Volume 12, Issue 2, Summer 2012, Page 1-100

Mineralogy, Petrography and Chemistry of Two Local Plasters, Iraq

Ibraheem R. Baddi; Zeki A. Aljubouri

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 1-16
DOI: 10.33899/earth.2012.36277

The mineralogy, petrography and chemistry of two local plasters
(Rasheed and Madae'n) and a dental stone were studied. Mineralogical study
by x-ray diffraction spectrometer proved that the three gypsum products consist mainly of bassanite or hemihydrate (CaSO4. 0.5 H2O) with minor amounts of gypsum and anhydrite. The petrography of the studied thin sections, reveals that the two local plasters consist of dispersed prismatic, monoclinic crystals with
ill-defined edges (bassanite of the β-hemihydrate). Dental stone consists of more packed, prismatic monoclinic crystals with well-defined and sharp edges
(bassanite of the α–hemihydrate). Compressed powders of the two local plasters improved their crystal shapes and edges and made their outlines similar to dental stone or (α–hemihydrate).
Chemical analyses of Rasheed and Madae'n plasters suggest that they consist of more than (96%) bassanite with small amounts of gypsum and anhydrite. Based on these compositions, the two local plasters are suitable for moulding, casting and constructional purposes. They are unsuitable for surgical plasters.

Geotechnical Maps of West and Pump Canals and their Branches of the Southern Jazirah Irrigation Project – NW Iraq

Seham I. Al-Azzo; Azealdeen S. Al-Jawadi; Hadeer G. M. Adeeb

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 1-12
DOI: 10.33899/earth.2012.36280

The main object of this work is to establish some of geotechnical maps of western canal, the pumping canal and their branches in the Southern Jazirah Irrigation project NW Iraq. Data have been collected, with different depths, from the drilled 218 boreholes. The data divided into three zones depending on the depth of each zone 5 meters, the first one is 0-5 m., the second is 5-10m. and the third is 10-15m. The mean values of engineering properties, represented by Atterberg limit (Liquid limit, Plastic limit And Plasticity index) and bulk density have been adopted as basis to prepare these maps.. The purpose of this division is to ensure information about these properties especially, for construction and agriculture purposes in order to helps designer in distribution of small and large constructions all over the project. The results show that the mean value of plasticity index reached 25 which is vital in ensuring non disturbance in soil while packing. The soil is characterized with swelling and shrinkage potential by having liquid limit rang between (40-50) and plastic limit between (30-20). Liquid limit and plasticity index have been used in soil classification of each zone. To illustrate the distribution of these properties SURFER program has been utilized. The engineering –geological maps show that the distribution of most engineering properties tends to improve towards west and south west of the project, except that the medium bulk density in site of pump stations which are deemed the best density for establishing such stations .Whereas the values of the bulk density were between low to very low in the whole project, whereof such bulk are useful in agricultural purposes because of the tendency of its water absorption and the reduction in surface runoff.

Microfacies and Depositional Model Jeribe Formation (Early Middle Miocene), Northwestern of Iraq

Nawrast S. Al-Ayobi; Sattar J. Al-Khafaji; Abdul Aziz M. Al-Hamdani

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 13-28
DOI: 10.33899/earth.2012.36296

It appears that the tectonism throughout early middle Miocene played an important role in the variations and distribution of facies zones within Jeribe basin. Although, the domination of the lagoonal influences within the most studied exposed succession; microfacies analysis revealed the influences of many other shallow environmental zones. Intermittent tectonic uplifts in basement blocks are reflected by successive secondary marine regressions toward the center of the basin in Sheikh-Ibrahim area. However, this regression had led to the termination of the Jeribe successions at studied area. This is represented at study area by a thick development of tidal flat facies overlain by a fresh lake facies at eastern parts; however it is exclusively represented by a thin bed of tidal flat facies at the western parts.

Structural Analysis and Tectonic Interpretation of Brittle Failure Structures at Perat Anticline – NE Iraq

Mohsen S. Dawlat; Rabeea Kh. Al-Hamdani; Hadeer Gh. M. Adeeb; Ibrahim S. Al-Jumaily

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 17-42
DOI: 10.33899/earth.2012.36293

