Iraqi National Journal of Earth Science

A spectroradiometer have been used in the practical stage of the present study for testing the spectral reflectance response of two samples (Marl and Limestone) from Jabal Sinjar. The test was performed in the spectral rage of
(350 - 2500 nm). From landsat image satellite, three band combinations have been used to produced two color composed images, first one (1, 2, 5), while the second (1, 5, 7) to ensure the coincidence between the practical behavior of tested samples and laboratory testing results.
The result shows that the limestone rock sample has an ability to reflect the spectral incident rays more than the marl rock sample.

Fifteen samples from the lower part of Shiranish Formation, Sinjar anticline, northwest Iraq, are investigated in order to identify calcareous nannofossils species of which twelve species are recorded as follow; one species of holococcoliths, seven are heterococcoliths and four are nannolith. On the basis of the above assemblages two biozones are proposed from oldest (at bottom) to youngest
(at top):

2- Tranolithus phacelosus Interval Zone(Part) (CC23)
1- Lithraphidites praequadratus Partial Zone(Part) (CC22)

The above biozones are correlated with other calcareous nannofossils biozones from regional view led to conclude that the section is late Campanian in age.

The study of the lithoogical columns in 20 oil wells selected from many southern Iraq oil fields proved that these two movements (Second Austrian Alpine and Laramide) affect the diversity, as well as the vertical and lateral sediments distribution in the studied area. Two models were observed for the effect of Episode 2 in the sediments understudy.
The first one is direct represented by the lateral and vertical thickness variation. Whereas the second is indirect represented by the changes in sea level and accommodation space, these two factors have great effect on sediments diversity. The intensity of the second Austrian Alpine is greater that of Larimidian movement causing the heterogeneity in the lateral and vertical thickness of Ahmadi, Rumaila and Mishrif formation, and the relative homogeneity in the thickness of Upper Tanuma, Saadi, Hartha, Shiranish, and Tayarat Formations. The sediments of the Second Austrian Movement characterized by their shallowing upward facies except Rumaila Formation which exhibits sub basinal facies due to the relative sea level changes. Furthermore, the Laramidian sediments characterized by deepening upward facies represented by Upper Saadi and Shiranish formations.

Seismic activity has been studied at Mosul dam reservoir for the period January to 20th July 1990. 33 micro-earthquakes of magnitude up to 3 ML were located. Nearly all earthquake epicenters were located within a radius of less than 25 km from the dam site. All the hypocenters, except one, were located at depth less than 2km from the lake's surface, which means there is no change occurred in the seismicity behavior from the previous monitoring period March 1986 to end of December 1987.

This study describes and discusses the feasibility of the development of an inexpensive filter- photocell system suitable for quantitative colour measurement of ore minerals under the reflected-light microscope. In this study, reflectance measurements of eight minerals were obtained using broad band coloured filters with spectral transmissions approximating to those theoretically required. Using this method, only three measurements of the intensity of reflectance for each mineral and the standard (SiC) were taken using red, green and blue (RGB) filters.
Colour values obtained in this study are compared with IMA/COM reference values and are satisfactory to within ±1%. Also, the obtained colour values revealed that it might be possible to apply this simple, rapid and direct method in studies where low-cost instrumentation is required, especially in the teaching of ore mineral identification and quantitative colour theory. It is worth mentioning that although the results of this study are promising, conventional spectral reflectance measurements (380- 740 nm) will remain the best recommended method for obtaining the most accurate colour values.

Alqosh plain lies about 40 km to the north of Mosul city surrounded by several Taurus anticlines (E-W direction). The anticlines are separated by a wide syncline underlying the plain .The M-U Eocene rocks are exposed in the core of those anticlines which are overlain by Fat'ha, Injana and Meqdadya Formations.
The field survey of the earth resistance measurements was carried out at three locations (Alqosh, Boawzan, Bayban) in the study area, depending upon some geomorphological, geological and geotectonic features. Three azimuthal directions are used appling Offset Wenner Array (OWA) with fifteen spacing intervals.
The OWA survey was represented by cartesian and polar graphs depending on the calculated mean percentage. The results displayed pseudo electrical anisotropy representing by lateral variations at small electrode spacings, while electrical anisotropy effects are shown in large spacings..
The present study indicated varied fractures having frequencies, directions and dips that are parallel and vertical to the structural axes with vertical and medium dips. as well as, minor and medium fractures extending for several spacings. The current study showed large frequency fractures that are inclined to the fold axes especially in Alqosh and Bawzan. In addition, an inverse relationship appeared between electrical anisotropy frequencies and lateral variations in the study area.

Petrographical, petrophysical and facies studies of seven surface and subsurface locations of Fat'ha Formation from Mosul area and Kirkuk oil field, reveal that the diagensis played an important role in the evolution of the nodular sulfate as petroleum cap rocks; and this role increases with an increase of diagenetic growth and compaction. The occasional presences of bitumen inclusions within both, nodules and the host material of some sulfate bed bases is thought to be formed due to early leakage of the hydrocarbon through the host material. This leakage was gradually diminished and finally stopped due to the growth and the packing of the sulfate nodules and the disappearance of the most of the host material.

Structural study was carried on the eastern part of Bekhair anticline
(Duhok section ) to test the folding phases within the formations related to Cretaceous and Tertiary period .This study adopted the structural contour maps in fold geometrical and structural analysis by construction of the Cretaceous and Tertiary formation contacts. The fold axes for the different structural contours were drawn .
The study found that there was an anticlockwise rotation of seven degree in the fold axis direction .This result supported ( or agreed ) with the results obtained from fold geometric analysis by stereographic projection ,which indicates that the studied fold were underwent more than one phase of folding .