Pollen Record Preservation Processes in the Salem Neck Sewage Plant Shell Midden (19-ES-471), Salem, Massachusetts, U.S.A.

Initial tests on the three-dimensional movement of starch in sediments

“…Asafinalpointofcomparison,thenotionofstarchesmovingthrougharchaeologicalsediments maybeconsideredinlightofpreviousresearchintopollengrainmovement.Pollenmovementthrough sediments under the influence of water (or percolation) is well studied (Dimbleby 1985;Horrocks and D'Costa 2003;Kelso 1993Kelso , 1994aKelso , 1994bKelso et al 1995;Kelso et al 2000), and relevant to the present studythankstooverlapingrainsizeswithstarch. Dimbleby(1985)produceddetailedtheoreticalmodels ofpollenmovementandpreservationatarchaeologicalsites,andhisconclusionsbroadlysuggestthatthe lower one looks in a sediment profile, the higher the percentage of older pollen, and the higher the percentageofdegradedpollengrains,oneshouldfind.Samplestakenfromhigherupinaprofileshould contain mixtures of washed-down pollen of various ages, trending towards a high percentage and frequencyofrecently-depositedpollengrainsatthesurface.Inaddition,becauseoftheinterplaybetween percolation and degradation (including differential decomposition), the absolute numbers of pollen grains recovered from a given sample will show a more complex pattern than that calculated via percentages(Dimbleby1985:5).SubsequentempiricalresearchsupportsDimbleby'sresults(e.g.Horrocks andD'Costa2003;Kelso1994a,1994b;Russell1993),andemphasisesthenecessityofnotjustrecording thepresenceofparticulartaxawithinagivensample,butevaluatingtheentiremicrofossilassemblageto accuratelyidentifytheinfluenceofmovementanddegradation.Suchresultshaveobviousimplications fortheconductofsediment-starchanalysis.…”

Remains of the day-preservation of organic micro-residues on stone tools

“…In soils with high bioactivity (measured through proxies including precipitation, soil moisture and pH, vegetation growth and presence of earthworms) residues decay fast. A protective microenvironment, such the microscope slide or a sediment cover, may protect residues from precipitation and ground water movement similar to the way pot sherds protect pollen (Barton, 2009;Haslam, 2004;Kelso et al, 1995Kelso et al, , 2000. It is argued elsewhere that residues, or any organic materials for that matter, decay fast unless equilibrium with the environment is established (Barton, 2009;Barton and Matthews, 2006;Barton et al, 1998;Raiswell, 2001).…”

Recovering Ethnobotanical and Local Environmental Pollen Data from an Exposed Archaeological Site in Northeastern North America: Locus 2 at the Carns Site, Cape Cod National Seashore, Massachusetts

“…A pollen record of changing edaphic conditions was recovered from a stratigraphic sequence taken under flat rocks and artifacts (1 × 1.5 to 3 × 4 inches in size) in an abandoned 1640s potter's barrow pit used for trash disposal at Jamestown, Virginia . A pollen sequence collected under shells (averaging 4 × 6 centimeters in size) in a shell midden at Salem, Massachusetts recorded prehistoric deciduous forest, while soil samples from the top, middle, and bottom of the midden profile were dominated by historical-era Eurasian weeds (Kelso et al, 1999).…”