scholarly journals Constraints on the behaviour and content of volatiles in Galápagos magmas from melt inclusions and nominally anhydrous minerals

2021 ◽  
Author(s):  
Matthew Gleeson ◽  
Sally Gibson ◽  
Michael Stock
Keyword(s):  
Melt Inclusions ◽  
Melt Inclusion ◽  
Careful Consideration ◽  
Volatile Content ◽  
The South ◽  
Nominally Anhydrous Minerals ◽  
South Eastern ◽  
Galapagos Archipelago ◽  
Wide Range ◽  
Basaltic Magmas

Despite their relatively low concentration in most oceanic basalts, volatile species (e.g. H2O, CO2 and S) have a disproportionately large influence on a wide range of mantle and magmatic processes. However, constraining the concentration of H2O (and other volatiles) in basaltic magmas is not straightforward as submarine glass analyses are influenced by assimilation of hydrothermal brines, and the melt inclusion record is often reset by post-entrapment processes. Nevertheless, in this study we show that it is possible to reconstruct a detailed history of the volatile content of basaltic magmas through integration of multiple discreet volatile records and careful consideration of secondary processes. We present new analyses of volatiles in olivine-hosted melt inclusions, melt embayments and nominally anhydrous minerals (NAMS, clinopyroxene and orthopyroxene) found in basalts erupted on Floreana Island in the south-eastern Galápagos Archipelago. Our results indicate that the Floreana magmas, which are characterised by the most radiogenic Pb and Sr isotope signatures in the Galápagos Archipelago, contain H2O concentrations between 0.4 and 0.8 wt% (at a melt Mg# of 0.65, where Mg# = Mg/(Mg + Fe) molar). These are marginally greater than the H2O contents of magmas beneath Fernandina in the western Galápagos Archipelago (cf. 0.2–0.7 wt% H2O at Mg# = 0.65). While the volatile content of magmas from the western archipelago follow trends defined by concurrent mixing and crystallisation, NAMs from Floreana reveal the presence of rare, volatile-rich magmas (~2 wt% H2O) that form as a consequence of reactive porous flow in mush-dominated magmatic systems beneath the south-eastern Galápagos. Furthermore, the Floreana magmas have similar H2O/light Rare Earth Element ratios to basalts from the western Galápagos but contain F/Nd and Cl/K ratios that are ~2 – 3 times greater, indicating that the mantle source of the Floreana lavas might represent an important halogen reservoir in the Galápagos mantle plume.

scholarly journals What lies beneath? Reconstructing the primitive magmas fueling voluminous silicic volcanism using olivine-hosted melt inclusions

Geology ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 504-508 ◽  
Author(s):  
Simon J. Barker ◽  
Michael C. Rowe ◽  
Colin J.N. Wilson ◽  
John A. Gamble ◽  
Shane M. Rooyakkers ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Melt Inclusion ◽  
Taupo Volcanic Zone ◽  
Mantle Dynamics ◽  
Silicic Volcanism ◽  
Depleted Mantle ◽  
Basaltic Magmas ◽  
Show Evidence ◽  
Basaltic Melts ◽  
Eruptive Centers

Abstract Understanding the origins of the mantle melts that drive voluminous silicic volcanism is challenging because primitive magmas are generally trapped at depth. The central Taupō Volcanic Zone (TVZ; New Zealand) hosts an extraordinarily productive region of rhyolitic caldera volcanism. Accompanying and interspersed with the rhyolitic products, there are traces of basalt to andesite preserved as enclaves or pyroclasts in caldera eruption products and occurring as small monogenetic eruptive centers between calderas. These mafic materials contain MgO-rich olivines (Fo79–86) that host melt inclusions capturing the most primitive basaltic melts fueling the central TVZ. Olivine-hosted melt inclusion compositions associated with the caldera volcanoes (intracaldera samples) contrast with those from the nearby, mafic intercaldera monogenetic centers. Intracaldera melt inclusions from the modern caldera volcanoes of Taupō and Okataina have lower abundances of incompatible elements, reflecting distinct mantle melts. There is a direct link showing that caldera-related silicic volcanism is fueled by basaltic magmas that have resulted from higher degrees of partial melting of a more depleted mantle source, along with distinct subduction signatures. The locations and vigor of Taupō and Okataina are fundamentally related to the degree of melting and flux of basalt from the mantle, and intercaldera mafic eruptive products are thus not representative of the feeder magmas for the caldera volcanoes. Inherited olivines and their melt inclusions provide a unique “window” into the mantle dynamics that drive the active TVZ silicic magmatic systems and may present a useful approach at other volcanoes that show evidence for mafic recharge.

