Teaching Volcanic Petrology in Limited Time Jim Nicholls: Calgary, Alberta, Canada The Mineralogical Sciences: Endangered topics in geoscience curricula

One Contributing Factor Students specialize as undergraduates: Petroleum geologists, Environmental geoscientists, Geophysicists, Etc. Why Did This Happen? Created courses labeled Rocks and Minerals or Earth Materials or something similar. Learning Objective like: Students will develop the ability to Identify Rocks and Minerals How has specialization been accommodated?

Mineral Science is more than identifying rocks and minerals! Crystallography Mineralogy Geochemistry Petrology Optics and Diffractometry The list goes on and on … BUT

Ask a Couple of Critical Questions Why should any geoscientist know something about the mineral sciences? What should they know about the mineral sciences? Depends on topic, but put everything on the table. Justify all content. Example: Volcanic Petrology. Geoscience is a profession with a focus on the Earth. Mineral sciences are part of that focus; any geoscientist should know something about them.

Geoscientists Should be Able Read, Understand, and Review the Popular Literature

What’s written about igneous rocks in the popular literature ? Geoscientific context: Extensive, done well. Stories are nearly always about volcanoes and volcanic phenomena. Rock names: few, simple, unused or undefined. Textures: names seldom used or described.

What to Leave Out? Plutonic rocks Rock names Texture names Leaving this one out really sucks! (Well, almost)

What to Include (1) Geoscientific context No more Rocks in Boxes Descriptions of textures o Fragmental rocks (Explosive eruptions) o Flow rocks (Quiet eruptions) o Glassy rocks Mafic – felsic continuum Silica content versus Mafic index

What to Include (2) Activity of silica Activity of alumina Mineral assemblages reflect activities. Activities can be related to chemistry.

Conceptual model: Activity of sugar in water o Sugar – water solutions provide a physical, conceptual model (Kitchen stove, refrigerator, freezer). o Taste, stir, poke Learning to relate specific mineral assemblages to chemical activities on a relative scale Using Activity: Challenges Learning the concept Applying concept

Minerals and a SiO 2 Students recognize whether a few different minerals are either present or absent from a rock. They can then infer relative activity of SiO 2 or Al 2 O 3.

Minerals and a Al 2 O 3

Rock Space Rock Space encompasses 90% or more of volcanic rocks on Earth. Emphasizes the diversity of volcanic rocks on Earth. Simple to use and easy to learn.

Rock Names Provide Comfort and Support The IUGS Classification has 179 root names (Le Maitre, 2002) o Muscovite Granite – a modified name o Granite – a root name o Basalt, Andesite, Rhyolite, Obsidian

Rock Names with Comfort and Support Rhyolite Andesite Basalt Where, in Rock Space, Does Comfort and Support Fall? Rhyolite Andesite Basalt Obsidian

Explosive Eruptions, Craters, Calderas, and Activity of SiO 2

Quiet Eruptions, Lava Flows, and Activity of SiO 2

Organizational concepts come before facts. Facts are learned by applying organizational concepts to case studies.

Acknowledgements Dr. Paul Hoskin Dr. Leslie Reid Mavis Stout Dr. Frank Brown Dr. Thure Cerling Erin Ernst Colin Rowell Michelle Speta Elissa Lynn A detailed expression of the concepts described here can be down loaded from: