Cooking Rocks: Teaching About Diagenesis on Earth and Mars

ABSTRACT

The hands-on homework activity Cooking Rocks uses iron oxide–cemented sandstone to teach undergraduate students about diagenetic (postdepositional) minerals and how they can change in sedimentary rocks. Students bake a piece of goethite-cemented sandstone (commonly known as picturestone) to understand properties of iron oxide minerals and spark dialogue about similar diagenetic minerals on Mars. This activity is representative of more than 25 activities developed in the National Aeronautics and Space Administration's Mars for Earthlings education and outreach project. Mars for Earthlings curriculum is a resource for teachers that is designed for teaching undergraduate students at an introductory general science level. The engagement, exploration, explanation, elaboration, and evaluation pedagogical format encourages student-driven inquiry to teach students the concept of diagenesis and how to run an at-home experiment to observe a diagenetic mineral transformation from goethite to hematite. The activity generates outcomes to assess student learning of natural Earth processes and the implications for water and similar diagenetic processes in the hematite spherules, dubbed “blueberries,” discovered on the Mars landscape. Instructors may easily adapt the material to fit small or large class sizes, as well as online or distance-learning courses.

Key words::

• Mars
• planetary science
• hematite
• goethite
• space education

Acknowledgments

We gratefully acknowledge the financial support provided by NASA Education and Public Outreach for Earth and Space Science Grant NNX11AH29G. We thank the editors and anonymous reviewers who provided helpful input. We appreciate the work of Clay G. Jones and Joseph N. Moore of the Energy & Geoscience Institute of the University of Utah for XRD sample preparation and analysis. Quintin Sahratian of the University of Utah assisted with some sample preparations and the muffle furnace.