• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 373
  • 227
  • 84
  • 23
  • 21
  • 20
  • 12
  • 12
  • 12
  • 12
  • 12
  • 12
  • 7
  • 7
  • 5
  • Tagged with
  • 974
  • 262
  • 137
  • 68
  • 66
  • 62
  • 59
  • 58
  • 56
  • 55
  • 53
  • 50
  • 49
  • 47
  • 46
  • 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.
51

The mammals of the Chiricahua Mountain region, Cochise County, Arizona

Maza, Bernardo George, 1931- January 1965 (has links)
No description available.
52

Geology of the central Dome Rock Mountains, Yuma County, Arizona

Crowl, William James January 1979 (has links)
No description available.
53

The Laurentians : a study in geomorphological development.

Parry, J. T. (John T.). January 1963 (has links)
Francis Xavier Garneau, the French-Canadian historian, gave the name Laurentian mountains to the dissected edge of the Canadian Shield along the St. Lawrence valley, and the early geologists adopted the same name for the complex of metamorphic and igneous rocks in this area. [...]
54

Congestion effects in valuation of recreation land using revealed preference methods an application to rock climbing resources at New York's Shawangunk Ridge /

O'Hara, Michael E. January 2007 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Dept. of Economics, 2007. / Includes bibliographical references.
55

Music heard deeply : song and ethnic interaction in the Cherokee Ozarks /

Castro, J. Justin. January 2008 (has links) (PDF)
Thesis (M.A.) History--University of Central Oklahoma, 2008. / Includes bibliographical references (leaves 118-136).
56

Stratigraphic framework, structural evolution and tectonic implications of the eastern Blue Ridge sequence in the central Appalachians near Warrenton, Virginia /

Kasselas, Grigorios D. January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Six maps included in back pocket. Vita. Abstract. Includes bibliographical references (leaves 115-116). Also available via the Internet.
57

Geology and ore deposits of the Little Dragoon Mountains

Enlows, Harold Eugene, 1911-, Enlows, Harold Eugene, 1911- January 1939 (has links)
No description available.
58

Geology and mineralization in the Lorraine property area : Omineca Mining Division, British Columbia.

Koo, J. January 1968 (has links)
The Lorraine property area occupies the north eastern part of the Duckling Creek syenite located within the central part of the Hogem batholith in British Columbia. The rocks of the Lorraine property area consist of "metasomatic syenites" or "fenites" formed by the metasomatism of the fractured Hogem diorite. They are believed to have been derived from a hypothetical alkaline magma formed beneath the diorite. The residual magma differentiated from the alkaline magma, produced late dykes and hydrothermal fluid. A K-Ar date, 170±8 m. y.(Lower Jurassic) may correspond to both the minimum age of the fenites and the maximum age of the sulphide mineralization at the Lorraine property. Also, the age may mark the time point dividing the first division and the second division of the Hogem batholith. The characteristic minerals of the successive stages of alteration are 1. biotite, 2. albite, 3. orthoclase, if. quartz, 5. sericite, 6. chlorite, and 7. epidote. The altering fluid contained concentrations of soda, potash, silica, hydrogen sulphide, water, and a minor amount of lime. The primary sulphides are bornite, chalcopyrite, and pyrite. The Lorraine deposit posseses no noticeable gossan, but contains secondary copper minerals such as covellite, chalcocite, azurite and malachite. The deposit is divided in plan into three mineral zones on the basis of the primary sulphide assemblages. The dykes, mafic rocks, and fractures were the main controls of mineralization. The composition of the hydro thermal, fluid changed as sulphur reacted with iron of the host rock to form pyrite. The reduced sulphur ratio appears to have caused deposition of bornite and chalcopyrite. In the mineral zones pyrite was replaced progressively by chalcopyrite and bornite. The best classification for the Lorraine deposit is xenothermal. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
59

Geology and geochronometry of the coast plutonic complex adjacent to Douglas, Sue and Loretta channels, British Columbia

Runkle, Dita Elisabeth January 1979 (has links)
Five major units were mapped in shoreline exposures of the Coast Plutonic Complex adjacent to Douglas, Sue and Loretta Channels: 1) paragneiss and migmatite of the Central Gneiss Complex, 2) quartz-biotite schist, amphibolite, quartzite,and marble of the Metasedimentary Rocks, 3) quartz diorite and quartz monzonite of the Kitkiata pluton, 4) granodiorite of the Quottoon pluton and 5) Agmatite, composed of early xenoliths of banded metamorphic rock, middle stage intrusions of granitic rock, and late pegmatite, aplite and lamprophyre dikes. Pressure estimates of 7 ± 1 kb for this part of the Coast Mountains are arrived at from the stable assemblages in a kyanite-staurolite schist, and by comparison with pressures published for areas along strike to the north. Amphibolites provide a low temperature estimate o f 550°C. Calcsilicate assemblages place the high temperature limit of metamorphism between 560 and 660°C at 5 kb. Elevated pressures would increase temperature somewhat. The area is structurally characterized by a well developed, steeply dipping foliation that strikes northwest, widespread isoclinal folds with axial plane foliation parallel to regional foliation, and a moderate to steeply plunging fold axis lineation. Interference structures show that the abundant isoclinal folds deform earlier approximately northeast-trending folds. Later tight to isoclinal folds deform the regional foliation. Metamorphic recrystallization outlasted deformation. The Kitkiata pluton has an initial ⁸⁷Sr/⁸⁶Sr ratio of 0.7042 to 0.7043, depending on its age. One radiogenic Sr-rich sample gives a model date of 165 ± 11 Ma, but the possibility of anomalous initial ⁸⁷Sr/⁸⁶Sr ratio makes this result highly uncertain. The Quottoon pluton gives a whole-rock isochron of 51 ± 2 Ma with 0.7045 ± 1 initial ratio. The low initial ratios indicate a preponderance of mantle-derived magma of Mesozoic or early Cenozoic age in the plutons studied. Sr isotopic composition of the Central Gneiss Complex is compatible with late Paleozoic-early Mesozoic ages for precursor detrital and volcanic strata and local presence of marine carbonate with moderately enriched ⁸⁷Sr/⁸⁶Sr. The generally low radiogenic Sr content of these core gneisses rules out an origin by remobilization of greatly older rocks. Plutons of the Coast Plutonic Complex may have been generated by partial melting of the Central Gneiss Complex, and emplaced not far from their source of origin during regional metamorphism, as the surrounding rocks cooled from maximum temperature and pressure of metamorphism. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
60

Distribution and variability of some chemical parameters in the soils of a forested hillslope

Rollerson, Terrence Paul January 1981 (has links)
Trends in soil chemistry are studied on a 300 meter long hillslope in the Cascade Mountain Range of southwestern British Columbia. Although trends are not wholly consistent from horizon to horizon, the following general statements can be made: pH tends to increase downslope; exchangeable calcium, exchangeable magnesium and cation exchange capacity decrease noticeably downslope; carbon may decrease slightly downslope; nitrogen, carbon/nitrogen ratio, percent base saturation, exchangeable sodium and exchangeable potassium remain effectively constant downslope. Soil chemistry is shown to be related to horizon, slope position and parent material. Variability among chemical species increases in the sequence: pH, percent base saturation, carbon/nitrogen ratio, cation exchange capacity, nitrogen, exchangeable calcium, percent carbon, exchangeable potassium, exchangeable sodium, exchangeable magnesium. Variability fluctuates among soil horizons but not so noticeably with slope position. A slight increase in variability with the size of the area sampled is evident. / Land and Food Systems, Faculty of / Graduate

Page generated in 0.0434 seconds