Notes on the geology of the Glass Mountains ; Geologic exploration of the southeastern front range of Trans-Pecos Texas

Abstract

Accompanied by 4 illustrations -- Exploratory geologic map of a part of the Front Range in Trans-Pecos Texas. Plate 1 : Sketch map of the Glass Range showing locations of the geological sections. Plate 2 : Horizontal sections in the Glass Mountains. Plate 3 : Vertical sections of the anthracolithic sediments in the Glass Mountains. Illustrations for Geologic Exploration of the Southeastern Front Range of Trans-Pecos Texas: Plate 1a : Ordovician-Maravillas formation at its typical locality in Maravillas Gap. Plate 1b : Banded cherts in Rough Creek shale member of Tesnus formation. Plate 2 : Photomicrographs of Radiolaria in Santiago Chert. Plate 3 : Sketch sections of Hercynian folding in the Marathon Basin. Plate 4a : Elephant Mountain, a mesa of trachytic lava. Plate 4b : Southwest face of Iron Mountain showing weathering of intrusive syenite-porphyry by exfoliation and along nearly vertical joint planes. Plate 5a : Summit ridge of Santiago Range, composed of sharply folded Fredericksburg Comanchean limestone. Plate 5b : Rio Grande river entering a canyon in westwardly-tilted fault block just east of the mouth of Stillwell Canyon Plate 6 : Sketch structure sections across the Santiago Range and the Sierra del Carmen Plate 7a : Fault scarp of later Comanchean limestone forming east side of Sierra Larga, Sierra del Carmen. Plate 7b : Widening of Rio Grande valley in the Vegas, showing alluvial terraces. Plate 8a : Caballos Mountain ridges of Caballos novaculite, looking south 75 degrees west from the summit of CaballosMountain. Plate 8b : Strike ridges of Hercynian folding in the southeastern part of the Marathon Basin. University of Texas bulletin ; no. 1753 : Sept. 20, 1917