Uhler.] 50 (Jan. 6, 
north, north-east and north-west ascends by a series of sloping terraces, 
each grading seventy feet or more, to a level of about five hundred feet 
above tide. This is about the highest limit reached by the variegated 
clays and gravel which can be shown to belong to this formation. North 
of the city the Baltimorean extends back through the country to a dis- 
tance of twelve miles, but it does not rise over the tops of the highest hills, 
and is often interrupted by the ridges of Archeean and other rocks. 
Various changes have occurred to the clays of this formation of which 
a few examples may be cited. 
Where cuttings have been made for streets ou the north-east side of Bal- 
timore, and at a point about two miles further east, the iron clays have 
been dislocated, presumably by floods of water, which have transported 
and dropped them in large lumps, often two or more feet in thickness. 
These are mixed in huge piles, and in two places have been thrust over 
the top of the ferruginous sandstone in such a way as to reverse the order 
of the series, 
About one mile east of the city, the dark lead-colored clay forms a 
monumental pile which formerly rose more than eighty feet above the ad- 
joining surface, but it has lost a part of one side by a fault that has pro- 
duced a downthrow of about seven feet in depth. Another fault, in Fede- 
ral hill near the end of Warren street, has pushed up the northern end 
fully seven feet above its proper level. The effects of this dislocation 
were evident in the broken condition of the beds for about one hundred 
feet in that direction, while towards the south and south-east there was no 
break or disturbance in the continuity of the strata. 
The red and variegated clays which overlie the iron-bearing member are 
seen to lie in the hills along the Washington railroad at a much greater 
elevation than the mixed sandy loam and ferruginous sands which belong 
above them. This is owing to the fact that in many places the iron-ore 
series was deeply denuded before the newer beds were laid down; and in 
some places there are evidences that the next later deposits have been torn 
off and transported to a distance. 
The iron-ore masters insist that the iron-bearing clays rest in detached 
domes upon the underlying white sand, but this does not correspond with 
our observations as far as they have gone. We have traced them in a 
continuous series nearly all the way from the Gunpowder river to the 
Relay house, a distance of twenty miles, and again on the other side of 
Elk ridge to near Annapolis junction. 
Beneath the city of Baltimore these clays bend down, but have been 
penetrated or passed through by all the deep wells of the region, and they 
are found to possess flexures, one of which carries them beneath the mid- 
dle and eastern branches of the Patapsco river and brings them up on the 
opposite shores. In the southern continuation of Federal hill they dip 
down thirty feet in a distance of four blocks, about 1200 feet ; but they 
are discoverable at the bottom of the deep channel of the river and again 
form hills a mile beyond on the opposite shore. Nine miles south of 
