Bulk Density

the percent water content contained within sediments.  To determine the bulk density of the sample a simple mathematical calculation was used (Initial mass-Final mass/Initial Mass)*100.  This equation was used for every sample to produce a bulk density profile for each core.

Carbon/Nitrogen Ratios

    helps to determine paleoenvironment.  If the ratio is large and more Carbon is present then Nitrogen there is a more terrestrial input.  If more Nitrogen is present then Carbon the ratio will be smaller representing a more marine environment

Cesium-137 and Lead-210

    were analyzed within sediments to provide sedimentation rates and in some cases provide an age framework for the samples.

AMS Radiocarbon Dating

    Samples were sent to the University of Arizona to be dated with their Accelerated Mass Spectrometer (AMS) to provide an age range for the sample.  AMS counts the rate of decay of 14C within the sample and compares that rate with Libby’s “Curve of Knowns” to determine the age of the sample.  The ranges received were calibrated to calendar years using the “Calib Radiocarbon Calibration” from http://radiocarbon.pa.qub.ac.uk/calib

Foraminifera

    Collins et al,1999 proved that foraminifera found within sand layers could be used as a tool for correlation of overwash sand layers from intense hurricane events.

Thin Sections based on Francus and von Merkt

    Thin sections were taken from the face of the cores by thin-walled aluminum boxes (dimensions 15x3x0.5 cm).  These flat sub-cores are taken at selected intervals particularly over boundaries and sedimentary structures.  The sub-cores were then placed over a liquid nitrogen bath to freeze the sediments and structures in place.  Then the samples were placed in a freeze-dryer to remove all water from the samples.  Next they were impregnated with epoxy and placed in a vacuum to remove all bubbles and preserve the orientation of sediment grains within the sub-cores.  All above procedures are based on methodology by von Merkt (1971) and Francus (1997).  These samples were sent to National Petrographic Service for thin sectioning.  Next, back-scattered electron (BSE) images were taken of the thin sections.  These images combined with software provided by Pierre Francus provide quantitative data of size, shape, orientation and packing of the grains forming the sedimentary micro-structures (Francus and Karabanov, 2000).