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.
With this EarthCache, you will discover many fossils in Bethune!
But where are they? Well they are hidden in the stones of the buildings!
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:
Waypoint 1: The stairs of the Theater of Béthune
1-. With the help of the Identification Key, find the name of the fossils in the stairs of the Theater.
Waypoint 2: Wall of the Louis Blaringhem High School
2-. What is the size of the biggest coral visible here? Look carefully at the fossil, what is the shape that is repeated several times?
Waypoint 3: The Post office of Béthune
3-. With the help of the identification key, find the name of fossils A and B hidden on the following picture. Measure the average diameter of fossils C.
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