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Master of Arts
No full textthesisThe Mineral Range is located in Beaver and Millard Counties In southwestern Utah. The range is about thirty miles long and averages five miles in width. The southern end of the range can be reached via Utah State Highway 21 which connects the towns of Beaver, Adamsville, Minersville, and Milford; there are many dirt roads which also traverse the range. The purpose of the present Investigation is two-fold: (1) to make a thorough study of the relationship between the Precambrian metamorphic complex on the west side of the Mineral Range and the Mineral Range pluton, and (2) to summarize in detail the petrogenesis of the Mineral Range pluton. Liese (1957) and Earll (1957) have described the sedimentary rocks of the Mineral Range; therefore, only a brief summary of the stratigraphy condensed from these two theses is presented here. The Cambrian is represented by the Prospect Mountain quartzite, Pioche shale, and a series of undifferentiated limestones. The Ordovician and Silurian are missing. Resting on top of the Cambrian is a series of undifferentiated lower Paleozoic limestones and dolomites. Devonian sediments have not been found; the Mississippian is represented by the Topache limestone; the Permian by the Coconino(?) sandstone and Kaibab limestone; the Triassic by the Moenkopi formation; the Jurassic by the Navajo sandstone and Carmel formation; the Cretaceous by the Claron-Indianola conglomerate; and the Recent by lake beds and other alluvium. A Laramide thrust is responsible for the Prospect Mountain quartzite resting on top of middle Cambrian limestones in the northern Mineral Range; also, a zone of cataclastic metamorphism north of Cave Canyon is interpreted by the author as a thrust zone. The southern and southeastern part of the Mineral Range is a homocline with beds dipping southeast and striking northeast. A prominent set of high-angle faults strike east-west in the southern and northern part of the range; north trending Basin and Range faults cut all previous structures. The following list summarizes the igneous rocks recognized in the Mineral Range by the author: (1) rhyolite porphyry dikes and plugs In the southern part of the range, (2) dellenite porphyry dikes in the northern part of the range, (3) lamprophyre (spessartite) dikes along the west side of the range, (4) the Minersville volcanics in the southern part of the range, (5) the Ranch Canyon volcanics in the central part of the range, and (6) Pleistocene and Recent basalt flows found around the borders of the range. All of the igneous rocks with exception of the basalt flows and possibly the Ranch Canyon volcanics are Tertiary in age. The Precambrian (?) gneisses, schists, granodiorites and adamellites along the west side of the range are described and named the Wildhorse Canyon series. Also, an extensive zone of cataclastic metamorphism north of Cave Canyon is described as well as small tactite and skarn zones found around the periphery of the Mineral Range pluton and the Lincoln stock. The Mineral Range pluton is the largest body of granite in the state of Utah. It is over twenty miles long and the maximum width is six miles. The Lincoln stock (adamellite) and its apophyses crop out south of Cave Canyon fault on the west side of the range and are thought to be basic apophyses of the Mineral Range pluton. An extensive ""inclusion zone"" found along the western part of the Mineral Range pluton is described and shown on the geologic map. Also, numerous migmatites, pegmatites, and aplites which were found to be gradational with each other are described. The chief criteria used and accepted by most petrologists to distinguish granitized granite from magmatic granite are presented and applied to the Mineral Range pluton. Those criteria diagnostic of magmatic injection were not found in the pluton while all but two out of thirteen major criteria for granitization were present In the Mineral Range pluton or the Lincoln stock. The tectonic setting of the pluton is evaluated in terms of Misch (I949), and the zone of emplacement Is evaluated in terms of Buddington (1959). The following is a summary of the petrologic and tectonic history of the Mineral Range as interpreted by the author: Precambrian sediments and possibly plutonic rocks were metamorphosed and eroded before Paleozoic time. Paleozoic and Mesozoic deposits are relatively thin (12,000 feet) and for this reason it is believed that this area represents the western margin of the Colorado Plateau. Floods of conglomerate were deposited in this area during Coloradoan time; the area was folded and domed (E. Montanan?) and the Mineral Range pluton was formed (L. Montanan?) during late Cretaceous time; thrusting and cataclastic metamorphism occurred during Paleocene time; lamprophyres, rhyolite and dellenite porphyry dikes were intruded during mid-Tertiary time and east-west high-angle faulting commenced; the Minersville volcanics were deposited and Basin-range faulting commenced in Oligocene time; epeirogeny and erosion and finally deposition of the Ranch Canyon volcanics occurred during Plio-Pleistocene time; basalt flows, lake beds and other alluvium were deposited during Pleistocene and Recent time
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Episodic growth of juvenile crust and catastrophic events in the mantle
Get PDFP(論文)Episodic growth of continental crust and supercontinents at 2.7,1.9,and 1.2 Ga may be caused by superevents in the mantle as descending slabs pile up at the 660-km seismic discontinuity and then catastrophically sink into the lower mantle. A superevent cycle involves supercontinent breakup that initiates both slab avalanches and the onset of formation of a new supercontinent; arrival of slabs at the D" layer triggers mantle plumes that rise and bombard the base of lithosphere producing juvenile crust trapped in the growing supercontinent; and shielding of the mantle beneath the new supercontinent results in a mantle upwelling that eventually breaks the supercontinent as the cycle starts over. Superevents comprise three or four events each of 50-80 My duration, each of which may reflect slab avalanches at different locations and times at the 660-km discontinuity. Superplume events in the late Paleozoic and Mid-Cretaceous may have been caused by minor slab avalanches as the 660-km discontinuity became more permeable to the passage of slabs. The total duration of a superevent cycle decreases with time probably reflecting the cooling of the mantle.departmental bulletin pape
Master of Arts
No full textthesisThis georeferenced KMZ file is part of Kent C. Condie\u27s thesis "Petrogeneis of the Mineral Range Pluton, Southwestern Utah". These files can be displayed in Google Earth
A planet in transition: The onset of plate tectonics on Earth between 3 and 2 Ga?
No full textAbstractMany geological and geochemical changes are recorded on Earth between 3 and 2 Ga. Among the more important of these are the following: (1) increasing proportion of basalts with “arc-like” mantle sources; (2) an increasing abundance of basalts derived from enriched (EM) and depleted (DM) mantle sources; (3) onset of a Great Thermal Divergence in the mantle; (4) a decrease in degree of melting of the mantle; (5) beginning of large lateral plate motions; (6) appearance of eclogite inclusions in diamonds; (7) appearance and rapid increase in frequency of collisional orogens; (8) rapid increase in the production rate of continental crust as recorded by zircon age peaks; (9) appearance of ophiolites in the geologic record, and (10) appearance of global LIP (large igneous province) events some of which correlate with global zircon age peaks. All of these changes may be tied directly or indirectly to cooling of Earth's mantle and corresponding changes in convective style and the strength of the lithosphere, and they may record the gradual onset and propagation of plate tectonics around the planet. To further understand the changes that occurred between 3 and 2 Ga, it is necessary to compare rocks, rock associations, tectonics and geochemistry during and between zircon age peaks. Geochemistry of peak and inter-peak basalts and TTGs needs to be evaluated in terms of geodynamic models that predict the existence of an episodic thermal regime between stagnant-lid and plate tectonic regimes in early planetary evolution
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