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Another rock in the road EarthCache

Hidden : 2/22/2012
Difficulty:
1.5 out of 5
Terrain:
1.5 out of 5

Size: Size:   not chosen (not chosen)

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Geocache Description:

You will visit 2 glacial erratics and compare them, while learning about some of the glacial history of the northeastern part of KS. No container to find or log to sign, just a couple of neat spots in a small town.

Congrats to StealthRT for FTF!

Idea borrowed from TerraViators' cache: 'A Radically Bolder Landscape' (GC2CZHZ). Once I visited that cache, I recalled a similar rock in my childhood hometown. I've wanted to place a cache here for sometime, but now with the rock being completely paved up to, I thought it was impossible. Had never thought of a virtual/earth cache!



Another rock in the road

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Glacial erratics are unique because they are not native to their surrounding landscape, meaning they were transported from a different location. Their native locations are often many, many miles away. In the case of glacial erratics, the transportation method was ice. As the glaciation periods ended and the ice retreated, these rocks were left behind. They range in size from pebbles to giant boulders. Since they were transported from a different geographic location, they often differ greatly from the bedrock that is found below where they currently reside. Because of this, it is often easy to find out where the rocks were transported from. The picture below is of an erratic called 'The Giebichenstein' located in Stöckse, Germany.


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One of the most common glacial erratics found in Kansas is Sioux Quartzite. This type of rock is natively found in region around the intersection of the states of Iowa, South Dakota, and Minnesota. Sioux quartzite has a very distinct color. The color is related to the compounds that bond it together. It's physically very different than the bedrock found in NE Kansas (which is mostly limestone, with sandstone and shale found also). The physical composition of Sioux Quartzite made it a great choice as a building material, as seen in the Pipestone Historical Museum in Pipestone, MN pictured below.

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When the town of McLouth, KS was being laid out, the contractor was unable to move the rock and it was left in it's spot. The road (Granite Street) was made to go around the rock. I can remember much more of this rock sticking out of the ground when I was a kid growing up nearby; there even used to be grass around it. But now, asphalt has been paved right up to it:

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The boulder was left in it's current location (N 39° 11.768 W 095° 12.362) during the most recent glaciation period, called Pleistocene Epoch, about 700,000 years ago. The image below shows the glacial extent during the Pleistocene.


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During the Pleistocene, the glacial extent reached into the northeastern portion of Kansas. In addition to the glacial erratics found in NE Kansas, there are also many other indicators that glaciers once reached here; including loess deposits and moraines. The map below shows the area of the state that was covered in ice.

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Although this is quite the story to tell people passing through town (and definitely a driving hazard); this is not the only glacial erratic located in McLouth. The second set of coordinates (N 39° 11.983 W 095° 12.938) will bring you to another example in a nearby park:

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Feel free to visit the nearby park and/or local businesses while in town. Also look for other nearby caches I've placed ;)


Read more about the history of glaciers in Kansas here: http://www.kgs.ku.edu/Publications/PIC/pic28.html

Read more about glacial erratics here: http://en.wikipedia.org/wiki/Glacial_erratic

Read more about Sioux Quartzite here:http://en.wikipedia.org/wiki/Sioux_Quartzite

Read more about the Pleistocene Epoch here: http://en.wikipedia.org/wiki/Pleistocene

Read more about the town of McLouth, KS here: http://en.wikipedia.org/wiki/McLouth,_Kansas


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***TEST TIME! To receive credit for finding this cache, email me the answers to these questions:***


1. What color(s) are the two rocks? Compounds of what element give them their distinct color?

2. In addition to color, what other similarities are there between the two rocks? (think about surface features). What caused these features in the rock?



*Pictures are optional, but welcomed.


NOTE: Please be respectful of the neighbors in the area. The first rock is in the middle of a public street, but there is no 'parking.' You should be fine pulling off to one side of the rock and getting out to observe it, just be respectful of private property. The second rock is located in a public park with nearby parking, but is closed after 11pm daily.


Picture credits: pics are linked to the webpages I found them on. Those that are not linked are personal pictures. Special thanks to smithjr for helping with this cache.

Additional Hints (Decrypt)

Pna'g zvff vg! Whfg qba'g eha vg bire! (lrf, gung unf unccrarq)

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)