Browse Items (1651 total)

Thin-bedded greywacke and chert.

This specimen is extremely rich in sillimanite. European geologists refer to such lithologies as "khondolites." This locality is very near some of the old graphite production sites west of Hague.
Thin section shows sillimanite, garnet, k-feldspar.

This rock type is characteristic of the light colored layers in the Sacandaga Formation. The mineralogy consists of garnet, feldspar, and quartz. Occasionally, sillimanite and skeletal oxides occur. Both plagioclase and microcline are present. Quartz…

This medium grained facies is one of a number of anorthositic sheets that intrude throughout the stratigraphic section of the southern Adirondacks. A chemical analyses of specimens from this outcrop yield results that are almost identical with…

The specimen was collected from the Oregon Dome Massif. The Oregon Dome is similar in all respects to the anorthosites described and analyzed by Buddington (1939) for the Adirondack High Peaks region (Marcy Massif). Texturally, the present specimens…

The locality near Northville, NY represents the only example of this assemblage that has been encountered to date (1980) in the Adirondacks. The original lithology is that of a typical olivine metagabbro. During granulite facies metamorphism,…

This specimen is typical of the metaigneous charnockitic rocks associated with the massif anorthosites in the Adirondacks. With variation in the quantity of modal quartz, the rock qualifies as either a charnockite or a mangerite. Quartz content is…

This granite post-dates deformation and metamorphism. Silver got a U/Pb zircon age of 1125 Ma. This is a most unusual rock type. This rock has small quantities of fayalitic olivine and ferrohedenbergite that occur with mesoperthite and quartz. It…

This particular charnockite has been described, with analyses by deWaard and Romey, "Petrogenetic Relationships in the Anorthosite-Charnockite Series of the Snowy Mountain Dome," in Anorthosite Volume, New York State Museum Memoir 18, p.307-315. In…

This specimen is representative of the pyroxene-plagioclase granulites that form from gabbros in the Adirondacks. This famous locality has been discussed, with analyses, by Buddington, 1939, Analysis 64L Table 15, and also in deWaard's 1965 type…

OCR PDF of supplemental information for the Plutonic Magma Series- Southwestern New Hampshire collection.

OCR PDF Supplementary information for the Flysh Molasse suite.

OCR PDF of supplemental information for the St. Francois Mountains collection.

OCR RPD of supplemental information for the Volcanic Phenomena Suite - The Hawaiian Islands of Hawaii and Oahu

OCR PDF of supplemental information for the Meta-Pelite Suite, Shelburne, Nova Scotia collection. This file outlines the descriptions of every sample in suite as well as providing geologic context to the area and the suite itself.

Image is of the North Side of the Tanzawa Mountains (Wikipedia)

OCR PDF of supplemental information of the "Sedimentary and Igneous Franciscan Assemblage - California" collection.

Macroscopic: Low-grade metamorphic (zeolite facies) black siltstone with idiomorphic pyrite porphyroblasts. Microscopic: Very fine grained quartz and muscovite with large pyrite phenocrysts. Thin section picture in XPL unless noted in the picture…

Macroscopic: Slate (low grade shale metamorphism) samples with visible thin black beds. Samples were found interbedded with siltstones represented by sample NS-1. High angle between bedding and cleavage. Microscopic: Very fine grained quartz,…

Macroscopic: Argillite bearing spessartine garnet formed through reaction with the surrounding rock during metamorphism. Microscopic: Abundant medium-sized garnet phenocrysts within a very fine grained matrix. Thin section pictures in XPL unless…