Project Abstract (Taken from a recent conference poster):

The Willamette Valley during the Terminal Pleistocene was an environment in constant flux, creating a changing world for the early inhabitants of the Pacific Northwest. The valley floor contains an extensive record of Pleistocene ecology and archaeology; however, the information is locked within a complex stratigraphic sequence. Using a Geoprobe direct push coring rig, 13 sediment cores were extracted from surficial deposits in the Mill Creek watershed at Woodburn High School. The core samples were analyzed on Oregon State University’s Itrax core scanner, returning high-resolution optical imagery, radiograph images, and x-ray fluorescence (XRF) data. The XRF data is used to construct a chemostratigraphic profile of the study area in order to define and model the distribution of sediments potentially related to late Pleistocene-aged archaeological sites.

Research Question, etc:

I am seeking to explore methods of constructing chemostratigraphic frameworks of sediments at both archaeological and non-archaeological sites. The method that is most typically used to define chemostratigraphy at archaeological sites is portable x-ray fluorescence of previously described stratigraphy, and using multivariate statistics to separate the strata by chemistry. Using an Itrax Core Scanning machine, sediment cores extracted from a drainage at Woodburn High School were scanned and continuous high-resolution x-ray fluorescence (XRF) data was acquired. Using wavelet analysis, I hope to be able to define the site stratigraphy and use it to construct a 2D and 3D representation of the subsurface landscape.

Project Dataset:

The dataset consists of XRF data taken at 2mm intervals, from 65 1.5 meter core samples. These cores come from 14 different boreholes covering the majority of the defined study area which is approximately a 200×50 meter area. The data is organized into 14 CSV files containing the XRF results.

Hypothesis:

Through preliminary testing I have seen potential in using this method to successfully identify stratigraphy. If the result of the preliminary test translates across all 14 boreholes, the construction of landscape wide stratigraphic profiles from the borehole samples and wavelet analysis is very likely.

Approaches:

Throughout the term, and through the process of conducting analysis of the Woodburn sediments, I hope to learn how to better utilize and interpret wavelet analysis data, as well as digitally construct 2D and 3D stratigraphic profiles using interpolation methods.

Breaks in stratigraphy can be shown clearly through changes in color or texture, and multivariate techniques have been very useful to identify them. This method has proven useful to confirm the chemostratigraphy of a site when the XRF measures have an attributed strata. Wavelet analysis allows the user to see possible changes in geochemistry, which gives way to possibly identifying geochemical breaks in strata from borehole data that does not contain established stratigraphic names and boundaries.

In order to conduct the analysis, elements had to be selected in order to do both univariate and bivariate analysis. There were a variety of ways that I could have selected the data, but ultimately, in the test sample, I chose to look at the elements that had the most obvious changes. This allowed me to really understand how wavelet analysis works versus a regular line graph. For the final analysis, I will look at similar completed work, and select the best elements to conduct bivariate analysis with for XRF based mineral studies.

Expected Outcome:

Visually, I would like to create a stratigraphic profile for each of the four transects at the site, as well as a 3D representation of the site using ArcScene. As for the data, I would like to create a type stratigraphy that archaeologists can reference in order to help find early archaeological sites in the Willamette Valley  

Significance:

The results of this project will hopefully help archaeologists understand the stratigraphy and possibly the environmental conditions in the Woodburn, Oregon area, and possibly the Willamette Valley. The sediments buried in this site could contain clues into which sedimentary deposits that archaeological sites could be hidden in, or at least hidden near.

My Level of Preparation:

I am pretty knowledgeable in ArcGIS and the rest of the Arc/ESRI suite of programs. My python skills are average, with better skill in ArcPy. As for R, I have taken courses that deal with it, and am steadily improving my skills.