GRAPHIC GRANITE
Graphic granite (a.k.a. runic granite; a.k.a.
runite) has an odd but distinctive type of crystalline texture. Graphic
granites are typically bimineralic (K-feldspar & quartz) and consists of
interpenetrating crystals (quartz in K-feldspar), in a way that somewhat
resembles ancient
cuneiform writing (ÒgraphicÓ).
These rocks occur in pegmatitic granite intrusions.
Graphic granite (~8 cm across) from the Precambrian of Russia's Kola
Peninsula.
Geologic unit & age - apparently from a Paleoproterozoic granite
pegmatite intrusion, Belomorian Terrane (Kola Province), Baltic Shield
(Fennoscandian Shield).
Locality:
Enskoye, east of Kovdor, ~257 km west of the town of Apatity in the
southwestern Kola Peninsula of far-northwestern Russia.
Graphic granites (above & below) from the Precambrian of Russia's
Kola Peninsula.
Geologic unit & age - apparently from a Paleoproterozoic granite
pegmatite intrusion, Belomorian Terrane (Kola Province), Baltic Shield
(Fennoscandian Shield).
Locality:
Enskoye, east of Kovdor, ~257 km west of the town of Apatity in the
southwestern Kola Peninsula of far-northwestern Russia.
Graphic granite with whitish-gray K-feldspar and dark gray quartz.
Geologic unit & age: Ruggles Pegmatite, Grafton Pegmatite Field, New
Hampshire Plutonic Series, Devonian
Locality:
Ruggles Pegmatite Mine, near Grafton, southern Grafton County, western New
Hampshire, USA.
Graphic granite (above & below) with K-feldspar & quartz.
Geologic unit & age: Eight Mile Park Pegmatite District, Mesoproterozoic,
~1.430-1.474 b.y.
Locality:
3A Road roadcut north of Royal Gorge Bridge, west of Canon City, south-central
Colorado, USA.
Graphic granite with whitish-gray K-feldspar & dark-gray quartz.
Geologic unit & age: pegmatitic granite intruding schist,
Paleoproterozoic, ~1.695-1.715 b.y.
Locality:
Rt. 16 roadcut southeast of Custer, Black Hills, western South Dakota, USA.
Graphic granite with whitish K-feldspar & dark-gray quartz from
North Carolina, USA.
Graphic granite with whitish K-feldspar & medium-gray quartz.
Geologic unit & age: Sherman Granite, Mesoproterozoic, 1.4 b.y.
Locality:
Sybille Canyon, southern Laramie Mountains, southeastern Wyoming, USA.
Graphic granite (above & below) with whitish K-feldspar &
dark-gray quartz from the Precambrian of Zhitomir, Ukrainian Shield,
northwestern Ukraine.
