Fossil Excavation and Jacketing

Friday, July 23, 2010

Learn the major steps involved in getting a dinosaur fossil safely out of the ground.]
Digging up Dinosaurs:
Tools for Excavation
A variety of tools are used to unearth a dinosaurs fossil. Field crews use large tools like shovels and even jackhammers to remove the rock and dirt surrounding a fossil. As they get close to the bone they uses smaller tools like picks and rock hammers. Fossils that are crumbling are covered with special glues to help keep the pieces together.
Removing the Overburden
The first step in removing a fossil is to carefully remove the matrix (dirt and rock) that is covering the top of it. This may mean just dusting it off, or it could mean removing part of a mountainside!
Isolating the Fossil
Field crews (usually volunteers and students) carefully excavate around the edges of a fossil to isolate it on a pedestal of matrix below.
Plaster Cap
Field crew members cover the isolated fossil first with wet paper towels, and then with plaster coated burlap strips. The paper towels protect the fossil from the plaster. The plaster dries into a hard shell or jacket that protects the fossil.
Fossil Removal
With the top of the fossil safely inside the plaster cap, workers dig through the rest of the matrix underneath the fossil. They usually leave quite a bit of matrix that will be removed by preparators (workers who are skilled in cleaning fossils) back at the lab. The fossil is finally free from the ground and is rolled onto the side that has already been jacketed.
The second half of the plaster jacket is made to cover the exposed bottom of the fossil so that the entire specimen is encased in a hard shell of plaster for its trip back to the lab.
Notes about the fossil’s location and other information are sometimes sealed inside a plastic bag inside the jacket. Labels are written on the outside of the jacket.


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