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A model of constrained utility maximizing behaviour is developed to explain how a representative individual allocates his ski days amongst alternative sites. The physical characteristics of the ski areas and the individual's skiing ability are explicit arguments in the utility function; the budget allocation is given along with the parametric costs to ski (including travel costs, entrance fees, equipment costs and the opportunity cost of his time). Shares (a site's share being the proportion of ski days that the individual spends at that site) are derived and assumed multinomially distributed, a stochastic specification which maintains the inherent properties of the shares. Maximum likelihood estimation confirms the basic hypothesis that costs, ability and characteristics all are important determinants of the sites' shares. / Arts, Faculty of / Vancouver School of Economics / Graduate

The geomorphological behaviour of steep jointed rock slopes has been studied using distinct element method computer models. In order to model steep slopes effectively, methodologies need to be combined from the studies of environmental modellers, geomorphologists and engineers. The distinct element method is ideal for the study of the development of jointed rock masses as the discontinuum approach can model the progressive failure of rock blocks along discontinuities. Initial, theoretical modelling identified the limiting boundary conditions between the multiple block failure mechanisms of toppling, sliding and toppling-and-sliding, based upon the discontinuity geometry for a theoretically modelled limestone rock mass. It is demonstrated that joint dip, friction angle and spacing exert the greatest control upon rock mass failure mechanisms. Two field locations, the Colorado Plateau and the Isle of Purbeck, have been chosen to provide a link between theoretical modelling and classic rock mass landforms which are controlled by variation in discontinuity geometry. In the Portland Limestone of the Isle of Purbeck, it is the joint geometry variation which influences development. Bedding steepens and average block size decreases in the coastal rock cliffs from east to west. Comparison between the model outputs highlighted that there is an increase in the rate of simulated cliff retreat from Winspit in the east to Durdle Door in the west. The Colorado Plateau rock cliffs form large, embayed plan-form escarpments and detached monoliths. It is the variation of joint set spacing in the cap-rock of cuesta-form composite scarps that controls development. Model results suggest there is a continuum of rock mass landforms, with buttes becoming detached at plan-form necks in the escarpment as determined by the joint geometry. The results show excellent similarity with the landforms observed in the field. This thesis introduces a research tool that can provide an understanding of slope behaviour.

Thesis (Ph. D.)--Columbia University, 1927. / Vita. Reprint from University of Denver business review, vol. III, no. 1.

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The Rosita Hills volcanic centre is an alkali-calcic mid-Tertiary caldera complex overlying ortho- and paragneissic basement on the eastern margin of the Wet Mountains graben in southcentral Colorado. There were two mineralising events at the Rosita centre. Au, Ag and base metal mineralisation occurred in a phreatomagmatic breccia pipe at the northern margin of the complex. Later, Ag and base metal mineralisation occurred in veins in the centre of the complex. Mapping, petrological and XRD studies outline 4 alteration facies related to hydrothermal activity at the centre. Propylitic/argillic, K-feldspar-sericitic, advanced argillic and silicic alteration assemblages are recognised. The areas of most intense alteration are controlled by the dominant structural trends within the caldera. Sub-volcanic magma movement is postulated as the dominant cause of the fracture patterns. A lithogeochemical grid survey for Au, Ag, Sr, Rb, Cu, Pb, Zn and Mn across areas of hydrothermal alteration reveal complex patterns indicative of multi-stage hydrothermal activity. District-wide Sr, Zn and Mn depletions are related to the propylitic/argillic alteration. Au, Ag, Rb and Cu enhancements are related to the K-feldspar-sericite alteration. Late stage advanced argillic alteration modified the trace element dispersion patterns by leaching previously formed enhancements. Stable isotope studies (O and H) of whole rock and mineral separate (quartz and sericite) samples from veins and hydrothermal eruption breccias show that the hydrothermal fluid had both meteoric and magmatic components. δD values from whole rock samples show a crudely concentric pattern centring on areas of sericitic and advanced argillic alteration in the middle of the lithogeochemical grid. Fluid inclusion data from vein gangue minerals (quartz, baryte and sphalerite) and from silicified rock in the advanced argillic alteration zone again show that the hydrothermal fluid had more than one component fluid. A highly saline, high temperature fluid occurs in quartz associated with base metal mineralisation. Less saline inclusions occur in the upper parts of the system in the silicic alteration. The data indicate that mixing of these two end-member fluids precipitated the vein mineralisation. The source of metals in the Bassick breccia pipe orebody was a highly differentiated magma body underlying the breccia pipe. Incipient ring faulting probably controlled the emplacement of the magma. Other similar breccia pipes in Colorado are postulated as overlying Cu-Mo porphyry mineralisation. The source of the metals in the Rosita vein orebodies was the volcanic host rocks (and the Precambrian basement?). The Rosita Hills vein mineralisation shows features typical of adularia-sericite systems in the western United States. The Au:Ag ratio in these deposits can be related to the origins of the crust underlying the deposits.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis (Ph. D.)--University of Chicago, 1913. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." "Reprinted from Publication 263 of the Carnegie institution of Washington." Bibliography: p. 382-384.