Iraqi Bulletin of Geology and Mining

Shari playa is an elongated N–S depression located about 35 km NE of Samarra city, central Iraq. A combination of the bands 2, 3 and 4 of the Landsat imagery was used to study the structural lineaments and water seepage analysis. Three sets of principal lineaments were detected. They are oriented in NW – SE, NE – SW and N – S; they may reflect faults or fault systems. The NW – SE direction is affected by the nearby Hemrin Mountain and also by the Pre – Miocene deep seated faults. The NE – SW direction is parallel to that of Greater Zab and Lesser Zab Rivers which are also parallel to the Amij – Samarra – Halabcha deep seated fault, which intersects Shari playa. The N– S direction is parallel to the proposed Tigris Fault. These fault systems are responsible for the water seepage in the playa. The stresses applied in the region probably activated movements along old lineament systems, resulted in the formation of a graben structure in Shari playa area. The estimated age of the playa is about 6000 – 6500 years B. P.

Fault shape at depth and the depth to the corresponding detachment were estimated from calculating bed length and excess area balance in cross–section and graphically from associated hangingwall roll–over fold profile.
Six different construction techniques were used on the same initial cross–section which is derived from converting a chosen seismic profile to a true depth section with equal vertical and horizontal scales. The graphical construction techniques include Chevron, modified Chevron, inclined shear, constant – slip, and flexural – slip models. Because these construction models vary considerably, since they assume different mechanisms by which the hangingwall deforms, the resultant fault shapes and their corresponding detachment depth differ according to the construction technique used. Therefore, the geometric construction models cannot provide a unique answer about the geometry of a listric normal fault at depth and the depth at which it flattens, particularly in areas of limited seismic and well data. They may define a range of possible solutions. However, the constructions show that the fault soles at deep level irrespective of the technique used. The results show good agreement with the available geophysical and geological information.

A detailed geological survey in Karbla and Najaf area has been carried out by the authors and others including a lot of geological sections, traverses, document points and mapping, beside drilling boreholes, to investigate the origin and distribution of the celestite in the studied area. The work indicates that the main celestite deposit is concentrated as a narrow strip of about 200 m width along both Tar Al–Najaf and Tar Al–Sayyed, then decreases downwards within Karbala–Najaf Plateau. It is scattered along both tars (cliffs), either within certain areas, extending to many kilometers or within isolated sections, in very limited areas. Abu–Jir Fault is the main and the principle controlling factor on the distribution of the celestite, in the studied area in addition to the lithology, porosity and permeability.
The celestite has been found in the upper part of Injana Formation and the lower part of Dibdibba Formation within sandstone, siltstone or silty claystone beds, but more concentrated in the sandstone beds of Dibdibba Formation. It is differentiated in the field either by its heavy weight in a tough, cliff–forming siltstone or silty claystone beds or as colourless needle–shaped crystals in heavy, tough sandstone beds. Generally, three main horizons of celestite are present in different levels in both formations, but more horizons may be present in other areas. The celestite is formed from the combination of Sr from the deep ground water and the SO3, which was supplied from the surrounding environment due to high ground water level and continuous evaporation. The thickness of the celestite–bearing beds ranges from (0.1–0.5) m. The Sr concentration is up to 34% whereas the celestite concentration is up to 74.8 %.

A reconnaissance survey in the Euphrates River from Al–Qaim to Nassiriya showed the following types of mollusks: Corbicula (Corbicula) fluminalis MULLER, Unio tigridis BOURGUIGNAT, Mytilus sp., bellamya cf. bengalensis LAMARK, Melanoides sp. and Melanopsis nodosa FERUSSAC. The distribution of these mollusks is variable in the river basin; generally the pelecypods are common in the northern sector whereas the gastropods are found in the southern sector only. The most common species in the whole river is C. (Corbicula) fluminalis MULLER, followed by Unio tigridis BOURGUIGNAT. On the other hand, Bellamya cf. bengalensis LAMARK is the commonest species in the southern sector. The distribution of these mollusks in the Euphrates River seems to be controlled by water salinity, type of dissolved salts, speed of water flow, TSS, BOD and COD contents of the river water. The northern sector of the Euphrates River is characterized by faster flow, lower salinity, better aeration, lower TSS, TDS, BOD and COD concentrations and an HCO3, SO4, Ca, Mg water type. In the southern sector the river flow is slower and remarkably higher in TSS, TDS, COD and BOD concentrations relative to the northern sector.

