THE MINERAL INDUSTRY OF MAINE 389 
 
gravel from these two counties was nearly 2 million tons below the volume
of the previous year. Five municipalities in Androscoggin County, and one
each in Hancock and Penobscot Counties, recovered sand and gravel for local
roads, ice control, and maintenance. 
 Additional Interstate construction for the northern half of the State was
not anticipated before the middle of 1969. Two sections of 1—95 were
under construction, one near Augusta and the other near Brunswick. Completion
of this portion was expected in 1970. 
 Commercial production, 18 percent of the total, was reported from all counties
except Lincoln and Piscataquis. Production was centered mainly, in decreasing
order, in Cumberland, York, Penobscot, Androscoggin, and Hancock Counties,
which accounted for 74 percent of the commercial output. Almost all of the
material was shipped by truck. 
 A total of 76 commercial operations was reported during the year having
a combined output of over 2 million tons. Of these, 49 reported production
of less than 25,000 tons; 15 ranged from 25,000 to 50,000 tons; nine ranged
from 50,000 to 100,000 tons; and three produced between 100,000 to 200,000
tons. Eightyfive percent of the sand and gravel was washed, screened, or
otherwise prepared; commercial producers processed 47 percent of their output,
while Governmentand-contractor operations processed 93 percent of their total
output. 
 
 Stone.—Lack of new contracts and adverse summer weather conditions
curtailed production of dimension granite in Hancock, Knox, and York Counties.
Crushed granite was produced commercially in Cumberland, Knox, and York Counties.
Output of dimension granite included rough and dressed construction stone,
monumental and architectural stone, as well as rubble, curbing, and flagging.
Knox County continued as the leading limestone-producing area; output was
also reported in Aroostook 
- and Kennebec Counties. Dragon Cement Co. and Lime Products Corp. announced
plans to enlarge their quarry and plant facilities at Thomaston and Union,
respectively. Miscellaneous stone quarried near Westbrook was used as concrete
aggregate, roadstone, and riprap. Slate mined underground by Portland-Monson

Slate Co., near Monson, was marketed as electrical slate, floor tile, and
flagging. 
 Granite produced by The John Swenson Granite Co., Inc., from its Pink quarry
near Wells and from its Green quarry near York was used for construction
of break-water and dock facilities in a major harbor improvement project
at Wells. The $2 million project which has been under construction since
1961 was nearing completion at yearend. The basin will have a capacity for
100 moorings of which about 30 will be of the heavy-duty type for larger
crafts and the remainder for smaller boats. The company also announced plans
to open a black granite quarry in southern Maine. Development of the quarry,
near Wells, was expected to be completed in early 
1968. 
 
METALS 
 
 Callahan Mining Co. continued development of its open-pit copper-zinc mine
in Hancock County. Construction of the concentrating mill was completed late
in 1967 and initial processing of the ore was expected to start early in
1968. The copper and zinc minerals are extremely susceptible to oxidation
changes from weathering which affect their metallurgical characteristics.
The company planned to coordinate mining and milling so that the ore broken
in the pit will be fed directly to the mill with stockpiling kept to a minimum.
The present production schedule indicates the complex will be in operation
for 6 years and may employ an estimated 75 persons when it attains full production.
Northern Canada Mines Ltd., has made arrangements to start exploratory drilling
on land owned by Scott Paper Company in Somerset County. In midyear, Humble
Oil & Refining Company announced a letter of agreement with Spooner Mines
and Oil Ltd., for the geophysical and geochemical exploration of 621 square
miles of Spooner holdings in North central Maine. 
 Noranda Mines, Ltd., continued its diamond drilling program south of Jackman,
in Somerset County. Black Hawk Mining Corp., a subsidiary of Dennison Mines,
Ltd., Toronto, Ontario, suspended all work at Blue Hill. The operation will
remain in a standby condition until economic and employment conditions become
more favorable. Knox Mining