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Full-Text Articles in Physical Sciences and Mathematics
Petrology And Mineralogy Of Tertiary(?) Volcanic Rocks Of Snowville Area, Utah, And Tertiary-Quaternary(?) Volcanic Rocks Of Table Mountain And Holbrook Areas, Idaho, Yunshuen Wang
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Basalt flows occur in the Snowville area of north-central Utah and the Table Mountain and Holbrook areas of south-central Idaho. All basalt flows are aphanitic in groundmass, and contain olivine, plagioclase, augite, and opaque oxides. They can be distinguished by texture. Snowville basalt has predominantly subophitic to intergranular textures. Table Mountain basalt is fine grained, with stumpy groundmass plagioclase and equant ilmenite crystals. Holbrook basalt has pilotaxitic to intergranular textures, with the presence of plagioclase phenocrysts and characteristic exsolution lamellae in Fe-Ti oxides. The olivine grains in Holbrook area are intensely oxidized to Fe-Ti oxides.
Snowville basalt contains olivine phenocrysts …
Sequential Thrusting Beneath The Willard Thrust Fault, Wasatch Mountains, Ogden, Utah, Tad William Schirmer
Sequential Thrusting Beneath The Willard Thrust Fault, Wasatch Mountains, Ogden, Utah, Tad William Schirmer
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The downstructure of viewing geologic maps, balanced and cross sections, and hanging-wall-sequence diagrams are applied to produce the first comprehensive synthesis of the structure below the willard thrust sheet.
Development of the duplex beneath the Willard thrust may be explained with a "piggyback" thrust model where younger thrust slices form below and fold an older, overlying thrust sheet. Progressive failure of the footwall ramp of the Willard thrust sheet extended the sole thrust eastward and produced a duplex consisting of thrust slices (horses) which adhered to the overriding thrust sheet where it ramped from a lower sole thrust to an …