• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 487
  • 126
  • 84
  • 76
  • 43
  • 19
  • 19
  • 19
  • 19
  • 19
  • 19
  • 10
  • 10
  • 10
  • 10
  • Tagged with
  • 1061
  • 477
  • 236
  • 154
  • 98
  • 94
  • 85
  • 79
  • 74
  • 67
  • 65
  • 62
  • 57
  • 55
  • 50
  • 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.

The gabbros and associated intrusive rocks of Harford County, Maryland ...

Insley, Herbert, January 1928 (has links)
Thesis (Ph. D.)--Johns Hopkins University, 1919. / Vita. Published also in the Report of the Maryland Geological survey, 1896, v. 12, pt. IV, 1928.

Geologisch-petrographische Untersuchungen am Südwestrand des Gotthardmassivs (Nufenengebiet) ...

Eichenberger, Robert, January 1924 (has links)
Inaug.-diss.--Basel. / Curriculum vitae: p. [484]. Benützte Literatur: p. 481-483.

On the stratigraphical and structural geology of the Kemi area, northern Finland

Härme, Maunu. January 1949 (has links)
Academical diss.--Helsinki. / "Mrs. A-L. Okko ... translated the greater part." From the Bulletin de la Commission géologique de Finlande, nio 147. Bibliography: p. 58-60.

Geologisch-petrographische untersuchung des porphyrgebietes zwischen Lago Maggiore und Valsesia ...

Käch, Max, January 1903 (has links)
Inaug. diss.-Basel. / Extrait des Eclogæ geologicæ Helvetiæ, vol. VIII, no. 1. Includes bibliographical references.

Yamdrok melange, gyantze district, Xizang (Tibet), China /

Liu, Jianbing. January 2001 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 192-211).

Sedimentology and sequence stratigraphy of tidal sandstone bodies : implications for reservoir characterisation

Wonham, Jonathan Philip January 1993 (has links)
Analysis of the facies and sequence stratigraphy of tidally-influenced, siliciclastic-dominated successions from five different areas has allowed a survey and comparison of the sedimentological and architectural characteristics of a variety of tidal sandstone body types. This study is concerned with: (i) describing these different sandstone body types; (ii) analysing the controls on sandstone body internal architecture, external geometry and connectivity, and (iii) outlining the implications of such studies for reservoir characterisation. Facies analysis of the studied successions by previous workers has identified the importance of tidal processes in sandstone body deposition, however, the application of sequence stratigraphy suggests reinterpretation of a number of facies. This applies, in particular, to facies interpreted as shelf sand wave deposits which have previously been recognised in all of the field study areas. These facies are now reinterpreted as incised valley fill deposits following the recognition of: (i) the estnarine facies and facies associations which make up these sandstone bodies, and (ii) the presence of sequence bounding erosional unconformities at the base of these sandstone bodies. The studied basins show contrasting subsidence rates and structural styles. Two successions from foreland basin settings have been studied: the OligO-Miocene Marine Molasse (=IOOOm thick) of the Digne-Valensole basin, and the Eocene Figols Group (",600m thick) of the Ager basin. Two orders of type-I depositional sequence, with thicknesses of lOs and l00s of metres respectively, have been identified from both areas. Passing upwards, both successions show a change from an overall transgressive to regressive setting interpreted to reflect increasing rates of sediment supply through time. Sandstone bodies of the Marine Molasse include: (i) estuarine incised valley fills; (ii) tidal inlets; (iii) delta mouth bars, and (iv) tidal flat channels. These units vary from a few metres thick and few hundred metres wide to several lOs of metres thick and several kilometres wide. Sandstone bodies of the Figols Group, by contrast, are developed within large incised valleys approximating to the scale of the Ager basin itself (6-7km wide, 15km long). These sandstone bodies are sharp-based estuarine mouth bars. The mouth bars themselves may be further compartmentaIised into erosively based sandstone lenticles «6m thick, 200m wide and <600m long) which are interpreted to have formed by the migration of very large-scale dune bedforms. The deposits of the Lower Jurassic Tilje and St0 Formations were developed within extensional basins of the Norwegian shelf and show much slower subsidence rates. The studied successions are dominated by tidal flat, tidal channel and tidal delta mouth bar deposits. Tidal flat parasequences are either coarsening- then fining-upwards or simply fining-upwards in character. Identification of retrogradationally stacked tidal flat parasequences suggests that sandstone-dominated intervals may be identified using sequence stratigraphy. The Lower Cretaceous Woburn Sands succession (up to 120m thick) shows the development of two depositional sequences in the Leighton Buzzard area. The majority of the succession consists of incised valley fill deposits showing a regressive estuarine facies association. New evidence which supports this interpretation includes the recognition of tidal flat deposits at the top of the incised valley fill, overlain by a well developed initial flooding surface. This sandstone-dominated succession shows the development of laterally extensive clay drapes which strongly compartmentalise the sandstone body. These clay drapes are interpreted to develop in the toe of laterally migrating sand banks and form an important and hitherto unreported permeability barrier type. The identification of incised valley fill deposits in a nwnber of basin settings has allowed a survey of the variability of this type of sandstone body. Incised valleys vary according to whether they show: (i) a single or a composite fill; (ii) a siliciclastic or mixed siliciclastic/carbonate infill; (iii) a retrogradational or progradational infill; (iv) presence or absence of an estuary mouth barrier, and (v) infill dominated by very large-/large-scale cross-beds or mediwn-/small-scale cross-beds. The infill character of individual incised valleys is shown to be controlled by the relative importance of rate of relative sea level rise, sediment supply and tide-dominance. Successively developed incised valleys show changing infill character related to the superimposition of low and high order cyclic controls on relative sea level change.

