NO. 23.] CENTRAL CONNECTICUT IN THE GEOLOGIC PAST. 35 



the fall of night across the long-enduring world of ancient life, 

 let the vision, like a far-traveled bird, take homing flight, and 

 watch while returning to the Age of Man the unrolling of the 

 landscapes which record the flow of time. 



In the late Paleozoic the view rests upon the vaguely outlined 

 New England Alps, the result of a profound crustal revolution; 

 one of a series of generations of Appalachian mountains, whose 

 earlier members are even more imperfectly known. The greater 

 heights shine with storm and ice and fire. Earthquake and ava- 

 lanche and volcanic outbreak speak in deep-voiced tones of the 

 upstriving of mountains. But gray torrents, rushing through 

 gorges far below, sweep along the mountain debris fed to them, 

 and with this burden grind their dark gorges deeper. 



At last the upbuilding forces cease and the mountains begin 

 to waste away. The Paleozoic era is left behind, and the Age of 

 Reptiles dawns. The mountains are imperceptibly worn low and 

 a somber vegetation devoid of flowers spreads inward from the 

 plains and valleys. Primitive reptiles and insects follow, to re- 

 people a land which during the reign of alpine mountains had 

 been an almost lifeless waste. 



At length a new movement becomes pronounced; down- 

 sinking of long troughs or basins begins, accompanied by the 

 uplift of neighboring areas. The sediments from the uplands are 

 in excess of the amount needed to level up the subsiding areas, 

 with the result that, although in seasons of storm much of the 

 wide expanse is covered with running streams and temporary 

 lakes, in the recurrent times of drought the streams give way to 

 shifting sands, and the lakes shrink, leaving behind them flats of 

 mud which dry and crack. This continued filling up by the load- 

 ing of those areas starting to sink, accentuates the movement, and 

 causes the greatest sinking to be on the margins 'of the basin 

 where the greatest amounts of sediments are received. The local 

 intensities of the strains produce breaks in the foundation, and 

 movements take place on the fault planes which on the farther 

 sides sharply bound the basins. Profound earthquakes mark each 

 slip of the crust blocks against each other and attend the repeated 

 rejuvenation of the marginal cliffs. As the observer continues 

 his age-long watch, sediments are seen to gradually extend over 

 the basin floor and blanket the low interior hills which at first 



