Teaching geologic time and rates of landscape evolution with dice
Kate Ruhl, Massachusetts Institute of Technology
Landscape evolution provides a convenient framework for understanding geologic time and rates because students can observe how processes like erosion and deposition shape their surroundings. In this example, students build 3-D sandbox models based on topographic maps and design and stage a "virtual adventure race." Sandbox landscapes are used to illustrate erosional processes,while local examples are used to discuss landscapes as transient or steady over different time- and length scales. Dice experiments illustrate radioactive decay and the shape of the age equation curve, and 14C dating, geochronology and thermochronology are introduced as "stopwatches" that start when a plant dies, a crystal forms, or a rock nears the surface and cools to a certain temperature. The sandbox model and thermochronometer "stopwatches" are combined to measure erosion rates and rates of landscape change. Ultimately, model rates (cm/hour) calculated from stopwatch times on the order of seconds can be related to geologic rates (km/My) calculated from real million-year-old samples.

Relative Dating of Geologic Materials
Steve Mattox, Grand Valley State University
This lessons allows students to constuct the basic principals used to understand relative geologic time and the skills used to construct the geologic time scale.