T111 Topics in Geoarchaeology: Reconstructions of Ancient Landscapes and Paleoenvironments (Posters)

Monday, 10 October 2011
9:00 AM - 6:00 PM
Hall C

PALEOENVIRONMENTAL RECONSTRUCTION OF THE TURNER FARM ARCHEOLOGICAL SITE, MAINE, BASED ON PALYNOLOGICAL REMAINS

Paper number: T111-7
Program: Technical Sessions
Time: 9:00 AM – 6:00 PM

Authors

Abstract

Analysis of palynomorphs from the Turner Farm site located on North Haven Island in Penobscot Bay, Maine, is of paramount importance in developing a paleoenvironmental reconstruction. The site, with its rocky shore and adjacent salt marsh, is of particular historical, cultural, and geologic interest due to its use as a shell midden by Paleo-Indians beginning over 4,000 years ago. Two parallel cores, penetrating salt marsh peat down to underlying postglacial marine sediments, were taken to procure palynomorphs and plant and insect macrofossils. The 3.05 m pollen core was sampled at 5-cm intervals and processed using traditional methods. Analysis of material from these cores facilitated reconstruction of the changes in local vegetation over time by natural and human causes, through qualitative and quantitative investigation of palynomorphs.

Radiocarbon dating of the oldest peat sample yielded a basal age of 4310 ± 140 years. Additional samples have been submitted for dating to provide higher resolution; ages will in turn be utilized to correlate deviations in the vegetational record and historically significant dates in human history. This research was initiated in pursuit of better understanding how people—Paleo-Indians and Europeans alike—impacted the environment through alteration of regional vegetation and marine wildlife. This investigation seeks to determine at what points in North Haven’s history the vegetation was altered merely by normal geologic and biologic processes and at what point changes, such as clear-cutting and the introduction of new agricultural crops, came at the hand of humans.

Palynomorphs recovered from the core reveal a spectrum of paleoenvironments. Basal samples evince a more restricted vegetational environment. Dominated by monolete and trilete fern spores as well as Poaceae and Cyperaceae pollen, these palynomorphs are indicative of an open, wetlands environment. In contrast, younger sediments at the top of the core yielded a more diverse assemblage of pollen grains comprised of Picea, Betula, Alnus and Quercus. The increasingly frequent emergence of such grains in the pollen record denotes the reintroduction of tree growth contiguous to the wetland region of the salt marsh. The presence of charcoal supports a hypothesis of clear-cutting for agricultural purposes.