Teaching Mineralogy from the Core to the Crust

Article excerpt

ABSTRACT

Mineralogy is commonly the first difficult geology course that a student major encounters. To provide a solid foundation and context for learning mineralogy, and, in an effort to enhance retention of information and facilitate learning, the 'typical' sequence in our mineralogy course is restructured using the whole Earth as a reference framework. This method provides a context in which to teach the materials that comprise our Planet. Beginning with the Earth's core, simple native elements are introduced, followed by minerals with increasing complexity as discussion moves outward to the Earth's crust. Key theoretical concepts are seamlessly interwoven into discussions of various portions of the Earth, rather than being considered initially in a separate section. This flexible framework allows individual courses to be tailored to the needs of the department while maintaining a strong tie to geology and establishing links to societally-relevant issues.

INTRODUCTION

Mineralogy is typically the first core curriculum course encountered in a major's program for Geology after an introductory course. Thus, mineralogy represents a significant leap, not only in the kind of information to be learned, but in the detail accompanying that information. In recent years, discussions have focused on the manner in which this course should be taught and what material should be covered (e.g. Hawthorne, 1993; 1996; Teaching Mineralogy workshop, see Brady, et al., 1997; 2002 IMA symposium). Approaches range from course content emphasis on crystallography and material sciences to that of 'traditional' systematic mineralogy. Generally, the systematic mineralogic approach directly ties to the petrologic environment exemplifing how minerals can be used to interpret Earth's processes. A continuum of emphases and approaches between these end-members exists. In most instances, mineralogy courses attempt to strike a balance, tailored to, for example, the departmental focus and needs, length of class, degree of difficulty, and the instructor's interests.

In an effort to provide a mechanism for better student retention of mineralogic information, while maintaining a strong tie to geology, the typical sequence of crystallography, crystal chemistry and systematic mineralogy was reorganized at Louisiana State University (LSU) using Planet Earth as the reference framework. Using this approach, many crystallographic concepts are woven into discussion of earth materials, and mineralogic products are directly related to the geologic processes of formation. This contrasts with a course discussing most of the theoretical basis (e.g. polymorphic transformations) prior to mineral discussions (e.g. aluminum silicates). Reorganizing the mineralogy course in this way maintains the necessary petrologic focus in the LSU Geology and Geophysics Department. This style of organization also provides consistency in our geologic curriculum by teaching a solid Earth foundation with references back to the basics of introductory geology, while preparing students for future geology courses with a strong field emphasis. Because minerals form the foundation of our Planet, they are fundamental to many areas of the earth sciences and to allied sciences such as material science, chemistry, physics and environmental science. This approach, however, may not be as useful for those students from allied disciplines whose needs do not rely on an Earth framework. This paper discusses the course organization, highlights and details selected topics, and includes some of the recognized benefits and drawbacks using this approach.

COURSE ORGANIZATION - CORE TO CRUST

At the outset of this sophomore (2nd year) mineralogy course, it is important to establish several basic concepts of mineralogy prior to discussions of mineral systematics (in whatever sequence). Class begins with a brief review of the physical properties of minerals to provide a linkage back to physical geology and chemistry, and to set the stage for linking microscopic aspects to macroscopic and observable properties of minerals. …