136 CONTRIBUTIONS TO THE GEOLOGY OF MAINE. [bull. 165. 
Microsections cut from the rock at the north and south ends of the 
mountain revealed the same composition, although varying in relative 
size and abundance of the compound fragments. The materials found 
are rounded, lengthened fragments of sandy schists or slates, which 
have been bent and stretched, and rounded fragments of sandstone 
composed largely of quartz and feldspar grains, which in places are 
broken into parts that have moved since fracture. The general cement 
is of quartz grains, with some feldspar and numerous sheared frag- 
ments of slate. 
The Mars Hill conglomerate is quite distinct from all other sand- 
stones and conglomerates so far found in northeast Maine. The 
absence of igneous fragments is noticeable, and the great abundance 
of slate fragments makes it almost a slate conglomerate. The sheared 
and broken condition of the whole mass and of its individual pebbles, 
and its intimate association with the crumpled and brecciated slates and 
limestones at its base, indicate an age at least as great as the Aroostook 
slated limestone, and it is considered, on lithologic grounds alone, to 
belong to that series. 
MAPLETON SANDSTONE. 
Nearly all the eastern half of Mapleton Township is overlain by red 
sandstones and conglomerates, which form rounded hills, with many 
good exposures. Outcrops occur on the State road about 3 miles 
from Presque Isle and on the Mapleton road about li miles from the 
village. 
Winslows Hill section. — This section affords the best opportunity for 
study. An east-west road that branches from the State road about 
li miles from Presque Isle Village runs over the top of the hill and 
crosses the strike of the different beds. The outcrops on the hill form 
a reasonably complete series, and will be described as representing the 
whole Mapleton sandstone area. Beginning at the east base of the 
hill and extending about halfway to Winslow's house is a series of 
reddish-brown sandstones and coarse conglomerates in beds 10 to 30 
feet thick. The heavier beds of conglomerates are near the bottom 
and become inconspicuous toward the top of the hill. The compact 
beds of fine red sandstone appear to be first-class building material, 
although the dip into the hill will make quarrying expensive. 
Above these coarse and fine red rocks are other fine-grained sand- 
stones, which are gray in color and have much the appearance of the 
Chapman sandstones. They form the top of the hill, and occur in 
thick beds, with an occasional stratum of coarse material a few inches 
in thickness. 
The thickness of the whole series as exhibited by this section is 215 
feet, of which 180 feet is of the red sandstones and conglomerates. 
