656 GLACIEK-EEOSION THEORY 



ridge, on the south-west, and due south by a confused mass of unim- 

 portant low hillocks, composed of chalky indurated marl. From this 

 point the trough rises along the Valley of Arabah to a point 35 miles 

 north of Akabah, where it attains a height, in round numbers, of about 

 500 feet above the level of the western arm of the Eed Sea, or 1,812 

 feet above that of the Salt Lake. For an excellent summary of the 

 facts the reader may be referred to Mr. George Grove's article on the 

 ' Salt Sea' (' Smith's Dictionary of the Bible,' vol. iii. p. 1173). The 

 geological formation of the tract is nummulitic and Jurassic, with dykes 

 of basalt, which abound along the Lake of Tiberias. 



The physical features of the tract have led almost all good autho- 

 rities to infer — 1. That a long straight fissure or crevasse, caused by 

 mechanical disturbance, extended from Antioch to the Red Sea. 2. 

 That a strait connecting the Mediterranean with the Gulf of Akabah 

 was scoured out along this fissure forming the trough of the Jordan. 

 3. That the extremities of the trough were elevated, cutting them off 

 from the two seas. 4. That the Jordan probably flowed at one time 

 into the Gulf of Akabah. 5. That simultaneously with the upheaval 

 of the Akabah ridge, the valley of the Jordan was depressed through a 

 violent mechanical convulsion. G. That, as a result of the last opera- 

 tion, the chasm constituting the precipitous deep basin of the Dead Sea 

 was left. How was this chasm formed ? That it was a volcanic crater 

 is negatived by all the facts known on good authority ; for details vide 

 Dr. Anderson's Report and Russegger's Sections. Let us apply to the 

 conditions the hypothesis so stoutly advocated, of glacier-erosion as the 

 formative agent of lake-basins. The excavation to such a depth of a 

 rocky area of 250 square miles, would involve an enormous terminal mo- 

 raine, without reference to transported blocks and detritus, derived from 

 the head and upper course of the glacier. Nothing corresponding has been 

 observed by any explorer at the southern end of the Dead Sea. The 

 salt-ridge ofKhashm Usduni, the detached pillars of salt, and the unim- 

 portant eminences of chalky indurated marl, traversed by the Wady el 

 Jeib, are not in accordance with the usual physical character of a moraine. 

 To an argument so conclusive it may be needless to add others. But the 

 lowest point to which Dr. Hooker traced the moraines of ancient glaciers 

 on Lebanon was 6,172 feet above the sea. Could the ridges at the 

 head of the Jordan have yielded a stream of ice which must have 

 travelled 150 miles to reach the sultry chasm of the Dead Sea, and 

 then scoop it out? How explain the string of the three lakes, El Huleh, 

 Tiberias, and the chasm of the Ghor, with the sixty-mile trough 

 between the two last? Erosion by marine or fluviatile action might 

 account for the general excavation of the trough along the line of a 

 fissure ; but how can it be made to explain the sudden, irregular, pre- 

 cipitous chasm, so much below the general level, which is met with in 

 the basin of the Salt Lake ? That chasm occurs, at the point of greatest 

 depression, where, to use a figurative expression, the back of the trough 

 appears to have been broken during the convulsion which caused the 

 subsidence. But, for the present argument, it is sufficient to indicate 

 that the Valley of the Jordan presents along its course three well- 

 marked lake-basins, the formation of which stems irreconcilcable with 

 the hypothesis of glacier-erosion. 



I shall now revert to the lakes of Lombardy, which I had in view 