The extraction and recovery of alumina (Al2O3) from white kaolinite clay in hydrochloric acid solution was investigated on laboratory scale. The extraction rate was found to increase with calcination temperature (up to a certain limit), calcination time and acid concentration. Under optimum conditions of 720oC calcination temperature for 45 min with 28% HCl, by weight and 45 min leaching time at 100oC, alumina extraction was about 99 % .The recovery of alumina by gas (Hydrogen Chloride) precipitation technique has proven satisfactory and it was of about 93%, with purity of about 99.98% Al2O3.This purity of the produced alumina was found in accordance with that of commercial grade, which is in the range of (99 – 99.5)% Al2O3.

Three surface sections of Sargelu Formation were chosen for the purpose of this study, Naokelekan village (near Rowanduz), Gara mountain (southern Amadia), and Banik village (northeast of Zakho) Northern Iraqi Kurdistan. At all these localities, the upper part of Sargelu Formation is characterized by interesting black chert beds.
The petrographic study of chert beds was based on 25 thin sections. This study revealed fossils similar to those described in limestone units of the same formation, but with clear signs of silicification. By combination of field observations and petrographic studies, it can be concluded that chert beds are formed by diagenetic reorganization of silica, which is mostly of biogenic origin, mostly from radiolarians. Complete replacement of some thin limestone beds(or thin parts of them) by silica resulted in the development of chert beds. Dissolution of radiolarians, either within chert beds or in neighboring limestone beds, provides a major source of silica for this process.

The results of the present study revealed that clastics of Al–Amij Formation (Middle Jurassic) in the Western Desert are composed of three sedimentary major cycles, including secondary cycles in each of them .Grain size analysis of the sediments shows domination of coarsening upwards trend .This is the criteria of delta environment. On the other hand, in some places the fining upwards grading is evident indicating alluvial environment.
The sands of Al–Amij Formation are mainly composed of quartz fragments with almost rounded edges and silica content ranging between (72 – 76.6) %.Heavy minerals content in the sand ranges between (0.63 – 0.88) % in the grain sizes ranging between (0.063 – 0.250) mm. The heavy minerals in sands of Al–Amij Formation are composed of transparent stable minerals such as zircon, rutile and tourmaline and few amounts of semi–stable minerals such as staurolite. The black opaque minerals are ilmenite and magnetite and the brown opaque minerals are hematite and goethite. The zirconium concentration in the sands ranges between (778 – 872) ppm in area (A) and between (779 – 871) ppm in area (B). The titania (TiO2) concentration in area (A) is (1.1–1.2) % and (1.2 – 1.3) % in area (B).
Petrogrographic and mineralogic studies show that the minerals containing zirconium and titanium in sands of Al–Amij Formation are zircon (0.5 – 4.3) %, rutile (2.5 – 3) %, ilmenite and altered ilmenite. The study showed positive relation between titanium and thorium and weak positive relation between zirconium and thorium .The source of radiation seems to be thorium and uranium.
The study concluded that sands of Al–Amij Formation are poor in zircon, rutile and ilmenite and they are concentrated in the fine to very fine grain size fractions of the sands .They contain clay and iron impurities and other enclosures, resulting in complex and expensive extraction processes. Moreover, the specifications of the concentrates obtained by preliminary tests do not meet industrial demands.

