scholarly journals Isotope-geochemical (Sm–Nd, Rb–Sr, REE, HFSE) composition of the University foidolite-gabbro pluton, Kuznetsk Alatau ridge, Siberia

2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Agababa A. Mustafaev ◽  
◽  
Igor F. Gertner ◽  
Keyword(s):  
Subduction Zones ◽  
Titanium Content ◽  
Oceanic Islands ◽  
High Alumina ◽  
Geodynamic Setting ◽  
Alkaline Magmatism ◽  
Island Arcs ◽  
Alkaline Rocks ◽  
Wide Range ◽  
The University

The University foidolite-gabbro pluton is located among the Cambrian carbonate-volcanogenic deposits. Its composition is dominated by moderately-alkaline and alkaline mafic rocks, broken by dikes of ijolite-urtites, nepheline and alkaline syenites. The chemical composition of igneous rocks is characterized by low silica contents (SiO2 = 41–49 wt. %), wide variations of alkalinity (Na2O + K2O = 3–19 wt. %; Na2O / K2O = 1.2–7.2 wt. %), low titanium content (TiO2 = 0.07 1.59 wt. %) and high alumina content (Al2O3 = 15–28 wt. %), which corresponds to the K-Na derivatives of the basic alkaline formation. By the content of rare earth elements, alkaline rocks (104–246 ppm; La/Yb(n) = 5.79–12.73) are more differentiated derivatives than gabbro (94–111 ppm; La/Yb(n) = 6.87‑6.95). All varieties are characterized by low concentrations of most highly charged elements (Nb, Ta, Zr, Hf + Y), which in terms of accumulation are located between the basalts of oceanic islands and basalts of island arcs. The presence of negative Nb–Ta anomaly and the relative enrichment of Rb, Ba, Sr, and U indicate the probable interaction of plume material with previously formed accretionary complexes of subduction zones. The primary isotope 87Sr/86Sr ratio (~ 0.705 – 0.706) and a wide range of εNd (T) from +3.2 to +8.7 in the rocks also indicate a mantle-crustal nature and a complex geodynamic setting of the Paleozoic alkaline magmatism of the Kuznetsk Alatau. The obtained results of Sm‑Nd dating suggest the formation of moderately-alkaline gabbroids in the Early Paleozoic (494–491 ± 36 Ma), with the intrusion of dikes of alkaline rocks of the Middle Paleozoic age (394 ± 16 and 389 ± 37 Ma).

scholarly journals The Paleozoic-Aged University Foidolite-Gabbro Pluton of the Northeastern Part of the Kuznetsk Alatau Ridge, Siberia: Geochemical Characterization, Geochronology, Petrography and Geophysical Indication of Potential High-Grade Nepheline Ore

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1128
Author(s):  
Agababa A. Mustafaev ◽  
Igor F. Gertner ◽  
Richard E. Ernst ◽  
Pavel A. Serov ◽  
Yurii V. Kolmakov
Keyword(s):  
Trace Element ◽  
Subduction Zones ◽  
Isotope Analysis ◽  
Crustal Contamination ◽  
Titanium Content ◽  
High Alumina ◽  
Isotopic Signatures ◽  
Ground Magnetic ◽  
Two Stages ◽  
The University

Geological, geochemical and ground magnetic techniques are used to characterize the University alkaline-gabbroid pluton and crosscutting N-S trending alkaline dikes, located northeast of the Kuznetsk Alatau ridge, Siberia. Trace element concentrations and isotopic compositions of the igneous units were determined by XRF, ICP-MS and isotope analysis. The Sm-Nd age of subalkaline (melanogabbro, leucogabbro 494–491 Ma) intrusive phases and crosscutting alkaline dikes (plagioclase ijolite, analcime syenite 392–389 Ma) suggests two stages of activity, likely representing separate events. The subalkaline and alkaline rocks are characterized by low silicic acidity (SiO2 = 41–49 wt %), wide variations in alkalinity (Na2O + K2O = 3–19 wt %; Na2O/K2O = 1.2–7.2 wt %), high alumina content (Al2O3 = 15–28 wt %) and low titanium content (TiO2 = 0.07–1.59 wt %). The new trace element data for subalkaline rocks (∑REE 69–280 ppm; La/Yb 3.7–10.2) of the University pluton and also the crosscutting younger (390 Ma) alkaline dikes (∑REE 10–1567 ppm; La/Yb 0.7–17.8 ppm) both reflect an intermediate position between oceanic island basalts (OIBs) and island arc basalts (IABs). The presence of a negative Nb–Ta anomaly and the relative enrichment in Rb, Ba, Sr, and U indicate a probable interaction of mantle plume material with the lithospheric mantle beneath previously formed accretion complexes of subduction zones. The isotopic signatures of strontium (εSr(T) +3.13–+28.31) and neodymium (εNd(T) +3.2–+8.7) demonstrate the evolution of parental magmas from a plume source from moderately depleted PREMA mantle, whose derivatives underwent selective crustal contamination.

