This month’s Accretionary Wedge calls for posts on our favorite geological illustrations. Some of my personal favorites are drawn by Dr. Kurt Hollocher from Union College. His collection of hand-drawn thin sections is enough to make any petrologist drool.
One of Dr. Hollocher’s most whimsical illustrations involves the AFM chemographic projection. Chemographic projections are often used in metamorphic petrology to plot complex compositions on two-dimensional triangular diagrams. A popular chemographic projection for metapelites is the AFM diagram, which represents Al2O3, FeO, and MgO at its corners. In his series of AFM diagrams, Dr. Hollocher has a little fun with the retrograde garnet-out reaction.
Special thanks to Dr. Kurt Hollocher for the fantastic illustrations and the permission to use them in our Accretionary Wedge Post.