MAPPING AND VISUALIZING STRATIGRAPHY IN 3D SPACE WITH UAV AND SFM PHOTOGRAMMETRY AT OLDUVAI GORGE, TANZANIA

The multidisciplinary research conducted at Olduvai Gorge, Tanzania has been formative to our understanding of human evolution, as its ~ 2 Ma of fossiliferous strata contain record of 4 hominin species and 3 lithic technologies. Despite this, because of its geographic remoteness, large areal extent, and complex depositional environment a comprehensive, digitally available geological map of the site does not currently exist, often complicating geological fieldwork and contextualization of archaeological research.

A continuous segment of the gorge, extending from central areas of established archaeological productivity across multiple faults and paleoenvironmental facies towards less-studied areas was imaged using an Unmanned Aerial Vehicle (UAV) with a 12-megapixel camera. Transects were imaged from both nadir (-90°) and oblique angles (-20° to -40°), to ensure accuracy and coverage in the gorge’s steep topography. The images were then used to create a georeferenced 3D model of the area with Structure from Motion (SfM) Photogrammetry. The confluence of high-resolution source imagery (4247 x 2826), usage of a High-Powered Computing system for model creation, and the prevalence of compositionally distinctive ‘marker’ volcaniclastic beds within the Olduvai strata makes it possible to trace the boundaries between sub-meter scale sedimentary beds in 3D space. This delineation of geological bodies, in addition to drawing fault planes in 3D space forms the essence of a 3D geological map, wherein we visualize stratigraphy in a more accurate and dynamic fashion than is possible with dependency on hand-drawing, the human perspective, or even static aerial imagery.

Among the most immediate applications for this 3D map are in planning fieldwork and bolstering notes therefrom, alongside refining the geological and paleoenvironmental contexts of archaeological and paleontological work.