Mineralogical–geochemical constraints on intrusives in central Anatolia, Turkey: tectono-magmatic evolution and characteristics of mantle source

2005 ◽  
Vol 142 (2) ◽  
pp. 187-207 ◽  
Author(s):  
N. İLBEYLİ
Keyword(s):  
Mantle Source ◽  
Central Anatolia ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Alkaline Rocks ◽  
Rock Types ◽  
Slab Breakoff ◽  
Wide Range ◽  
Cretaceous Magmatism ◽  
Geochemical Constraints

Collision-related rocks intrude metamorphic rocks overthrust by ophiolitic units to make up the Central Anatolian Crystalline Complex. A wide variety of rock types were produced by the latest Cretaceous magmatism in the complex. These rocks can be divided into three distinct units: (1) calc-alkaline (Ağaçören, Behrekdağ, Cefalıkdağ, Çelebi, Ekecikdağ, Halaçlı, Karamadazı, Kösefakılı, Terlemez, Üçkapılı, Yozgat); (2) sub-alkaline (Baranadağ); and (3) alkaline (Atdere, Davulalan, Eğrialan, Hamit, İdişdağı, Karaçayır). The calc-alkaline rocks are metaluminous/peraluminous I- to S-type plutons ranging from monzodiorite to granite. The sub-alkaline rocks are metaluminous I-type plutons ranging from monzonite to granite. The alkaline rocks are metaluminous to peralkaline plutons, predominantly A-type, ranging from foid-bearing monzosyenite to granite. These plutons crystallized under varying pressures (5.3–2.6 kbar) and a wide range of temperatures (858–698 °C) from highly oxidized magmas (log fO2 −17 to −12). All intrusive rocks display enrichment in LILE and LREE compare to HFSE and have high 87Sr/86Sr and low 143Nd/144Nd ratios. These characteristics indicate that these rocks are derived from a mantle source containing large subduction components, and have experienced assimilation coupled with fractional crystallization (AFC) during uprise through crust. The coexistence of calc-alkaline and alkaline magmatism in the complex may be ascribed to mantle source heterogeneity before collision. Either thermal perturbation of the metasomatized lithosphere by delamination of the thermal boundary layer or removal of a subducted plate (slab breakoff) are the likely mechanisms for the initiation of the collision-related magmatism in the complex.

scholarly journals Estimation of Secular Change in the Size of Continents for Understanding Early Crustal Development

2020 ◽  
Vol 8 ◽  
Author(s):  
Hikaru Sawada
Keyword(s):  
Continental Crust ◽  
Mantle Convection ◽  
Subduction Zones ◽  
Hot Spot ◽  
Oceanic Islands ◽  
Secular Change ◽  
Island Arcs ◽  
Secular Changes ◽  
Clastic Rocks ◽  
Essential Parameter

