HIGH RESOLUTION GPS MAPPING IN A VERTEBRATE TAPHONOMIC QUARRY
TURNER, L. E., Dept. of Mathematics and Physical Sciences, email@example.com;
CHADWICK, A. V., Dept of Biology, Southwestern Adventist University, Keene, TX
SPENCER, L., EHRC, 4736 Carberry Ck. Rd., Jacksonville, OR 97530
Taphonomic and related sedimentary studies depend upon precise
information about field relationships for reconstruction of events in
the history of burial and fossilization of organisms. Until recently,
this meant overlaying the field relationships with a physical grid and
sketching the details in two dimensions. While this technique has been
satisfactory for preserving relationships in two dimensions, the procedure
left three-dimensional relationships very difficult to reconstruct.
We have applied high-resolution GPS mapping and digital photography to a
taphonomic quarry, and have satisfactorily reconstructed the field
relationships in three dimensions using Arcview GIS software. Vertebrate
fossils (principally dinosaur bones) were exposed in the quarry using
standard field techniques. When bones were adequately exposed and pedestaled, they were photographed
in their field relationships using a Nikon digital camera. A variable
number of points (ranging from one for small fragments or teeth, to many
for large bones) were then taken directly from the exposed bone using a
Javad GPS having a resolution of 1 cm or less. The points and photographs
were transferred to a laptop computer at the end of each day, and processed
into individual bone files.
These files were converted into three dimensional shape files and the
photographs of the bones were overlaid on the three-dimensional GPS data in
the computer and displayed in Arcview 3-D module. The resulting
three-dimensional reconstruction was highly satisfactory for retaining
field relationships and for data analysis.
The results give surprising insights into the processes of death and burial
and enable predictions to be made about future discoveries. The procedure
also enables us to preserve field relationships that might have been lost
using older mapping techniques.
presented at the GSA 2000 meeting, Reno, NV, Nov 2000