High-Resolution Geophysical Characterization of Geology and Acoustic Water Column Signatures in Willamette Valley Reservoirs, Oregon, USA

Summary

This is an abstract from the "Future Directions for Archaeology and Heritage Research in the Willamette Valley, Oregon" session, at the 88th annual meeting of the Society for American Archaeology.

Inland flood-control reservoirs represent a novel analog for studying submerged terrestrial landscapes. The same scale and time-independent processes that impact coastal environments through sea-level changes are also produced through a reservoir’s annual draft and fill cycles. Within these reservoirs, geophysical data collected during high water levels can be ground-truthed with terrestrial methods during drawdown. Here, we present Chirp sub-bottom and sidescan sonar data collected within reservoirs of Oregon’s Willamette Valley investigating the suitability of these methods for identification of paleolandforms and archaeological sites in drowned river valleys. These data are used to test the human altered lithic detection (HALD) method, which uses acoustic signatures in the water column of Chirp data to detect submerged stone age sites containing human altered lithics. The HALD method has previously been field tested in limited geographic settings. We present observations of water column noise that appear generated by materials other than human altered lithics and the results of field experiments that test the water column noise signatures of human altered obsidian, historic and modern glass, flaked crystalline basalt, and quarried chert. The data suggest more work is needed to fully develop the HALD method across a wide range of geographic settings and materials.

This Resource is Part of the Following Collections

• Future Directions for Archaeology and Heritage Research in the Willamette Valley, Oregon   •
• Society for American Archaeology 88th Annual Meeting, Portland, OR (2023)

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Record Identifiers

Abstract Id(s): 35654.0