USING GRAIN SIZE ANALYSIS AS THE BASIS FOR AN UNDERGRADUATE SEDIMENTOLOGY RESEARCH EXPERIENCE

The classic sedimentology paper by Visher (1969)*, which relates grain size distribution to sediment transport processes, is often cited in undergraduate sedimentology text books in discussions about sediment grain size variation. A research project based on the analyses and hypotheses presented by Visher (1969) has been developed as a research experience for undergraduate sedimentology students. The project exposes students to many aspects of geologic research including critical analysis of a scientific paper, sample collection, laboratory and statistical analysis, interpretation of data and presentation of results.

Teams of students are assigned to test one of the hypotheses presented by Visher (1969), that the grain size distribution of modern beach sediments reflects the varied transportational agents that act in beach environments. After initial reading and discussion of the paper, each team designs and implements a sampling strategy to collect beach sediment. Subsequent grain size analysis of the sediment is carried out using a Beckman-Coulter laser particle size analyzer but sieving techniques could also be used. Teams produce histograms and probability curves from the grain size data for each sediment sample. These statistical analyses facilitate the study of grain size distribution and sorting, and allow for consideration of how these attributes are related to the transportational agents that affect samples from specific beach locations. Teams consider how their results compare to those of Visher (1969) and whether their results support his hypothesis. The project culminates with submission of research reports from individual students and a class discussion, during which teams present their results and conclusions.

*Visher G., 1969, Grain size distribution and depositional processes, Journal of Sedimentary Petrology 39: 1074-1106