530 Trof. J. W. Judd — On Volcanos. 



denuding action which has effected the complete removal of every 

 trace of the strata of the same age from the whole of the country 

 around. 



But even in respect to geological times comparatively much more 

 recent, we find abundant evidence of the occurrence of movements 

 of considerable extent, if of less violence, in this portion of the 

 earth's crust. On the southern side of the great mountain axis, 

 where disturbances seem to have been prolonged to a later period 

 than on its northern margin, there have been subsidences sufficient 

 to permit of the accumulation of more than 3000 feet, of Pliocene 

 or Subapennine strata ; and these subsidences have been followed by 

 upheavals, which at some points, as in Sicily, have raised the 

 marine beds to heights of more than 3000 feet above the sea-level. 

 And here again we find the evidence in Eastern Europe quite in 

 accord with that found in the West. For example, the Congerian 

 and Paludina strata of Sclavonia, the equivalents of the Pliocene 

 of Western Europe, have a thickness of more than 2000 feet; and 

 they have been clearly subjected to very considerable local disturb- 

 ances during those movements of upheaval, through the agency of 

 which they are now exposed at the surface. 



That even in post-Pliocene times movements of no insignificant 

 amount took place, we have also abundant evidence. In our own 

 country, marine shells at an elevation of 14:00 feet in Moel Tryfaen 

 and 1200 feet at Macclesfield tell of subsidence and re-elevation 

 during the so-called Glacial period, of which these measures are the 

 minimum limit. The evidence derived from these marine shells at 

 such great elevations can only indeed be got rid of by such violent 

 hypotheses as those of the Universal Deluge sweeping everything 

 before it in its passage, or of Messrs. Belt and Croll's " ice-caps,*' 

 which scrape up ocean-bottoms and push them on to mountain-tops. 

 For our own part, if compelled to choose between these two hypotheses, 

 we should decidedly confess to a preference for the older, which has 

 also the advantage of being an orthodox one. 



Nor were the movements which took place in our own country in 

 post- Pliocene times by any means exceptional, for there are many 

 facts which point to more extensive and violent ones having occurred 

 during that period in the Western Alps. 



The great changes which were brought about during the same 

 period in the physical geography of Eastern Europe (though there, 

 probably from local causes, unattended with those extreme glacial 

 conditions which characterized Western Europe and Eastern America) 

 bear witness to the continued activity of the subterranean forces. 

 Nor have we any reason for doubting that these forces still retain 

 some of their activity — difficult as it may be to demonstrate their 

 effects by means of the monuments belonging to the insignificant 

 periods of human history. 



Now all the facts derived from a study of the positions assumed 

 .by Tertiary strata of different ages, both in Western and Eastern 

 Europe, point to the same conclusion — namely, that within and 

 around the great mountain axis of the Eastern continent subterranean 



