325 
[Davis . 
1891.] 
clay. . . . North of New York City the altitudes of the terraces 
have been determined at a few points as follows : Mouth of Croton 
River, 100 feet ; Peekskill, 120 feet ; West Point, 180 feet ; Fish- 
kill, 210 feet ; Schenectady, 340 feet.” The terraces here men- 
tioned seem to be regarded as approximately indicating the level 
of the water in which they were formed ; their height at New 
York City being 75 to 80 feet, and increasing northward. 
3. Catskill lies about half way between Fishkill and Schenec- 
tady, and therefore should indicate a depression of an amount 
intermediate between the figures given by Merrill for these two 
points. According to the best determinations that I could make 
by aneroid on two visits, the Catskill delta front stands at a 
height of 280 feet above sea-level. Those who wish to examine 
this interesting deposit and the fine terraces subsequently cut in 
it by the stream, should take the narrow gauge railroad from 
Catskill village to Cairo ; a mile walk north to the iron bridge 
over the Catskill brings one to the face of a great “ cobble 
field,” as it is well named, a remnant of the old delta ; following 
down on the left bank of the stream by the road to Leeds as far 
as the foot-bridge back of Salisbury Manor, S, fig. 3, and there 
crossing to the right bank and going on to Gillig’s flag station, 
G, fig. 3, near Leeds, the best remnants of the delta and the 
trench deposits may be examined in an easy day’s walk ; reaching 
the. flag station in time to return by train to Catskill in the early 
evening. 
The accompanying sketch map is constructed by tracings of 
a county atlas, with hurried notes in the field. The sketchy 
contours indicate the slopes of the hills of Hamilton sandstones, 
enclosing the Catskill trench ; the cobble and pebble fields are 
dotted, the clay flats in the Marcellus valley near Leeds are 
marked with broken lines ; the Helderberg rocks at Leeds are 
shaded with close lines ; and the present flood plains are left 
blank. The altitudes in the text are determined by aneroid, and 
need revision. 
In the following account of the stream deposits, and their 
present terraced form, I shall first describe the remnants of the 
valley filling, and infer from these the conditions that existed at 
the close of the estuaried stage in the history of the region ; after 
this, the present form of the valley will be considered, and the 
changes from the preceding to the present stage determined. 
