INVESTIGATING METHODS FOR HISTORIC BRICK TYPOLOGIES ANALYSIS IN THE PACIFIC NORTHWEST: HHXRF AND THIN SECTION PETROGRAPHY AT TUMWATA VILLAGE, OREGON CITY, OREGON

Despite providing data on changing technologies and international trade, bricks are an underutilized resource in the historical archaeology of the Pacific Northwest. Prior research by the Confederated Tribes of Grand Ronde Community of Oregon at tumwata village has documented over a century (c1840-c1940) of brick use during the urbanization of Oregon City, Oregon. This study explores the feasibility of constructing typologies for historic bricks from tumwata village using thin section petrography and handheld X-ray fluorescence spectrography (hhXRF). Thin section petrography with a polarizing light microscope was used to create typologies from 15 red brick samples collected from three 19th century structural remains. Elemental signatures for 73 samples from two debris piles were determined using a Bruker Tracer 5g hhXRF to examine inter-manufacturer patterning. Qualitative and quantitative statistical analysis provided mixed results due to high intra-source variability. While neither method should be used in isolation, both petrography and hhXRF showed potential to aid in the interpretation of bricks from tumwata village and the Pacific Northwest.