2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 290-6
Presentation Time: 9:00 AM-6:30 PM

3D MODELING OFF-GRID: PHOTOGRAMMETRY AS A FIELD RESOURCE FOR CREATING POLYGONAL MODELS OF FOSSIL MATERIAL AT OLDUVAI GORGE


SWARTZ, Sarah M. and NJAU, Jackson K., Geological Sciences, Indiana University, 1001 E. Tenth Street, Bloomington, IN 47405, saswartz@indiana.edu

Olduvai Gorge, Tanzania, is historically significant as the birthplace of paleoanthropology. Formed as an incisional basin consequent to the East African Rift System, nearby volcanism dates the area to the Lower Pleistocene. The Olduvai Antiquities Station, once the permanent camp of the decades-long Leakey family excavations, continues to hold unstudied fossil material from historic and ongoing digs. Ecologic and functional morphology of the fauna housed at Olduvai could yield important insights into the evolutionary transitions forced by climate fluctuations in the formerly lacustrine region. 3D digitizations of skeletal material are becoming commonplace in paleontological studies of morphology; however, the primitive nature of the site restricts the use of traditional laser scanning devices. In lieu of costly scanning equipment, structure-from-motion based photogrammetry software can be used with limited resources to build 3D polygonal representations of fossils and artifacts held at remote locations.

Protocols were established to digitize vertebrate specimens of interest, with a particular focus on primate material from Beds I and II. Fossils were photographed under various lighting conditions, indoors and outdoors, using a Canon DSLR camera. Test models were constructed in the field using the standalone software package PhotoScan 1.1 (Agisoft LLC) on a MacBook Pro. All electricity employed in the processing was reliant on two rooftop solar panels. By assigning control points to the material, multiple models were built of each specimen and merged into a final scaled model for later analysis. The photographic data collected was able to produce models of comparable quality to laser scanning techniques. Photogrammetry has broad potential in the paleontological and geological field sciences. In areas where conditions prohibit advanced laser tomography, photogrammetry provides another option. Additionally, numerous collections held abroad are proprietary to the country of origin, where access to material is often limited. 3D digitization using alternative approaches can provide avenues of collaboration and communalism amongst researchers across the globe. This preliminary study highlights the benefits and shortcomings of photogrammetry as a precision field technique.