QUARRIES IN PENOBSCOT COUNTY. 147 
Rock structure: There is a marked flow structure in places horizon- 
tal and parallel to the rift, but in others quite irregular. The sheets, 
from 1 to G feet thick, are horizontal or slightly undulating on the 
quarry face, but at the west side dip 20° to 30° west. They increase 
in thickness downward and at the bottom of the quarry appear to run 
out ("grow on"), making quarrying in that direction increasingly 
difficult. A vertical joint, striking N. 35° E., is coated with crystal- 
line calcite and epidote. The rock adjacent to it for an inch or two 
contains much pyrite and also chlorite, probably derived from alter- 
ation of hornblende. The rift is horizontal and the grain vertical 
north-south, but disappears on the west side. Vertical basalt or dia- 
base dikes, with northeast -southwest courses, form the north and 
south walls of the quarry, 4 feet and 22 inches thick, respectively. A 
5-inch one occurs 25 feet north of the south wall. A thin section of 
a half-inch branchlet from this dike is described on page 48. Sap is 
confined to the upper sheets. There are some knots. 
The plant consists of 3 derricks and 1 hoisting engine. 
Transportation: Derricks lift the blocks from the quarry to the 
cutting shed and from that to the cars of Grand Trunk Railway. 
The product is used entirely for bridges and stations on the Grand 
Trunk Railway. Specimen buildings: The vestibule, first story, and 
trimmings of Grand Trunk Railway station at Portland, Me.; the 
Grand Trunk Railway station at Battle Creek, Mich. 
PENOBSCOT COUNTY. 
The quarries in Penobscot County are in the town of Hermon. 
The Hermon Hill quarry is on Hermon Hill, 5J miles northwest 
of Bangor. Operator, Dr. H. F. Hanson, Bangor, Me. 
This black granite (specimen 106, c) is an altered diabase por- 
phyry of dark-green color and fine texture, with porphyritic crys- 
tals of black hornblende up to three-fourths inch in diameter. The 
rock consists, in descending order of abundance, of hornblende, cal- 
cite, a much-altered feldspar (plagioclase), and magnetite, together 
pith secondary actinolite, fibrous serpentine, and chlorite. It con- 
tains sufficient calcite (lime carbonate) to make it effervesce with 
pold dilute hydrochloric acid. It takes a very fine polish and cuts 
fery light, but the presence of the calcite exposes it to attack by the 
tarbonic acid of the atmosphere. It is therefore more suitable for 
ndoor work. Ora W. Knight, State assayer of Maine, reports that 
t contains a very small amount of platinum, which is very irregu- 
arly and unevenly distributed." 
| The quarry, opened in 1000, measures 25 by 20 feet and from 5 
o 12 feet in depth. 
— ■■ — . 
a Letter addressed to Doctor Hanson October 3, 1905. 
