564 The Formation of Cape Cod. [September, 
raines north of this line and probably contemporaneous with 
that of Cape Cod is found, as recently shown by Prof. Chamber- 
lin,’ stretching across Ohio, and represented in Southern Michi- 
gan, in the Kettle moraine of Wisconsin, and the Leaf hills of 
Minnesota; while its farther continuation seems to be in the 
Coteau des Prairies and the Coteau de Missouri of Dakota and 
British America, reaching north-westward, according to Mr. G. 
M. Dawson% to the North Saskatchewan river, three hundred and 
fifty miles west of Winnipeg lake. These deposits, like the 
moraines of Southern New England, are made up entirely of 
drift materials, partly unstratified, with abundant boulders, and 
partly stratified gravel and sand, in hills one hundred to 
three hundred feet high, of very irregular contour, with many 
enclosed hollows and occupying a width of from one to thirty 
miles. They lie upon the uneven surface of the rocky strata, 
being continuous across valleys and ranges of highland, which 
in Wisconsin undulate eight hundred feet- in vertical height 
while the elevation of this entire series varies from sea-level at 
Cape Cod, to two thousand feet above it at the north line of 
Dakota. In the Western States the front of the ice-sheet is shown 
by Prof. Chamberlin to have been lobed, producing acute angles 
in its terminal moraine, with medial moraines extending north- 
ward from them; corresponding to which we find a deflection of 
ninety degrees in this series of hills on Cape Cod at North Sand- 
wich with the massive medial range of Pine and Manomet hills 
a few miles farther north, in Plymouth. The same lobed charac- 
ter appears also to have marked the ice-sheet at its greatest 
extent, leaving a large driftless area in Wisconsin, and making 
angles similar to those of a later period in its frontal line, as 
indicated by the drift-hills of Martha’s Vineyard and Nantucket. 
The north end of the modified drift of Cape Cod is at High 
Head ; and the whole of Provincetown, at the extremity of the 
peninsula, consists of sea sand with no pebbles. This sand. has 
come from the erosion by the sea of the east shore of the cape; 
has been swept north and west by tidal currents to its present 
place in the lee of this breakwater; lifted by the waves into beach- 
ridges and further raised by the wind into hills a hundred feet in 
1 « On the Extent and Significance of the Menara Kettle Moraine,” in Trans- 
actions of Wisconsin Academy of Science, 1878, with maps. 
— *In Quarterly Journal of Geological Society, oer XXXI, pp. 614-623, with map. 
