Download or read book Vertical and Lateral Variations in a Welded Tuff written by Ted Richard Dinkel and published by . This book was released on 1969 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: "During the Tertiary period, nuée ardente type eruptions spread large deposits of welded tuffs over southwestern Utah and southeastern Nevada. The Wah Wah Springs Tuff is a member of one of the most extensive of these units, the Needles Range Formation of Oligocene age. Its known outcrop area is estimated at 13,000 square miles. Relief was slight in the area during the time of eruption to enable the flows to spread over so large an area. In an effort to analyze the lateral and vertical continuity of the member, a petrographic study was undertaken. The average composition of the Wah Wah Springs Member was found to be 1.78% quartz, 25.9% andesing (An44.2), 4.0% biotite, 6.% hornblende, 0.3% diopside, 1.6% magnetite totaling 39.8% crystals, with no significant lateral variations throughout its studied extent. Vertical variations in mineral concentration were found. These variations are due to a time differential between successive eruptions forming a single cooling unit. The variations record changes occurring in the magma chamber or mixing of mamas before or during eruption. The density and relative porosity of the bulk rock samples were also analyzed. The vertical variations found in these parameters are indicators of the degree of welding. The changes in welding found in the Wah Wah Springs Tuff correspond to the changes described in much of the published literature. These changes are a moderately welded tuff at the base grading into a densely welded zone approximately one-third of the distance to the top of the member and gradual decrease in welding upwards, to a degree lower than that at the base"--Abstract, leaf ii.
Download or read book Tertiary Welded Tuffs of the Ryan Spring Area Needle Range Beaver County Utah written by Peter Carlyle Rauch and published by . This book was released on 1975 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Needle Range of southwestern Utah is composed of Paleozoic sediments overlain by a thick sequence of Tertiary volcanic rocks primarily of the welded tuff class. The area has undergone at least four stages of post-eruptive structural deformation. The most significant stage is that which formed the range by normal Basin and Range type faulting. The faults strike northwest and tilt the volcanic layers northeast. The volcanic section is composed primarily of the Needles Range Formation (Oligocene) overlain by the Isom Formation and underlain by several flows and ash flows, one of which has been tentatively correlated to the Escalante Valley Tuff. Between the Lund and Wah Wah Springs members of the Needles Range Formation, a previously unnamed crystal-poor, vitric-lithic welded tuff of unknown lateral extent occurs. Because of its good exposure and apparent lack of faulting near Ryan Spring, Beaver County, Utah, the writer proposes to name this unit the Ryan Spring Tuff. At its type section the Ryan Spring Tuff is 1120 feet thick and primarily dellenitic with an average partial chemical composition of: SiO2, 73.8%; K2O, 5.1%; CaO, 2.7%; TiO2, 0.3%; and Fe2O3, 2.4%. The average mineral composition is: quartz, trace; alkali feldspar, absent; plagioclase, 9.1%, biotite, 1.5%; hornblende, trace; and opaque oxides, 0.6%, The total crystal content is 11.2% with the remainder being composed primarily of glass, pumice, and lithic fragments. The tuff has an average bulk density of 2.240 gm./cc., an average grain density of 2.449 gm./cc., and an average porosity of 8.51%. Vertical variations in chemistry, mineralogy, density, and porosity have led to some interesting hypotheses concerning preemptive changes in the magma and post-eruptive changes in the tuff due to alteration and compaction. There is no definite explanation to account for the variations in chemical and mineralogical composition. These variations may be due to pre-eruptive stratification of the magma chamber. Still another possibility might be post-eruptive deuteric alteration and leaching of ions by weathering. Variations in density and porosity are caused by multiple eruption and compaction phases"--Abstract, leaves ii-iii
Download or read book Geological Survey Professional Paper written by Geological Survey (U.S.) and published by . This book was released on 1973 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1984 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Quaternary and Pliocene Yellowstone Plateau Volcanic Field of Wyoming Idaho and Montana written by Robert L. Christiansen and published by . This book was released on 2001 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ash flow Tuffs written by Charles Edward Chapin and published by Geological Society of America. This book was released on 1979 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Names and Descriptions of New and Reclassified Formations in Northwestern Wyoming written by John David Love and published by . This book was released on 1989 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water resources Investigations Report written by and published by . This book was released on 1998 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Abstracts of Theses written by University of Missouri at Rolla and published by . This book was released on 1971 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Short Papers in Geology and Hydrology written by and published by . This book was released on 1964 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Short Papers in Geology and Hydrology Articles 122 172 written by Geological Survey (U.S.) and published by . This book was released on 1964 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Juntura Basin written by J. Arnold Shotwell and published by . This book was released on 1963 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transactions of the American Philosophical Society written by and published by . This book was released on 1963 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Held at Philadelphia for promoting useful knowledge.
Download or read book R027 Stratigraphy of the Tertiary ash flow tuffs in the Yerington district Nevada written by and published by NV Bureau of Mines & Geology. This book was released on with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Encyclopedia of Geology written by and published by Academic Press. This book was released on 2020-12-16 with total page 5634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Geology, Second Edition presents in six volumes state-of-the-art reviews on the various aspects of geologic research, all of which have moved on considerably since the writing of the first edition. New areas of discussion include extinctions, origins of life, plate tectonics and its influence on faunal provinces, new types of mineral and hydrocarbon deposits, new methods of dating rocks, and geological processes. Users will find this to be a fundamental resource for teachers and students of geology, as well as researchers and non-geology professionals seeking up-to-date reviews of geologic research. Provides a comprehensive and accessible one-stop shop for information on the subject of geology, explaining methodologies and technical jargon used in the field Highlights connections between geology and other physical and biological sciences, tackling research problems that span multiple fields Fills a critical gap of information in a field that has seen significant progress in past years Presents an ideal reference for a wide range of scientists in earth and environmental areas of study
Download or read book Bibliography of Theses in Geology 1967 1970 written by and published by . This book was released on 1973 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Emplacement of Silicic Domes and Lava Flows written by Geological Society of America. Meeting and published by . This book was released on 1987 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
