Geology of The Great Caldera

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Big Mac
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Geology of The Great Caldera

Post by Big Mac »

I looked at the map and saw it was called "The Great Caldera":
Image

I thought it looked like an underwater crater so looked up "caldera" on Wikipedia and found that a caldera is something slightly different an area formed by land collapse, rather than a volcanic crater that you might get from a massive explosion. So it looks like there was volcanic activity around the outer "lands" and that caused the inside to collapse below sea level and form a new sea.

That seems pretty interesting, as it seems like a less violent thing that could maybe destroy the inner land, without causing everyone on the outer lands to die. And with Calidar being a world with magic, maybe it might even be possible for a faction (like the Draconnic Knights) to cause a circle of land to drop to kill off a rival faction located in the centre of a pre-collapse continent. So I'll be interested to see how the history of Calidar explains the pre-Great Caldera era.

One other thing that interests me about this caldera concept is a word that features on one of the pictures in that Wikipedia artilc about calderas. That picture features an island called Wizard Island* that was formed as a "cinder cone" in a later erruption to the one that caused a volcano called Mount Mazama to collapse into a caldera (which filled with a lake called Crater Lake).

* = It is a cool name, but it is a specific name for a specific island inside a specific caldera. It is not a generic term.

Anyhoo, looking at what is going on with Wizard Island makes me wonder if Araldûr and Phrydias are islands created by volcanic activity. Is this the case? Or is one or both of them the peak of a mountain that collapsed into the sea when the caldera formed?
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Re: Geology of The Great Caldera

Post by Ambreville »

Nothing that complicated, really. A cosmic collision occurred during the planet's formative years. The impact and the world's inherent magical core produced the gigantic formation of the Great Caldera. The mountain in the center is a result of the impact (no volcano, actually), although some of the mineral from the asteroid is embedded in the rock deep below what is now a dwarven kingdom. The Draconnic Knights are powerful, but not that much. Some land could have collapsed, as described in the "scientific" definition of a caldera. Don't forget this is a fantasy world. Issues with geology are fascinating, but not absolutely mandatory here. :)
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Re: Geology of The Great Caldera

Post by Thorf »

If you're interested in impact craters, David, check out the Wikipedia page on them:

https://en.wikipedia.org/wiki/Impact_crater

The Great Caldera is massive - bigger than any crater in our solar system. It nevertheless shares features with its smaller real world companions, with a central uplifted area and a huge crater rim around the outside.

Above all, it happened a long, long time ago, so many features of the current geographic area are likely due to erosion, further smaller impacts, and who knows what other earthshaking events that have occurred in the aeons since the original massive impact.

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Re: Geology of The Great Caldera

Post by Big Mac »

Ambreville wrote:Nothing that complicated, really. A cosmic collision occurred during the planet's formative years. The impact and the world's inherent magical core produced the gigantic formation of the Great Caldera. The mountain in the center is a result of the impact (no volcano, actually), although some of the mineral from the asteroid is embedded in the rock deep below what is now a dwarven kingdom. The Draconnic Knights are powerful, but not that much. Some land could have collapsed, as described in the "scientific" definition of a caldera.
Thanks for the clarification, Bruce.

I guess this is a bit like the "mountain" that hit Krynn during the Cataclysm. :)
Ambreville wrote:Don't forget this is a fantasy world. Issues with geology are fascinating, but not absolutely mandatory here. :)
True. I was just trying to guess what was going on, from the small amounts of information you had give us. I guess that more details will emerge later as you develop this.
Thorf wrote:If you're interested in impact craters, David, check out the Wikipedia page on them:

https://en.wikipedia.org/wiki/Impact_crater

The Great Caldera is massive - bigger than any crater in our solar system. It nevertheless shares features with its smaller real world companions, with a central uplifted area and a huge crater rim around the outside.
Thanks. Maybe something like the cross-section diagram of the impact crater could help, when a gazeteer gets done.
Thorf wrote:Above all, it happened a long, long time ago, so many features of the current geographic area are likely due to erosion, further smaller impacts, and who knows what other earthshaking events that have occurred in the aeons since the original massive impact.
Yep. I'll be looking forward to a timeline eventually getting done that explains that history stuff. I like a bit of history. It sets the scene. :)
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