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Two Years Before the Mast EarthCache

Hidden : 9/30/2015
Difficulty:
1 out of 5
Terrain:
1 out of 5

Size: Size:   other (other)

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Geocache Description:

Richard Henry Dana was the author of the famous book named "Two Years Before the Mast". That book made Dana Point famous, and also who it was named after. This earthcache brings you to a memorial to Richard Henry Dana which will explain the geology of some of the material in the making of it.

Marble is one of the most beautiful naturally occurring rocks. It's why it's in our homes, floors, and art sculptures. In this piece, the marble is just below Richard Henry Dana's feet where his name is stated. Now that you know where the marble is, let's discuss how it's formed.

The first thing you need to make marble is dead organic matter and a lot of it. This comes from dead sea life that over millions and millions of years have sank to the bottom of the ocean. Overtime, these layers of dead organic matter become hardened due to the weight of more dead material being laid against it. This newly formed rock is called limestone.

Overtime, the ocean moves and the sea floor gets deeper at a subduction zone, at convergent plate boundary. Here, the rock subjects over the continental crust because it is more dense. Eventually, the rock reaches the upper mantel and begins to melt. Depending on how long, how deep, and the type of rock can determine the outcome. Limestone, when melted naturally forms marble, thus making it a metamorphic rock. This rock is exposed close to the surface when the plate starts to rise instead of subducts.

Works Cited

http://geology.com/rocks/marble.shtml

www.quora.com

TO LOG A FIND ON THIS CACHE YOU MUST E-MAIL (NOT THE GEOCACHING.COM MESSAGE CENTER) ME THE CORECT ANSWERS BEFORE YOU LOG A FIND. ANY INCORRECT ANSWERS WILL RESULT IN A DELETED LOG

**No group emails will be accepted as for me, this is a form of cheating. If this happens, all your logs will be deleted. Any incorrect or inaccurate answer will result in a deleted log, so don't let this happen to you!**

1. Two Years Before the Mast on the first line of your email.

2. Describe the texture AND color of marble at this location.

3. Describe the weathering process of this rock. Is there any rusting or corrosion? If so, where do you see it and why is this occurring?

4. Why are there no fossils in this rock even though marble was originally limestone?

5. Would you expect to see fossils in this rock if you split it open?

Additional Hints (No hints available.)