A degree programme in geochemistry.
The Colorado School of Mines (CSM) was born in 1869 of the need for technical expertise in the booming mining industry of the West. Development and growth of the petroleum industry led to addition of petroleum engineering and petroleum refining engineering to the mining and metallurgical engineering offerings of CSM. Replacement of the grizzled prospector with the modern explorationist equipped with sophisticated data collection and interpretation tools, necessitated degree programs in geophysics and finally in geochemistry to complement geology and geologic engineering.
The graduate programme in geochemistry (MS and PhD degrees) was instituted at CSM in 1961. Contrary to usual practice in the United States, however, this programme was housed in a department of chemistry rather than a department of geology. The result is a programme based on application of a firm foundation in chemical principles to geological systems. The inherent interdisciplinarity is enhanced by extensive collaboration with colleagues in the Department of Geology and Geological Engineering and the Department of Environmental Sciences and Engineering Ecology. Degree programmes in theses other departments complement rather than compete through emphasis on distinct research areas.
Since 1961, 76 MS degrees and 32 PhD degrees in geochemistry have been conferred on students from all over the world. The majority have taken industrial jobs in either exploration or environmental yields but others have entered academe or governmental research groups.
Applicants most often hold a baccalaureate degree in geology; however, some have degrees in chemistry and a few in other fields. Undergraduate level proficiency is expected in general geology, mineralogy, petrology, physical chemistry (especially thermodynamics), and in two of inorganic, organic, or analytical chemistry. Deficiency course requirements are imposed on those who cannot demonstrate such proficiency via examination upon initial enrollment. Most students will have two or three such deficiency requirements.
Two specific courses are required of all geochemistry students: an introduction to geochemistry and a survey of geochemical analysis. The introduction includes discussion of those phenomena responsible for distribution of the elements throughout the cosmos, of the thermodynamics and kinetics of the interactions of natural waters with those minerals with which they are in contact, of the primary processes governing the deposition and transformation of organic matter in geologic settings, of the roles of microorganisms in geochemical processes, and of the chemical processes involved in magmatic systems.
The course in geochemical analysis introduces the student to sampling statistics and its application to problems such as sampling design for geochemical surveys, to some of the special problems of sample preparation with geological samples, and to a wide variety of instrumental methods of analysis which are available to the geochemist, including the various types of spectrophotometry, mass spectrometry, chromatography, x-ray methods, and electrochemical methods. Treatment of these methods focuses on the types of samples to which they may be applied, the sample preparation problems, the precision expected, interferences and limitations, and time/cost effectiveness. Both laboratory and field methods are included. These two courses constitute prerequisites for more advanced, specialized geochemistry courses.
Additional coursework for MS students must total 18 semester hours (in addition to the six semester hours for the two required courses); at least six of those hours must be in geochemistry courses. Candidates for the PhD must take at least one three-hour graduate course in each area of geochemistry (aqueous/environmental, bio/organic, and igneous) and in three of four areas of chemistry (inorganic, organic, physical, or analytical) and at least 12 semester hours of courses in geology. A minimum of 36 hours of coursework is required for the PhD. Geochemistry course offerings include:
Geochemistry of igneous rocks - The geochemical characteristics of the various types of igneous rock suites are surveyed. Application of major element, trace element, and isotope geochemistry to problems of their origin and modification is discussed.
Organic geochemistry - Organic carbonaceous materials occurring in geological situations are studied. The biological origin of the organic matter is discussed with special emphasis on contributions of microorganisms from extreme environments. Biochemical and thermal changes which convert the organic compounds into petroleum, oil shale, and other carbonaceous matter and principal analytical techniques used for the characterization of organic materials in the geosphere are described.
Geochemistry in petroleum source bed evaluation - Analytical techniques used by the petroleum industry in evaluating oil and gas source potential are compared. Oil-source rocks and oil-oil correlation methods are developed and practiced. Ongoing world-wide programmes in petroleum geochemistry are surveyed.
Sedimentary and environmental geochemistry - Topics include: mobility of the elements in air, water and the surficial environment; geochemical cycles of elements and chemicals of environmental interest; plant composition, animal and human health in relation to the natural environment; acid deposition and other processes affecting water quality; environmental aspects of fossil fuel processing; and sampling design in large scale environmental studies.
Aqueous geochemistry - Topics include: quantitative evaluation of the homogeneous and heterogeneous equilibria of surface waters and groundwaters; stability relationships of ionic and other stability field diagrams; and effects of ionic strength, temperature, complex ion formation on solubilities, and ionic form of major and minor species in water.
