Geologic units containing Augen gneiss

Augen gneiss
Gneissic rock containing augen (large lenticular mineral grains or mineral aggregates having the shape of an eye in cross section)
Subtopics:
(none)

Alabama - Connecticut - Massachusetts - North Carolina - New York - Pennsylvania - Rhode Island - South Carolina - Virginia

Rhode Island

Esmond Igneous Suite - augen granite gneiss (Late Proterozoic)
Esmond Igneous Suite - augen granite gneiss - Pale- to dark-gray, medium- to coarse-grained, granite gneiss characterized by large feldspar porphyroclasts (> 1 cm). Composition ranges from tonalite to granodiorite to quartz monzonite. Composed of sodic plagioclase, quartz, microcline/orthoclase, biotite, opaque minerals; hornblende and epidote common in more mafic types; accessory apatite, sphene, allanite, and zircon; secondary chlorite. Typically massive, but with strong penetrative foliation and lineation defined by major minerals. Commonly contains structurally conformable layers of amphibolite. Includes most rock mapped formerly as Ponaganset Granite Gneiss and Ten Rod Granite Gneiss.
Esmond Igneous Suite - granite gneiss (Late Proterozoic)
Esmond Igneous Suite - granite gneiss - Pale-gray to pale-pink, fine- to medium-grained granite gneiss, rarely with porphyroclasts of microcline/orthoclase. Composition ranges from quartz monzonite to granite. Composed of sodic plagioclase, quartz, microcline, biotite, opaque minerals; minor muscovite common, garnet more rare; accessory apatite and zircon; sphene and hornblende present in some rocks; secondary chlorite. Typically massive, but with strong penetrative foliation and lineation defined by major minerals. Commonly associated with, and in part gradational into, augen gneiss. Includes rock mapped formerly in part as Ponaganset Granite Gneiss, Scituate Granite Gneiss, Ten Rod Granite Gneiss, and Hope Valley Alaskite Gneiss.