- Look across the road to the south (primarily) and also at some of the large boulders on the North (extra) to answer these questions:
- Are the smaller stones (clasts) that make up the cliff face/boulders all the same size or do they vary? What size(s) do you see.
- Are the smallers stones (clasts) the same color/composition, if not explain differences?
- Based on the composition would you say the stones (clasts) are of the same or different origin.
- Are the stones rounded, or broken up? Does this tell you it is a breccia or a congolmorate?
- If you are submitting answers for other cachers that is with you please let me know who.
- Add a photo of you from the location or of an identifiable item (paper with trackable name). Posting a photo pulled from the internet, or photoshopped will result in instant deletion.
A rock fragment that is broken of another rock is know as a clast. These clasts often become cemented together into a larger rock. When this happens the rock is known as a clastic rock. Sometimes there may be a large amount of cement, and othertime almost nothing. That cement can be of many origins itself. Volcanic, sedimentary, or from explosions or impacts.
Breccia is a stone that is made from broken or shattered stone. It can be from a larger rock face that it breaks off of, and then the sediment evently bonds it together, impacts of metiors, volcanic eruptions, or faulting can cause these materials to break up then become solid.
Congolomorate clastic rock is a different type of rock. It is made from clasts that have been rolled or had the edges knocked off. Stones that are rolled down a river bed, down channels, or rolled about the ocean floor that cement together are referred to as conglomorates. Another type is from stone that is deposited from glaciers. They have been dragged and rolled by the ice to be rounded.
In the end stones that have rounded edges, even if only slightly are referred to as a conglomorate. While those with sharp edges are referred to as breccia.
Another note is the size of stones. If the conglomorates are of even size it usually is because the water was of even speed and dropped the same size stone around the area. They may be different stone types. A conglomorate that is at the base of a mountain stream may have many different clast types as different layers break off and roll down the mountain.