The size of continents is an essential parameter to understand the growth of the continental crust and the evolution of the solid Earth because it is subject to tectonism and mantle convection and affects the preservation of the crust. This article reviews the secular change in the size of continents on the early Earth, focusing on terrigenous clastic rocks, especially quartzose sandstones occurring on relatively large continents. The earliest continental crust in the Hadean or early Archean was produced with a width of ∼200–500 km, similar to modern oceanic island arcs along subduction zones or oceanic islands in hot spot regions by mantle plume heating. Through the collision and amalgamation of such primitive continental crusts, continental blocks over 500 km in width and length evolved and appeared by ca. 3.5 Ga. Through further amalgamation, during ca. 3.3–2.5 Ga, the Archean continents emerged with widths and lengths greater than 1,000 km, which were still smaller than those of modern continents. Continents with widths and lengths of nearly 10,000 km have existed since ca. 2.4 Ga (early Proterozoic). Further analyses of the composition and formation mechanism of clastic rocks will help reveal more quantitative secular changes in the sizes of continents.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

Biodiversity in Vegetation and Ecosystems»: symposium on the occasion of the retirement of Prof. Dr. Fred J.A. Daniels (Munster, Germany, July 11, 2008)

2008 ◽  
pp. 123-124
Author(s):  
N. V. Matveyeva
Keyword(s):  
Wide Range ◽  
65Th Anniversary ◽  
The University

July 2008 in Münster (Germany) hosted a Symposium on the occasion of the 65th anniversary of Professor of the University of this city, Fred Daniels (Frederikus Josephus Alphonsus Daniëls). The title of this Symposium «Biodiversity in Vegetation and Ecosystems» reflected the wide range of interests of the celebrant.

Evolution of Orogenic Plateaus at Subduction Zones - Sinking and raising the southern margin of the Central Anatolian Plateau

2018 ◽  
Author(s):  
David Fernández-Blanco
Keyword(s):  
Tectonic Evolution ◽  
Subduction Zones ◽  
Inversion Tectonics ◽  
High Discharge ◽  
Anatolian Plateau ◽  
Surface Uplift ◽  
Southern Margin ◽  
Wide Range ◽  
Forearc Basins ◽  
Orogenic Plateaus

Orogenic plateaus have raised abundant attention amongst geoscientists during the last decades, offering unique opportunities to better understand the relationships between tectonics and climate, and their expression on the Earth’s surface.Orogenic plateau margins are key areas for understanding the mechanisms behind plateau (de)formation. Plateau margins are transitional areas between domains with contrasting relief and characteristics; the roughly flat elevated plateau interior, often with internally drained endorheic basins, and the external steep areas, deeply incised by high-discharge rivers. This thesis uses a wide range of structural and tectonic approaches to investigate the evolution of the southern margin of the Central Anatolian Plateau (CAP), studying an area between the plateau interior and the Cyprus arc. Several findings are presented here that constrain the evolution, timing and possible causes behind the development of this area, and thus that of the CAP. After peneplanation of the regional orogeny, abroad regional subsidence took place in Miocene times in the absence of major extensional faults, which led to the formation of a large basin in the northeast Mediterranean. Late Tortonian and younger contractional structures developed in the interior of the plateau, in its margin and offshore, and forced the inversion tectonics that fragmented the early Miocene basin into the different present-day domains. The tectonic evolution of the southern margin of the CAP can be explained based on the initiation of subduction in south Cyprus and subsequent thermo-mechanical behavior of this subduction zone and the evolving rheology of the Anatolian plate. The Cyprus slab retreat and posterior pull drove subsidence first by relatively minor stretching of the crust and then by its flexure. The growth by accretion and thickening of the upper plate, and that of the associated forearc basins system, caused by accreting sediments, led to rheological changes at the base of the crust that allowed thermal weakening, viscous deformation, driving subsequent surface uplift and raising the modern Taurus Mountains. This mechanism could be responsible for the uplifted plateau-like areas seen in other accretionary margins. ISBN: 978-90-9028673-0

Tassos Papacostas and Maria Parani (eds.), Discipuli dona ferentes. Glimpses of Byzantium in Honour of Marlia Mundell Mango. Β υζ ά ν τ ι ο ς. Studies in Byzantine History and Civilization 11. Turnhout: Brepols Publishers, 2017. XXX, 486, 111 b/w figures.

