Modelling clay volcano demonstration - coring and mapping
Modelling clay volcano demonstration - Part 5
Now that you've built a modelling clay volcanic pile (www.flickr.com/photos/31678681@N07/7798032948/), see if you can determine the internal structure using core samples.
(This is even more fun if you have two teams making volcano models, then you can swap models to try to guess the other team’s flow history). The core sample gives you an idea of the layer sequence at a sample location.
To make a core sample, use a clear plastic drinking straw and carefully push into the pile at a sample point. By using a clear plastic straw, you can see the layers without having to push them out. By carefully selecting sample locations, you can get an idea of the hidden layer structure and the build history of the pile. Just like a real volcano, the lower layers are almost always older, while the upper layers are almost always younger. Use your core samples to create a cross-section diagram of your model stratovolcano. To do this, take multiple core samples in a line across your model – we’ll call this your desired transect.
Using a piece of paper, draw out the layer sequences as we did in Figure 7 (below) – make sure you note any thin layers. Next, show the colors that are observed on the surface along your transect. Take more sample cores as needed. Line up the layer sequences and show where the layers might pinch out, or pinch in. This will give you a geological map of a cross-section of your stratovolcano.
To check your map, use a sharp knife to cut across your transect line and reveal the internal structure of your stratovolcano. (Caution! Too dull a knife will blur the layers). If you used aluminum foil in the first step, pulling the volcano apart should be easy.
Congratulations! You've just used surface expression, deep core sampling, and geological mapping to derive the history of your volcanic construct!
Image and graphic credit: Mike Malaska
Modelling clay volcano demonstration - coring and mapping
Modelling clay volcano demonstration - Part 5
Now that you've built a modelling clay volcanic pile (www.flickr.com/photos/31678681@N07/7798032948/), see if you can determine the internal structure using core samples.
(This is even more fun if you have two teams making volcano models, then you can swap models to try to guess the other team’s flow history). The core sample gives you an idea of the layer sequence at a sample location.
To make a core sample, use a clear plastic drinking straw and carefully push into the pile at a sample point. By using a clear plastic straw, you can see the layers without having to push them out. By carefully selecting sample locations, you can get an idea of the hidden layer structure and the build history of the pile. Just like a real volcano, the lower layers are almost always older, while the upper layers are almost always younger. Use your core samples to create a cross-section diagram of your model stratovolcano. To do this, take multiple core samples in a line across your model – we’ll call this your desired transect.
Using a piece of paper, draw out the layer sequences as we did in Figure 7 (below) – make sure you note any thin layers. Next, show the colors that are observed on the surface along your transect. Take more sample cores as needed. Line up the layer sequences and show where the layers might pinch out, or pinch in. This will give you a geological map of a cross-section of your stratovolcano.
To check your map, use a sharp knife to cut across your transect line and reveal the internal structure of your stratovolcano. (Caution! Too dull a knife will blur the layers). If you used aluminum foil in the first step, pulling the volcano apart should be easy.
Congratulations! You've just used surface expression, deep core sampling, and geological mapping to derive the history of your volcanic construct!
Image and graphic credit: Mike Malaska