Iraqi Bulletin of Geology and Mining

The Paleocene succession in the Iraqi Western Desert, represented by Akashat Formation, is developed through six third order cycles. Local tectonism and eustacy caused the subdivision into several cycles. The K/T boundary is represented by a transgressive surface; correlated with the major Global Paleocene Transgression. The Early Paleocene succession was mainly controlled by the eustatic component and the resultant eustatic subsidence. During the Middle Paleocene; a major transgression had caused the extension of the basin eastward and shows interbedding of basinal-deep-shallow open marin facies reflecting minor relative sea level fluctuation. The Late Paleocene consists of a retrogradational pattern of deep or basinal facies of the TST bounded by a maximum flooding surface (MFS); this MFS is determined by marls rich with planktonic foraminifera of Late Paleocene age (Globanomalina pseudomanirdii Zone). This cycle ends up with a characterastic zone of coprolites rich with oysters, Operculina spp., Nummulites deserti, Lenticulina sp., and Late Paleocene planktonic (keeled).

The petrographic and biostratigraphic study of the Eocene rocks of South Samawa indicates the existence of the two Eocene formations: Rus and Dammam. Detailed petrographic examination of the carbonate rocks of the Rus Formation has led to the distinction of one microfacies (gypsiferous bioclastic miliolidic dolowackestone) and one lithotype (fine crystalline dolostone). In Dammam Formation, three main microfacies are recognized (mudstone, wackestone and floatstone), two lithotypes (crystalline dolostone and crystalline dedolostone) and one lithofacies (claystone). Each of the microfacies is subdivided into several submicrofacies depending on the components of the rock. The carbonate rocks of the Eocene are inferred to have undergone extensive diagenetic events including dolomitization that appear to have been widespread, dedolomitization, neomorphism, micritization, dissolution and porosity developments, cementation, physical compaction and silicification. These microfacies are interpreted as having been deposited in different environments (platform margin sand shoals, open marine, shallow restricted and evaporitic platform interior). Biostratigraphically, miliolids are the common fossils recognized within the Rus Formation and assigned to the Early Eocene age and restricted environment, while the Nummulites gizahensis – Nummulites discorbinus assemblage zone and other associated fossils represent the Middle Eocene age of the Middle Dammam Formation with Shoal environment.

This study deals with facies analysis and depositional environments of Injana Formation (Upper Miocene) in Zawita, Amadiya and Zakho areas. The lower part of the formation at Zakho and Zawita comprises reddish brown mudstone and greenish grey marl representing mudflats (transitional environments). At Amadiya logged succession some coarsening upwards successions are recorded at the lower part representing deltaic environment. The upper part, which is the major part, consists principally of repeated fining-upwards succession nested above each other in a general coarsening upwards in the sand fraction. The Injana Formation comprises seven lithofacies which form eight facies associations. Mudflats and deltaic facies association represent the transitional environments and are of relatively limited thickness and restricted to the lower part only of the formation. Channel floor, point bar, chute and chute bars, abandoned channel, crevasse splay and interchannel floodbasin facies associations represent the high-sinuosity stream (meandering river) forming most of the upper part of the logged successions.
The fining-upwards succession starts with a scour surface at the base of current bedded fine to coarse sandstone with occasional intraformational conglomerates followed by mudstone. In the logged successions, five basic architectural elements are identified: Downstream accretion, Lateral accretion, Floodplain fines, Crevasse splay and Abandoned channel elements. Facies analysis revealed that the upper part of the Injana Formation represents fluviatile deposits basically meandering river system (high – sinuosity streams).

