14 On the Physical Geology of the United States, §c. 
in others,) corresponds with the supposed position of the warm 
equatorial current and the cold polar flow, favorable to the devel- 
opment of animal and vegetable life in the one case, while in 
the other, few traces of organization have been preserved.* 
5. The amount of deposition has been greatest where currents 
must have been obstructed by conflict with each other and had 
their velocities lessened, and where islands and irregularities of 
the bottom of the former ocean produced the same effect. 
6. The coal formations of the United States are situated 
where, from the contour of coasts, islands, and the bottom of the 
ocean, the grand eddies would necessarily be formed, and in 
which plants brought from the tropics or other sources would 
float and circle around until they sunk.t 
7. That the cretaceous and tertiary formations, as characterized 
by abundant remains of organic existence, extend little farther 
to the north than Sandy Hook, caused it is believed by the polar 
flow through the Hudson valley, having mixed with the warm 
Gulf Stream and cooled the waters too wien? to favor.. the de- 
velopment of organic life.$ 
. That the red sandstone fichoaticpi oenh iol ons Car- 
chen to a, Point on the Hudson, and also believed to have 
been formed by the Gulf Stream, stops abruptly on the west 
shore of the Hudson River.. The farther extension of the for- 
mation in that direction seems to have been cut off by the polar 
current flowing through the Champlain and Hudson valley, 
sweeping away the materials that were brought into it by the 
Gulf Stream. || 
9. The fossil shells thus far found in the quaternary Dontciaion 
of the Champlain and Hudson valley are of an arctic character, 
corresponding to those of the Gulf of St. Lawrence, and those 
of Scotland, Denmark, Norway, and Sweden,1. indicating with 
* Natura) History of New York, Part IV, Geology of Ist District, by W. W. 
Mather, pp. 274-275, 277-278, 295-296, 
1 ees pp- 129, 148-151, 293-295, 273-274, 289-293, 295-296, 299. 
275, 295-296. 
§ rad pp- 150-151, 274-275, 299. 
|| Idem, p. 293. The ssidenans of a polar current in this valley during the qua- 
ternary and drift epochs had already been adduced; those of more ancient times, 
during the deposition of the Silurian mole are subsequently adduced when Areat- 
ing of the rocks of the New York syst 
1 Idem, p. 278; also Annual Geol. iat of N. Y. 1841, p- 47, by Mr. Conrad. 
