The Mineralogical and Geochemical Properties of Near-Crater Tephra from Erebus Volcano, Antarctica Based on the Ejecta of the 2000 Eruption

摘要

Multidisciplinary petrologic, mineralogical, and geochemical studies have been carried out for the first time concerning near-crater tephra from the world-largest intraplate stratovolcano (Erebus). The volcano is characterized by a unique basanite-phonolite effusive lineage. We studied the grain-size and chemical compositions of the tephra and the concentration of trace elements in it, the mineral phase composition, lithogenic gases encapsulated in the tephra, an atomically dispersed carbonaceous substance, and the isotope composition of carbon in it. We came to the conclusion that the tephra studied here can be treated as an explosive analogue of anorthoclase lava phonolites that terminate the continuous series of magmatic differentiates known as the Erebus lineage.