Date: 18 November, 2019

Dataset Title: Magnetometer Survey Data from the Weeden Island Site (8Pi1), Florida (2013-2014)

Dataset Creators: Timothy J. Horsley and Christina P. Sampson

Dataset Contact: timhorsley@gmail.com

Funding: Museum of Anthropological Archaeology (University of Michigan)

Research Overview: The research was conducted as part of a University of Michigan dissertation project. Geophysical survey took place at the Weeden Island site in St. Petersburg, Florida in November 2013 and December 2014. This dataset includes the results of magnetometer survey, which was performed after an initial magnetic susceptibility survey of a portion of the site to identify areas of human activity and occupation. 

Methods: 
We used a Bartington Grad601-2 dual fluxgate gradiometer to survey four areas, two with approximate areas of 15 x 15 m, one 30 x 20 m area, and one 20 x 20 m area. In each area, we cleared vegetation including saplings and undergrowth. In 2013, while collecting data for Survey Areas 1 and 2, both gradiometer sensors were used to collect data at a sample interval of 0.125 m along traverses spaced 0.5 m apart. Each line was walked in opposite directions (sometimes referred to as bi-directional). In 2014, while collecting data for Survey Areas 3 and 4, we used just a single gradiometer sensor and collected data along traverses walking in one direction only. Due to the subtle nature of the archaeological anomalies and the large number of trees and other obstacles, this unidirectional methodology produced higher quality data by reducing striping defects caused by different sensors and orientations, although survey speed is significantly slower. 
Processing of magnetometer data was limited to clipping of the data, sensor destripe to reduce striping in the 2013 data (survey grids 1 and 2) due to sensor mismatch, and interpolation. TerraSurveyor version 3.0.34.10 was used to create composite files included here.

File Inventory: 
The files are organized into folders as described below in order to be readable within TerraSurveyor:

-Weedon2013_Areas1-2: This folder contains data from Survey Areas 1 and 2.
  -comps: This folder contains "composites," the files that TerraSurveyor uses to process and display data from the surveyed area.
    m1.xcp: Survey area 1 composite
    m1zai.xcp: Survey area 1 composite
    m1zaiL.xcp: Survey area 1 composite
    m2.xcp: Survey area 2 composite
    m2ziL.xcp: Survey area 2 composite
  -graphics
    m1zai_-1p5to1p5: Survey area 1 BW
    m1zai_-2to3Fe: Survey area 1 BW likely iron 
    m1zai_-4to4col: Survey area 1 color
    m2zi_-1p5to1p5: Survey area 2 BW
    m2zi_-2to3Fe: Survey area 2 likely iron 
    m2zi_-4to4col: Survey area 2 color
  -grids: This folder contains data downloaded from the field instrument for Survey Areas 1 and 2.
    m1_0.dat
    m1_0.hdr
    m1_0.xgd
    m2_01.dat
    m2_01.hdr
    m2_01.xgd
site.ini: Descriptive information for the areas surveyed to produce data in this folder

-Weedon2014_Area3: This folder contains data from Survey Area 3.
  -comps: This folder contains "composites," the files that TerraSurveyor uses to process and display data from the surveyed area.
    m1.xcp: Survey area 3 composite
    m1a.xcp: Survey area 3 composite
    m1ca.xcp: Survey area 3 composite
    m1cazi.xcp: Survey area 3 composite
    m1cazic1p2.xcp: Survey area 3 composite
    m1cm.xcp: Survey area 3 composite
  -graphics
    m3cazi_-1p5to1p5: Survey area 3 BW
    m3cazi_-2to3: Survey area 3 likely iron BW
    m3cazi_-2to3Fe: Survey area 3 likely iron color
    m3cazi_-4to4col: Survey area 3 color
  -grids: This folder contains data downloaded from the field instrument for Survey Area 3.
    m1a_01.dat
    m1a_01.hdr
    m1a_01.xgd
    m1a_02.dat
    m1a_02.hdr
    m1a_02.xgd
    m1a_04.dat
    m1a_04.hdr
    m1a_04.xgd
    m1b_01.dat
    m1b_01.hdr
    m1b_01.xgd
    m1b_02.dat
    m1b_02.hdr
    m1b_02.xgd
site.ini: Descriptive information for the areas surveyed to produce data in this folder

-Weedon2014_Area4: This folder contains data from Survey Area 4.
  -comps: This folder contains "composites," the files that TerraSurveyor uses to process and display data from the surveyed area.
    m4.xcp: Survey area 4 composite
    m4czic5.xcp: Survey area 4 composite
  -graphics
    m4czi_-1p5to1p5: Survey area 4 BW
    m4czi_-3to4Fe: Survey area 4 likely iron
    m4czi_-4to4col: Survey area 4 color
  -grids: This folder contains data downloaded from the field instrument for Survey Area 4.
    m2_01.dat
    m2_01.hdr
    m2_01.xgd
    m2_02.dat
    m2_02.hdr
    m2_02.xgd
site.ini: Descriptive information for the areas surveyed to produce data in this folder

Use and Access: 
Files can be opened and viewed in the program TerraSurveyor.