USING UNDERGRADUATES AND SMART PHONES TO TRANSLATE A TRACE-RICH HORIZON TO A SCALABLE, MANIPULATABLE TEMPLATE FOR STATISTICAL, INTERPRETIVE, AND ARCHIVAL PURPOSES

The Lower Atoka Formation exposed along Interstate 49 in northwest Arkansas depicts drastic facies changes over a couple of meters of section. These facies shifts depict an early stage in the development of the Arkoma Basin and the quickly changing sites of accommodation brought about by basin fill and flexure from the Pennsylvanian Ouachita Orogeny. Atop one laterally-extensive sandstone layer of medium thickness exists plentiful traces of a handful of ichnogenera, interpreted to be the deeper range of Cruziana ichnofacies. The modal trace is preserved in positive relief and is sinuous in plan-view; these range from the centimeter- to decimeter- scale in length, and may cover ~5 cm square area, but many seem incomplete.

The goal of this research was to develop a way to canvas a large area and archive trace position and shapes without much information loss. This is in order to prepare for exposures that possess plenty of traces, but are not always accessible due to seasonal conditions such as high water or debris cover. Using current-generation smartphones, a team of 4 were able to successfully gather spatial data to compose a map with high fidelity between field exposure of the trace-bearing surface and resulting map that was built using scanning-vector graphics software. The highly detailed reconstruction also provided an open template to ask a number of statistical questions about the trace fossils and their arrangement. Some adjustments will be made to the method of data collection and combining those data in the future. The updated method will be deployed for sites that are normally unavailable or only ephemerally accessible.