Missing Chapters of Geological History. 25 



of the successive strata in our country; or, in other words, 

 using once more the language of Professor Ramsay, if we 

 assume that the causes producing physical change were the same 

 in former times as they are now, both in kind and intensity, 

 then, " the upheaving, contorting, and dislocation of the strata 

 and the vast denudations they underwent before re-sub- 

 mergence, generally represent a period of time longer than 

 that occupied respectively by the deposition of the formation 

 disturbed, or of that which overlies it unconformably." 



Many of the great physical breaks range widely, and 

 might turn out to be much more extensive were we able 

 to examine geologically the rocks beneath the sea. At all 

 times deposits have been chiefly formed under water. At 

 the present time this must undoubtedly be the case, and 

 we have no reason to suppose that it was ever otherwise. Of 

 the vast tracts of the earth either covered by water or other- 

 wise inaccessible we know not what they might teach, but we 

 are sure they would abound with valuable lessons. If, in some 

 cases, they proved the break to have ranged more widely, they 

 would in others fill up the gap. But the gaps and intervals 

 may be wider and larger than the preserved portions. During 

 the long interval when species were changing, water was not 

 idle. Every modern deposit is made of material stolen from 

 some previously deposited rock, whether in its original state or 

 after metamorphosis, and to provide this new material there is 

 no supply beyond what is obtained from the denudation and 

 destruction of the older one. Who can doubt, then, that the 

 older one may often have disappeared altogether. 



In looking at the list of physical breaks, one is struck by 

 the fact that the Palgeozoic series, especially the older portion, 

 exhibits the greatest number of important breaks. This may 

 have something to do with the comparative poverty of such 

 rocks in fossils. But it is not to be wondered at that these 

 rocks, which, more than any others, have been alternately 

 depressed and elevated, and which have been exposed to 

 enormous pressure at great depths, and also to all other 

 causes of change, should have undergone so great an amount 

 of metamorphosis as to have obscured and destroyed their 

 fossil contents ; and we need not be surprised if during the vast 

 periods needed for these operations, there has been swept away 

 to form more modern rocks far more than has been left behind. 

 Let the reader consider the somewhat analogous case of the 

 Cyclopean wall of some old Greek or Etruscan city, originally 

 constructed long before the historic period. Century after 

 century this wall has served as a quarry from which all the stones 

 wanted for the use of succeeding inhabitants of the neighbour- 

 hood have been drawn. The squared blocks of the first wall 



