Archives
Geology Picture of the Day - Amethyst
Posted on Wednesday, April 16, 2008 @ 8:16 am by Dave Schumaker
Today’s geology picture of the day is a beautifully captured specimen of amethyst from Cripple Creek, Colorado.
Geology Picture of the Day - Fault Scarp
Posted on Thursday, April 3, 2008 @ 7:28 am by Dave Schumaker
In 1872, an earthquake stuck near the town of Lone Pine, California located in the Owens Valley. It was believed to have been about a M7.8 event. The earthquake destroyed most of the buildings in the town and killed 27 people. The fault scarp from the event is still visible today, just east of the town.
This is a fascinating spot, and pretty impressive when you can see in person how much movement one event can cause. And thousands of these events helped to create the Sierra Nevada mountains a short distance away.
The USGS has a geologic map (warning, PDF file) of the Lone Pine Quadrangle as well. More information about the map is located here.
Geology Picture of the Day - Vanadinite
Posted on Wednesday, April 2, 2008 @ 10:14 am by Dave Schumaker
Found this interesting picture crop up on flickr. It’s a reddish mineral named vanadinite (also known as descloizite). The white mineral beneath the vanadinite is barite.
From the Wikipedia entry:
The color is deep cherry-red to brown or black, and the crystals are transparent or translucent with a greasy lustre; the streak is orange-yellow to brown; specific gravity 5.9 to 6.2; hardness 31/2. A variety known as cuprodescloizite is dull green in color; it contains a considerable amount of copper replacing zinc and some arsenic replacing vanadium. Descloizite occurs in veills of lead ores in association with pyromorphite, vanadinite, wulfenite, etc. Localities are the Sierra de Cordoba in Argentina, Lake Valley in Sierra County, New Mexico, Arizona, Phoenixville in Pennsylvania, and Kappel (Eisen-Kappel) near Klagenfurt in Carinthia.
I messaged emeraldcitycreative on flickr about the origins of this specimen. She acquired it from a Spanish miner who originally found it in Morocco.
(Side note: I really need a spell checker with geologic names and terms. All the papers or posts I write are nothing but a sea of red.)
Geology Picture of the Day - Cake
Posted on Tuesday, April 1, 2008 @ 7:04 am by Dave Schumaker
Awhile back, I posted about my favorite geology t-shirts (which at the time, I didn’t know was apart of a geoblogosphere game called The Accretionary Wedge). One of my favorite shirts was made by Tim Babb and featured sedimentary layers in the form of a cake. Today’s geology picture of the the day recreates that shirt with something near and dear to my heart: food.
Geology Picture of the Day - Ash Cloud at Kilauea
Posted on Thursday, March 27, 2008 @ 11:30 am by Dave Schumaker
I thought I’d continue the theme of volcanoes and Hawaii by featuring this photo taken yesterday at the Halema’uma’u Crater on Kilauea.
The Hawaiian Volcano Observatory has more pictures and information.