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Title: The Valles natural analogue project

The contact between an obsidian flow and a steep-walled tuff canyon was examined as an analogue for a highlevel waste repository. The analogue site is located in the Valles Caldera in New Mexico, where a massive obsidian flow filled a paleocanyon in the Battleship Rock tuff. The obsidian flow provided a heat source, analogous to waste panels or an igneous intrusion in a repository, and caused evaporation and migration of water. The tuff and obsidian samples were analyzed for major and trace elements and mineralogy by INAA, XRF, X-ray diffraction; and scanning electron microscopy and electron microprobe. Samples were also analyzed for D/H and {sup 39}Ar/{sup 4O} isotopic composition. Overall,the effects of the heating event seem to have been slight and limited to the tuff nearest the contact. There is some evidence of devitrification and migration of volatiles in the tuff within 10 meters of the contact, but variations in major and trace element chemistry are small and difficult to distinguish from the natural (pre-heating) variability of the rocks.
Authors:
; ;  [1] ;  [2]
  1. Sandia National Labs., Albuquerque, NM (United States)
  2. Alaska Univ., Fairbanks, AK (United States). Geophysical Inst.
Publication Date:
OSTI Identifier:
25011
Report Number(s):
NUREG/CR--6221; SAND--94-0650
ON: TI95004333; TRN: 95:006924
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Dec 1994
Research Org:
Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering; Sandia National Labs., Albuquerque, NM (United States)
Sponsoring Org:
Nuclear Regulatory Commission, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; 58 GEOSCIENCES; RADIOACTIVE WASTE FACILITIES; HYDROLOGY; TUFF; FLUID FLOW; TEKTITES; RADIOACTIVE WASTE DISPOSAL; FLUORINE; CHLORINE; MIGRATION; ENVIRONMENTAL TRANSPORT; VITRIFICATION; CHEMICAL ANALYSIS; HEAT TRANSFER; ELEMENTS; TRACE AMOUNTS; Yucca Mountain Project