Iraqi National Journal of Earth Science

A graphical method of determining the possible presence of a remanent component of magnetization in two dimensional igneous masses within the basement is described. It is required to assume that the same source produces well defined gravity and magnetic anomalies. The method involves taking the ratios of distance between peaks of maximum values of gravity and magnetic for various angles of field inclinations. Ratio of maximum positive and maximum negative values for various angles of field inclinations are also used. These ratios are plotted against field inclinations. Examples of anomalies are taken from the western desert area of the stable shelf in Iraq.

The present study deals with the succession of the Aquitanian stage, which includes: Ibrahim, Azaknd, Anah Formations, and intervening of Ibrahim with Azkand Formation. These formations are divided into seven microfacies, based on different sedimentological and paleontological criteria. These microfacies are: Planktonic foraminiferal lime wackestone, algal lime wackestone-packstone, lime wackestone, foraminiferal lime packstone-grainstone, lime bindstone-framestone, lime mudstone microfacies, and fossiliferous lime packstone - grainstone microfacies.
According to the attribute of these microfacies and their microfossils remains like foraminifera and algae, the depositional environment situated in middle shelf to supratidal environments.

Seismic activity has been studied at Mosul dam reservoir for the period from March 1986 to December 1987. More than 250 micro-earthquakes of magnitude up to 3.2 ML were observed, of which 180 were located. Nearly all earthquake epicenters were located within a radius of less than 25km from the dam site. Cluster of epicentres was observed in the eastern embankment of the reservoir. Most of the hypocenters were located between the ground-surface and 2km of depth.

Changes in the nature of land use activities, in time and space, often result in land cover changes and, as such, are an indication of land management activities. This research represents an attempt to evaluate the ability of using the new version of Anderson's classification system up to the third level in the land use and land cover classifications of Ninevah Governorate using Landsat TM7 imagery.
The study area represents one of the most varied and complex geomorphic landscapes in Iraq, and characterized by irregular land use and different land cover in the geomorphic distribution of landforms. Geomorphic agent represent the main factors in the spatial distribution of soil types, lithological escarpments, and the existing land use patterns.
The land use and land cover map shows the whole of the apparent activities up to the third level according to the USGS system, and 27 classes of land use are shown in the final map.
The results show that visual analyses of satellite images, applying methods similar to those commonly used for aerial photo analysis, are sufficient for observing features shown on 1:100,000 scale Landsat images. Digital classification is appropriate for some applications, but it was found that land use and land cover mapping projects of the type described here are not among them. These data were utilized to draw a new regional land use and land cover map of Ninevah Governorate at a scale of 1:250,000 .

تThe pumping test and recovery data of the three wells Al-Ourba, Al-Qadiseya and Hettin distributed in the Al- Shimal District, north of Iraq. were analyzed using Hantush method, Walton method and Theis Recovery method to derive the hydraulic parameters such as transmissivity (T) and hydraulic conductivity (K) of the water bearing formations. The results of analyzed data show that the average transmissivity (10, 4.7 and 7.8) m2/ day, of wells Al-Ourba, Al-Qadiseya and Hettin respectively, and the average hydraulic conductivity (0.17, 0.12 and 0.20) m/day of these well respectively.
The results of pumping test also show that water table return to static condition during (30-40) minute after (600) minute of pumping of each well.

A total number of (32) marl samples of Fat'ha Formation (Middle Miocene) was collected from four selected localities in northern Iraq. Geochemical study included the analysis of (13) major and minor oxides by x-ray fluorescence and wet chemical methods and (7) trace elements by (XRF). The study shows that the oxides (SiO2, Al2O3, TiO2, Fe2O3, FeO, most MgO, Na2O, K2O, MnO, P2O5 and H2O+) are in the detrital fraction which comprises around (58%) of total mineral phases. These are clay minerals (39%), quartz (15%), iron oxides and Ti-minerals (3%) and feldspar (1%). The oxides (CaO, some MgO and CO2) comprise the chemical fraction, the carbonates (~ 42%). The trace elements (Co, Ni, Ga, Rb, Zr and some Sr) are within the detrital fraction, mainly the clay minerals and iron oxides. The elements (Ba and the remaining Sr) are within the carbonate fraction. The oxides and elements of the detrital fraction, in general, have a negative correlation with oxides and elements of the chemical fraction. The red colour of marl sediments is primary caused by the red pigment of haematite. The green colour is secondary and resulted from the reducing environments, initiated by the presence of organic matter.

