Academic journal article Journal of Geoscience Education

Toward the Improvement of Reasoning and Writing Skills in Sedimentary Geology

Academic journal article Journal of Geoscience Education

Toward the Improvement of Reasoning and Writing Skills in Sedimentary Geology

Article excerpt

ABSTRACT

A series of exercises has been gathered into an inquiry-based writing assignment for an undergraduate course in sedimentary geology, the purpose of which is to improve students' skills in geological reasoning, problem solving, and writing. The seven exercises contain petrographic data relating to the mineral composition of detrital sediments, and these data are to be plotted in various formats including QFL triangular diagrams, X-Y graphs, and histograms. Students then write an interpretive report explaining the results and meaning of each individual plot and integrating the results into a general discussion of the major controls on composition. Although the objective of each data set tends to be readily apprehended, students must rely on their own powers of geological reasoning to interpret these seven exercises. Their synthesis addresses the most important factors that control or influence detrital mineral composition: parent rock, tectonic setting, topography in source area, climate, transport distance, durability of grains, depositional environment, and diagenesis. In the final analysis, students come to realize the complexity involved in the making of a detrital sediment.

INTRODUCTION

West Virginia University requires each academic department to offer a specially designed course with a strong emphasis on writing skills. The purpose of such a writing component is to provide undergraduate students with the skills and knowledge necessary to communicate effectively. In the Geology Program, this requirement falls to the senior-level course in sedimentary geology.

In developing writing assignments for this requirement, we wanted to avoid the traditional term paper. The term paper generally takes much of the semester as the student writes everything he/she finds in reference books and on the internet about a single theme. Ominously the one grade for a term paper often weighs heavily in the determination of the course grade. Also, plagiarism of another's ideas or words, knowingly or unknowingly, can be a problem in the writing of any library report. Instead we chose to incorporate actual geological problems into six shorter (two weeks each) writing assignments through the semester. In this way, the student would gain experience in problem-solving and geological reasoning in a number of areas within sedimentology as well as in strengthening his/her writing skills.

One of our six inquiry-based homework assignments addresses the mineral composition of detrital sediment. Students are presented with seven sets of petrographie data-the relative proportions of quartz, feldspar, and lithic grains in a sediment or rock-which they must plot on a QFL triangular diagram, X-Y graph, or histogram for analysis. All of these plots have previously been published in the geological literature, first in the primary sources of information (references cited below) and again in the petrology textbook by Blatt (1992). The data sets cover detrital sediments from diverse geological settings and ranging in age from Paleozoic to Holocene. After completing the graphs, students write an interpretive report on the totalof this information. First, they explain tne results and meaning of each individual plot. second, and more importantly, they synthesize tne results into a comprehensive discussion of the major controls on mineral composition that can be generalized to detrital sediments of all ages worldwide.

The assignment is made early in the semester before many class lectures address the topic of sediment composition. Furthermore, the textbook (Prothero and Schwab 2004) discusses but does not emphasize interpretive petrology. Although the objective of each data set tends to be readily apprehended, students must rely on their own powers or geological reasoning to interpret these seven exercises. To boost interest in the homework assignment, it is presented as a competition among students in the class: the student who writes the best paper will receive this year's Nobel prize in Sedimentary Geology. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.