To log this earthcache:
Please contact me through my profile with the answers to the following questions. Please send the answers before logging your find, you don't have to wait for a reply to log it, if there is a problem I will contact you.
1) Fossils are most common in which type of sedimentary rock?
2) For each waypoint you will see a photograph below to help you locate a specific example of a fossil.
Using the information in the Earthcache lesson below, identify the type/s of fossil hidden by the blue section at each waypoint stage and describe their sizes (length & width).
3) Take a photo of yourself or your GPS or a thumbs up or something with your Geocaching name with any example of a fossil other than the specific examples the Earthcache focuses on (and which I have masked on the cache page photographs for obvious reasons). See samples at the end of the cache page; please do not post spoilers in your photographs.
Answers without the requisite photo and /or answers sent are liable to be deleted without comment.
| Waypoint 1 - Posted Coordinates: |
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| 2nd row up, 1st cladding tile from the right. |
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| Waypoint 2: |
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The Lesson
Limestone is a sedimentary rock, which means it was formed from small particles of rock or stone that have been compacted by pressure. It is formed in two ways. It can be formed with the help of living organisms and by evaporation.
Most limestones form in shallow, calm, warm marine waters. That type of environment is where organisms capable of forming calcium carbonate shells and skeletons can easily extract the needed ingredients from ocean water. When these animals die, their shell and skeletal debris accumulate as a sediment that might be transformed into limestone. Limestones formed from this type of sediment are biological sedimentary rocks. Their biological origin is often revealed in the rock by the presence of fossils.
Some limestones can form by direct precipitation of calcium carbonate from marine or fresh water. Limestones formed this way are chemical sedimentary rocks. They are thought to be less abundant than biological limestones.
Fossils are the preserved remains or traces of animals, plants, and other organisms from the remote past that can be found in rocks. There are many factors that can contribute to the likelihood of an organism being preserved as a fossil. Fossils are most common in limestones. That is because most limestones consist partly or mostly of the shells of organisms.
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BELEMNITES
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BIVALVES
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AMMONITES
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BELEMNITES were squid-like animals that lived in the open sea and were active swimmers and predators. The fossil that is most commonly preserved is the solid internal skeleton, known as the guard or rostrum, which is usually bullet-shaped. Belemnites are common in limestone and shale. In cross section, the guard appears as a small solid white circle, often with concentric rings. In long section, belemnites appear as long, narrow, cigar- or bullet-shaped white features tapering to a point at one end.
Belemnites were named after the Greek word for javelin or dart - belemon - In mythology, they were believed to have been thrown down from heaven as thunderbolts.
BIVALVES are shellfish with two hinged valves and are still alive today (e.g. clams and mussels). They lived on or within the sea floor and fed by filtering food particles from seawater. Bivalves are common fossils in limestone. In cross section, the shells appear as paired white curved or oval shapes. In long section, they often appear as two matching white semicircles or elongated curved shells lying side by side. Unlike brachiopods, both valves are usually the same size and shape.
AMMONITES are very common fossils in limestone and shale, and are especially useful as index fossils for dating rocks. They were free-swimming marine animals related to the modern squid and octopus, and lived in coiled, chambered shells. As the ammonite grew, it moved into new chambers, sealing off the old ones. In cross section, ammonites appear as large circular or spiral shapes with curved white lines marking the internal chambers. In long section, the shell may appear as a curved or elongated structure with repeated chamber divisions visible inside.
Ammonites were once thought to be curled-up sea snakes.
As mentioned above, to log this earthcache:
Please contact me through my profile with the answers to the following questions. Please send the answers before logging your find, you don't have to wait for a reply to log it, if there is a problem I will contact you.
1) Fossils are most common in which type of sedimentary rock?
2) For each waypoint you will see a photograph above to help you locate a specific example of a fossil.
Using the information in the Earthcache lesson above, identify the type/s of fossil hidden by the blue section at each waypoint stage and describe their sizes (length & width).
3) Take a photo of yourself or your GPS or a thumbs up or something with your Geocaching name with any example of a fossil other than the specific examples the Earthcache focuses on (and which I have masked on the cache page photographs for obvious reasons). See samples below; please do not post spoilers in your photographs.
Answers without the requisite photo and /or answers sent are liable to be deleted without comment.
Congratulations to (your name could be here) on the FTF
