Final Report on the Archaeological Intensive Survey for the Thompson Island Salt Marsh Restoration Project, Boston Harbor Islands, Massachusetts

Author(s): Leith Smith; Allen Gontz

Year: 2006

Summary

A salt marsh restoration plan for Thompson Island in Boston Harbor calls for the removal

of a stone berm that prevents tidal flushing of an existing salt marsh/pond on the central

east side of the island. Lack of daily tidal exchange has resulted in a stagnant water body

with severe algae blooms and encroachment by the invasive plant species, common reed

(Phragmites australis). The restoration plan includes archaeological investigation of the

proposed construction/demolition area as well as the inter-tidal zone and marsh/pond

bottom that may be subject to erosion once the blocked outlet is reopened. The

construction area was tested with a series of ten, 10 m-interval shovel tests arranged in

four transects. Sand and gravel predominated with a low density of late nineteenth and

twentieth century waterworn ceramics, glass, brick and coal. The south and west marsh

perimter was previously tested with 20 m-interval shovel tests by Barbara Luedtke in

1993 with only late nineteenth and twentieth century artifacts found. The remaining east

and north tidal zone, therefore, was tested with nineteen, 20 m-interval shovel tests.

These revealed sandy clay loam soils and a low density scatter of mostly waterworn late

nineteenth and twentieth century artifacts. Two gray siltstone flakes and some shatter

were identified in one test in [REDACTED]. Array tests

revealed an additional gray-green chert flake. The marsh bottom was remotely imaged

using a StrataBox subbottom profiler to search for potential submerged anomalies.

Shallow conditions and gas-charged sediments obscurred some readings, but a paleo

drainage channel was identified approximately 2 m below the marsh bottom. Although

one small Native American activity locus was identified, it was

recommended that the project proceed as planned.

Cite this Record

Final Report on the Archaeological Intensive Survey for the Thompson Island Salt Marsh Restoration Project, Boston Harbor Islands, Massachusetts. Leith Smith, Allen Gontz. Andrew Fiske Memorial Center for Archaeological Research Cultural Resource Management Study ,18b. Boston, Massachusetts: University of Massachusetts. 2006 ( tDAR id: 371745) ; doi:10.6067/XCV8GQ6VT1

Spatial Coverage

min long: -71.027; min lat: 42.277 ; max long: -70.875; max lat: 42.342 ;

Notes

Redaction Note: Information relating to the location of prehistoric sites, features, and artifacts has been redacted from this document.

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