the florida state university college of arts and sciences evolution of ...

2.3 St. Vincent Island shoreline changes based on historic charts. (Source:
Stapor, 1973)............................................................................................................................30
2.4 Age distribution of archaeological sites in the lower Apalachicola
River watershed, including St. Vincent Island. Symbols indicate
approximate known age of the oldest artifacts found at all dated sites
within the lower watershed. Contours show the maximum age of the
enclosed sites, indicating a close connection between delta migration and
human settlement patterns. Contours are dashed where uncertain.
Patterned area northwest of the modern Apalachicola delta is the “Late
Pleistocene” delta. (Source: Donoghue and White, 1995).......................................................31
2.5 Archaeological sites on St. Vincent Island. (Source: Braley, 1982)..................................32
3.1 a) Collecting a vibracore. b) Collecting samples by trenching and
hammering a short section of aluminum pipe into the vertical face . ......................................46
3.2 Demonstration of the basis of luminescence dating. The event being
dated is the setting to zero of the luminescence signal that was acquired at
some point in the past. The zeroing of this signal occurs through exposure
to sunlight during erosion, transport and deposition. Once the material is
buried the signal begins to build again. (Source: Lepper, K., NDSU,
http://www.ndsu.nodak.edu/ndsu/klepper) ..............................................................................47
3.3 OSL processes represented by the conduction band model. The
mineral is exposed to nuclear radiation. The binding electrons are excited
above their ground states. As the electrons return to their ground states,
some become trapped in defects in the crystal lattice (represented by “T”).
When the mineral is exposed to light or heat the defects are emptied and
light is emitted. (Source: Aitken, 1991)..................................................................................48
3.4 Effects of natural radiation on sediment particles. Silt-sized grains are
irradiated by alpha, beta, gamma and cosmic radiation but sand-sized
grains are only irradiated by beta, gamma and cosmic radiation, since
alpha particles have a short range and only penetrate the outer rind of
sand-sized grains. Of the four radiation types that contribute to the dose
rate, cosmic radiation has the greatest penetration. (Source: Aitken, 1998)............................49
3.5 Sample removed from large core samples. The shaded area represents
the 100 grams collected as a dating sample. (Source: Forrest, 2003)......................................50
3.6 Riso TL/OSL measurement system schematic in side view. This
system consists of a turntable in which there can be 48 sample aliquot
positions. The table rotates and when a sample disc reaches the position
of the lift, it is raised for measurement of luminescence. A beta source
(i.e. Sr-90) is positioned remotely from the measurement position and
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