The topography of Iraq is unique in its kind, where all rain fall of the country migrate towards the Mesopotamian depression, whether via valley floods or infiltration to the ground aquifers. The Euphrates and Dammam Formations are important ground water aquifers. They are close to the Euphrates River basin and are rich in vast quantities of ground water under high pressure, especially in the Dammam Formation, where the water head may be about 10 m higher than the average ground level in Abu Skhair area where the uranium deposits are located.
The design for the mining operations in Abu Skhair was based on underground mining by excavation of a vertical shaft to isolate ground water of the aquifer, followed by horizontal tunneling to extract the ore. This way of excavation may represent a grate hazard to the miners during operation where there is a possibility of ground water explosion in these tunnels, due to high pressure, via joints and cracks natural or induced by using of explosives during mining, which is a case taking place in many mines in the world.
In order to find solutions to this problem this theoretical study was carried out, as one of the suitable solutions that can be applied in case of these deposits are exploited. This method may be applied by drilling of 16 wells in the area to be used to pump water continuously by about 15800 m3 / day. The amount of the water to be pumped varies according to the location of each well. The total amount of the water to be pumped should lower the ground water level by about 93 m below its static level.
The ground water pumped from these wells may be used for agriculture. It has a TDS of 3000-4000 mg/l and the S.A.R. value does not exceed 10

The study area is located in the northeastern part of Iraq, and lies at intermediate area between Qulqula and Azmur Mountains. The location gave Savanna properties to the climatic conditions and prevalence of primary and secondary permeabilities. This paper deals with the evaluation of the hydrochemical properties of the spring water that influx through out the year, in addition to asses their uses.

The Tanjero Formation and the Lower Unit of the Red Beds Group are considered here as discharge zone in the area and at the same time they are regarded as recharge zones due to the combination of the structural – lithological – climatical – geomorphological factors. In addition to the systematic distribution of water springs in the Tanjero Formation due to the systematic distribution of the lithological facies and the secondary fractures. As well as the outcrops of Balambo, Kometan and Shiranish Formations are considered as recharge zones for ground water, which are flowing towards Tagaran River. This direction is corresponding to the topographic setting of the area.
Although limited numbers of water samples were analyzed, the present study revealed three types of ground water. The first type is carbonate – calcium water, which is common type in Tanjero Formation .It is of fresh, neutral and hard to very hard characters, with little content of metallic ions, not polluted by organic matter, drinkable and suitable for agricultural and industrial uses. The second type is carbonatic – sulphatic – sodumic, which is uncommon type in the Tanjero Formation. It is of brackish, basic and fresh characters, with little content of metallic ions , not polluted by organic matter, drinkable and suitable for industrial uses, but not for agricultural uses. The third type is carbonatic – calciumic – magnisumic, which is common in the Lower Unit of the Red Beds Group. It is of fresh, neutral and very hard characters, with little content of metallic ions, not polluted by organic matter but slightly by soluble hydrogen sulphide, drinkable and suitable for agricultural uses. Most of the hydrochemical analysis of the water springs reflects the marine origin, which is mixed with rain water in the aquifers.

This study proved that the kaolinitic clays of Amij Formation (Middle Jurassic) are suitable for ordinary brick, roofing (red tiles) and floor tiles. The samples were subjected to a temperature of 850Co and that of red tiles to 1050Co. The results were compatible to the Iraqi and Egyptian specifications for brick industry.
The bricks produced in this experiment are characterized by colour homogenity, plane surfaces and lack of cracks and fissures .This study recommends adapting the kaolinitic clay of Amij Formation to be used in brick and tiles industry and to upgrade these experiments to a pilot plant level.

Makhool dam (under construction, which is stopped neither to) is located on the Tigris River about 30 km northwest of Baiji town. The reservoir extends to Sharqat vicinity. The exposed rocks within the reservoir area belong to the Fatha and Injana Formations. The former consists of marl, claystone, limestone and gypsum in cyclic nature. Whereas, the latter consists of claystone, siltstone and sandstone, in cyclic nature too. The western limits of the reservoir are bounded by scarps which belong mainly to Makhool and Khanoogah anticlines. Major parts of these scarps suffer from unstable slopes, along them many mass movements are developed. Moreover, the scarps are potential areas for development of mass movements, which will increase after construction of the dam, due to major change in water level. This will consequently change the properties of the exposed rocks and soils in the banks of the reservoir. The expected mass movements will influence on the stability of the dam, especially if they took place together at once.
The slopes and scarps of the western limits of the reservoir are divided into five zones. For each zone different characters are mentioned with estimating conditional and average probability of landslides occurrence. Moreover, unique terrain units are defined.