578' Prof. T. G. Bonneij — T/ie KisJion and Jordan Valleys. 



a ' trough-fault,' why not a ' trough valley,' or, if we wish to be very 

 precise, a ' trough-fault valley ' ? But a new word, especially if 

 a little improper, seems to be as fascinating to some geologists as it 

 is to children ! 



No one doubts that the physical features of Palestine have all been 

 developed since the age of the Nummulitic Limestone ; their broad 

 outlines were probably determined, as we shall presently see, by 

 the beginning of glacial times.' To excavate the broad * Kishon 

 valley ' requires, in my opinion, not only a heavier rainfall, but also 

 a much larger drainage area than now exists. It is obviously 

 a ' beheaded ' valley ; ^ the two streams descending to the Jordan 

 on either side of Jebel Duhy have trespassed westwards and pushed 

 the watershed in that direction. In other words, I consider the 

 Kishon valley to be older than that of the Jordan, and still to 

 retain, west of the passes, its principal ancient features. ' But where 

 was the original watershed? If it were to the west — somewhere 

 out in the Mediterranean — then Jebel Duhy must have been an 

 island dividing the river into two channels ; a thing possible, but 

 the less probable hypothesis. The features described above appeared 

 to me, when I visited, the country, to demand a watershed well 

 to the east of the line connecting Tabor with Gilboa over Duhy. 

 The watershed may have disappeared in the trough-faulting which 

 determined the Jordan valley ; but I doubt, apart from other 

 obvious difficulties, whether that would be far enough to the east, 

 and am disposed to place it on the Syrian highlands nearer to that 

 from which streams now descend westwards to the Jordan, because 

 the lower part of the valley, the present Kishon, seems to me so 

 deep, level, and flat that it could only have been made by a stream 

 not much less important than that of the Jordan itself. I am 

 unable to identify the old course of its upper waters with any 

 existing valley ; but that is not surprising, because the amount 

 of subsidence in the Jordan trough has maintained, if it has not 

 accelerated, denudation on its western flank, ^ while cutting off 

 the supply has left the lower part of the ancient valley — the 

 Esdraelon-Acre trench — very much as it was.'^ So I suppose the 

 movement which first raised the Syrian highlands (including 

 Palestine) above the sea culminated at an axis still indicated by 

 the head waters of the Jarmuk, the Zerka, and many other streams, 



1 It is almost ueedless to observe that in tliis interval nuicli -work was doue in 

 ' making scenery ' all round the Mediterranean border. 



2 My friend Professor J. W. Gregory emphasises this conclusion in his "Great 

 Rift Valley" (pp. 253-255), but I may say that each of us reached it independently 

 of the other, and we take opposite views as to which was the executioner. The 

 sketch-map inserted above (Fig. 1), for which I am indebted to his kindness and 

 that of his publisher, Mr. J. Murray, brings out very clearly the extent of the 

 trespass. 



^ The outlet of the Orontes (Nahr-el-Asi), perhaps also of the Leontes (Nahr-el- 

 Litany), may be contemporary features in the structure of Syria. 



* To this," of course, I attribute the westward trespassing of the shorter streams on 

 that side. 



5 To behead a valley, as we can see in the case of the Inn between St. Moritz and 

 the Maloya, practically puts a stop to erosion in the uppermost basin. 



