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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The geology of the Floras Creek area, Curry County, Oregon

Bounds, Jon Dudley 01 January 1982 (has links)
The Floras Creek area, east of the town of Langlois, near the southwest Oregon coast, includes Colebrooke Schist (a klippe of metamorphosed pelitic sediments of Jurassic age), Jurassic Otter Point Formation (a melange complex), and lower the middle Eocene Roseburg and Lookingglass Formations, part of a sandstone-shale sequence occurring more extensively in other areas. The Colebrooke Schist occurs in the south-central part of the area, bounded on the Otter Point and Roseburg. The Lookingglass is exposed as a small (1.5 sq. km) block in the north-north-west part of the area. Two major structural trends are found in the Floras Creek area; an older Mesozoic east-west normal fault trend which is truncated by younger serpentinitefilled, north-south shear zones. The younger fault trend was active into the Tertiary as the faults cut the Eocene. Detrital modal analyses of sandstones suggest that the Otter Point is related to the coeval Dothan Formation of the interior Klamath Mountains, in the same way that the Franciscan is related to the Great Valley sequence in California. The detrital modal analysis indicates that the Otter Point is trench-slope deposited sediments as is the Franciscan and the Dothan is forearc basin deposits similar to the Great Valley.
2

Geology and hydrothermal alteration, Glass Buttes, Southeast Oregon

Berri, Dulcy Annette 01 January 1982 (has links)
The Glass Buttes volcanic complex consists of many domes and individual vents that erupted both rhyolitic and basaltic lavas during the late Miocene to early Pliocene. The east half of the complex, in the vicinity of Little Glass Butte, contains interfingering, finely flow-banded rhyolite and black obsidian flows. The youngest unit, an obsidian, has been dated at 4.9 m.y. East of Little Glass Butte lie two northwest-trending ridges, Antelope and Cascade Ridges, composed of two or more overlapping exogenous domes that formed along northwest-trending faults.
3

Geology of the southcentral margin of the Tillamook Highlands; southwest quarter of the Enright Quadrangle, Tillamook County, Oregon

Cameron, Kenneth Allan 01 January 1980 (has links)
The Tillamook Highlands is a largely unmapped volcanic pile located in the north end of the Coast Range of Oregon. The 36 square miles of T. 1 N., R. 8 W., on the southcentral margin of the Highlands, was chosen for detailed study. The study area is composed of Eocene age sedimentary and volcanic units which were deposited in a filling basin. The lowest units were deposited in moderate to deep marine waters; the uppermost were deposited subaerially.
4

