PALEOEVIRONMENTAL RECONSTRUCTION OF THE TURNER FARM ARCHEOLOGICAL SITE, MAINE, BASED ON PLANT AND INSECT MACROFOSSIL REMAINS

The Turner Farm archaeological site on North Haven Island, Maine, is of great importance to climate researchers and archaeologists alike. The site lies on the southern coast of the island and is bordered on one edge by a brackish water marsh, on another by the ocean, and on the final side, by the Turner Farm itself.

Work in the 1980s indicated the marsh developed in response to postglacial sea-level rise, accompanied by beach-ridge development that blocked off an older stream drainage that had eroded a channel into underlying Presumpscot Formation postglacial marine sandy silts. A preliminary radiocarbon age determination on basal organics in the section indicates peat accumulation began at 4310 ± 140 radiocarbon years bp (SI-2216).

Two parallel 3-m peat cores were taken from this marsh in the summer of 2010. These cores contain the story of vegetative colonization and the impact of the Paleo-Indians, European settlement, and environmental change to the present. These cores were then sampled at regular intervals, one core for pollen and the other for plant and insect macrofossils.

Basal organic sediments have yielded only seeds of elderberry (Sambucus) and blackberry or raspberry (Rubus). Seeds of marsh sedges (Carex) first appear at 2.46-2.52 m depth; first conifer needles appear before 0.51-0.53 m. Conifer needles indicate that pre-European forest coverage around the basin was mixed fir-spruce; historical 19th-Century photos show the site completely deforested, while the modern forest is virtually 100% spruce. Examples of other macrofossils found include Foraminifera, fragments of beetles, and charcoal. Analysis of these yields the local environment at each time period, which can be correlated to radiocarbon ages sampled throughout the cores. The pollen data give a wider picture of which wind-pollinated plants were growing in downeast Maine during the period studied, while the macrofossil data give a localized picture of the environment surrounding the Turner Farm Archaeological site. The two can then be correlated to give a complete vegetative history from 4,000 years ago to present.

Work is continuing on the basin, with expectation that 12 pending radiocarbon dates will permit correlation of the pollen and macrofossil records to the adjoining archeological site.