Mediaevistik ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 333-337
Author(s):  
Natalia Teteriatnikov
Keyword(s):  
Late Antiquity ◽  
Oxford University ◽  
Present Volume ◽  
Wide Range ◽  
Byzantine Period ◽  
The University ◽  
Vast Territory ◽  
Byzantine History

The present volume is a tribute to Marlia Mango on the occasion of her retirement from the University service of Kings College, Oxford University. All essays, written by her students, offer the result of their research and express a profound gratitude to their teacher. The essays tackle a wide range of subjects covering a vast territory from Constantinople to its periphery as well as Italy. Chronologically diverse, research materials span from late antiquity to the late Byzantine period.

scholarly journals Beyond cultural and geographical proximity: delving into the factors that influence the dynamics of academic relationships between students in higher education

2021 ◽  
Author(s):  
José-Vicente Tomás-Miquel ◽  
Jordi Capó-Vicedo
Keyword(s):  
University Students ◽  
Academic Research ◽  
Past Research ◽  
Academic Networks ◽  
Level Data ◽  
Wide Range ◽  
Specific Stage ◽  
The University ◽  
Proximity Dimensions ◽  
Shed Light

AbstractScholars have widely recognised the importance of academic relationships between students at the university. While much of the past research has focused on studying their influence on different aspects such as the students’ academic performance or their emotional stability, less is known about their dynamics and the factors that influence the formation and dissolution of linkages between university students in academic networks. In this paper, we try to shed light on this issue by exploring through stochastic actor-oriented models and student-level data the influence that a set of proximity factors may have on formation of these relationships over the entire period in which students are enrolled at the university. Our findings confirm that the establishment of academic relationships is derived, in part, from a wide range of proximity dimensions of a social, personal, geographical, cultural and academic nature. Furthermore, and unlike previous studies, this research also empirically confirms that the specific stage in which the student is at the university determines the influence of these proximity factors on the dynamics of academic relationships. In this regard, beyond cultural and geographic proximities that only influence the first years at the university, students shape their relationships as they progress in their studies from similarities in more strategic aspects such as academic and personal closeness. These results may have significant implications for both academic research and university policies.

scholarly journals Institutional Restructuring in Response to the Changing Mission of Land Grant Colleges Cook College, Rutgers University – The State University of New Jersey

1973 ◽  
Vol 2 (2) ◽  
pp. 297-304
Author(s):  
Daymon W. Thatch ◽  
William L. Park
Keyword(s):  
Higher Education ◽  
New Brunswick ◽  
Colonial America ◽  
Revolutionary War ◽  
The State ◽  
State University ◽  
Arts And Sciences ◽  
Rutgers University ◽  
Wide Range ◽  
The University

Rutgers University was chartered as Queen's College on November 10, 1766. It was the eighth institution of higher education founded in Colonial America prior to the Revolutionary War. From its modest beginning in the New Brunswick area the University has grown to eight separately organized undergraduate colleges in three areas of the State, with a wide range of offerings in liberal and applied arts and sciences.

Children and Youth With Fetal Alcohol Spectrum Disorders: Summary of Intervention Recommendations After Clinical Diagnosis

2010 ◽  
Vol 48 (5) ◽  
pp. 330-344 ◽  
Author(s):  
Tracy Jirikowic ◽  
Julie Gelo ◽  
Susan Astley
Keyword(s):  
Fetal Alcohol Spectrum Disorders ◽  
Clinical Sample ◽  
Demographic Variables ◽  
Children And Youth ◽  
Standards Of Care ◽  
Fetal Alcohol ◽  
Wide Range ◽  
Spectrum Disorders ◽  
The University ◽  
Fetal Alcohol Spectrum

Abstract Children with fetal alcohol spectrum disorders (FASDs) present with a wide range of developmental disabilities; however, clinical standards of care after a diagnosis are not well established. This retrospective review summarizes the types of intervention recommendations generated by an interdisciplinary FASD diagnostic team for 120 children ages 0.2 to 16.5 years receiving an FASD diagnosis at the University of Washington FAS Diagnostic & Prevention Network Clinic. Intervention recommendations documented in a FASD diagnostic summary report and submitted to each patient's medical record were subject to masked review and content analysis. Intervention recommendations were compared across 3 FASD diagnostic groups and selected demographic variables. The results show the type and frequency of services, supports, and resources recommended to a clinical sample of children with FASD.

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