54 Hugh J. L. Beadnell — Flowiiig Wells, Kliarga Oasis. 



south of which the White Chalk is let down some 300 metres on to the 

 floor-level of the oasis, it and the underlying shales being bent into 

 an almost symmetrical oval basin or centroclinal fold. In all probability 

 the isolated eminences near Bulaq, Gala, and Girm Meshim mark the 

 prolongation of the line of fault southwards, and it may quite possibly 

 continue throughout the depression. 



The difference in level on either side of the line of disturbance is as 

 a rule very marked, the floor of the depression on the downthrow side 

 being very considerably lower than that on the west or upthrow side. 

 As might be expected, the line of partial or complete fracture directly 

 affects the water-supply, and one of the most noteworthy features 

 of the country south of Jebel Ter is the grouping of all the most 

 important wells near but on the upthrow side of the fault, in spite of 

 the ground on this side being at a considerably higher level. Probably 

 the sandstones rise gently to the west, in which case the underground 

 flow in this neighbourhood may be from west to east, which would 

 account for the best yields being obtained from bores put down near 

 but to the west of the fault; on the other side, although the actual 

 surface level is lower, the water-bearing sandstones occur at a deeper 

 level, and possibly the line of fracture in great measure cuts off the 

 supply.' 



Ball reported that the most striking evidence of faulting in the oasis 

 was between Jebel Ter and Jebel Tarif, but although the possibility 

 of this fault being connected with and causing the tilted strata of the 

 Gorn el Gennah is referred to, he finallj' appears to have abandoned 

 this view, as his map shows the fault as extending over only a com- 

 paratively short distance lying midway between Jebel Ter and Jebel 

 Tarif and running in a JST.IS'.E. and S.S.W. direction. This misplacing 

 of the line of fracture led Ball to believe that the majority of the wells 

 were on the east or downthrow side of the fault, whereas, as I have 

 shown, they are in reality on the opposite or west side, the actual line 

 of flexure passing almost direct from Jebel Ter through the Gorn el 

 Gennah. 



Surface -tvater Sandstone. 



The stratigraphical position of the beds of this division will be seen 

 by reference to the section. They have an average thickness of 

 45 metres, and consist almost entirelj- of sandstones of varying degrees 

 of coarseness, often highly ferruginous, and containing occasional beds 

 of aluminium and magnesium sulphates. Bands of shale are met with 

 here and there, but as a rule are confined to the upper and lower 

 portions of the series. IMembers of the group outcrop on the nearly 

 level floor of the oasis over large areas to the east of the line of 

 disturbance, while to the west, where, as I have shown, the general 

 elevation of the beds is higher, they form the foothills of Jebel Tarif, 

 Jebel Ter, and the high cliffs which rise to the north of IJm el 

 Dabadib and Ain Lebekha. Probably the sandstones which form the 

 surface of the desert between Kharga and Dakhla and cover large 

 areas to the south of these oases, also belong to this group. 



1 Op. cit., pp. 95-97. 



