Geoslice Earthcache EarthCache

Geoslice Earthcache

At the posted coordinates you will find a vertical slice of sedimentary rock taken from the ground underneath you.

There are three types of sediment: rocks, or clastic sediment; mineral deposits, or chemical sediment; and organic sediment, composed primarily of organic material. There are also three general processes involved in the transport of sediment from higher altitudes to lower ones, where they eventually are deposited: weathering, mass wasting, and erosion.

The lines between these three processes are not always clearly drawn, but, in general, the following guidelines apply. When various processes act on the material, causing it to be dislodged from a larger sample (for example, separating a rock from a boulder), this is an example of weathering. Assuming that a rock has been broken apart by weathering, it may be moved farther by mass-wasting processes, such as creep or fall, for which gravity is the driving factor. If the pieces of rock are swept away by a river, high winds, or a glacier (all of which are flowing media), this is an example of erosion.

Read the information sign at your feet and answer the following questions: 1. How many different scenes are depicted over the past 18,000 years? 2. Which processes (weathering, mass wasting, and erosion) resulted in the sedimentary rock in front of you? 3. Why do you think scene II deposited so much more sediment than any of the other scenes depicted in the slice? Email me the answers to these questions and include a photo of yourself next to the Geoslice in your log. Logs that do not include a photo or are not followed up with an email with the answers to the questions will be deleted.