Results 41 to 50 of about 286 (180)
Abstract The origin of the compositional dichotomy between high‐Ti and low‐Ti basalts in continental flood basalt provinces remains debated. Most existing studies attribute this dichotomy directly to variations in primitive magma composition to circumvent the complexities of significant evolutionary processes, such as multiphase fractional ...
Zongpeng Yang +6 more
wiley +1 more source
We present a petrologic study of the post-collapse rhyolites from Valles Caldera (New Mexico, USA) to evaluate changes in magmatic storage conditions following the eruption of the Upper Bandelier Tuff (UBT). We assess likely phenocrysts through textures,
Magdalen Grismer, Laura Waters
doaj +1 more source
ABSTRACT The processes involved during subduction initiation (SI) remain poorly constrained, in part due to the rarity of geological archives. Ophiolites and their underlying metamorphic soles are thought to form during subduction zone infancy and may thus provide critical constraints. Metamorphic soles are derived from oceanic crust of the lower plate
François Fournier‐Roy +11 more
wiley +1 more source
ABSTRACT Understanding the pressure of emplacement of granitic intrusions is crucial to understanding the exhumation history of plutons and constraining the tectonic setting of magma emplacement. However, P–T and geochronological constraints from exhumed plutons are often characterized by large uncertainties, especially in shallow crustal settings with
Samuele Papeschi +4 more
wiley +1 more source
Magma Plumbing During the 2014–2015 Eruption of Fogo (Cape Verde Islands)
Phenocrysts in volcanic rocks are recorders of magmatic processes that have occurred at depth before and during a volcanic eruption. Our petrological investigations of stratigraphically controlled tephrite and phonotephrite samples from the latest ...
Andreas Klügel +3 more
doaj +1 more source
Arc Heat Flow and Magmatic Heat Budgets
Abstract We evaluate hydrothermal heat loss from 11 volcanic‐arc segments (∼6,000 km of arc length, ∼10% of the global total), motivated by the observation that much magmatic heat ultimately crosses the land surface as heated aqueous fluid. Heat loss takes place by volcanic eruption, geothermal heat conduction to the surface, fumarolic (vapor ...
S. E. Ingebritsen +7 more
wiley +1 more source
ABSTRACT The absence of jadeite in regions where subduction of continental crust has been documented by other high‐pressure (HP) or ultrahigh‐pressure (UHP) minerals is striking. This study presents only the second discovery of jadeite in the crystalline rocks of the Erzgebirge, a region known for its occurrences of microdiamond, coesite and omphacite ...
Ondrej Lexa +3 more
wiley +1 more source
Abstract The southern Appalachian orogen preserves a complex distribution of metamorphism and deformation varying in timing, magnitude, and spatial extent. These complexities give rise to disparate interpretations for southern Appalachian tectonic evolution, which complicates the testing and interpretation of tectonic models in this system.
Nicholas E. Powell +8 more
wiley +1 more source
Magma storage and plumbing of adakite-type post-ophiolite intrusions in the Sabzevar ophiolitic zone, northeast Iran [PDF]
Subduction-related adakite-type intrusive rocks emplaced into the late Cretaceous–Paleocene Sabzevar ophiolite zone, northeast Iran, range from Mg-andesite to rhyodacite in composition.
K. Jamshidi +4 more
doaj +1 more source
Abstract Peridotites record the compositional evolution of the lithospheric and asthenospheric mantle across plume‐related lithospheres, convergent margins, and rift‐related volcanic environments; however, their tectonomagmatic affinities are commonly difficult to resolve using traditional low‐dimensional geochemical discrimination diagrams.
Swarnendu Roy, Koushik Sen
wiley +1 more source

