158 J. H. Perry—Fossil Coal Plant. 
sponds (as I am informed by Professor Dana) to the American 
Subcarboniferous. 
ee ee mmm 
N.W Mica Schist. Granite. Mica Schist. Gneiss. 8. E. 
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The section represented in the accompanying figure has in 
the center the granite knoll, and extends to the northwest only 
far enough to show the mica schist resting against the granite. 
To the southeast the section cuts through the mica schist into 
the gneiss which lies to the east and southeast toward Mans- 
field and Wrentham. The gneiss and mica schist are conform- 
able, having a general strike northeast and southwest, and 
where the section was made a dip of 75° to 85° to the north- 
west inclined away from the granite. ‘ 
The outcrop of the coal-bearing strata of the mica schist 18 
about half a mile northeast from the top of the granite knoll. 
Here the strike is northwest by southeast at about right angles 
to the strike of the mica schist outcropping not more than an 
eighth of a mile distant to the east. The dip is about 50° to 
the northeast, the strata leaning toward the granite. The fact 
that the same rock, identified by peculiar markings as well as 
by constitution, varies so greatly in dip and strike within 80 
short a distance, indicates an additional disturbance to that 
which tilted the whole mica schist and gneiss to their present 
position and transformed them to their present condition. This 
additional disturbance was the forcing up from beneath of the 
granite knoll, breaking or bending the strata to the northeast 
and north, away from that to the east. This thorough working 
over of the rocks containing the carboniferous deposit has 
transformed this deposit for the most part into graphite; and 12 
the specimen, mentioned above, the carbon is in the form of 
graphite though the sears of the plant are distinctly preserved. 
It is my purpose to follow the rocks to the southeast and 
then to the west during the next season. So faras I have gone, 
I find my results agreeing quite closely with those of Professor 
E. Uitchcock. ; 
High School, Worcester, Mass, 
