantities of eroded sediments.