Logging tasks
At the cache location look about you. You should be kind of close to the end of the art but still on shore on the beach. There are three large boulders here that you can look at.
- Visit the location, tell me who is in your party that your are submitting answers for. Please answer next to each other. If one of you waits it may be deleted, and you need to submit your answers yourself.
- Looking at the rocks do they all seem to have the same amount of gasses trapped in them?
- Look about at some of the others in the area. Why do you suppose there are differences?
- What type of lava flow do you think these came from?
- Add a photo of you from the location or of an identifiable item (paper with trackable name) Have the jetty in the background. Posting a photo pulled from the internet, or photoshopped will result in instant deletion.
Intro
The lake area has many different looks. This is a piece of art that is considered one of the finest "landscape art" pieces in the word. It was made completely from the basalt rocks that exist on the shore and up on the hill
Basalt
Basalt is a very common rock that is made when lava or magma cools. However depending on if there are gases present, the pressure, and the temperature of formation, and the environment that it is formed in, you can get very different looking rocks.
Block Lava
This type of basaltic lava forms with very few gaseous bubbles. The silica content is fairly high and the temperatures tend to be lower than other types (2012° F). Because of less gasses, it tends to have a smooth, glossy surface. It creeps slowly and is very dense
A'a
This is Hawaiin for hard on the feet. The lava flows of these have very rough and jagged survaces. It is more viscou8s than other types and flows slowly. Moving like a mass of broken rubble. The surface cools, and breaks up as it moves, then never softens again. So it is a mass of sharp, jagged edges. Those flows are pretty much impassable to those on foot, and can destroy hiking boots. The temperiatures tend to be about 2100° F
Cinders
In the early stages of a basaltic eruption, lava his highly charged with gases. As it approaches the surface and pressures drop, the gas expands raplidly, pushing the materual upward. An explosion takes place throwing it out. The lava cools rapidy and fall to the surface. Thes pieces tend to be a few mm it size to baseball size. They build up and create a cone around the volcano. The temperatures are around 2170° F
Pahoehoe
Is a smooth lava. It takes is name from the Hawaiian word for "ropy". Parhohoe lava flows are highly liquid, and flow easily. The surface of the flow cools and forms a thin crust, and the flowing lava below it drags it along, forming a layer that looks like ropes or coils. The temperatures of this are also very high 2170° F with a lower amount of gasses than cinders. Many more gas voids will be in these.