GUYE MINE SKARN DEPOSIT
Snoqualmie Mining District, King County, Washington, USA
LOCALITY IMAGES


GEOLOGY
Skarn Deposit, periphery of Snoqualmie Batholith - late Oligocene to early Miocene (28 Ma[million years ago] to 22 Ma).

The Denny Mountain skarn (tactite) deposit is exposed along the Guye and Chair Peak saddle. The skarn formed by metasomatism of Jurassic/Triassic age sedimentary rocks during intrusion of the Snoqualmie Batholith.

MINERALS
*ANDRADITE-
Ca3Fe3+2(SiO4)3 - Occurs as mm-scale crystals embedded in massive calcite (marble).
*CALCITE-
CaCO3 - Occurs as metamorphosed limestone (marble) within the skarn deposit.
*DIOPSIDE-
Fe2+Fe23+O4 - Occurs as light olive green euhedral crystals to about 1 cm.
*MAGNETITE-
Fe2+Fe23+O4 - Occurs as black euhedral crystals up to about 1 cm embedded in calcite (marble) and as massive monomineralic rock.
*QUARTZ-
SiO2 - Occurs as thin mm-scale euhedral crystals in small veins, associated with massive magnetite.

* photographed

 
ANDRADITE and MAGNETITE

 
ANDRADITE and MAGNETITE on green DIOPSIDE,
 embedded in massive CALCITE
(paritally dissolved during specimen preparation)

 
CLINOZOISITE (unconfirmed)
with BYSSOLITE (unconfirmed)

 
QUARTZ on massive MAGNETITE


REFERENCES
(Under Construction)