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Lava Top Butte is one of more than 400 late Pleistocene to early Holocene basaltic cinder cones located on the flanks of Newberry Volcano, a massive composite volcano centered about 30 miles southeast of Bend, Oregon. Located in the immediate vicinity of this distinctive cone are at least 18 small lava tubes, four of which show evidence of prehistoric occupation (Greeley 1971, Dudley et al. 1979, Larson 1982, Skinner 1983). These tubes range in length from only a few feet to 180 feet and include two perennial ice caves, a significant prehistoric resource in an area with few dependable year-round water sources. In 2004, after an absence of many years, we returned to the caves to finally begin to complete some long overdue obsidian research.
Vent Cave, a lava tube that drained a large vent area located to the right of the cave. Above right: Looking out from severely-disturbed interior of Vent Cave. Pothunters in search of artifacts have completely overturned the floor of the 40-foot long cave.
"permanent" ice that was found in the inner chamber of the cave was almost completely gone.
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Trace element studies of obsidian artifacts from the caves of Lava Top Butte indicate, not surprisingly, that most of the items originated from obsidian sources located only a few miles to the south in Newberry Caldera, Newberry National Volcanic Monument. Our research here involved obsidian characterization and hydration studies with special attention paid to the role of disturbed sites and perennial ice caves in regional archaeological research. When completed, we will present the results of trace element and hydration investigations of artifacts from the cave sites and will discuss our views concerning the articulation of these sites in the local patterns of obsidian procurement and use.
from the Newberry Volcano obsidian source group. The rod-shaped prismatic microlites (about 10 microns long) and the stretched vesicles are typical of obsidian from that source.
associated with the caves at Lava Top Butte.
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Dudley, James, Rick Bryant, and David Eisler. 1979. Cultural Resource Overview of the Deschutes National Forest, Oregon, Volume II. Report prepared for the Deschutes National Forest, Bend, Oregon, by Pro-Lysts, Eugene, Oregon. Greeley, Ronald. 1971. Geology of Selected Lava Tubes in the Bend Area, Oregon. Oregon Department of Geology and Mineral Industries Bulletin 71, Portland, Oregon. Larson, Charles V. 1982 Descriptions of Central Oregon Caves: With Special Emphasis on Ice Caves. In An Introduction to Caves of the Bend Area: Guidebook of the 1982 NSS Convention, edited by Charles V. Larson. National Speleological Society, Huntsville, Alabama. Skinner, Craig E. 1983. Obsidian Studies in Oregon: An Introduction to Obsidian and An Investigation of Selected Methods of Obsidian Characterization Utilizing Obsidian Collected at Prehistoric Quarry Sites in Oregon. Unpublished Master's Terminal Project, Interdisciplinary Studies, University of Oregon, Eugene, Oregon.
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Click HERE to download an interim report that includes the XRF and obsidian hydration analysis of the Lava Top Butte artifacts.
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