Rocks In A Stream EarthCache
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These coordinates will get you to the parking lot.
This Earthcache is designed to expose you to the classification of grain size and roundness.
I would suggest printing this page out and both scale images.
What you will need:
GPSr
Camera
Ruler with mm scale
Magnifying Glass OPTIONAL
I found the ruler and magnifying glass at the local dollar store.
Hand Towel
This Earthcache focuses on one of the basics of sedimentology [the study of sediments] mechanical weathering. A stream channel is one of the best places to show the effects of mechanical weathering, the breaking down of rock material. The movement of water wears larger rocks down into smaller ones the velocity, force, of the water also transports these rocks. Since the flow of the water is dependent on the amount of precipitation and time the weathering and transport of this material is ever changing.
Particle sampling can be divided into two large components, namely particle size and particle shape. Both are equally important in particle sampling
Using the Wentworth Scale requires measuring particle and applying this to the classification grade.
(visit link)
Using the Powers' Scale of Roundness take any particle you want and compare it with the pictures shown on the chart.
(visit link)
Remember to print out the images above.
Requirements:
At N 40 19.037 W 080 13.146 and N 40 19.049 W 080 13.114 along Millers Run
1. Using the Wentworth Scale and the Powers Scale of Roundness below, measure a few rocks and email me the Wentworth Grade classification and their roundness.
2. Looking at the stream bank visually how many “grades” can you see?
3 What is your observation of the roundness of the deposits?
Submit the answers above in an email to me.
Guidelines for Submittal
(Updated 1 January 2011)
Requests for photographs must be optional. Exceptions to this guideline will only be considered if the requested photograph is related to an Earth Science logging activity such as recording a phenomenon. This particular guidelines was updated on 1 January 2011. All EarthCaches must conform to this guideline as photo requests are considered "additional logging requirements" (ALRs) and follow the guidelines set forth by Geocaching.com.
Existing EarthCaches that do not meet this guideline must be updated to comply. Cache owners may not delete the cacher's log based solely on optional tasks.
As of 1/1/11 the photo becomes an option…
3 At N 4019.053 W 080 13.126
Post a picture of your GPSr at the entrance to the nearby footbridge. If you like you can post a picture of yourself at the bridge.
So why is this important to a geologist? The next time you see a chunk of concrete see if you can apply this knowledge to the material that makes up the concrete. BTW… there is plenty of concrete along the stream bank.
I would like to thank Donald A. Gennuso Cecil Township Manager for making this possible.
References:
Wentworth Scale
Adapted from
(visit link)
Powers Roundness Diagram
www.earthstudies.co.uk/GeographyIndividua...aphy%20G3/Powers%20...ness.html
Additional Hints
(No hints available.)