GEOLOGY OF MOUNT DESERT. 49 



against enormous resistances, and that it involved the 

 movement of gigantic masses. The granitic belt is at least 

 twelve miles long and seven wide. No one can give any 

 measure of the former greater height to which it ascended ; 

 and certainly he would be a daring geologist who would set 

 a limit to the unsounded depths from which it rose. The 

 uprising may have required many historic ages ; it may 

 have been relatively rapid ; but that it was progressive, and 

 not instantaneous, is easily seen by a closer examination of 

 the minor events recorded along its margins. 



Much of the lowland is covered by glacial drift and by 

 postglacial marine clays ; but along the seashore the rocks 

 are swept clean, and their surface is continuously visible. 

 The bare ledges and cliffs of Hunters Beach Head, as well 

 as of many other similar points on the southern coast, 

 afford wonderfully clear illustrations of the processes of the 

 granitic intrusion. Here we may follow the granite wedg- 

 ing its way into narrowing cracks among the older rocks. 

 Great fragments of older rocks of various kinds are caught 

 off in the granite and mixed together in confusion. Some- 

 times a block is found to be divided by granite-filled fis- 

 sures, and yet its several parts may still lie so close to one 

 another that they can be matched with certainty ; thus 

 proving that after the block was broken from the wall of 

 the vast fissure it was further fractured, and the minor 

 cracks thus opened were filled by the mobile granite. This 

 may be seen on the eastern side of the Narrows of Somes 

 Sound, and along the shore ledges to Smallidge Point south 

 of Wasgatt Cove. The granite rock, now so rigid, then so 

 liquid, or at least then yielding so perfectly under the 

 pressures that were exerted on it, entered into the nar- 

 rowest little crevices, following them down to hair-like 

 fineness. Nowhere in the world may the traveller find 

 better, illustrations of the manifold processes of deep-seated 



intrusions than are here exhibited on the wave-swept ledges 



4 