An integrated remote sensing data and Geographic Information Systems (GIS) were applied in geomorphological study of Dewana drainage basin, Sulaimaniyah Governorate, northeastern Iraq. The basin is considered as a good example of small scale drainage basins of a mountainous terrain with variable geomorphological processes and landscapes. Major basin divides are recognized by the homoclinal ridge of Baranan Mountain to the northeast and Sagerma Mountain to the southwest.
Satellite images as well as Digital Elevation Model with topographic, geologic, and structural maps were used in addition to field investigations to perform a geomorphological analysis, classification, and mapping.
Arc GIS 9.3 was used to digitize, measure and draw the spatial data of this analyses. General geomorphic mapping and classification of the basin's landforms using genetic origin; as a base for the grouping show that it includes five major groups or units. These units are: Structural origin, Denudational origin, Structural-Denudational origin, Fluvial origin, and Anthropogenic origin. Each of these five units includes related different subunits which were mapped on a 1: 150, 000 scale map to show special distribution and relation between the different landforms. Discussion of the five units and their subunits were made in term of their relation to geology, topography, drainage network as well as originating geomorphic process. The fluvial process is the most effective one, which generates most of the recent and pronounced landform groups such as: dry valley deposits, flood plain, valley fills, river terraces, alluvial fans, galleys, badlands. Other important processes are mass wasting activities.

Prediction of aquifer drawdown is important for the management of groundwater system especially in arid and semi-arid regions in which groundwater is a major source for agricultural and domestic requirements. Khanaqin area, northeastern Iraq, is under water stress due to increasing demand of groundwater for different purposes. The use of mathematical model is an important tool to predict the status of the aquifer drawdown. In this study we have used the MODFLOW model to simulate the aquifer in both steady and transient states. Good agreement of the simulated steady state heads with the observed ones is noticed. For transient simulation, the model was run for one year starting from January, 2013 to December, 2013, and the results were compared with the observed head of the three monitoring wells (w4, w8 and w28). The calibrated model is used to predict the drawdown of the groundwater for 4 years under three scenarios: 1) present discharge conditions maintained, 2) discharge increase at rate of the irrigation need in the future, i.e from 5L/ sec to 10 L/sec, 3) increasing well drilling for the next 4 years at specific locations. These scenarios and the resulted head distribution urge for integrated management program for the conjunctive use of both surface and groundwater recourses of the study area.

The average concentrations of heavy metals (Pb, Cu, Ni, Cr, and Cd) with the polycyclic aromatic hydrocarbons (PAHs) in the soil of Kirkuk Oil Refinery and the surroundings were determined in 15 selected locations. The sample collection was carried out in two periods: October 2010 and March 2011. In comparison with other studies, the concentration levels of heavy metals show that the values are within or lower than those of other studies, except for the concentration of Cd in the two periods, which are higher. The average concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil indicates 3.5 ppb in October, while in March it is 14.2 ppb.
The model of cumulative effect of PAHs, determined by GIS program for both sampling periods, shows an increase of concentration in wind directions away from the site of Kirkuk Oil Refinery.

This study includes the implementation of a method for the analysis of rockfall hazard along roads and motorways. The method is the Rockfall Hazard Rating System (RHRS) developed by the Oregon State Highway Division. This method was implemented on rock cuts along Mirawa main road, north of Shaqlawa summer resort, in Kurdistan Region, north Iraq.
Seven road cuts are rated according to RHRS and the results showed that most of the studied rock cuts of Mirawa area are classified as moderate hazard and needs remedial measures with moderate urgency, because their rockfall hazard rating values are between 300 – 500. The other two rock cuts (Sites 1 and 6) are classified with low hazard and needs remedial measures with low urgency, because their RHR values are less than 300. Accordingly, a geological map with rockfall hazard sites was prepared for Mirawa main road.

Due to the variation in the characteristics of Al-Kend Hill clays )Nineva Governorate), this study was prepared to determine the properties of these clays, and to identify the best method for the production of building bricks. Two methods of forming clay were used to produce clay brick samples: extrusion (2.5  3.8  7.5) cm and pressing cylinder shape (3.5  5.4) cm, then dried at room temperature for 48 hr and for 24 hr at 110 °C using the laboratory oven. After drying the samples, they were burned at different elevated temperatures (750, 800, 850 and 1100) °C according to certain firing program for 2 hr socking time.
The effect of several parameters on the properties of the laboratory samples were studied: (particle size distribution of the raw material, effect of submerging the raw material in water, effect of firing temperatures (750, 800, 850, 1100) °C and the relationship of all variables with different burning temperatures and the methods of forming (extrusion, pressing).
The results show that firing extruded samples at 800 °C (K8-2, K3-3, K1-1) are successful being within the specification limits of the Iraqi standards No.25, 1993.