Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 112 for “"dikes"”.
-
Clastic Dikes
<p>Clastic dikes are tabular bodies of clastic material transecting the structure and bedding of the enclosing rock. The dikes may be either straight and parallel or irregular, sinuous, or zigzag, and they may be either closely spaced or distantly spaced. The thickness of the dikes ranges from a …
-
The effect of dikes on water surfaces in a mobile bed
Dikes, also referred to as groynes, have been used on rivers in both the U.S. and abroad to solve river engineering problems dating back to the nineteenth century. They are the prominent tool used to maintain navigation depths and prevent bank erosion on many major rivers in the world. A dike is …
-
Intense Shallow Magma Sediment Mingling within Dikes at Guffey Butte Maar, Idaho
… mingling in a non-explosive environment. Exposed dikes cut through both lake Idaho sands and silts and Guffey Butte pyroclastic deposits. Through a combination of field mapping, microtexture measurements from 36 thin sections, and geochemistry (whole rock major and trace elements using XRF and …
-
Improved dating of Canadian Precambrian dikes and a revised polar wandering curve.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1971.
-
Electron Microprobe Study of Diabase-Granite Contact Zones in Composite Dikes, Mount Desert Island, Maine
Made available in DSpace on 2014-12-11T18:09:55Z (GMT). No. of bitstreams: 1 7121240.pdf: 2896233 bytes, checksum: 3ef43ff314bf0174515e82f8a55f24e3 (MD5) Previous issue date: 1971
-
Geochemistry, Thermochronometry, Petrogenesis, and Geometry of Igneous Dikes in Central Arkansas: Implications for Mississippi Embayment Evolution
… (U-Th/He), and geometry of 11 igneous dikes from the AAP. These data reveal that dikes are potassic-ultrapotassic and extremely enriched in incompatible elements relevant to OIBs and MORBs. Combined with data from other studies, the Nd isotopic ratio values demonstrate that lamprophyres …
-
Geochemistry of mafic dikes from the Coastal New England magmatic province in southeast Maine, USA and Nova Scotia, Canada
Mid-Late Triassic-age alkali-basalt dikes were emplaced along the coast of New England between 240-200 Ma. Known as the Coastal New England (CNE) magmatic province, this dike swarm is the immediate magmatic predecessor to the formation of the Central Atlantic Magmatic Province large igneous …
-
PETROLOGIC AND GEOCHEMICAL ANALYSIS OF INTERMEDIATE TO MAFIC MAGNETITE-BEARING VOLCANIC FLOWS AND ASSOCIATED DIKES IN THE KNIGHT RANGE, GRANT COUNTY, NEW MEXICO
… which is intruded by Proterozoic diabase dikes that contain ~12% magnetite. Important to this study are the Tertiary intermediate to mafic volcanic rocks and dikes in this package that are magnetite-bearing. Field work was initiated to investigate significant volumes of previously …
-
Mineral-Scale Sr Isotopic Study of Plagioclase in the Mafic Dikes of the North American Wall and the Diorite of the Rockslides, Yosemite Valley, California.
The North American Wall mafic dikes and the diorite of the Rockslides mafic complex in the intrusive suite of Yosemite Valley show evidence of mixing with their host granites as well as with earlier components. Whole rock major element variation diagrams indicate the mafic rocks mixed with a more …
-
Igneous intrusions and thermal evolution in the Raton Basin, CO-NM: contact metamorphism and coal-bed methane generation
Tertiary mafic dikes and sills intrude coal-bearing formations of the Raton Basin. This study investigates the role of intrusions in generating methane from coal. Coal samples at four different outcrops were analyzed by vitrinite reflectance, carbon isotopes and petrography. Reflectance values at …
-
Petrogenetic study of the Porcupine Lake mafic intrusive complex, Trinity terrane, northern California
… East-west trending mafic-to-felsic aphanitic dikes intrude the plutonic rocks, with high dike concentrations (>80%) in the southern portion of the complex; Gabbro and mafic dikes display subduction-related enrichment of light-ion lithophile elements and high degrees of depletion of high-field …
-
Utilizing archival data to assess historic changes in flood flow conveyance of the Mississippi River
… the 1-D scenario model assessment suggest wing dikes may broadly affect flow conveyance in two ways: (1) through direct interaction with flow and (2) indirectly by their effects on channel geometry and roughness. Direct effects of wing dikes on flood stage were assessed by constructing two 2-D …
-
Petrology of the Cenozoic igneous rocks of the Tinton district, Black Hills, South Dakota - Wyoming
… an alkalic ring dike complex, lamprophyre dikes and intrusive breccia.</p> <p>Precambrian rocks are represented by a sequence of metapelites thst have been intruded by metabasite and granitic pegmatite dikes. The schistosity of the metapelites strikes NNW with a consistent westerly dip of …
-
PETROLOGY, GEOCHEMISTRY, AND AGE OF EXTENSION IN THE LOST TRAIL PASS DIKE SWARM, SOUTHWEST MONTANA
… EFDS at LTP, and the LTP pluton into which the dikes are emplaced, further constrains the timing of regional extensional tectonics during the Eocene. Classifying variations in lithology and geochemistry in these rocks provides insight into the petrogenetic relationships between the rocks in this …
-
PETROLOGY, GEOCHEMISTRY, AND AGE OF EXTENSION IN THE LOST TRAIL PASS DIKE SWARM, SOUTHWEST MONTANA
… EFDS at LTP, and the LTP pluton into which the dikes are emplaced, further constrains the timing of regional extensional tectonics during the Eocene. Classifying variations in lithology and geochemistry in these rocks provides insight into the petrogenetic relationships between the rocks in this …
-
Formation of mineralogical zonations in ophiolites through reactive porous flow : a modeling study
… section of many ophiolite sequences, dunite dikes are present. Around dunite dikes at the Josephine and Trinity ophiolite, a sequence of lithologies consisting of plagioclase lherzolite, lherzolite, and harzburgite is present. This sequence of rocks has been interpreted to be the result of …
-
Paragenetic Evolution of the Robertson Deposit: Eocene Intrusion Related Gold Deposit in the Northern Shoshone Range, Nevada
… an early ilmenite-bearing diorite, andesite dikes, hypabyssal dacitic porphyry dikes, composite ilmenite-bearing granodiorite, granitic porphyry dikes (formerly called feldspar porphyry dikes), pebble dikes, and subvolcanic rhyolitic dikes. The purpose of this study is to characterize gold …
-
Volcanic stratigraphy and lithochemistry of the lower Jurassic Hazelton group, host to the Eskay Creek precious and base metal volcanogenic deposit
… the western limb of the Eskay Creek antic line. Dikes feed the rhyolite domes. Four distinct rhyolite flow dome facies have been defined including peripheral facies of pyroclastic rocks, and feeder, outer, and internal flow facies. Facies reflect stages and processes of dome growth, and define …
-
Analysis of flood hazard under consideration of dike breaches
River reaches protected by dikes exhibit high damage potential due to strong value accumulation in the hinterland areas. While providing an efficient protection against low magnitude flood events, dikes may fail under the load of extreme water levels and long flood durations. Hazard and risk …
-
Geology and Structure of Kodachrome Basin State Reserve and Vicinity, Kane and Garfield Counties, Utah
… mechanism of formation of the clastic pipes and dikes found in the region of Kodachrome Basin State Reserve, I found it necessary to understand the depositional environments of the different members and formations within the study area. Mapping and study of the rock units of the Carmel, Entrada, …
Page 1 of 6