
You are looking for the Boy Scout/ Girl scout hut.
Missouri is famous for its geodes, which, while not entirely sedimentary in origin, often have a sedimentary shell. These geological marvels are particularly concentrated around the Warsaw Formation. It’s key to remember that geodes can appear unassuming from the outside, yet house a treasure trove of minerals like quartz and calcite within.
Geodes are crystal-lined cavities in rocks. The crystals are formed when minerals precipitate or settle out of groundwater in underground rock cavities.
The minerals deposited may vary, but in Missouri most geodes consist of quartz,chalcedony, and calcite. They commonly form in limestone and can be found in many places around Missouri.
Most geodes contain clear quartz crystals, while others have purple amethyst crystals. Still others can have agate, chalcedony, or jasper banding or crystals such as calcite, dolomite, celestite, etc. There is no easy way of telling what the inside of a geode holds until it is cut open or broken apart.
Geodes are not found randomly here and there. Instead they are usually found in large numbers in areas where the rocks have formed in a special geochemical environment. Most geodes localities are in
A) volcanic deposits such as basalts and tuffs
B) sedimentary carbonate deposits such as limestones and dolomites.
Geodes in volcanic rocks are the most widely known and sought-after. Voids in basaltic lava flows often are infilled with agate, quartz, opal and other material delivered by hydrothermal water or groundwater. Some voids are spaces occupied by gases that failed to escape the lava flow before its surface crusted over.
Geodes in sedimentary rocks are usually found in limestones, dolomites, and calcareous shale. In these deposits a gas-filled void can serve as the opening for geode formation. Shells, tree branches, roots and other organic materials often decay away to leave a void for the formation of mineral materials. These cavities can be filled with quartz, opal, agate or carbonate minerals. They are generally smaller than the geodes formed in volcanic rocks.
To get credit for this earthcache, at the coordinates listed you will find the front of the hut, but those on the sides are also made of geodes.
Please answer the following questions from the above information or by observation:
1.These geodes can be either volcanic rock or sedimentary rock? Can you tell by looking at them which one it is?
2. How are geodes formed?
3. Some of the crystals are broken open. ,What color are the crystals inside?
4.Please post a picture with your log of you or your GPS, car keys etc. in this area.