This earthcache is available from Scenic 40, which runs parallel to Interstate 68.
Logging Requirements: S
end the answers to #1-#5 to me through my geocaching profile/Message Center.\. DO NOT post the answers to any logging requirements on this site.
1. List the name “GC**** Hampshire Formation EC” in the first line of your email. This is done automatically in Message Center. Group logging is fine.
2. Identify “rainbow color” shade(s) visible in the rock-exposure
3. Identify how tall the Hampshire formation is at this location (at least what is visible)
4. Identify one SIMILARITY and one DIFFERENCE between the rock at this exposure and ANY other rock exposure in this area (either at another earthcache, or at exposures on this road slightly uphill or downhill from this spot…you passed several on your way here, regardless of which direction you came from!
5. Does the Hampsire Formation originate as sand or dirt? In other words, when it crumbles, does it turn into sand or fine dust?
6. (Re-allowed since 2019, Required from July 2022) Post a picture of yourself and/or your GPS with your log that shows you near GZ. DO NOT show any of the pertinent information panels in your picture or your log may be deleted.
I will only respond if you have incomplete logging requirements. Go ahead and log your cache.
You may wish to drive the ½ mile or so uphill to the VIEW from Town Hill. It gives a GREAT view of Sidling Hill and the valley below….WOW!
Geology - Formation of the Hampshire Formation
The area west of what is now the Allegheny Mountains (the Acadian Mountain event actually built mountains much taller than the present Alleghenys), was a shallow sea. A variety of layers were created as sediment settled 1,000’s of feet deep. Compression and plate tectonics altered the layers of sandstone and siltstone created a variety of features and rock colors (depending on the minerals and organic matter present in the sediment layers. According to accepted geological theory, in Ordovician time/Silurian time, the "Taconic Mountains" were created largely by the Continent of North America slamming into some "continent fragments" and islands in the area that is now western Maryland. Of course, tall exposed mountains begin to erode, which these did, creating a huge sediment wedge to the west of the mountain range. This wedge of sediment is slammed up against the remnants of the Taconic Mountains and becomes part of a new mountain building event, the Acadian Mountains.
Specifics of Hampshire Formation:
This layer is more resistant to erosion and thus is often exposed when other layers have been worn away. Its distinctive coloring makes it beautiful to any hobbyist or geologist. It was deposited by alluvial fans during the late Devonian period, and the sediment that was deposited contains more resistant minerals than other layers in this group. This means that the “shallow sea” of earlier times had largely disappeared, leaving an exposed plain of sediment. The rivers washing millions of tons of sediment from the mountaintops to the east deposited these as the water SLOWED DOWN as it arrived on the flat plain. The result? A huge deposit of more resistant sedimentation – largely because the source of the minerals is far away from this location.
Resources:
Means, John. Roadside Geology of Maryland, Delaware, and Washington, D.C.Missoula, Montana: Mountain, 2010. Print.