Magma flow regimes in sills deduced from Ar isotope systematics of host rocks

Magma Composition and Igneous Rocks

Introduction In the following chapters we will find that nearly all of the varied aspects of volcanism are either directly or indirectly controlled by the chemical composition of magma and the rate at which it cools and solidifies. If you are to understand and appreciate subsequent discussions of volcanoes and related volcanic phenomena, it is essential that you have a good grasp of the basic c...

Heat-Transfer-Model Analysis of the Thermal Effect of Intrusive Sills on Organic-Rich Host Rocks in Sedimentary Basins

Flow banding in volcanic rocks: a record of multiplicative magma deformation

Banding in obsidian from Big Glass Mountain (BGM), Medicine Lake volcano, California, and Mayor Island (MI), New Zealand, provides a record with a 1/wavenumber power-spectral density and multifractal characteristics. The samples are compositionally homogeneous, with banding defined by variable microlite content (BGM) or vesicularity (MI). In both samples, banding formation is well explained by ...

Osmium isotope systematics of ureilites

The Os/Os for 22 ureilite whole rock samples, including monomict, augite-bearing, and polymict lithologies, were examined in order to constrain the provenance and subsequent magmatic processing of the ureilite parent body (or bodies). The Re/Os ratios of most ureilites show evidence for a recent disturbance, probably related to Re mobility during weathering, and no meaningful chronological info...

Triple oxygen isotope variations in sedimentary rocks

Relatively large (P0.2&) O anomalies in the geologic record have been used to recognize atmospheric processes such as photochemical reactions and to trace changes in the partial pressures of O2 and CO2 in Earth’s atmosphere through time. However, recent oxygen isotope measurements of terrestrial rocks, minerals and waters also reveal common, smaller (but statistically significant) deviations fr...