Hydrochemical systems - The geochemical behaviour of trace metals including actinides and their complexes in natural waters, with applications to environmental problems and mineral exploration and sorption and solubility controls on metal mobility with emphasis on modes of metal transport and fixation in soil and groundwater systems are explored.
Silicate chemistry - A structural approach is taken to the chemical and physical characteristics of silicates and their role in shaping the environment through geologic processes: magmatic differentiation, weathering, sedimentation.
Microbiology and biochemistry of pollution and waste treatment - The course emphasizes the basic biochemical reactions involved in pollution and waste treatment; effects of pollutants on human and animal health and on plants; the use of microorganisms in the treatment of sewage and industrial wastes and in recycling of wastes; and ecological effects of sewage, industrial wastes, and pesticides.
Environmental microbiology - The microorganisms of major geochemical importance, as well as those of primary importance in water pollution and waste treatment are described. Microbes and sedimentation, microbial leaching of metals from ores, acid mine water pollution, and the microbial ecology of marine and freshwater habitats are covered.
Biogeochemistry and geomicrobiology - This course is designed to give the student an understanding of the role of living things, particularly microorganisms, in the shaping of the earth. Among the subjects are the aspects of living processes, chemical composition and characteristics of biological material, origin of life, role of microorganisms in weathering of rocks and the early diagenesis of sediments, and the origin of petroleum, oil shale.
Mineralogy and geochemistry of clays - Structure and composition of clay minerals and related phyllosilicates; methods of identification; ion exchange and colloid properties; formation and occurrence in rocks and soils; and ceramic and hydrothermal reactions of clays and clay-producing systems are discussed.
Geochemical process control programming - Programming logic as applied to geochemical and related geological problems is introduced. Process and instrument control programming and methods of computer analysis of geochemical data are developed.
Nuclear and isotopic geochemistry - The principles of geochronology and stable isotope distributions with an emphasis on the application of these principles to important case studies in igneous petrology and the formation of ore deposits are presented. U, Th, and Pb isotopes, K-Ar, Rb-Sr, oxygen isotopes, sulfur isotopes and carbon isotopes are included.
The Main Component
Research is, of course, the principal component of the programme. The wide variety of geochemical investigations which constitutes the thesis/dissertation research of students may be roughly classified in four categories: biogeochemistry and organic geochemistry, environmental geochemistry, exploration geochemistry, and rock and mineral geochemistry.
Studies in biogeochemistry and organic geochemistry range from investigation of roles of microorganisms in formation of mineral deposits, in degradation of organic compounds in the environment, in leaching of metals from ores, and as potential exploration indicators for base and precious metals deposits to the puzzling task of elucidating the nature of humic substances.
A great diversity of environmental projects have been conducted often involving collaboration between chemists and geochemists within the department as well as with colleagues from other departments. Development of pyrolysismass-spectral methods for proportionation of air pollution sources, establishment of fundamental thermodynamic parameters for modeling the behaviour of radionuclides in aqueous systems associated with nuclear waste repositories, defining mechanisms of environmental degradation of anthropogenic organic compounds, the kinetics and thermodynamics of carbonate stone weathering by acid rain, and investigation of the role of organic ligands in mobilization of metal ions in sanitary landfills are examples of environmental projects.
Development of new geochemical exploration tools and defination of their limits and capabilities have been the focus of the exploration research. Methods involving measurement of aqueous phase species as well as gas phase species are of interest. One particular success of this programme was the development of a new method of petroleum exploration through collaboration of a geochemist and a mass spectroscopist. The technique, which involves passive collection of soil gases which are analyzed by Curie-point pyrolysis mass spectrometry using pattern recognition methods to interpret the complex data, is now in commercial use.
In the area of rock and mineral geochemistry, projects include investigation of the causes of clay and related mineral diagenesis, elucidation of the kinetics of complex carbonate formation, explanation of the formation and evolution of igneous rocks and their associated ore deposits from elemental and isotopic distribution data, and petrologic studies of meteorites.
The cross-fertilization resulting from location of a geochemistry degree programme within a department of chemistry has been well worth the effort needed to broaden viewpoints and vocabularies. The geochemists are learning from the chemists new tools with which to investigate geological systems and phenomena; the chemists are finding exciting new, real-world applications for their research ideas.
|Printer friendly Cite/link Email Feedback|
|Author:||Daniel, Stephen R.|
|Publication:||Canadian Chemical News|
|Date:||Mar 1, 1990|
|Previous Article:||The use of Gibbs energy diagrams in the teaching of organic chemistry.|
|Next Article:||Provision of a college-plant interface.|