44 The AinericdH GcohKjist. July, 1895 
Pinnacle pit, 80 feet tliickness oi' the lower gravel beds in the 
heart of the hill have a dip of 12°-15° to east or south of east. 
There are many local exceptions to the southward or east-of- 
south dip of the coarser beds, and some small sections show 
inclination in several and even opposite directions. Obviously 
a part of this local variation is due to disturbances by the ice 
thrust. Some of the diverse inclination may be due to origi- 
nal deposition in subaqueous cones by the changing torrents 
of water over an ice front subject to every possible variation. 
Where beds of fine sand and silt are steepl}^ inclined the in- 
clination may be wholly attributed to ice thrust. 
At two localities upon the south side of the range, one up- 
on Goodman street and the other east of South Clinton street, 
distinctly bedded and alternating sands and gravel have a 
high dip to east of south. At the former pit the dip is 10*^- 
14" to S, 15^^-30'' Vj. At the latter excavation the dip is 20° 
to east, var3ang to south. These beds show no disturbance, 
but are filled with angular and glaciated stones of large size. 
Upon the north flank of the hills and even to the heart and 
summit, as siiown at Monroe avenue and at South Clinton 
street, the beds have suffered great disturbance. This is 
shown in the coarse gravel beds by the loss of all stratifica- 
tion, and in the fine gravel, sands and silts b}^ their tumbled, 
tumultuous, disordered character. In all the pits there is 
much faulting. This is the chief kind of disturbance in the 
deeper parts of the hills, and in some sections it is truly sur- 
prising. 
The sand beds upon the south Hank of the hills have an ap- 
proximately horizontal position ;ind are without faulting or 
other disturbance. The structure of the beds indicates cur- 
rents sometimes westward, or parallel with the range, some- 
times west of sf)utli, or obliquely across the range, and some- 
times east of south, or more directly across the trend of the 
range. The large sand pit near Brighton shows current lam- 
ination in the fine sands and silts produced by flow of water 
varying from east to south. The heavy beds of fine sand 
south of Cobb's hill show currents S. 45°-60° W. The deep 
cut on Goodman street reveals a direction of current west of 
south. 
The structure of the hills would seem to be explained by 
