Summary of Adirondack bedrock geology.
Marble on the banks of the Hudson River, Warrensburg.
Marble on the banks of the Hudson River, Warrensburg, showing "fish hook" type detached fold hinge of amphibolite caught up in the marble.
Marble on the banks of the Hudson River, Warrensburg, showing complexly folded amphibolite and calc-silicate rock.
Marble on the banks of the Hudson River, Warrensburg, looking at very coarse marble and "xenoliths" of charnockite.
Outcrop between Minerva and Newcomb. This is a charnockite containing large xenocrysts of gray andesine like that in the anorthosites. These apparently have become detached or somehow mixed from the anorthosite margin. These xenocrysts become more common toward the anorthosite margin.
Outcrop between Minerva and Newcomb. Extra large andesine crystal.
Outcrop between Minerva and Newcomb. Another extra large andesine crystal.
Outcrop between Minerva and Newcomb. The largest andesine crystal at this outcrop.
Explanation of the zoning found in metamorphic "coronas" found in an olivine metagabbro. On the right is the corona stratigraphy, on the left is part of the reactions thought to generate the coronas.
Mt. Marcy type anorthosite on its southern margin. Large andesine crystal at top center is ~20 cm long.
Reddish garnet-rich ferrodiorite dikes crosscutting the Mt. Marcy-type anorthosite. This material is thought to represent the residual liquid from anorthosite crystallization that was mobilized into fractures.
Garnet-rich metamorphic reaction rims between pyroxene and plagioclase in Mt. Marcy-type anorthosite.
Fold hinge in quartzite, in a "condolite"-bearing outcrop.
Closeup view of the "condolite" rock itself.  It is rich in garnet and sillimanite.
Quartzite, with glacial polish.
Metamorphosed graywackes that have undergone partial melting.
Closeup view of the deformed pegmatite at the bottom of the picture above.
Feldspar augen derived from dismembered pegmatites in the metamorphosed graywacke above.
Garnet in a pegmatitic layer in the metamorphosed graywacke.
Folded garnet-biotite-rich and pegmatite layers in the metamorphosed graywacke.