Episode 348 - "Hot Juicy Magma"

Forms in fractures of rocks already in place, so it an INTRUSIVE feature
Form at right angles to the direction of extension in the area - nature’s frac jobs
Can be super thin or super thick, but generally are self-consistent
Can have multiple periods of injection or even multiple compositions of injection over time
Can get en echelon patterns, rings, and cones (last two common with caldera volcanism)
Magmatic are the most well known and form when magma flows into a crack and cools into a sheet.
The igneous rock is generally more weathering resistant so we get cool weathering features
Can be rhyolitic, but mostly basaltic
Rate of cooling determines grainsize (slow = big) and big near the center
Can have columnar jointing
Big phenocrysts orient with flow direction - cool! AMS studies show this.
These are awesome when you get them radially around a volcano!
Horizontal dikes are called sills
Clastic dikes are formed by sediments episode 177 (https://www.dontpanicgeocast.com/177)
Can be formed with fluid pressure
Cracks in permafrost that fill in
Fun Paper Friday
One plus one equals two, right? Sure, but you won't get published saying it that way.
Siegfried, John J. "A first lesson in econometrics." Journal of Political Economy 78.6 (1970): 1378-1379. (https://www.journals.uchicago.edu/doi/abs/10.1086/259717)
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John Leeman
- www.johnrleeman.com (http://www.johnrleeman.com)
- @geo_leeman (https://twitter.com/geo_leeman)
Shannon Dulin
- @ShannonDulin (https://twitter.com/ShannonDulin)

Forms in fractures of rocks already in place, so it an INTRUSIVE feature
Form at right angles to the direction of extension in the area - nature’s frac jobs
Can be super thin or super thick, but generally are self-consistent
Can have multiple periods of injection or even multiple compositions of injection over time
Can get en echelon patterns, rings, and cones (last two common with caldera volcanism)
Magmatic are the most well known and form when magma flows into a crack and cools into a sheet.
The igneous rock is generally more weathering resistant so we get cool weathering features
Can be rhyolitic, but mostly basaltic
Rate of cooling determines grainsize (slow = big) and big near the center
Can have columnar jointing
Big phenocrysts orient with flow direction - cool! AMS studies show this.
These are awesome when you get them radially around a volcano!
Horizontal dikes are called sills
Clastic dikes are formed by sediments episode 177
Can be formed with fluid pressure
Cracks in permafrost that fill in

Fun Paper Friday

One plus one equals two, right? Sure, but you won't get published saying it that way.
Siegfried, John J. "A first lesson in econometrics." Journal of Political Economy 78.6 (1970): 1378-1379.

Contact us:

Show

Support us on Patreon!
www.dontpanicgeocast.com
SWUNG Slack
@dontpanicgeo
[email protected]

John Leeman

www.johnrleeman.com
@geo_leeman

Shannon Dulin

@ShannonDulin