Iraqi National Journal of Earth Science

Thirty eight planktonic foraminiferal species were recorded from the Kometan and Gulneri Formations in the subsurface section of Jambur well No. 46, northern Iraq. On the basis of stratigraphic ranges of the recorded foraminifera the studied sequences are attributed to Helvetoglobotruncana helvetica, Marginotruncana sigali, Dicarinella primitiva, D. concavata, Rosita fornicata and Globotruncanita elevata Zones. The Gulneri Formation is Middle to Late Turonian in age, whereas the Kometan Formation ranges from Late Turonian to Early Campanian.

A detaild morphotectonic study has been carried out for the Mushora Dagh Anticline. This anticline is situated to the northwestern part of Iraq about (95) km from Mosul City. The morphotectonic map deduced from the enhanced space imagery showing the existence of seven morphotectonic units, differences in their lithologic and morphologic characteristics, which has been affected by local and regional tectonic movements.
The morphotectonical analysis method included: first, study of directional analysis of structural lineaments and relation between their direction and the tectonic movements through the successive geological periods. Furthermore, upward concavity of the longitudinal profiles represents evidence of the appearance of some anomalies that can be attributed to a number of geologic and tectonical factors. Finally, three high anomaly values appeared while determining the index sinuosity of the Tigris River. These values agree with the first appearance of the surfaces of the transverse and longitudinal faults of Mushora-Dagh Anticline and the axis of this anticline.

Yamama Formation (Valanginian-Early Hauterivian) carries a special economic importance, since it represents one of the well known oil reservoirs southern Iraq. To evaluate the organic material contents of this formation an organic geochemical study was conducted. A total of 58 out of 227 previously collected and described core samples were analysed using pyrolysis method; these samples represent five oil wells which are distributed over West Qurna (WQ) field.
The organic material of the selected samples were separated then analyzed using Rock-Evaltechnique.The organic geochemical data confirm that the Yamama rocks of WQ field represent a source rocks that posses a poor to very good properties depending upon the quantitative evaluation of petroleum potential (PP) and total organic carbon (TOC). The source rocks were thermally matured except in some few samples found at depth below 3700 m. These samples were exceeded the maturation stage leading to the formation of pyrobituminous layer of variable thickness. Most of Yamama organic matters were related to type II kerogen that produces oil and gas prone. Few samples are related to type III kerogen that produces gas prone.

the study of dhiban Fn.(Early Miocene )included the examination of four core holes . three of them the Shiekh Ibrahim area and one from Sasan area -west of mousl city . the succession of carbonates and Evaporates sedimentary facies indicated the deposition of Dhiban Fn.sediments in coastal lagoons and adjacent tidal flats which have developed as a consequence of sea regression through the second sedimentary cycle of lower Miocene.
Isopach map of the region shows that Shiekh ibrahim areawasthe north eastern marcgin of the basin during this cycle.
the configuration of diagenetic processes and in particular dolomitization of the dhiban and older rocks ( Euphrates and Serekagni Fns.) in the sequence cuold be interpolated via a vcariety of mechanisms namely: reflux, mixing and evaporativce pumping.

