MAGMATIC DIFFERENTIATION AT SILVERBELL, ARIZ

Magmatic filtering of mantle compositions at mid-ocean-ridge volcanoes

Earth’s dominant form of magmatism occurs at mid-ocean ridges (MORs), producing the igneous crust for two-thirds of the planet’s surface and conveying significant heat and material fluxes from the mantle to the world’s oceans. Mid-ocean-ridge basalt (MORB) magmas form from upwelling compositionally heterogeneous mantle1 by aggregation of near-fractional melts beneath spreading centres2. Multipl...

Using Magma Mixing/Mingling Evidence for Understanding Magmatic Evolution at Mount Bidkhan Stratovolcano (South-East Iran)

Mount Bidkhan stratovolcano is located in the central Iranian volcanic belt. It is composed of several types of pyroclastic deposits, lava flows and intrusive bodies. Textural and chemical characteristics of plagioclase phenocrysts from the eruptive products volcanic edifice, record complex magma mixing events over the lifetime of the volcano. Evidences such as xenocrystic high Al+Ti clinopyrox...

The Couonino Forest Experiment Station near Flagstbff, Ariz

The largest pine forest on the North American Continent estends from north-central Arizona in a southeasterly direction into southwestern New Mexico, a distance of approsiinately 250 miles The forest occupies an extensive plateau, known as the Colorado Plateau, which has a general elevation of from 6,000 to 8,000 feet above sea level, with numerous peaks the highest of which reaches an altitude...

Studies of Magmatic Systems

Magmatic Processes : Physicochemical Principles

The viscosities of eight melt compositions in the System albite-H20-F20_1 have been determined at high pressure and temperature. Measurements were performed using the falling sphere method at 1000-1600°C and 2.5 to 22.5 kbar. Fluorine and water strongly decrease the viscosity of albite melt at all pressures and temperatures investigated. The viscosity of a fluorine-bearing albitic melt decrease...