254 



EAST AFRICAN FLORA AND FA UNA 



present position when a stream from the south could flow 

 directly into the Golden Valley. 



This, however, has now been diverted owing to the occur- 

 rence of a band of clay east and west across its former 

 course ; the Mole has cut its way eastward along the clay, as 

 it is soft and easily removed by water, and thus has absorbed 

 into its own basin the stream that originally flowed northward 

 down the Golden Valley. 



The Esdraelon Gap was probably formed in exactly the 

 same way. It occurs on the face of the plateau of Endor and 

 Nain, which presents a steep face to the west, and a long 



Wcahhn WnfeishcJ 



Si^ of North Doihhs 



Wea I dm V/a tci sh cc! 



•^W;WJVV>Y/J D ojun s , 



Original Course of Golden Valley 

 Stream and the Mole. 



Present Arrangement : the Golden 

 Valley beheaded by T-shaped 

 Course of the Mole. 



Fig. 14. — -Diagrams illustrating the Beheading of River Valleys. 



gradual slope to the east. Originally the plateau must have 

 extended farther to the west, continuing to rise in that 

 direction, so that the rain that fell on it flowed into the 

 Jordan. The Wadi el Muwali, a tributary of the Kishon 

 however, now flows at the foot of the steep western face of 

 the hills. It has cut its way into the plateau, and drained 

 the streams that once rose farther to the west, just as the 

 Mole has diverted the Golden Valley stream. The Wadi el 

 Muwali has therefore " beheaded " the Jalud and cut away 

 the upper part of its basin. What now appears as a notch 

 in the western edge of the plateau is therefore only a section 

 across the upper part of the valley eroded by the Jalud, when 

 this stream rose much farther to the west. 