. The present study is concerned with the characteristics and quality of Tigris water passing through in Mosul city. Twelve samples were collected from the river in the area between upstream and down stream of the city. Six samples in Summer and (6) samples in Winter, as well as, sample of the rain water falling on the city were collected. The physical and chemical analyses showed relative increase in most of the concentrations of the principle components of the river, as well as high concentrations of the trace elements through downstream Mosul city, where a large quantities waste water is drained to (around 500000 m3/day) the river. The results also show that chemical major ions concentrations during rainy season is less from there than dry one this because of the lightening factor and the spreading of falling rain water with low concentrations of ions and also the slightness of the evaporation processing during this season. Results shows that Tigris water is generally are not within the world standard levels of drinking water.

Khor Al-Zubair is a shallow arm, semi restricted channel, located at the northwestern part of the Arabian Gulf. The study area ( Hajam island ) is situated at the southern part of the channel, comprised sandy, silty and muddy sediments.
Systematic description is made for the studied pelecypod shells assemblage, which are collected from the Hajam island in Khore Al-Zubair. These assemblage include nine species belonging to seven genera and six families. These species are; Barbatia helblingii, Pinctada margaritifera, Pinctada radiate, Spondylus (Spondylus) gaederopus, Diplodonta (Diplodonta) rotundata, Semele sinensis, Circe (Circe) scripta, Circe (Circe) intermedia and Bassina (Bassina) calophylla.

Gypcrete with a thickness between (4 - 8) meters occur at the upper part of Fat`ha Formation at Mahalabia area, northwest of Iraq. The gypcrete consists of several zones which are lacking stratification. It has been divided on the basis of textures and characteristic structures into three types. These are from bottom to top: subsurface crust, followed by friable gypcrete and the hard surface gypcrete. This last crust is exposed at the surface and consists of gypsum polygons of different shapes and sizes and are characteristic of this zone. The three zones were formed by different diagenetic processes caused by groundwaters and the alternation of dry and wet periods. Calcrete as well as gypcrete also formed due to these processes. The calcrete exhibits alpha fabrics which often reveal the influence of physico-chemical processes and calcite pseudomorph after gypsum. All these features indicate that the calcrete is associated with gypsum crust, probably during the early stages of diagenesis through pedogenesis. The source of gypsum and carbonates of these crusts were most likely the bed rocks of Fat`ha Formation. The majority of gypsum crystals were formed insitu, mainly from groundwaters by displasive growth within the host sediment.

Fourteen sample from the stratigraphic interval (1330-1600m.) in the borehole KH5/1 were studied palynoogically. The samples yielded well preserved and diversified palynomorphs except one sample at depth (1330m.) was barren.
Identification of (54) species of acritarchs belong to (29) genera and (16) species of Chitinozoans belong to (9) genera, (16) species of miospores belong to (13) genera and (6) species of Scolecodont belong to (4) genera was the conclusion of this study.
Comparision with similar palynomorphs in different parts of the worlds indicates clearly Upper Silurian (Ludlow) age for the samples studied. The Palynomorphs and especially the acritarchs reveal that the studied section was deposited in near

The major part of the exposed anticline of Jabal Ain Al – Safra consists of Pila Spi Formation (M.U.Eocene) and contains five water springs (Ain Al– Safra, Squf, karawan, Semmak Baadra).
The Pila Spi rocks consist of different proportions of calcite and dolomite at different areas, within the eastern limb of Jabal Ain Al– Safra anticline. Grain size, joints densities and fractures are also different.
The present study has concluded that Ain Al– Safra waters compared with other spring waters within the area have high concentration of the ions of (Ca, Mg, Mn, Fe, Cu, Co ) especially manganese (Mn).this is possibly because the under ground waters before reaching Ain Al– Safra spring pass through relatively thick gently dipping rocks, rich in calcite and have fine grain size and also pass tow layers of marl interbedded with carbonate rocks.
These conditions plus the pressure of CO2 and the effect of the (pH) value allow water to dissolve carbonate minerals and becomes relatively enriched in the above ions.