POT-331 P-3 Slot 273 6/23/15 16:19 cue 03 1604 Erosion of the Earth’s Surface Slide Show Presentation 20-min. Rossmoor resident, Geographer and PhD in Mineralogy, Dr. Barrie Bieler, presented his slide show on the geological issue of the erosion of the Earth’s surface - a natural process which is usually made by rock and soil being loosened from the earth's surface at one location and moved to another. Dr. Bieler presented images demonstrating this usually slow process that changes the landscape by wearing down mountains, filling in valleys, and making rivers appear and disappear