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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



tions from within to the outer crust, and not mere subtractions from 

 one spot and additions to another. Without such an extensive in- 

 ternal agent in a former condition of the planet, the geologist would 

 indeed be sorely puzzled to explain how many of the earliest sediments 

 began to be formed. Once admitted however, and he has no diffi- 

 culty either upon this head or upon the disruptions specially under 

 consideration. For if, as I believe, the agency from within was then 

 much more intense and prolific than any which now prevails, so can 

 we very well imagine how the ruptures and oscillations of the crust 

 were greater, and how the translation of materials on the occasion of 

 such changes was more violent and dispersive than anything of which 

 we can form an opinion from actual observation. 



The other hypothesis, by which incalculably vast masses of the 

 hard rocks that once filled mountain gorges or broad valleys were gra- 

 dually ground down and removed by the ordinary action of the sea, 

 is inconsistent with the facts above narrated. Still more is it set 

 aside by an appeal to the great fractures which have affected so many 

 other parts of the earth's crust ; for these prove that the agency by 

 which many geological revolutions were effected was as abruptly 

 violent, as the increase of sediment during long ages of repose was 

 gradual and analogous to what is now going on. 



In maintaining, in common with many other writers, that there 

 was a much greater intensity of fracture in former stages of the planet 

 than now, I also infer, that such dislocations must have been accom- 

 panied by torrents of water then set into play ; which, whether they 

 may have been salt, and be called waves of translation, or fresh, and 

 were obtained from subterranean sources, must have powerfully aided 

 such sudden strains and fractures, and thus have effected in a short 

 time that which under ordinary circumstances could not have been 

 done in thousands of years. Any ordinary tidal action we can con- 

 ceive would, I repeat, have left signs either of successive sediment or 

 of water-worn pebbles, and would not have afforded the clear proofs 

 that have been adduced either of sweeping denudations down to the 

 bare framework of the rocks, or of angular drift distributed in bands 

 and patches at various altitudes. In accounting for such facts, the 

 advocate of the tidal action of the sea meets with insurmountable dif- 

 ficulties at the very threshold of his position. Instead of rounded 

 pebbles in the last-formed detritus of the South-east of England, he 

 sees both on this and 6n the other side of the Channel near Calais, 

 that where there is a true water-worn beach, it lies beneath local drifts, 

 in which all is fragmentary and tumultuous ; and hence he is not 

 authorized to appeal to the mere forms of the escarpments of chalk, 

 or to insulated pyramids or outliers of that rock, as proofs that the 

 sea, as we now understand its action, could have produced any such 

 results. We, who take the opposite view, assert, that the shattering 

 and breaking down of rock-masses by upheavals and depressions, were 

 the first steps in accomplishing such ends, and that the sudden action 

 of waters incident on such great oscillations was the chief denuding 

 agent, and simply left the outline of the rocks when desiccated to be 

 acted on for after- ages by diurnal atmospheric action. 



