AVO Logo
Site Map | FAQ |
Alaska Volcano Observatory
You are here: Home > Samples > 18
Sample info : 18
Sample ID:18
Station ID:18
Latitude:56.58
Longitude:-169.63
Datum:NAD83
Date Sampled:1948-01-01
Sample Type 1:Lava
Text Description:
Ore basalt, forming a sill or dike. To the eye and under a low power lens the rock appears dark and almost dense because of its unusually high percentage of ore. It is very fine grained with some odd, small phenocrysts of plagioclase (optical constants corresponding to An60), and a very few, small phenocrysts of olivine that are almost wholly resorbed and often obscured by tiny grains of ore (hematite?) which have grown along closely spaced cleavage planes. Some olivines have been effectively replaced by ore. The profusion of ore gives the rock its distinctive character.

References:
Geology and petrology of the Pribilof Islands, Alaska


Sample Location

URL: www.avo.alaska.edu/samples/sample_info.php
Page modified: August 7, 2013 07:43
Contact Information: AVO Web Team

@alaska_avo
alaska.avo
Receive volcano updates by email: USGS VNS