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Publication Extents

Not all publications have extents, not all extents are completely accurate
Ultramafic rocks of the Eagle quadrangle, east-central Alaska
Helen L. Foster, Terry E.C. Keith
1974, Journal of Research of the U.S. Geological Survey (2) 657-669
More than 97 separate occurrences of ultramafic rocks, some of which are included in a north west-trending zone of alpine-type ultramafic rocks, have been mapped in the Eagle quadrangle, east-central Alaska. They are divided into three groups primarily on the basis of degree of serpentinization. Group I consists of lens-shaped bodies...
Structure of Sierra Madera, Texas, as a guide to central peaks of lunar craters
Keith A. Howard, Terry W. Offield, H. G. Wilshire
1972, GSA Bulletin (83) 2795-2808
Like hundreds of other lunar craters of probable impact origin, Copernicus contains central peaks presumed to expose rocks uplifted from beneath the crater floor. A possible analog of these peaks on Earth is the central uplift of the Sierra Madera cryptoexplosion structure, a probable impact scar (astrobleme) in stratified Permian...
Impact breccias in carbonate rocks, Sierra Madera, Texas
H. G. Wilshire, Keith A. Howard, Terry W. Offield
1971, GSA Bulletin (82) 1009-1018
Two main types of deformational breccia occur in the Sierra Madera cryptoexplosion structure: monolithologic breccias composed of shattered rock of a single lithology and mixed breccias composed of rocks of several lithologies. Monolithologic breccias generally show no mineralogic signs of shock deformation, but a few samples are shatter-coned in a...
Shatter cones at Sierra Madera, Texas
Keith A. Howard, Terry W. Offield
1968, Science (162) 261-265
Shatter cones abound in the central uplift of Sierra Madera and they occur as far as 6.5 kilometers from the center. Apical angles average near 90 degrees. Whole cones and full cones represented by diversely oriented cone segments in any structural block show relatively uniform orientations of axes and a...