![](../images/ball_good.gif)
acknowledgement
![](../images/ball_good.gif)
contents
![](../images/ball_good.gif)
introduction
![](../images/ball_spot.gif)
prevision work
![](../images/ball_spot.gif)
scope of the present work
![](../images/ball_good.gif)
gross lithologic variation
![](../images/ball_spot.gif)
previous lithostratigraphic classifications
![](../images/ball_spot.gif)
the duwi formation
![](../images/ball_good.gif)
granulometric analysis
![](../images/ball_spot.gif)
procedure
![](../images/ball_spot.gif)
size parameters
![](../images/ball_good.gif)
modal analysis and classification
![](../images/ball_spot.gif)
modal analysis
![](../images/ball_spot.gif)
classification of abu tartur phosphorites
![](../images/ball_good.gif)
geochemistry of phosphorites
![](../images/ball_spot.gif)
major elements in liffiya,liffita-maghrabi and maghrabi sectors
![](../images/ball_good.gif)
geochemistry of phosphorites
![](../images/ball_spot.gif)
trace elements in the liffiya-maghrabi sector
![](../images/ball_spot.gif)
zinc
![](../images/ball_good.gif)
geochemistry of black shales of the duwi formation
![](../images/ball_spot.gif)
calcium
![](../images/ball_spot.gif)
barium
![](../images/ball_good.gif)
effect of weathering on the chemical composition of phosphorites and intercalating shale
![](../images/ball_spot.gif)
method of study
![](../images/ball_good.gif)
effect of weathering on the x-ray differaction pattern of the phosphate mineral
![](../images/ball_spot.gif)
conclusion
![](../images/ball_good.gif)
summary and conclusion
![](../images/ball_good.gif)
references
![](../images/ball_good.gif)
الملخص العربى