OCTOBEE 18, 1912] 



SCIENCE 



499 



coal. Throiighoiit the central and western 

 portion the rock formations still lie rela- 

 tively flat and undisturbed; from the line 

 of the Mohawk valley and the southern 

 shore of Lake Ontario the successive strata 

 rise tier above tier until they culminate in 

 the Catskills to the east and the Pennsyl- 

 vania border. 



In 1836 James Hall was assigned this 

 level and supposedly uninteresting portion 

 of the state, the fourth district, which he 

 was told "was good enough for a young 

 man of twenty-five." The region was re- 

 garded as of little promise and was will- 

 ingly relinquished to him, and this proved 

 to be one of the happy accidents of geology, 

 for Hall's genius revealed the fact that 

 nowhere in the world does there exist so 

 complete a series of the older fossiliferous 

 rocks, such continuous records of the life 

 of the ancient inland sea; in wonderful 

 perfection the animals that lived in the 

 shallow waters and along our inland coast 

 have yielded the data for the paleontologic 

 researches of the master and his pupils 

 Merrill, Wliitfield, Clarke, and others. 



The second great drainage system, now 

 represented by the vestigial Hudson river, 

 is that which flowed from northwest and 

 southeast between the northern and south- 

 ern granitic masses of the Adirondacks and 

 the Hudson. This broad trough, or valley, 

 was developed east of the Appalachian up- 

 lift and included the Shawangunk' moun- 

 tains. In it were accumulated the sedi- 



' The Shawangunk Mountains belong to the 

 Appalachian uplift which succeeded the Carbon- 

 iferous, hence very much more ancient than the 

 later disturbances of the Highlands. The Cat- 

 skill uplift belongs to the same age of general 

 elevation as the close of the Carboniferous. It 

 escaped the general reduction of the rest of the 

 Alleghany Plateau for reasons not at present evi- 

 dent except in the hard nature of its rocks. The 

 Hudson Highlands region has gone through its 

 oscillations quite completely since the origin of 

 the mountains referred to. The Highlands have 

 gone far down after having been raised high, and 



ments washed down from the adjoining 

 mountains during Triassic and early Juras- 

 sic times, to form the red sandstones and 

 shales of the ' ' Newark System, ' ' extending 

 across the New Jersey border into Rock- 

 land county, and recently yielding at Fort 

 Lee one saurian of Triassic age. The great 

 red sandstone delta was in turn tilted and 

 heavily faulted, and along the fault lines 

 and between the strata of shale and sand- 

 stone welled up the great outpourings of 

 basaltic lava which formed the trap rocks 

 of the Palisades and parallel ridges to the 

 westward. 



Toward the close of the Age of Reptiles 

 the littoral strip began subsiding beneath 

 the Atlantic ocean, converting the shore 

 line into a coastal swamp over Long Island ; 

 but the greatest factor in Long Island's 

 history was the Glacial Epoch at the close 

 of the Age of Mammals, when the ice cap 

 extended downward from eastern Canada 

 over almost the whole of New York state 

 and left as its terminal moraine the long, 

 irregular line of hiUs of boulder, clay and 

 sand stretching along the northern shore 

 of Long Island across Staten Island, New 

 Jersey, Pennsylvania, and westward. To 

 this we owe our building clays. This great 

 ice sheet, as studied by Fairchild, Wood- 

 worth, and others, gave the final touch to 

 our landscape and to our agricultural 

 lands, gouging out valleys, blocking rivers, 

 piling heaps of detritus across valleys 

 during its slow retreat to the north, pro- 

 foundly modifying the topography of the 

 state, shaping the basins of many of our 

 lakes, the courses of our rivers, and the 

 character of our soil. At the beginning of 

 the ice retreat the cap so blocked the St. 

 Lawrence river valley that Lake Ontario 

 found its outlet along the Mohawk river 

 into the Hudson. All the life records of the 

 are now apparently on their way up again. This 

 statement relates to the relation of the Highlands 

 to the cutting down of the Hudson Eiver. (J. 

 M. C.) 



