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Heart Mountain, Wyoming, detachment lineations: are they in microbreccia or in volcanic tuff?

January 1, 1991

The concept of tectonic denudation followed by deposition of lower middle Eocene Wapiti Formation volcanic rocks on the exposed Heart Mountain detachment has been challenged by Hauge. His "extending allochthon' interpretation requires that the Wapiti Formation be fault emplaced and that lineations in a volcanic tuff overlying the fault north of Jim Smith Peak be fault striae in "microbreccia'. Our re-examination of the field evidence in minute detail indicates that these lineations were produced by flowage of volcanic rocks on a thin layer of air-fall tuff. The evidence indicates that this tuff was deposited on the detachment surface during the brief interval that the denuded surface was exposed. -from Authors

Citation Information

Publication Year 1991
Title Heart Mountain, Wyoming, detachment lineations: are they in microbreccia or in volcanic tuff?
DOI
Authors W. G. Pierce, W. H. Nelson, A.K. Tokarski, E. Piekarska
Publication Type Article
Publication Subtype Journal Article
Series Title Geological Society of America Bulletin
Series Number
Index ID 70016421
Record Source USGS Publications Warehouse
USGS Organization