A geological Reconnaissance of the San Pedro del Gallo Area, Durango, Mexico

Alor, Jerjes Pantoja January 1963 (has links)
The San Pedro del Gallo area 1.8 in the north-central part of Mexico, between 25°30' and 26°00' N latitude, and 104°00' and 104°20' W longitude. It covers approximately 1,900 square kilometers at the western edge of the Sierra Madre Oriental. The oldest rocks exposed in the area belong to the Villa Juarez Formation of possible Late Triassic age. These rocks, of continental origin, comprise siltstone, sandstone, conglomerate, tuff, and intercalated lavas of characteristic red color. Jurassic and Cretaceous rocks form a section with a maximum thickness of about 3,580 m. The sediments were deposited in the Mexican Geosyncline, west of the Coahuila Peninsula of pre-Aptian age. The Villa Juarez Formation is overlain with angular unconformity by orthoquartzite, quartzose sandstone, and limestone lenses of the La Gloria Formation of Oxfordian age. The La Casita Formation, which is stratigraphically above the La Gloria Formation, probably ranges in age from late Oxfordian to early Neocomian. It consists of thin-bedded limestone, black shale, and varicolored sandstone, with intercalations of coal seams and abundant ammonites. The Lower Cretaceous rocks of the area comprise the Coahuila Series, La Pena Formation, Aurora Limestone, and Cuesta del Cura Formation. Neocomian and upper Aptian rocks are represented by thin-bedded limestone, marl, and shale of the Taraises, Las Vigas, Parritas, and La Pena Formations. This sequence of rocks is overlain with apparent conformity by the medium- to thick-bedded bank-type Aurora Limestone of middle to late Albian age. A notable change of facies occurs laterally in the upper Albian and lower Cenomanian rocks, the lithology of the Aurora Limestone grading westward into the thin-bedded limestone with wavy bedding planes and black chert intercalations that characterize the Cuesta del Cura Formation. An erosional unconformity developed on the surface of the Aurora Limestone and Cuesta del Cura Formation is covered by the Indidura and Caracol Formations of Turonian to Coniacian age. These consist or thin-bedded, platy limestone, shale, and marl beds, which grade upward into a thick sequence of poorly fossiliferous calcareous sandstone, siltstone, and shale. A period of intense folding and erosion preceded the deposit of the non-marine Ahuichila Formation, of probable late Eocene and early Oligocene age. This formation was deposited with marked angular unconformity on all the older rocks, including the Villa Juarez Formation. Both, porphyritic and equigranular igneous rocks in the form of dikes, sills, plugs, and stocks intrude the bedded rocks of the area. They range in composition from quartz rhyolite porphyry to andesite and from granadiorite to monzonite. The rocks around the intrusive bodies have been metamorphosed irregularly as far as 100 m from the igneous contacts. Irregular tactite aureoles occur around intrusive bodies in the Descubridora district, west of Cerritos de Los Victorinos, and in the Sierra del Mimbre. Marble and recrystallized limestone is found west of Descubridora and in the Bajio del Bailon, and hornfels has formed in Cerrito de La Cruz and Cerrito de Las Liebres near San Pedro del Gallo, as well as in the southern part of the Sierra del Mimbre. Folowing emplacement of the intrusive bodies mineralizing solutions reacting with sedimentary rocks gave origin to the different mineralized zones in the region. The beginning of the Laramide Orogeny in the San Pedro del Gallo region is marked by Late Cretaceous uplift, which probably continued until middle or late Eocene time. Compressive forces acting in an east-west to northeast-southwest direction folded the Mesozoic strata into a series of narrow asymmetrical anticlines and synclines overturned to the east, with axial, planes almost parallel to the borders of the Coahuila Peninsula. Thrusting and faulting were important in the vicinity of San Pedro del Gallo. There is no conclusive evidence of large-scale post-Triassic and pre-Laramide deformation in the area. Extrusion of lavas ranging in composition from basalt to rhyolite, accompanied by extensive block faulting, occurred during Miocene and Pliocene time. Late Tertiary uplift began during the Pliocene. The streams were rejuvenated and there was increased erosion, which caused, together with a change of climate, the overloading of some streams and local blocking of drainage by alluvial fans in the valleys, giving rise to the Santa Ines Formation. Erosion, more than deposition is the dominant event at present. Contact metasomatic silver, lead, and copper deposits in the Aurora Limestone have been mined in the Descubridora, Parranderas , and Sierra del Mimbre districts. Fluorite and barite have been extracted from veins in the La Gloria Formation and the Aurora Limestone. Thin beds and seams of coal in the La Casita Formation were mined within the town limits of San Pedro del Gallo. No important mining activity exists at present in the area studied. The area has never been tested for oil.
5

Geology of the Gore Canyon-Kremmling Area, Grand County, Colorado

Barclay, C. S. Venable January 1968 (has links)
The Gore Canyon-Kremmling area is in the southwestern portion of the Kremmling 15-minute quadrangle, Colorado. Precambrian rocks are biotite gneiss, the Boulder Creek Granodiorite, granophyre dikes, and quartz veins. The Boulder Creek Granodiorite intrudes the biotite gneiss, and both of these units are cut by north-northwest-trending, granophyre dikes and quartz veins. Biotite gneiss contains structure elements of a northwest and a northeast fold system. Lineations and foliations in the Boulder Creek Granodiorite are generally concordant to the northeast fold system of the gneiss. Late Paleozoic to Mesozoic and Mesozoic sedimentary formations, in ascending order and with their approximate thicknesses, are the State Bridge Formation, 15 feet; the Chinle and Chugwater Formations undivided, 0-95 feet; the Sundance Formations 0?-100 feet; the Morrison Formation, 250 feet; the Dakota Sandstone, 225 feet; the Benton Shale, 340 feet; the Niobrara Formation, 600 feet; and the Pierre Shale. Quaternary deposits are terrace, landslide, and modern flood-plain deposits. Laramide rock deformation is related to the Park Reuse uplift and includes faulting and, in the sediments, some folding. Some of the faults, including the regional Gore fault, are Precambrian structures reactivated in Laramide time.
6

