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On the other hand, those in calc-alkalic rocks (0·7033–0·7042) show more complex characteristics, which can be best understood if at least three end-member components, a calc-alkalic basaltic ...
Read "Phase Relationships of Hydrous Alkalic Magmas at High Pressures: Production of Nepheline Hawaiitic to Mugearitic Liquids by Amphibole-Dominated Fractional Crystallization Within the Lithospheric Mantle, Journal of Petrology" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available …
The Guli, Bor-Uryakh and Odikhincha complexes belong to the Maimecha-Kotuy province, which is located in the northeastern part of the Siberian LIP (Russia) (Fig. 1 A).This province contains about 20 alkali-ultramafic plutonic complexes and volcanic suites (alkaline and tholeiitic basalts, tephrites, nephelinites and meimechites) (Egorov, 1970, Egorov, 1991; …
We show that trace elements in zircon and whole-rock samples that are diagnostic of unusually high-pressure magmatic differentiation and high hydration state and oxidation state of their parent silicate melt are effective for discriminating copper sulfide-ore-productive arc magmas from infertile arc magmas.
Calc-alkaline. These are magmas having both high NaþKat high Mg# (Irvine and Baragar, 1971) and high SiO 2 at high Mg# (i.e., high SiO 2 at low Fe/Mg; Miyashiro, 1974); 'tholeiitic …
Alkalic Ultramafic Magmas in North-Central Montana, USA: Genetic Connections of Alnoite, Kimberlite and Carbonatite doi 10.29173/ikc1064. Full Text Open PDF Abstract. Available in full text. Date. Unknown. Authors. Unknown. Publisher. University of Alberta. Amanote Research. Note-taking for researchers.
Magnetite, a common mineral in alkaline magmatic complexes hosting giant epithermal Au deposits, is examined to obtain insights into the magmatic evolution and ore fertility of alkaline systems. Textural and compositional analyses of magmatic magnetite ...
Alkalic magmas at other ocean islands may also be gold rich, and oceanic hot-spot provinces may contain underappreciated gold resources. You do not have access to this content, please speak to your institutional administrator if you feel you should have access. You could not be signed in. ...
Native gold found in fresh basanite glass from the early submarine phase of Kilauea volcano, Hawaii, may be the first documented case of the transport of gold as a distinct precious metal phase in a mantle-derived magma. The gold-bearing glass is a grain in bedded volcanic glass sandstone (Japan Marine Science and Technology Center (JAMSTEC) sample S508-R3) …
Our results highlight that bubble formation in evolved alkaline melts is primarily controlled by the initial volatile (H 2 O and CO 2) content during magma storage.In these melts, bubble nucleation needs low supersaturation pressures (≤ 50–112 MPa for homogeneous nucleation, ≤ 13–25 MPa for heterogeneous nucleation), resulting in high bubble number …
Alkalic magmas provide a critical test for CO 2-fluxing because they typically have high magmatic CO 2 concentrations, inherited from their generation by low degrees of partial …
Despite of the relatively rare occurrence of alkaline igneous rocks on Earth, they are the most diverse group of igneous rocks due to variations in their mineral assemblages and geochemical compositions. Alkaline igneous rocks are generally characterized by Si undersaturation, and K-Na (and in some cases C) enrichment. Although there is no unified alkaline igneous rock …
Here we review the important reactions that control the concentration of carbon dioxide in our atmosphere: outgassing from magmas during volcanic eruptions and during magmatic activity; and uptake ...
Second, alkalic volcanism on Mars was predicted based on the mineralogy of the chassignite dunites [Nekvasil et al., 2007], and k-rich magmas were also predicted based on the mineralogy of the ...
The magmatic evolution of The Pleiades, a Quaternary alkalic volcanic complex in Northern Victoria Land (NVL), Antarctica, is investigated using major and trace element, and Sr, Nd and Pb isotopic data. The volcanic rocks can be subdivided into two distinct magmatic lineages based on petrography and whole-rock compositions: (1) a sodic silica-undersaturated lineage with …
The study area begins ca. 15 km west of Ardestan and stretches ca. 58 km towards the southeast (Fig. 1) where volcano–plutonic complexes are exposed in a NW trending belt over an area of ca. 58 × 17 km 2.Field relationships between the main bodies have been well-defined (e.g., Babazadeh et al., 2017, Babazadeh et al., 2019a, Babazadeh et al., 2019b).
