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U.S. Department of Energy
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Composition of augite and pigeonite in basalt flows that are candidates for a nuclear waste repository

Conference ·
OSTI ID:5532413
The abundance and composition of pigeonite are variable within single flows of basalt in spite of uniform bulk composition. These variations are spatially related to the occurrence of entablature and colonnade, which in turn apparently reflect the cooling history of the flow. Differences from one flow to another in the occurrence of pigeonite may be explained by the extent to which early-formed microphenocrysts of pigeonite react out during crystallization of the flow and the extent to which late-stage pigeonite rims are developed. The preservation of pigeonite in the entablature of flows such as the Umtanum tends to corroborate the proposed origin of entablatures and their attendant fracture patterns by relatively rapid cooling of the interior of these flows.
Research Organization:
Rockwell International Corp., Richland, WA (USA). Rockwell Hanford Operations
DOE Contract Number:
AC06-77RL01030
OSTI ID:
5532413
Report Number(s):
RHO-BW-SA-295-P; CONF-830815-12; ON: DE84001111
Country of Publication:
United States
Language:
English