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Title: Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico

Abstract

The geological structure of Mesita del Buey at Technical Area 54 (TA-54) was examined using precise surveying of the contact between units 1v and 2 of the Tshirege Member of the Bandelier Tuff at 3.5 km along the north wall of Pajarito Canyon and 0.6 km along the north wall of a tributary to Canada del Buey. Estimated structure contours on this contact indicate typical strikes of N40E to N70E along this part of Mesita del Buey, although the apparent strike of the tuff is E-W at the western part of the survey. Typical dips are 1.0{degree} to 2.0{degree} to the east or southeast, with an estimated maximum dip of 3.2{degree} near the west end of Material Disposal Area G. Thirty seven faults with vertical displacements of 5 to 65 cm were observed in outcrop along the Pajarito Canyon traverse, and, due to the incomplete exposure of the unit 1v-unit 2 contact, many more faults of this magnitude undoubtedly exist. The faults have a wide range in strike and have either down-to-the-west and down-to-the-east components of offset, although about 65% of the observed displacement is down-to-the-west or northwest. These faults are not clearly associated with major fault zones, indicated bymore » the general absence of larger-scale offsets or inflections along the unit 1v-unit 2 contact in areas where the small-scale faults were observed; they may instead record distributed secondary deformation across the Pajarito Plateau associated with large earthquakes on the main Pajarito fault zone 8--11 km to the west, or perhaps other faults in the region. The survey data also suggest that a 150--250 m wide zone of greater magnitude faulting is present near the west end of the traverse associated with a horst-and-graben structure displaying about 1.5--3.5 m of offset on individual faults, although the total amount of offset across this structure and its orientation are not known.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Los Alamos National Lab., NM (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
296668
Report Number(s):
LA-UR-98-2501
ON: DE99001217; TRN: 99:002451
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 23 Apr 1998
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; LANL; SITE CHARACTERIZATION; GEOLOGIC STRUCTURES; GEOLOGIC FAULTS; RADIOACTIVE WASTE DISPOSAL; RADIOACTIVE WASTE STORAGE; RADIOACTIVE WASTE FACILITIES; STRATIGRAPHY

Citation Formats

Reneau, S L, Broxton, D E, Carney, J S, and LaDelfe, C. Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico. United States: N. p., 1998. Web. doi:10.2172/296668.
Reneau, S L, Broxton, D E, Carney, J S, & LaDelfe, C. Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico. United States. doi:10.2172/296668.
Reneau, S L, Broxton, D E, Carney, J S, and LaDelfe, C. Thu . "Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico". United States. doi:10.2172/296668. https://www.osti.gov/servlets/purl/296668.
@article{osti_296668,
title = {Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico},
author = {Reneau, S L and Broxton, D E and Carney, J S and LaDelfe, C},
abstractNote = {The geological structure of Mesita del Buey at Technical Area 54 (TA-54) was examined using precise surveying of the contact between units 1v and 2 of the Tshirege Member of the Bandelier Tuff at 3.5 km along the north wall of Pajarito Canyon and 0.6 km along the north wall of a tributary to Canada del Buey. Estimated structure contours on this contact indicate typical strikes of N40E to N70E along this part of Mesita del Buey, although the apparent strike of the tuff is E-W at the western part of the survey. Typical dips are 1.0{degree} to 2.0{degree} to the east or southeast, with an estimated maximum dip of 3.2{degree} near the west end of Material Disposal Area G. Thirty seven faults with vertical displacements of 5 to 65 cm were observed in outcrop along the Pajarito Canyon traverse, and, due to the incomplete exposure of the unit 1v-unit 2 contact, many more faults of this magnitude undoubtedly exist. The faults have a wide range in strike and have either down-to-the-west and down-to-the-east components of offset, although about 65% of the observed displacement is down-to-the-west or northwest. These faults are not clearly associated with major fault zones, indicated by the general absence of larger-scale offsets or inflections along the unit 1v-unit 2 contact in areas where the small-scale faults were observed; they may instead record distributed secondary deformation across the Pajarito Plateau associated with large earthquakes on the main Pajarito fault zone 8--11 km to the west, or perhaps other faults in the region. The survey data also suggest that a 150--250 m wide zone of greater magnitude faulting is present near the west end of the traverse associated with a horst-and-graben structure displaying about 1.5--3.5 m of offset on individual faults, although the total amount of offset across this structure and its orientation are not known.},
doi = {10.2172/296668},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {4}
}