A Lithologic and Petrologic Reanalysis of a Lithic-Rich Tuff Within the Sierra Quemada Structure, Big Bend National Park, Brewster County, Texas

Boudreaux, Elisabeth L. 23 May 2014 (has links)
<p>The origin of the Mule Ear Spring Tuff (Tmet) member of the Chisos Formation of the Big Bend Group in Big Bend National Park (BBNP) (Maxwell et al., 1967) and its relationship to Sierra Quemada (SQ) is debated (a caldera versus a ring dike complex without associated collapse), as well as how the exact age of the Tmet relates to volcanic material present in and around the SQ structure. The main objectives were to identify main types of clasts present within the lithic-rich tuff and to determine the relative age of the lithic-rich tuff within SQ in order to help identify the type of structure and the type of activity&mdash;caldera with collapse or simply a ring dike. </p><p> Detailed lithologic and petrologic descriptions of hand samples and thin sections were performed to determine relationships of the clasts within the lithic-rich tuff to units outside of SQ. The identification and comparison of the samples produced a relative age of approximately 30.3 Ma to 33.7 Ma for the activity within SQ, which is comparable to published ages of Tmet. </p><p> Measurements of the clasts, along with the apparent thickness of the lithic-rich tuff, were compared with studies done on lithic-rich accumulations within modern and ancient calderas. The concentration and sizes of the clasts within the lithic-rich tuff from SQ are comparable to, or larger than, calderas with similar diameters to the SQ structure. The results are compatible with the formation of a typical resurgent caldera. The lack of lithic fragments younger than Tmet within the tuff is compatible with the age of Tmet. Therefore, the age of activity and formation of SQ occurred approximately 34 Ma. </p>

Quantification of flow impairment in faulted sandstone reservoirs

Manzocchi, Thomas H. P. January 1997 (has links)
No description available.

The petrology and petrophysics of the Pretty Hill formation in the Penola trough, Otway Basin /

Little, Bridget. Unknown Date (has links)
Thesis (PhD)--University of South Australia, 1996

Rock alteration and vein mineralization at the Buffalo Mine, Grant County, Oregon /

Pilcher, Stephen Hathaway. January 1959 (has links)
Thesis (M.S.)--Oregon State College, 1959. / Typescript. Includes bibliographical references (leaves 80-83). Also available on the World Wide Web.

Page generated in 0.0342 seconds