TY - JOUR
T1 - Obsidian provenancing and magmatic fractionation in central oregon
AU - Godfrey‐Smith, D. I.
AU - Kronfeld, J.
AU - Strull, A.
AU - D'Auria, J. M.
PY - 1993/10
Y1 - 1993/10
N2 - In many instances, geologically distinct obsidian flows located within even a relatively small geographic area can be uniquely identified by their chemical composition. This happens to be true for several obsidian sources from central Oregon. Internally each obsidian locality is chemically homogeneous, but the obsidian rocks from different collection sites exhibit chemical differences. Based on the geochemical variations and on K/ Ar dating of the end members of the chemical differentiation trend, these differences are related to the fractionation of a single Late Miocene magma chamber, dated at 6.5 Ma. By understanding the underlying causes of the chemical differences, constraints are disclosed that will govern the possible chemical variations of other, as yet unidentified but related obsidian flows. These can be useful for identifying the possible natural sources of obsidian artifacts which do not match known obsidian sources, and for suggesting possible geographic areas where these as yet undiscovered obsidian flows may be found. © 1993 John Wiley & Sons, Inc.
AB - In many instances, geologically distinct obsidian flows located within even a relatively small geographic area can be uniquely identified by their chemical composition. This happens to be true for several obsidian sources from central Oregon. Internally each obsidian locality is chemically homogeneous, but the obsidian rocks from different collection sites exhibit chemical differences. Based on the geochemical variations and on K/ Ar dating of the end members of the chemical differentiation trend, these differences are related to the fractionation of a single Late Miocene magma chamber, dated at 6.5 Ma. By understanding the underlying causes of the chemical differences, constraints are disclosed that will govern the possible chemical variations of other, as yet unidentified but related obsidian flows. These can be useful for identifying the possible natural sources of obsidian artifacts which do not match known obsidian sources, and for suggesting possible geographic areas where these as yet undiscovered obsidian flows may be found. © 1993 John Wiley & Sons, Inc.
UR - http://www.scopus.com/inward/record.url?scp=84989600546&partnerID=8YFLogxK
U2 - 10.1002/gea.3340080504
DO - 10.1002/gea.3340080504
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AN - SCOPUS:84989600546
SN - 0883-6353
VL - 8
SP - 385
EP - 394
JO - Geoarchaeology - An International Journal
JF - Geoarchaeology - An International Journal
IS - 5
ER -