Reading the Landscape in Todd County EarthCache

1. Observation: Estimate the width of the top of the landform and the height from its base to the highest point. Briefly describe how you made your estimate (for example: pacing, comparison to known objects, or map scale).
2. Interpretation: Based on your estimates, is the top wider than the height, or narrower than the height?
3. Synthesis: Using the Earth science lesson below, classify this feature as a mesa or a butte and explain your reasoning in 1–2 sentences.

📍 What You’re Looking At

From the posted coordinates, look west to observe an isolated, flat-topped landform rising above the surrounding terrain. Features like this are common in arid and semi-arid landscapes, where erosion acts slowly but persistently over long periods of time.

At first glance, this landform could reasonably be described as either a mesa or a butte. Although they look similar, geologists distinguish between these landforms using scale and proportion, not just appearance.

🪨 Earth Science Lesson: Mesa vs. Butte

Mesas and buttes are erosional landforms created when rock layers of differing resistance are exposed at the Earth’s surface. A harder, more resistant rock layer—often sandstone or limestone—forms a protective cap over softer rock beneath it.

As wind, water, and gravity erode the surrounding softer material, flat-topped features remain behind. Over time, continued erosion causes these features to shrink as their edges retreat.

A widely used geographic rule of thumb for classification is:

• Mesa: the top is wider than the feature is tall

• Butte: the top is narrower than the feature is tall

This simple comparison allows geologists to classify landforms in the field without specialized equipment.

⏳ Why This Location Matters

Landforms like the one you see here represent a moment in a long erosional sequence. Broad elevated surfaces can be reduced over time, transitioning from plateaus to mesas, and eventually to buttes as erosion continues.

By estimating proportions and applying a clear definition, you are using the same observational approach employed in geomorphology to interpret landscapes across the American Southwest and similar regions around the world.

📚 Further Exploration (Optional)

If you’d like to go deeper:

• Mesas and buttes often preserve clues about ancient environments and rock layers that once extended far beyond their present boundaries.

• Differences in erosion rates are influenced by rock type, fractures, climate, and drainage patterns.

• Similar flat-topped landforms have been identified on other continents—and even on Mars—where erosion operates under different conditions.

This additional context is not required to complete the EarthCache but helps place your observations into a broader geological framework.

✉️ Answer Submission

Please email your answers to the three logging tasks along with confirmation of your required photo. Thank you for helping preserve this site and for keeping answers out of public logs so others can enjoy the same learning experience.

📖 References

• Mesa and Butte. Science Clarified (2017).

• Davis, G. H. (1999). Structural Geology of the Colorado Plateau Region of Southern Utah. GSA Special Paper 342.

• Baker, D. M. (2008). Morphological analyses of mesas and knobs. GSA Abstracts with Programs, 40(2).