scholarly journals AN ONLINE 3D DATABASE SYSTEM FOR ENDANGERED ARCHITECTURAL AND ARCHAEOLOGICAL HERITAGE IN THE SOUTH-EASTERN MEDITERRANEAN

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 1-8 ◽  
Author(s):  
D. Abate ◽  
A. Avgousti ◽  
M. Faka ◽  
S. Hermon ◽  
N. Bakirtzis ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
The South ◽  
Archaeological Heritage ◽  
Heritage Sites ◽  
South Eastern ◽  
Digital Heritage ◽  
Wide Range ◽  
Outstanding Universal Value ◽  
Computer Scientists ◽  
3D Database

The World Heritage Convention, drawn by various international bodies in 1972, was designed to protect cultural or natural places of outstanding universal value so that future generations may be able to enjoy them. Responding to these principles as well as to the Charter on the Preservation of Digital heritage (Vancouver, 2003), this multidisciplinary project, which involves archaeologists, art historians, conservators and computer scientists, aims to create an open access, 3D interactive online geo-database of endangered architectural and archaeological heritage in the South Eastern Mediterranean basin; a region of tremendous cultural importance whose rech heritage is unfortunately threatened by both natural and human factors. A wide range of 3D modelling and topographic techniques have been applied to create accurate reconstructions of heritage sites, enriched by a extensive array of metadata.

Reconstructing LGM paleoglaciers and their ELAs along the southern fringe of the Eastern European Alps

2021 ◽  
Author(s):  
Lukas Rettig ◽  
Francesco Ferrarese ◽  
Giovanni Monegato ◽  
Paolo Mozzi ◽  
Matteo Spagnolo
Keyword(s):  
Large Scale ◽  
Equilibrium Line ◽  
European Alps ◽  
The South ◽  
Equilibrium Line Altitude ◽  
Radiocarbon Dates ◽  
Mountainous Regions ◽  
South Eastern ◽  
Wide Range ◽  
Southern Fringe

<p>The reconstruction of paleoglaciers and specifically the calculation of their equilibrium line altitude (ELA) is an important source of quantitative paleoclimatic information in mountainous regions. During the Last Glacial Maximum (LGM), the prealpine massifs in the south-eastern part of the Alpine chain (Venetian Prealps, Carnic Prealps and Julian Prealps) hosted several small valley glaciers and local ice caps that were isolated from the larger ice-streams occupying the major valleys. Because of their small size and independent dynamics these glaciers can be considered as excellent indicators of local climatic conditions. Although this potential has long been recognised and the sediments and landforms related to these glaciations have been mapped in a few areas, a regional perspective on this type of glaciation is still lacking. This is primarily due to the wide range of methods of ELA reconstructions that has been applied historically, which makes a solid comparison between different localities difficult.</p><p>Here, we present a detailed re-evaluation of local LGM glaciation in the south-eastern Alps based on a large-scale survey of remote sensing data and targeted field work at selected localities. Recently developed GIS tools were applied for the reconstruction of paleoglacier geometries and ELAs (Pellitero et al. 2015, 2016). The obtained values are used both to discuss regional climatic patterns during the LGM and site-specific topographic factors. A specific focus is set on the Monte Cavallo group, where glacial sediments from the LGM are covering a thick sequence of interstadial lacustrine deposits. A set of new radiocarbon dates from this succession provides a first chronological control on the onset of glacier expansion in this part of the Alpine chain.</p><p> </p><p>References:</p><p>Pellitero, R. et al. 2015. A GIS tool for automatic calculation of glacier equilibrium-line altitudes. Computers & Geosciences 82: 55-62.</p><p>Pellitero, R. et al. 2016. GlaRe, a GIS tool to reconstruct the 3D surface of palaeoglaciers. Computers & Geosciences 94: 77-85.</p>

scholarly journals The first find of LBK graphite-coated pottery in Lesser Poland: Więckowice, site 4, Kraków district

