Geology Picture of the Week, February 1-7, 2004

NASA Earth Observatory ^ | February 1, 2004

[cogitator]

This one was sure easy. The Brandberg is another one of those African features that stands out from space, and a unique hospitable environment in the hostile deserts of Namibia. Click on the picture below will provide the big image (~3.5 MB); in the big image, the striations in the metamorphosed gneiss are pretty remarkable. I sure wouldn't want to get lost there.

Brandberg Massif

[cogitator]

One of the readers from last week mentioned Ribbon Falls in Yosemite, which only flows during the spring floods. But it's also a very pretty and very high falls, so here's a bonus picture:

[cogitator]

** ping **

[gcruse]

Can't fool me. That top picture is Janet Jackson without the Ring of the Nipplungen.

[cogitator]

Can't fool me. That top picture is Janet Jackson without the Ring of the Nipplungen.

I am not ready for THAT close-up!

[Darksheare]

Just how BIG is this formation?

"The locals call it Dâures—the burning mountain. Its volcanism has long since stilled, but the granite core left behind apparently glows red in the light of the setting sun. The formation is a remnant of a long period of tumultuous volcanic and geologic activity on Earth during which the southern super-continent of Gondwana was splitting apart."

If it's the core of what once was a volcano, just how BIG was this volcano?

[Truth666]

Beats 100:1 NASA's paintshoped Mars.

[Darksheare]

It's impressive.
Whatever size it is.

[Mike Darancette]

Just how BIG is this formation?

The Brandberg Massif in Northern Namibia is the dominant geographic feature of the central Namib desert. This dome-shaped granite intrusion covers an area of 650 square kilometers and rises 2573 meters above the surrounding desert. --NASA

[cogitator]

Just how BIG is this formation?

I think I saw an online source that said 25x30 km, so 750 square kilometers. But the description isn't geologically accurate; plutons form subsurface and then they are exposed by erosion. You can tell because they're made out of granite! Exposed volcanic cores are basaltic and much smaller; Devil's Tower in Wyoming is the classic example.

Now, the pluton is obviously associated with volcanism/tectonism, but it isn't literally volcanic.

[Darksheare]

Ahh, thanks.
I was wondering if it was something similar to a supervolcano or had any volcanic features nearby or associated with it.

Would the yellowstone hotpot form anything similar should it 'solidify', I wonder.

[Barnacle]

I sure wouldn't want to get lost there.

I'd consider myself lost if I was anywhere near it.

[cogitator]

Would the yellowstone hot spot form anything similar should it 'solidify', I wonder.

Yes, it could, but the Yellowstone hot spot is probably a mantle plume, with an active magma supply. Plutons are more like "bubbles" of magma; once cut off from the magma, it can cool into granite.

[Darksheare]

Cool.

[JusCurious]

those are beautiful pictures!