PETROLOGY VIDEO SERIES: THE PROCESS OF GOING FROM MICROSCOPIC TO REGIONAL

The purpose of this project is to develop a step-by-step process for generating short videos to convey petrologic concepts viewable from both inside and outside traditional classroom settings. Using a multi-layered approach when teaching petrology allows students to analysize and absorb information from the microscopic, hand-sample, field location, and 30,000 ft. perspectives.

Petrologic studies of igneous rocks start with the identification of minerals and textures for classification. This is the first step in understanding the conditions during formation including emplacement and crystallization. For example, an igneous rock may have formed in a vertical dike intrusion situated along one of many fractures formed near a volcanic center. The volcanic center may or may not be visible from the landscape. In the field, these rock samples are placed within the context of a complex volcanic sequence with numerous pyroclastic or lava flows extruded from the volcanic centers. The dike intrusions provide a direct link to the magma source and the processes leading to solidification.

When observing the same rock at the microscopic level, it may become evident the plagioclase crystals show signs of oscillatory zoning. In this case, oscillatory zoning ranging from Ca-rich to Na-rich could reveal the possibility that a magmatic process occurred involving mixing and assimilation. Other minerals in the same sample may have reaction rims or eroded crystal faces, supporting similar conclusions as previously determined from the zoning.

Using videos for presenting geological research information maximizes viewing flexibility for aiding student learning and retention. Utilizing imagery and/or video from actual field locations will help transition students from a classroom setting and provides them the opportunity to view actual research being conducted in the field. This paper will explain the process used in developing these videos designed to help students and instructors increase discovery and learning.