Mineralogy Class Field Trip - 2005
Magnet Cove, Arkansas

Photos  © B.L. Dutrow

Field trip participants - 2005 Mineralogy class!

Stop 1: The (Metamorphosed) Novaculite Locality

the class with Jennifer in the lead.
Amy, Marianne, Ashley examining the novaculite

Contact metamorphism ( ~440C) caused recrystallization of  grains to produce a sugary texture (no cementing material). Avg. grain size is about 45 microns.
(brookite and rutile also present)
Nick and Mike collecting samples.
Stop 2: Trachytes and phonolites

In the fall leaves - holocrystalline and aphanitic outrops.
Alkali fsp, Na-plag, nepheline, analcime, diopside, bt, gar, hbl and/or aegirine.
Flow banding, ptygmatic injection features; small sedimentary and igneous xenoliths.
Stop 3: Carbonatite

Carbonatite outcrop displaying rhombohedral cleavage of the coarse-grained calcite. Accessory minerals: carbonate-apatite, monticellite, biotite, magnetite, pyrite, perovskite.
A short lunch by the creek

Stop 5: Pseudoleucite locality:

The creek with carbonatites
Garnet pseudoleucite syenite near contact with shale. Pseudoleucite (form of leucite replaced by nepheline and orthoclase), alkali fsp, melanite (garnet), aegerine, in fine grained groundmass.

Collecting at Stop 5
Stop 6: Shales along Lake Oauchita
Our Geo-float tour

Tour guide covering geologic features and history of the Lake.
"Tiger rock" - silica dissolution and ppt in fractures.

Angel staircases
Its a cool evening....

Mike and Jason staying warm
The final sunset.....