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Agnieszka Brzeska-Zastawna ◽  
Michał P. Borowski ◽  
Albert Zastawny
Keyword(s):  
Outer Surface ◽  
Vessel Wall ◽  
Cultural Significance ◽  
The South ◽  
South Eastern ◽  
Wide Range

In the years 2006-2011, at the site Więckowice 4, rescue excavations were carried out in the eastern part of anextensive (over 15 ha) multicultural zone. The most numerous are the remains of the LBK settlement from the “music note” phase. The south-eastern part of the settlement was explored, discovering lines of building pits and post holes belonging to 3-4 longhouses. A particularly unique discovery was a fragment of a LBK vessel with powdered graphite preserved on the outer surface. In addition to the LBK ornament of engraved lines, it is decorated in a manner referring to the ornamentation of the Eastern Linear circle (Tiszadob-Kapušany group). The presence of graphite on the vessel wall has been confirmed by the results of SEM-EDS analyses. This is the first such find in Lesser Poland. To comprehensively address the cultural significance of this find we provide an upto-date overview of graphite usage in a wide range of LBK contexts.

scholarly journals FEATURES OF ECOLOGY AND BIOTOPIC DISTRIBUTION OF RODENTS ON THE SOUTH-EASTERN SLOPE OF THE BOGOS RIDG

2020 ◽  
pp. 18-22
Author(s):  
Kamil Zubairovich OMAROV
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Eastern Slope ◽  
The South ◽  
Biotopic Distribution ◽  
South Eastern ◽  
Wide Range

As part of the inventory work in the Kosobsko-Keleb Reserve in 2017–2019, the species composition was identified and the relative abundance of rodents on the south-eastern slope of the Bogos ridge was estimated. It is shown that rodents inhabit a fairly wide range of biotopes on the south-eastern slope of the Bogos ridge, which is largely predetermined by the peculiarities of their ecology and the nature of their specialization.

Inter- and intra-regional patterns of stable isotopes in Dosidicus gigas beak: biological, geographical and environmental effects

2018 ◽  
Vol 69 (3) ◽  
pp. 464 ◽  
Author(s):  
Bi Lin Liu ◽  
Jing Yuan Lin ◽  
Xin Jun Chen ◽  
Yue Jin ◽  
Jin Tao Wang
Keyword(s):  
Pacific Ocean ◽  
Additive Models ◽  
Trophic Levels ◽  
Eastern Pacific ◽  
Eastern Pacific Ocean ◽  
Dosidicus Gigas ◽  
The South ◽  
Generalised Additive Model ◽  
South Eastern ◽  
Wide Range

We analysed stable carbon (δ13C) and nitrogen (δ15N) isotopes of 478 Dosidicus gigas specimens collected outside the Ecuadorian, Peruvian and Chilean exclusive economic zones in the south-eastern Pacific Ocean during 2009 to 2013. There were significant spatial differences both in δ13C and δ15N values across regions, with the lowest values off Ecuador and the highest values off Chile. A small intra-regional range of isotope values indicates that squid off Ecuador feed at the same trophic level with similar primary production. In contrast, a large intra-regional range of isotope values suggests that squid off Chile, especially Peru, migrate over a large geographic range and occupy a wide range of trophic levels. A generalised additive model was used to estimate the biological (mantle length and age), geographical (latitude, and distance to the shelf break) and environmental (sea-surface temperature and chlorophyll-a) effects on isotope values. Best fitted generalised additive models explained 54.0% of the variability in δ13C and 93.1% of the variability in δ15N. The yield relationships between isotopes and explanatory variables increase our understanding of D. gigas habitats, movement and feeding ecology in the south-eastern Pacific Ocean.

scholarly journals APLICATION OF LOCAL CEMENT FOR CEMENTING OIL WELLS IN THE SOUTH EASTERN REGION OF THE PANNONNIAN BASIN

2012 ◽  
Vol 1 (8) ◽  
Author(s):  
Zvonimir Bošković ◽  
Vladimir Čebašek ◽  
Nebojša Gojković
Keyword(s):  
Pannonian Basin ◽  
Oil Wells ◽  
Cement Stone ◽  
Eastern Region ◽  
The South ◽  
South Eastern ◽  
Wide Range ◽  
Temperature And Pressure ◽  
Oil Company ◽  
Cement Mixtures

