ANNIVERSARY ADDRESS OF THE PRESIDENT. Ivii 



But M. Lartet affirms that pebbles of this quartziferous porphyry 

 are found in the congiomerates of the " Nubian sandstone," near 

 Mount Hor, and that, as their eruption consequently took place 

 before the depression of the older Cretaceous strata, the porphyries 

 must, if there has been any recent elevation at all, have partaken of 

 it in common with the Cretaceous and Eocene strata, for which 

 movement the evidence is yet to be collected. 



Under such considerations the Dead Sea must be allowed an in- 

 dependent origin, connected by a continuous water-flow neither 

 with the Mediterranean nor with the Gulf of Akabah; and the 

 chemical reasoning on the peculiar character of the various salts so 

 largely dissolved in its waters lends a strong confirmation to such 

 views ; whilst if we test the phenomenon by the analogy of salt 

 lakes in other countries, there is no difficulty in accounting for its 

 saltness by the energetic evaporation, throughout a long series of 

 ages, of all the waters flowing down into its basin. 



However closely these two most recent observers may agree as to 

 the antiquity of the grand chasm of the Ghor, a great discrepancy 

 of opinion arises with respect to the mode of its formation. Dr. 

 Fraas looks upon it as a simple case of erosion from perfectly hori- 

 zontal strata — a statement upon which we are compelled to ask, 

 what has become of the eroded material ? And reckoning up only the 

 length from the north of the upper great lake to the end of the main 

 hollow, south of the other, about 150 miles, with the vast depth 

 and width of the entire depression, there is an astounding quantity 

 of debris to be accounted for, which, if we are unable to keep 

 open a water-route downhill to the Gulf of Akaba, leaves the 

 hypothesis untenable. On the other hand, M. Lartet, observing a 

 slight easterly inclination on the Judaean side of the Dead Sea, and 

 only higher strata exhibited there as compared with those that crop 

 out on the opposite shore of Moab, adopts the view suggested first 

 by Hitchcock*, that a fault or dislocation takes its course along the 

 line of the valley, having a heavy dovnithrow to the west, and 

 that, in fact, the present depression was produced by a relative 

 descent of the eastern side of the hill-district of Judaea during the 

 movements that raised the entire land from the sea. The soundings 

 taken by the American Expedition, showing a gradual inclination 

 from the western shore to a maximum depth of above ] 300 feet 

 near the eastern side, and the sudden plunging down to 900 feet 

 depth of this latter coast, add probability to a theory much more in 

 accordance with facts observed elsewhere than is the notion pro- 

 pounded some years ago by Eussegger, that the whole breadth of the 

 Ghor had been a subsidence caused by deep-seated volcanic action. 



Both Fraas and Lartet concur with the observations of all geolo- 

 gists who have visited this region, that the volcanic appearances 

 ascribed to it existed only in the minds of persons imbued with 

 preconceived notions and ignorant of the character of the simplest 

 stratified rocks ; but, penetrating as he did through the mountains 

 of the eastern coast, M. Lartet was able to confirm the statements 

 * Eep. Assoc. Amer. Geol. Boston, 1841-42, p. 348. 



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