Browse Items (25 total)

  • Collection: (ADK) Anorthosite-Charnockite and Metamorphic Suite --
    Adirondack Mountains, New York

Marble
This calcite marble is typical of most Adirondack metacarbonates. In the majority of instances, original dolomite has reacted to yield calcsilicates. Also present in these specimens are small, serpentinized droplets which may originally have been…

Orthopyroxene gabbro
This specimen is typical of the saturated gabbros of the Adirondacks. The plagioclases are generally in the range of An₄₀ and the orthopyroxenes average close to En₆₀. Antiperthite is locally developed. Scattered grains of ilmenite and garnet…

Megacrystic potassium feldspar gneiss
This lithology is characterized by 1-4 inch long megacrysts of microperthite in a groundmass of quartz, oligoclase, hornblende, orthopyroxene, garnet, and oxide. Although the contacts of this unit are everywhere conformable, the rock is believed to…

Pyroxene-quartz-plagioclase gneiss
This specimen consists of 50-60% andesine, 20-30% quartz, and minor pyroxene and hornblende. Associated with this lithology are 2-6 inch layers of pyroxene-plagioclase granulite and amphibolite. It is believed that the Royal Mountain Member gneiss…

adk_description.pdf
OCR PDF of supplemental information for the Anorthosite-Charnockite Metamorphic Suite-Adirondack Mountains, New York collection.