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Introduction:
What is a fossil? A fossil is the remain of a living organism who after his death was found buried in sedimentary rocks, it can be for example a living being (plant or animal) whose organism after his death was confronted with specific conditions which transformed his muscles into minerals.
The fossilisation :
The term 'fossilisation' refers to a variety of often complex processes that enable the preservation of organic remains within the geological record.
1 -. The animal died from natural or artificial causes. The factors of erosion (wind, water, etc ...), bacteria or scavengers, destroy the body decomposing soft tissue and spreading the remains in the environment in which he lived.
2 -. The body is buried in continental or marine areas and covered by sediments (mud, sand, volcanic ash, etc..).
3 -. With the weight of new sediments and over time the skeletal elements are transformed into fossils. Water flowing over rocks and sediments where the animal is buried, bring minerals that enter the bones or shells in the mineralizing slowly and turning them into fossils.
4 -. Sediments are compacted and become harder.
5 -. The sediment erosion allows fossils appear on the surface.
The EarthCache:
With this EarthCache, you will discover many fossils of ammonites; ammonites are only known on their fossil state. As the dinosaurs, these animals essentially lived at Mesozoic Period and disappeared 65 million years ago. There are molluscs whose soft body was sheltered by a shell which looks like the one of the snails whereas ammonites are not gastropods!
The dynamism which reigned during the drop-off of the sediments: a turbulent environment (beach, coast) where the action of wholes is important, wear out and break the shells.
Moreover here, the sandstone contains a lot of beds of vegetals remains which come from the emerged grounds. We can easily see these vegetals remains in the rock faces thanks to their coal aspect.
Reminder on "Earthcaches": There is no container or logbook on the given coordinates. Just visit the site and answer the questions by e-mail.There is no need to wait for my reply, feel free to log immediately after. If the answers are incorrect, I will let you know. Happy caching!
To validate your visit:
Information board "Quelques autres fossiles du Sinémurien inférieur..."
1-. How do we call a stratum with a lot of fossils of ammonites?
2-. Explain and justify which dynamism reigned on the site during the drop-off of the sediments.
Information board "Une roche extrêmement fossilifère : la lumachelle"
3-. How many diffferent species of marine animals were preserved in the lumachel of Hettange-Grande?
N 49° 24.665 E 006° 09.550
4-. What are the two different forms under which we found ammonites here? How many do you see from each form?(estimation)
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