GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. I93 



elevation of the earth's crust extended to the district which is now the White Moun- 

 tain chain. If we conceive indeed the whole of the wide tract of undulating and in 

 some places mountainous surface, from the upper Hudson and Lake Ontario, eastward 

 to Maine inclusive, and possibly a large territory north of the St. Lawrence, to have 

 emerged from the waters into permanent land, during the close of the Matinal period 

 and the first ages of the Levant, while the still wider spaces to the S. W. and N. E. 

 remained undisturbed, for the reception of later strata, we shall be able to interpret 

 many imijortant facts in the geological structure not only of this ancient district but in 

 that of the neighboring regions. 



The hypothesis which supjioses that the bed of the Appalachian ocean was violently 

 and extensively agitated by a succession of earthquake movements, at the end of the 

 Matinal and early in the Levant periods, resulting in the conversion of all northern 

 New York and New England, and probably the whole south-eastern border of that sea 

 into permanent dry land, supplies us in the first place with an explanation of the un- 

 conformable superposition of the Levant ui)on the i\Latinal rocks, discovered by one of 

 us in 1837 near the city of Hudson, and visible at a number of other points E. and N. 

 E. of the Catskills. It furnishes moreover a cause for the extremely wide diffusion, 

 and the coarse conglomeritic composition of the early Levant sandstones, amid the 

 pebbles and sand-grains of which, are many fragments obviously derived from the 

 uplifted and broken Matinal and Primal strata. It provides furthermore a physical 

 reason for the marked transition observable in the species, when we ascend from the 

 organic remains of the Matinal to those of the Levant formations. An era of paroxys- 

 mal action would be naturally the period of a modification in the conditions and forms 

 of life, for extensive and permanent changes would arise in the bed of the sea, the 

 waters would grow shallow in many places, would deepen in others, their temperature 

 and their currents would alter, and even the proportions of the elements held in chem- 

 ical solution, which are the very pabulum of the aquatic races, would sustain some 

 change. But perhaps the most interesting application of the hypothesis here referred 

 to, is the explanation it affords of the excessively crystalline or metamorphic condition 

 of the Appalachian deposits in the district supposed to have undergone this ancient ele- 

 vation. Upon this supposition these districts, embracing nearly all New England and 

 the Atlantic slope of the Middle and Southern states, were the areas of chief move- 

 ment, while the other portions of the Appalachian sea were but slightly affected. Here 

 therefore the crust underwent the maximum degree of dislocation and of heating, and 

 the newly precipitated surface sediments were rent, brought into contact with the in- 

 tensely heated veins and dykes of internal molten matter, and baked and probably 

 partially crystallized, while those of the remoter and still submersed tracts were but 

 slightly acted on. As these districts, the south-eastern and north-eastern parts of the 

 Appalachian basin, were the first to be invaded by igneous action, so they continued, 

 as it would seem, to be the quarter where this action was oftenest repeated, and where 

 at each epoch of disturbance, especially that which witnessed the final drainage of 

 the Appalachian sea, it was greatly the most energetic. The whole structure of the 

 VOL. II. 25 



