152 
GEOLOGY OF THE FIRST DISTRICT. 
transport of earthy materials seems to have been m.osily in a southwardly direction. The 
perfect regularity of deposition of the clay in horizontal strata, thinly laminated with sand, 
and the thickness of this and the sand beds, show the lapse of a considerable period of time ; 
but the extent, quality, and various phenomena of the depositions of clay and loam, are such 
as we might expect from water flowing with tidal currents, or with a steady current modified 
by the tidal flow, over a bottom and through valleys with the same forms they now present, 
but terminated by a more rapid current which has deposited the upper drift deposits. 
It may perhaps be considered out of place in this report on the geology of a part of New- 
York, to speak of the geology of other portions of our country ; but as the causes concerned 
in the production of many of the strata, and particularly those under consideration, were 
general over vast areas, I maybe permitted to bring in for elucidation such facts as have been 
observed. 
The geological reports of New-York, Ohio, Illinois, and Michigan, describe strata of blue 
and huff marly clays capped by sand or gravel beds. Both from the description, and from 
personal observation over most of the areas described, I am satisfied of the identity of age. 
The level at which these depositions now lie above the ocean, being so nearly horizontal, is 
remarkable, when we consider the vast area over which they are distributed. 
Prof. Emmons has described the clay and sand beds that I have called quaternary deposits, 
along Lake Champlain and the St. Lawrence ;* Prof. Vanuxem, similar ones through the great 
valley of the Mohawk and Black river, and in the continuation of the Mohawk valley to the 
west, and along the coast of Lake Ontario ;t Prof. Hall, similar beds through the extension 
of the flat country from the Mohawk valley, by the north and south lakes to the Genesee 
valley, and on to Buffalo, and along the coasts of lakes Erie and Ontario ;:j; and my own. reports 
contain descriptions of similar deposits throughout the Champlain and Hudson valley.^ My 
own reports, and those of the assistants on the geological survey of Ohio, describe similar beds 
in that State ; the reports of Dr. Houghton and his assistants, around the peninsula of Michi¬ 
gan ; those of Dr. Owen, in the northern part of Indiana; and my own observations and the 
reports of others, have satisfied me that deposits of the same age occupy a large extent of 
country in Illinois, Wisconsin, Louisiana and Arkansas. Prof. Hall has also described some 
similar deposits, as terraces, in Upper Canada, like those in New.-York, Pennsylvania, Ohio 
and Michigan ; and the heights have been obtained by admeasurement with the level. 
Col. Whittlesey has shown the levels of those in Ohio which skirt Lake Erie at a distance 
of one quarter to five miles, to be ninety to one hundred and twenty feet above the lake, or 
six hundred and fifty-four to six hundred and eighty-four feet above the ocean.|1 Towards the 
west end of Lake Erie, the terrace and ridge of an ancient beach recede from the lake far 
into the interior, showing bays up the valleys of all the principal streams, but parallel in its 
general trend to the Maumee river. In Michigan, a similar beach and terrace are described 
* New-York Geological Reports. f Rjirf- t Ibiil. 
() Geological Report of New-York, 1837, p. 64; 1838, p. 158, 160; 1839, p. 70, 79; 1840, p.220, 227; 1841, p. 71,75. 
11 Geological Report of Ohio, 1838, p. 103; 1839, p. 55. 
