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Home > Explore! > Bedrock Geology > Bath 100K Report > Mineral Resources

Bedrock Geology of the Bath 1:100,000 Map Sheet, Coastal Maine

Mineral Resources and Past Mining Activity

radiometric age determinations
Figure 53		 The principal economic extractive activity in the Bath map sheet is the production of sand and gravel from unconsolidated glacial deposits. Current bedrock mining activity is restricted to the quarrying of durable rock which is crushed and sized for fill and road metal. In addition, old spoils piles from pegmatite mines are being removed for fill. At present, there is no other bedrock mining of any consequence. Locations of quarries, mines, and prospects are shown on Figure 53.

Mining of feldspar has taken place from many pegmatites in the Topsham, Georgetown, and Phippsburg areas (Caldwell and Austin, 1957). The largest mines in the area were the Consolidated Feldspar Company mines in Topsham and Georgetown (Figure 53). In addition to feldspar, minor amounts of strategic mica were produced during World War II. Feldspar mining began in the mid-1800's and ceased in the middle to late 1950's. The last company to operate was the Consolidated Feldspar Company. After the closing of feldspar operations and the sale of the properties, Emery Booker of Brunswick attempted a commercial operation in Topsham, producing chicken grits by grinding and size sorting materials from the spoils piles. Today some of these pegmatites are being prospected and mined on a limited scale for mineral specimens and gemstones. Minerals other than feldspar and quartz that have been found in pegmatites in the map area include beryl, columbite, samarskite, allenite, uraninite (massive and small octahedral crystals), tourmaline, cleavelandite, apatite, dumortierite, chrysoberyl, rose quartz, garnet, cassiterite, cookeite, eosphorite, lepidolite, spodumene, zircon, torbernite, autinite, and uranophane (Thompson and others, 1991).

In the past, granite was produced from quarries at several localities in the Spruce Head pluton, and from a small number of quarries in the Waldoboro pluton and the Raccoon pluton within the map area. Smaller quarries were opened and operated in Bath, Phippsburg, Brunswick, and Bristol (Figure 53). The Clark Island Quarry near Tenants Harbor in St. George was opened in 1870 in biotite-muscovite granite of fine to medium even-grained texture in the Spruce Head pluton (Dale, 1907). As of 1905, the quarry opening measured 500 feet x 300 feet with an average depth of 25 feet. Long Cove Quarry (Figure 25) in the town of Tenants Harbor was opened in 1873, producing the same type of granite as from the Clark Island Quarry. As of 1907 the quarry was 1000' long, 500' wide, and an average of 40 feet deep (Dale, 1907). The Hocking Granite Quarry, located in St. George, at the very northern edge of the map sheet, produced granite essentially like that from the Clark Island Quarry and was one of the last operations in the area to close. As of 1960 most quarrying had ceased, but the company was producing crushed rock. The granite dust from this crushing operation was marketed under the trade name Vitamite as a soil additive for potash. Some small quarries were opened in gabbro-diorite of the Raccoon pluton. In the Waldoboro pluton, the only sizable opening in the Bath map sheet is the Round Pond Quarry in the town of Bristol. According to Dale (1907), the quarry was opened in 1885 and consisted of two openings, one 100 feet square, and the other 400 feet by 100 feet, each ranging in depth from 10 to 65 feet.

Seven small prospect pits in the coticule unit of the Cape Elizabeth Formation were encountered by Hussey during detailed mapping on Arrowsic Island and Georgetown Island (Figure 53). Most pits are small - generally less than 20 feet x 20 feet by 10 feet deep. One pit on Arrowsic Island just off Doubling Point Road has a nearby adit about 4 feet high that is presently flooded about three feet inside the opening (Figure 54). Morrill (1955) makes reference to iron mining and "emery" mining in Arrowsic, and apparently these openings (Figure 55 and Figure 56) were the prospects for iron ore (magnetite) and abrasive (garnet) which are abundant in the coticule. Since corundum has not been reported from here, it is not a true emery deposit. The prospects are believed to have been worked by the Bath Iron Mining and Manufacturing Company, a company chartered by act of the Maine Legislature in 1865. Figure 57 is a reproduction of the petition of a number of businessmen in the Bath area to the Maine legislature, and Figure 58 is a copy of the legislative document that established the Bath Iron Mining and Manufacturing Company. Prospecting operations apparently were carried out shortly after incorporation, and then quickly abandoned because of lack of sufficient ore for economic production of either iron or abrasive material. No mention of the Bath Iron Mining and Manufacturing Company or its operations of which the writer is aware appears in the Maine Mining Journal, published in Bangor between 1881 and 1883. Nor is there any mention of iron ore or emery mining in discussions of the results of the geological survey of the State of Maine during the late 1850's and earliest 1860's by Hitchcock (1861, 1862), or earlier by C. T. Jackson (1837, 1838, 1839).

flooded adit in Cape Elizabeth Formation
Figure 54		 iron and emery prospect pit
Figure 55		 spoils pile, arrowsic iron mine
Figure 56		 petition to form Bath Iron Mining and Manufacturing Company
Figure 57		 document authorizing Bath Iron Mining and Manufacturing Company
Figure 58

Marble from two localities in Brunswick, one north of the bridge to Great Island (Harpswell) and the other in East Brunswick, was quarried and burned for agricultural lime probably in the mid 1800's. The East Brunswick locality is a narrow strip mine following a local zone of marble in the Bethel Point Formation (SObp); and the other locality is a series of strip mines 10 to 15 feet wide and 8 to 10 feet deep following the white marble lens (the same unit as shown in Figure 19) in the amphibolite (SOsa) of the Sebascodegan Formation. A third locality, where lime was burned, but where there is no clear evidence of its having been mined, is on The Basin in Phippsburg near the grossularite mineral-collecting locality in the Cape Elizabeth Formation (Ocea). On the east side of the small point at the garnet locality can be seen the remains of the kiln that was used for producing quicklime.

Talc was mined in the early 1800's on a very limited basis from the 1-meter-wide pre-metamorphic sill within the Cape Elizabeth Formation on the east shore of Bailey Island (Jackson, 1837). Small blocks of quarried rock, possibly dating from this time, can be seen at that locality.

Flagstone was produced from a quarry in amphibolite of the Sebascodegan Formation on property that is now part of the Brunswick Naval Air Station. Production from this quarry ceased when the property was acquired by the Navy Department in the 1940s. Slabs of amphibolite probably produced from this quarry can be seen in many homes and businesses in the greater Brunswick area as patio pavers, retaining wall blocks, and dividing wall blocks.

Last updated on February 1, 2008