Interim geologic map of the Shirley Quadrangle, Massachusetts

Site Investigation Report Fort Devens Groups 3,5, and 6. Volume 1 of 2: Report Text

“…It is finegrained and consists of quartz and minor feldspar and ankerite, and it is commonly deformed by kink banding (Zen, 1983;Peck, 1975;Russell and Allmendinger, 1975). In outcrop it has alternating layers of brown siltstone and greenish phyllite.…”

“…Preliminary bedrock maps (at scale 2,000 feet/inch) are available for the Clinton quadrangle (Peck, 1975 and1976) and Shirley quadrangle (Russell and Allmendinger, 1975;Robinson, 1978). Bedrock information for the Ayer quadrangle is from the Massachusetts state bedrock map (at a regional scale of 4 miles/inch) (Zen, 1983) and in associated references (Robinson and Goldsmith, 1991;Wones and Goldsmith, 1991).…”

“…Major faults have been mapped, however, including the ABB Environmental Services, Inc. Peck (1975), Robinson (1978), Russell and Allmendinger (1975), and Zen (1983), and it adopts the nomenclature of Zen (1983). Because of limited bedrock exposures, the locations of mapped contacts are considered approximate, and the mapped faults are inferred.…”

“…The Oakdale Formation crops out most visibly on Route 2 just east of the Jackson Gate exit and on the east side of Jackson road approximately 500 feet north of the gate. It corresponds to the "DSsp" unit of Peck (1975), the "e2" unit of Russell and Allmendinger (1975), and the "ms" unit of Robinson (1978).…”

“…The abandoned Shaker slate quarry on the South Post is in rocks of the Worcester Formation. The unit corresponds to the "DSgs" and "DSs" units of Peck (1975) and the "e3" unit of Russell and Allmendinger (1975).…”