Jabal Sanam is a salt plug, with cap rocks characterized by the presence of evaporitic sequence, where gypsum forms large part of this sequence. The field observations showed that gypsum occurs in form of massive beds and veins, In addition four petrological types of gypsum are recognized; alabastrine, selenite, fibrous, and rocky gypsum. The examination of (61) thin sections besides the X-ray analyses proved that the available gypsum represents the dominant mineral with few to trace amount of anhydrite, dolomite and quartz. Petrographically, four types of gypsum textures are also identified; alabastrine, porphyroblastic, fibrous and granular. All these textures suggest a secondary origin of Jabal Sanam gypsum due to the hydration of pre-existing anhydrite. The hydration occurs when the cap rocks approach the ground surface. The connate and groundwater form the main source of hydration water.
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Tanjero Formation is an Upper Cretaceous (Campanian-Maastrichtian) unit, which crops out within the Imbricated and High Folded Zones in Northeastern Iraq. Its outcrop stretches as narrow northwest-southeast belt near and parallel to the Iranian border. The formation mainly consists of alternation of clastic rocks of sandstone, marl and calcareous shale with occurrence of very thick conglomerate and biogenic limestones.
In this study many sedimentary structures are found in the Tanjero Formation, which have paleocurrent importance. These structures are cross bedding interference ripple marks, imbricated pebbles, elongate rudist and belemnite, plant debris, sole marks, valleys and channels. Most of these structures are found in the lower part. The paleocurrent analyses, as revealed by these structures, are presented in rose and stereonet diagrams, which show south and southwest directions.
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Eighteen plankonic foraminiferal species belonging to five genera have been identified within the studied section of Shiranish Formation in Butmah well no.15; which is divided into four biozones. The first zone represents the Late Campanian age while the other three zones extend within the Early and Middle Maastrichtian age These zones are:
-Gansserina gansseri Zone
-Globotruncana aegyptiaca Zone
- Globotruncanella havanensis Zone
-Globotruncanita calcarata Zone
The age of the studied section in Butmah well no.15 has been fixed as Late Campanian to Middle Maastrichtian while the upper part of the Middle Maastrichtian and the whole Upper Maastrichtian are missing. According to this fact the contact surface between Shiranish and Aaliji Formations is an unconformity surface.

The present study has processed the gravity measurements which were prcviously reduced to sea level, using a constant density of 0.22 along two parallel traverses located to the north east of Guwair city near Upper Zab River. A geophysical model for each traverse was designed according to available geological data taking in consideration the lateral mass variation due to folding of the sedimentary sequences above the reduction plane.
The removals of the negative resultant gravity anomaly effects by the above processing have enhanced the gravity high. Furthermore, the geophysical models show the continuity of folding of stratigraphic sequence down to cretaceous rocks. This anticline (East Zab Anticline) seems to have the same structural characteristics of khurmala dome within Kirkuk Oil field. In addition, the study reveals that the axis of Zab structure is shifted to the north east due to the possible existence of strike slip fault trending NE-SW which causes the swinging of the surrounding fold axes.

Zalim spring which is located about (50 Km) east of Sulaimania city, considered as one of the largest spring in Shahrazoor area. The spring mouth is a semicircular and coming out from a small cave locating about 22m above the base of a vertical cliff. This study aims to draw the real geological and hydrogeological setting behind appearance of this wonderful spring. Also an attempt was made to assess the quality of the water, with particular emphasis on the influence of human and tourist’s impact on the contamination and pollution of this water during toursting season.
A geological map and a geological cross section were prepared showing the location of the spring, which is based on a detail survey achieved by the authors, covered both Iraq and even Iranian portion of the catchments.
Chemical analysis of water samples were taken from five sites along a route that is more subjecting to human impact than others. The results show satisfactory results according to (WHO) and Iraqi standards for drinking, irrigation and industry uses. Relative increase of Nitrate ions detected and PO4 ions exceeding natural background also detected.

Generally many major and minor karstic phenomenas have been identified and studied by many researchers at Mosul region, with emphasis mainly on sinkholes that developed at highly water-soluble rocks such as limestone, marly limestone and gypsum that dominated the local geological formations here. The caves in the present study which constitute one of the important karstic phenomena in the area were developed and formed in conglomeritic rocks of fluvial deposits of Quaternary age .This type of occurrence is internationally considered to be very rare. The reasons behind that is firstly the presence of certain type of conglomeritic rocks which consist of calcareous matrix cementing various types of conglomerate fragments. This is the main factor that should be present prior to any development and formation of the caves. The second factor is the abundance of high rate of rainfall leading to the enrichment of underground waters. It is suggested, in the present study that wet Pliestocene climate is the most probable time for the initiation and formation of the caves in the fluvial deposits. This has also been suggested for other karstic phenomenas formed in other geological formations of Mosul city and its neighborhood, north of Iraq.

Time sequential remote sensing data were used to detect the changes in landuse and its relation with the environmental pollution, in the southern and northern limbs of Allan and Atshan structures respectively, within Nineveh Governorate. Landsat imagery taken in January (2004) shows local reflection anomalies throughout the study area. This information is used in conjunction with the analysis of geological, geomorphological features and digital image processing, to confirm the local contamination. Such information is a prerequisite for any environmental pollution program in the study area.