Geology of North Craters of the Moon National Monument, Idaho

Sidle, William C. 01 January 1979 (has links)
The purpose of the investigation was to map the geology of the north end of Craters of the Moon National Monument and surrounding area. A stratigraphic sequence of Late Paleozoic sedimentary and Tertiary volcanic rocks was compiles and the structures of these rocks and contact relationships with intrusions were delineated. Grade and facies of contact metamorphism were defined. The Snake River Plain basalts were also mapped. The sources of these flows were determined where possible. Preexisting structures and relationships of vents to earlier faulting were explored in ascertaining extensions of the Great Rift Zone into the Pioneer Mountains. Petrographic descriptions of the rock units were completed. Study of the economic geology was not undertaken. The interested reader is referred to Nelson (1969) for descriptions of the mineral deposits in the Lava Creek Mining District.
7

The Geology of the Atlas Mine Area, Pima County, Arizona

Agenbroad, Larry D. January 1962 (has links)
The Atlas Mine is located on the northwest flank of the Silver Bell mountains; Silver Bell mining district, Pima County, Arizona. The deposit is high grade (?) sine-copper mineralization in an altered sedimentary sequence. Rocks in the area include Precambrian (?) alaskite; Permian (?) limestone, quartzite and siltstone; Tertiary (?) monzonite, quartz monzonite, quarts latite porphyry and dacite porphyry; and Quaternary alluvium. The limestone has been largely metamorphosed to a mass of tactite, siltstone has been locally metamorphosed to hornfels, and the quartzite has been silicified, locally shattered and altered. Mineralization is related to NE and E-W trending fault systems, and similarly trending intrusive dikes. Predominate ore minerals are sphalerite and chalcopyrite, associated with pyrite, specular hematite and “high temperature" silicates. Copper mineralization is related to the silicified sediments. Zinc mineralization is present in silicates but is more predominate in areas of recrystallized calcite and extensive garnetization, suggesting incomplete replacement of the original sediments by the silicates. Further exploration and development should be undertaken in areas of favorable structural control, and adjacent to favored intrusives.
8

Analysis of Model-driven vs. Data-driven Approaches to Engaging Student Learning in Introductory Geoscience Laboratories

Lukes, Laura 13 May 2004 (has links)
Increasingly, teachers are encouraged to use data resources in their classrooms, which are becoming more widely available on the web through organizations such as Digital Library for Earth System Education, National Science Digital Library, Project Kaleidoscope, and the National Science Teachers Association. As "real" data becomes readily accessible, studies are needed to assess and describe how to effectively use data to convey both content material and the nature of scientific inquiry and discovery. In this study, we created two introductory undergraduate physical geology lab modules for calculating plate motion. One engages students with a model-driven approach using contrived data. Students are taught a descriptive model and work with a set of contrived data that supports the model. The other lab exercise uses a data-driven approach with real data. Students are given the real data and are asked to make sense of it. They must use the data to create a descriptive model. Student content knowledge and understanding of the nature of science were assessed in a pretest-posttest experimental design using a survey containing 11 Likert-like scale questions covering the nature of science and 9 modified true/false format questions covering content knowledge. Survey results indicated that students gained content knowledge and increased their understanding of the nature of science with both approaches. Lab observations and written interviews indicate these gains resulted from students experiencing different pedagogical approaches used in each of the two labs. / Master of Science

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