362 Proceedings of the British Association. 



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lines. In illustration of the power of producing permanent lines 

 of elevation which earthquakes have exhibited in modern times, 

 the authors instance the Uilah Bund, an elevated mound extend- 

 ing fifty miles across the eastern arm of the Indus, which was 

 the result of the great earthquake of Cutch in 1819; and another 

 case recorded in " Darwin's Journal of Travels in South Ameri- 

 ca," which a traveller described as a line of elevation of the strata, 

 crossing a small rivulet, and shown in the fact that he found him- 

 self going down hill while ascending the dry deserted channel. 



Date of the Appalachian Axes, — The authors describe the 

 elevation of this chain as simultaneous with the termination of 

 the carboniferous deposits of the United States, and as the cause 

 which probably arrested the further progress of the coal forma- 

 tion. With one local exception on the Hudson, the whole series 

 seems to have been deposited conformably, without any emer- 

 gence of the land. That the elevation did not take place later, 

 is shown by the undisturbed condition of the overlying beds, ap- 

 proximately of the age of the European New Red Sandstone. 

 The elevation of the chief part of the great belt of metamorphic 

 rocks on the southeast side of the chain is referred to the same 

 great movement. In conclusion the authors remark, that an in- 

 comparably greater change in the physical geography of North 

 America, and perhaps of the globe, seems to have occurred at the 

 close of the Carboniferous epoch than at any previous or subse- 

 quent period ; and they consider these changes, and the effect 

 produced by them on the organic world, as affording some of the 

 highest subjects of geological investigation. 



Mr. Murchison confirmed the views given by the authors of 

 this paper, of the great break in the series of geological deposits 

 which occurs between the Palaeozoic rocks and later deposits: the 

 coincidence in the direction of some great chains in Europe and 

 America, belonging to the same geological period, was very strik- 

 ing. He was not prepared to give any opinion upon Prof. Rogers's 

 undulatory theory. Sir H. T. De La Beche described the gene- 

 ral character of the anticlinal and synclinal lines, and stated, that 

 whilst contortions of the strata sometimes assumed the character 

 of mountain chains, at other times they oocupied large tracts of 

 low ground, as in the comparatively flat country of South Wales. 

 He then made some observations on the space occupied by masses 

 of rock over certain areas; the older rocks of England, \i pitr 