Perat anticline is located about 100 km. northeast Mosul city. It extends
NW-SE for about 35 km through high folded zone of the foreland fold belt of the Zagros collision zone.
Joints were classified into sets and systems according to their relations with three mutually perpendicular tectonic axes. Tension sets are ac and bc, the first one formed by extension along fold axis accompanying direct compression perpendicular to fold trend, whereas the second is the product of relaxation that succeeded the primary compression. The shear systems are hko, hol and okl developed successively during direct compression and subsequent relaxation episodes of each tectonic pulse.
Planar calcite veins occupying ac, bc and hko joint sets and systems are also prevalent in the study area. Furthermore, singular and conjugate enechelon lenticular vein arrays are displayed within some carbonate units of study area. They enclose acute angles either with a or b tectonic axes indicating that they have been formed under two alternating stress regimes. The maximum horizontal compressive stress axis was perpendicular and parallel to the fold axis in the first and second regimes respectively.
The planar and lenticular vein arrays are associated with two orthogonal pressure solution sets (stylolite seams). The peaks of them refer also to the mentioned directions of the maximum horizontal compressive stress. The juxtaposition of these two brittle structure types reflects their kinematic interrelation and hence non-dilation deformation type.
Paleostress analysis of mesofaults falls into compressive, extensional and strike slip states. σ1 axis of compressive and strike slip states lies in normal and parallel orientations with respected fold axis. Whereas σ3 axis of extensional state lies normally to the same fold axis. This state seems compatible with the final uplift of the fold which supplemented also by development of bedding parallel stylolite seams with vertically pointing peaks.

Using Remote Sensing Techniques on the Study of Desertification and the Sand Dunes Movements in Biji Area Northern Iraq

Namik A. Daood; Waleed Y. Alubide

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 29-40
DOI: 10.33899/earth.2012.36289

Remote sensing techniques had been used to identify the total areas of the land covered with sand dunes for the region to the east of Lake Al-Thar Thar and towards Biji industrial town, and detecting the direction of its movement based on data obtained from the satellite images Landsat-5 (TM) 1990, and Landsat-7
(ETM +) 2000, also specify the land use of the region through the identification of sites of industrial plants, roads, water, rock, soils, and others. The results showed that the sand dunes presence as a characteristics bands as well as the possibility of determining the total area that covered by sand dunes during the specified interval time.
The results showed the great variety of the areas for the region covered with sand dunes and it ranging between (249.89) km2 in the year 1990 and about (643.92) km2 in 2000.The increases of the area covered by the sand dunes was due to the movement of sand dunes to the east of (Biji) and south-east towards Tikrit city, also many of the industrial establishment in the region was affected and exposed to the problem of sand drifting. This make the determination of the direction and the speed of movement of sand dunes taking into consideration when we planning for expansion of urban and industrial future of the industrial city of Biji.

Structural Analysis of Brittle Failure Structures in Spi Res Anticline - Northern Iraq

Nawal M. A. Othman; Ibrahim S. Aljumaily

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 43-78
DOI: 10.33899/earth.2012.36284

The present study involves different aspect of brittle failure structures at Spi Res Anticline within the foreland fold belt of north Iraq. It aims to decipher whether the late Cretaceous orogenic episode has any fracturing consequence to the rock sequence of this period at investigated area. This was accomplished by comparison of various fracture modes between Upper Cretaceous and Tertiary rock sequence exposed at studied area. The study area is prevailed with widespread joints and tabular veins, little mesoscopic faults and scarce of pressure solution surfaces (stylolite). Joint analysis showed two extensional sets (ac and bc) and three shear systems (hko, hol and okl). However, hko acute about a and b system was prevailed and followed by ac and bc sets. The openings of most of joint sets were filled later by calcareous or siliceous precipitations without any kinematic indications, some refers to extension normal with vein walls and for a single growth episode. A little number of striated mesoscopic faults were registered throughout both Cretaceous and Tertiary rocks in study area. Most of them are reverse, others are normal and strike slip. Further, two sets of stylolite seams were found scarcely, peaks of the first oriented parallel with the bedding dip, whereas those of the other set trended parallel to bedding strike. The kinematic analysis of mesoscopic faults and shear joints in study area gave a number of compressive and strike slip stress tensors. The maximum horizontal stress (δmax ) of these tensors lie in N-S, NE-SW, E-W and NW-SE general trends. Accordingly, they were organized into two compressive tectonic regimes. One representing the component normal to the orogenic front, acted in N-S and NE-SW directions. Whereas the other representing the component parallel with the orogenic front, acted in E-W and NW-SE directions. Both components were resulted from oblique collision of Arabian and Eurasian plates. However, these two compressive tectonic regimes are supported by a couple sets of stylolites with their peaks either normal or parallel to the trend of Spi Res Anticline. No brittle failure structures belonging to orogenic episode of Late Cretaceous were recognized in the Upper Cretaceous succession of study area in the present investigation.

On Some Ostracode Species of the Avanah Formation from Dohuk Area N. Iraq

Nisreen M. Aziz

Iraqi National Journal of Earth Science, 2012, Volume 12, Issue 2, Pages 79-92
DOI: 10.33899/earth.2012.36303

Six Ostracode species belonging to the Trachyleberididae and Xestoleberididae are recorded for first time from Avanah Formation (M.Eocene), Dohuk area,
Northern Iraq.These species are: Uroleberis globosa Ducasse 1967, Uroleberis sp., Acanthocythereis (Canthylocythereis) heijranensis sp. nov. Acanthocythereis (Canthylocythereis) sp., Acanthocythereis (Canthylocythereis) alacer Al-Furaih 1992, and Anommatocythereis beserensis sp. nov.