INTRODUCTION. CO 2 and H 2 O play significant roles in various aspects of magma generation, evolution, eruption, and mineralization, impacting both the lithosphere and …
The trivial quantities of CO 2 and H 2 O (or reduced combination of C–H–O–S) in the upper mantle have little effect on the abundant basalts, but H 2 O influences magmas generated in peridotite overlying subducted, hydrated oceanic crust, and CO 2 causes the generation of alkalic subsilicic magmas from peridotite beneath continental shields. PT sections through the (partly …
alkalic carbonated melts in a subsolidus peridotitic mantle is a widely occurring process, causing partial reactive crystallization of the original melts and leading to formation of primary alkalic magmas. The reacted melts have the potential to erupt as alkalic OIBs or to act as metasomatic flux to shallower source regions.
A tenet in developing thermal models for the lower crust based on U-Pb thermochronology is the notion that Pb undergoes thermally mediated volume diffusion at ambient lower-crustal temperatures.
Continental intraplate volcanoes, such as Erebus volcano, Antarctica, are associated with extensional tectonics, mantle upwelling and high heat flow. Typically, erupted magmas are alkaline and rich in volatiles …
Alkalic parental magmas for chassignites? Hanna NEKVASIL, Corresponding Author. Hanna NEKVASIL. Department of Geosciences, Stony Brook University, Stony Brook, New York 11794–2100, USA ... minerals and evolve upon crystallization at pressures above 4.3 kbar and water contents above ˜0.4 wt% to mildly alkalic basalt, silica-saturated hawaiite ...
"Alkalic" magmas are often richer in water and CO2, gases that drive explosive eruptions. Thus the compositional difference probably accounts for the abundance of pyroclastic cones. Trace element abundances in these lavas indicate that Floreana magmas are produced at shallower depth in the mantle and by smaller extents of melting than in the ...
Calc-alkaline arc magmatism at convergent plate margins is volumetrically dominated by metaluminous andesites. Many studies highlighted the importance of …
INTRODUCTION. Studies of magmatic volatiles offer insight into melt generation, magma transport and evolution, and global volatile cycles (e.g. Grove & Baker, 1984; Allard et al., 1991; Gaetani & Grove, 1998; Dixon et al., 2002; Wallace, 2005).Such efforts require knowledge of the behavior of volatiles in the pre-eruptive magmas, which is a challenge because …
The onset of major phase crystallization in calc-alkaline magmas is relatively well-understood through experimental studies, starting with amphibole, biotite, and plagioclase at temperatures …
T1 - Reactive Infiltration of MORB-Eclogite-Derived Carbonated Silicate Melt into Fertile Peridotite at 3GPa and Genesis of Alkalic Magmas. AU - Mallik, Ananya. AU - Dasgupta, Rajdeep. N1 - Funding Information: This work was funded by the US NSF grant EAR-0911442 and EAR-1255391 to R.D. PY - 2013/11. Y1 - 2013/11
DOI: 10.1016/J.EPSL.2010.06.002 Corpus ID: 129442014; Alkali metals control the release of gold from volatile-rich magmas @article{Zajacz2010AlkaliMC, title={Alkali metals control the release of gold from volatile-rich magmas}, author={Zolt{'a}n Zajacz and Jung Hun Seo and Philip A. Candela and Philip M. Piccoli and Christoph A. Heinrich and Marcel …
Low H 2 O ( (cid:3) 0 (cid:2) 1wt %) and CO 2 (0–0 (cid:2) 2wt %) contents and the evolved compositions of these indicate that Erebus magmas undergo shallow ( < 6km) crystallization before eruption, probably in a shallow storage region. Magmas from the surrounding volcanoes show no sign of shallow storage.
In this frame, it is crucial to investigate decompression-induced magma degassing as it controls magma ascent towards the surface and, in case of eruption, the eruptive style …