Lepidolite (left) Muscovite (center) Biotite (right) Image by author
Tag: geology
Garnet
Dodecahedral garnet crystal Image by author
You breccia!
I made some slices of one of the breccias from my research site, and look at how pretty they look! [Breccias are rocks composed of broken fragments of other rocks or minerals, all cemented together in a fine-grained matrix]
Eclogite
Besides its aesthetic beauty and awesome vibrant colors, eclogite is a very rare and important rock. Eclogites are mafic metamorphic rocks that are formed in subduction zone settings. They experience metamorphism at extremely high pressures (1.2 GPa), greater than those typical of the Earth’s crust, as well as medium to high temperatures. They are responsible… Continue reading Eclogite
Rapakivi granite
Wolf River Batholith (WI) - 1.45 Ga Ravakipi is a rather unusual, and distinctive, type of granite with rounded orthoclase (K-spar) crystals. These crystals typically have plagioclase rims, and hornblende and biotite are other common minerals present. Image by author
Azurite
Click HERE for more information on Azurite Image by author
Muscovite pegmatite
Image by author
Minnesota Morton Gneiss
Not only is the Morton Gneiss of Minnesota absolutely gorgeous, it’s also really freaking old. Zircon crystals in the gneiss have been dated to ~3.6 Ga [that’s 3.6 billion years old!] At their age, these rocks are from the Archean Eon, the second eon in Earth’s history (the Hadean is the first), which lasted from… Continue reading Minnesota Morton Gneiss
Would you consider compiling a list of geology related puns? I’d enjoy it very much. Also your blog is great and I love it.
Okay, here’s what I’ve got so far (some are common around the internet, others are things we’ve come up with in our geo department): Geology is the schist Rocks are really gneiss Do we have an apatite for geology? You breccia! All my faults are stress related Igneous is bliss That’s some perfect cleavage My… Continue reading Would you consider compiling a list of geology related puns? I’d enjoy it very much. Also your blog is great and I love it.
Prograding Delta Deposits
Typically when you think of a sediment deposit, you think of a fining upwards sequence. That means that the heaviest/coarsest stuff is going to be at the bottom and the lighter stuff is going to be at the top, ‘cause you know, gravity settling. In laterally migrating streams, we see these fining upwards deposits of sand under… Continue reading Prograding Delta Deposits
Emily Zawacki, Ph.D. 