Wells conditions are different in wide range of temperature and depth. Cement slurries in such conditions have to remain pumpable and after setting to stay homogenous in production well life. For cementing operations in  wide range of temperature and pressure and to accommodate cement slurries for individual well requirements more than 50 additives are now used for various API classes of cement. Laboratory in NIS – National oil company of Serbia, provides cement analysis of dry cement, tests on cement slurries and cement stone in compliance with methods prescribed by API standard, whereby quality and type of equipment fully meet the requirements. Adaptation of the local cement to the well conditions had already been done by these additives and by numerous tests of pure cement and cement mixtures we developed a palette of typical cement mixtures for cementing oil wells in the south eastern region of the Pannonian basin.

scholarly journals Fortification in the South-Eastern part of European Russia at the end of the XVI - beginning of the XVII centuries

2019 ◽  
Vol 8 (4) ◽  
pp. 171-177
Author(s):  
Eduard Leibovich Dubman
Keyword(s):  
Urban Planning ◽  
European Russia ◽  
The South ◽  
South Eastern ◽  
Initial Stage ◽  
Wide Range ◽  
Time Of Troubles ◽  
New System ◽  
Deep Crisis

The paper discusses the features of the Volga city fortresses (Samara, Saratov and Tsaritsyn) development at its initial stage in the second half of the 1580s by knyaz G.O. Zasekin. The task is to consider the process of their urban planning appearance and defensive structures development as well as the composition of the inhabitants at the end of the XVI - beginning of the XVII centuries. The source base of the study is archival and published narrative, acts and other sources. A wide range of studies have been used, mainly in recent decades. It is concluded that until the end of the Time of Troubles, the population of the Volga fortress cities consisted of service people and members of their families. The settlements performed both military and commercial functions on the Volga route, but in fact, all of them were fortresses. Their garrisons were mainly supplied by the sovereign bread and money salary and were not able to provide themselves through fishing and other activities. The events of the Time of Troubles contributed to a deep crisis in the life of the Volga cities, the death of Saratov and Tsaritsyn. It was only after the end of the Time of Troubles when their restoration took place and a new system of fortifications was created.

scholarly journals The Ins and Outs of Water in Olivine-Hosted Melt Inclusions: Hygrometer vs. Speedometer

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna Barth ◽  
Terry Plank
Keyword(s):  
Water Content ◽  
Water Loss ◽  
Melt Inclusions ◽  
Melt Inclusion ◽  
Water Concentration ◽  
Inclusion Size ◽  
Diagnostic Tools ◽  
Initial Water Content ◽  
Initial Water ◽  
Wide Range

The amount of water dissolved in magmas at depth beneath volcanoes is fundamental to a wide range of magmatic and eruptive processes due to water’s dominant control on magma generation, viscosity, and buoyancy. Since magmas degas most of their initial water content upon ascent and eruption, the primary record of magmatic water evolution exists within melt inclusions trapped inside crystals, especially olivine. However, the discovery of rapid H+ diffusion through olivine has called into question the fidelity of the melt inclusion water record. How compromised is the vast existing and growing dataset of melt inclusion water contents? What are the circumstances favorable for recording primary or pre-eruptive water concentration? Even if inclusions are compromised, diffusive water loss can be exploited to constrain magma decompression rates, a critical parameter that affects conduit processes. Here, we outline the current understanding of factors controlling water loss: the olivine/melt partition coefficient, the diffusive transport of water through olivine, the distance between inclusion and crystal rim, the melt inclusion size, and the exterior magma’s water evolution. We combine these parameters into a regime diagram that can be used to guide when melt inclusions may be used as hygrometers and when they are better suited to act as magma speedometers. We develop diagnostic tools to recognize where and when water loss has occurred in a magma’s ascent history, and we outline quantitative tools that may be used to restore the primary and/or pre-eruptive water content. The intent of this paper is to guide researchers in the interpretation of existing melt inclusion data, and to aid in the design of new studies that maximize the valuable information that melt inclusions may convey on the evolution of water in magmas prior to eruption.

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