Sample: 96-ARh-2
Sample ID: | 96-ARh-2 [1] [2] |
Station ID: | 96-ARh-2 |
AT Num: | |
Volcano: | Akutan |
Possible source: | |
Eruption: | |
Collector: | Richter, D. H. |
Date sampled: | 1996-00-00 |
Sample type 1: | Lava |
Color: | |
Final unit: | aau |
Text Description: | QTd - Extrusive rocks (Pleistocene and Pliocene). Domes or massive flows generally associated with small subaqueous cinder cones (QTc). Rocks exhibit spectacular columnar joints. They are greenish black to medium gray, porphyritic basalts (50.3-51.6% SiO2) containing phenocrysts of plagioclase (5-15%, 3-4 mm), clinopyroxene (1-10% 2-3 mm), and olivine (trace-3%, 1-2 mm) in a pilotaxitic groundmass. Whole rock 40Ar/39Ar mean age of the basalt is 1.55+/-0.04 Ma. |
Sample Location: |