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821.
822.
O. R. Eckstrand 《Mathematical Geology》1977,9(3):235-243
The Geological Survey of Canada (G.S.C.) has been involved in national appraisal of resources of certain commodities for nearly two decades beginning with a national study of iron deposits in 1955. In 1972, the first national appraisal to rapidly estimate total resources of Cu, Pb, Zn, Ni, Fe, Mo, and U in Canada was carried out largely by economic geologists. This exercise produced, among other things, a better definition of G.S. C. needs for building computer files in support of mineral deposits studies and mineral resource appraisal. Objectives of this paper are threefold: (1) to outline general methodology for the kind of mineral resource appraisal carried out by the G.S.C. in 1972; (2) to identify types of information required in that appraisal; and (3) to indicate types of information on mineral deposits for which it seems advantageous for the G.S.C. to construct computer files, and how these files relate to mineral resource appraisal. Methodology is fairly straightforward for appraisal of reserves (known, measured resources), but is much more problematic for appraisal of undiscovered resources. For the latter, G.S.C. economic geologists make use of two basic concepts: the deposit model, which is a generalized deposit type, distinguished by its geological attributes and host rock environment, and containing characteristic amounts of specified commodities; and the metallogenic region, which is a geographic area of more or less homogeneous geology deemed favorable for the presence of a particular deposit model. Background information required for appraisal of undiscovered resources includes the following: (a) data on distribution and geology of Canadian deposits and occurrences; (6) data on geology of important, foreign deposits; (c) knowledge of Canadian geology, commensurate with metallogenic requirements; (d) knowledge of current theories of ore-forming processes; and (e) appreciation of the amount, location, and effectiveness of past exploration in Canada. At present, only identity, location, and certain simple geological features of Canadian deposits are considered practical for a general computer file of mineral deposits. The fundamental activity of the G.S.C. in the sphere of mineral deposits is a number of broad studies on the geology of certain commodities in Canada carried out by economic geologists. Appraisal of mineral resources is based directly on the results of those studies, and is done by the same economic geologists. Construction of G.S.C. computer files is in response to needs defined by economic geologists, mainly in the context of their broad studies.This paper was presented at the International Geological Correlation Program (IGCP) Project 98 entitled Standards for Computer Applications in Resource Studies held at Loen, Norway, September 27–October 1, 1976. 相似文献
823.
This paper reviews the exploration history of the Barents Sea part of the Norwegian continental shelf. The main structural elements which so far have been identified in the Troms/Finnmark/Barents Sea region are outlined and discussed. Special attention is given to the selected Area I outside Troms, where according to latest government plans, drilling will start in 1978.At least two different fault systems are discribed in Area I. The salt diapirs in the Tromsø Basin and their location relative to the fault pattern are discussed. A schematic structural model for Area I is suggested. 相似文献
824.
O.R. Lehman 《Advances in water resources》1980,3(2):87-89
Oxygen exchange between a sheltered ‘model’ farm pond (6 m diameter and 2.5 m deep) and the atmosphere averaged 0.33 m/day for measurements made from April to December. This value was similar to those reported for isolated surfaces in sheltered waters and in laboratory tanks but below those of large, inland waters. Low average wind velocity (0.7 m/sec) probably caused the low O2 exchange rate. Interactions between air and water temperatures and precipitation may be important factors governing short-term O2 exchange in highly sheltered waters. 相似文献
825.
A continuum representation for soil which incorporates the concepts of hypoelasticity and critical state theory is proposed. General, three-dimensional constitutive equations are formulated to relate specific volume, stress, rate of deformation and rate of change of stress, resulting in a mathematical material model which exhibits phenomenological features typical of soil response. The general constitutive equations are specialized to represent the particular cases of isotropic compression, constant, volume deformation, uniaxial compression and biaxial deformation. Methods are suggested for determining the model parameters to represent a specific soil using conventional triaxial test data. Comparisons of stress-strain response with published experimental data are shown. 相似文献
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T.?P.?WagnerEmail author C.?O.?McKee J.?Kuduon R.?Kombua 《International Journal of Earth Sciences》2003,92(3):405-406
The south crater wall of a Quaternary tephra cone in the Highlands of Papua New Guinea collapsed on 20 April 1999 and sent a 150,000-m 3 landslide into its lake. Displacing 5–10% of the lake's volume, the landslide induced a 15-m-high wave which flattened vegetation throughout the crater interior, and broke over a low saddle in the crater's east rim where it destroyed two houses and injured 11 people, killing one. 相似文献