| الملخص | This work is an exploring investigation about the bituminous coal in northern Zakho, Duhok. The work area is located between Bank village at the east , and Sharanish village at the west . the bituminous coal is the oldest fossilized fuels in Iraq, it had been noticed in many regions in north of Iraq especially in northern Zakho area.
A bed of bituminous coal recorded, about six meters in thickness, in an area about two kilometers in width, the bed extension is about eleven kilometers in east-west general direction, in parallel with the regional strike; dip amount ranges from 35oto74o , dip direction ranges from 162o to 222 o . the bed is exposing or covering depending on the structural and geomorphological conditions. twelve of locations recorded and studied in the area in this work.
The bituminous rocks are found too as thin horizons within the overlying and underlying carbonate beds, which become more bituminous, dark, and foetid , where be close to the main bituminous bed, that may be explain that the bituminous substances deposited in the same time, or slightly after, the deposition, but before the lithification of the surrounding carbonate beds .
Petrographicaly, these bituminous rocks can be named in this study (clayey carbonate bitumen)in general, because the bitumen is mixed with other components but these rocks still flammable, and when they burn, they produce flame, black soot ,and bituminous smell , and large amount of carbon cinders ( 40% - 70%(,composed of sand , clay , and carbonate .
In the bituminous rocks, which have massive or papery form ,the ratio of bitumen vary from(100% ) to( 10%), when the bitumen decreases, other minerals increase like carbonate minerals as ( calcite, dolomite), silicates as ( quartz - chalcedony) and clay minerals as (kaolinite) , in these cases, the bitumen is coated the crystals of the these minerals or fills the cavities between them or occurs as dispersed patches .
According to chemical analyses, the average values of major components concentration are : L.O.I =49.03%, CaO=27.67%, SiO2=11.2%, MgO=4.02% , SO3=3.76% , Al2O3=2.56%, Fe2O3=2.05%.; Compositional materials range from( 42.96) to (4.33); trace elements averages in (ppm) are : Co=<10; Zn=690; Ni=194; Cu=62.4; U=<0.5; V=0.32; Cd=<27ppm.
Petrophysical analyses bulk density range from (1.35) gm/cm3 to( 2.95 ) gm/cm3 ; porosity is ranges from (1.739%) to 44.584%.)
Radioactivity readings of bituminous rocks are higher than upper and lower carbonate beds. | |
