Anatectic Granitic Pegmatites from the Eastern Alps: A Case of Variable Rare Metal Enrichment During High-Grade Regional Metamorphism. II: Pegmatite Staurolite As an Indicator of Anatectic Pegmatite Parent Melt Formation – A Field and Experimental Study

2018 ◽  
Vol 56 (4) ◽  
pp. 603-624 ◽  
Author(s):  
Jürgen Konzett ◽  
Christoph Hauzenberger ◽  
Thomas Ludwig ◽  
Roland Stalder
Keyword(s):  
Experimental Study ◽  
Regional Metamorphism ◽  
Rare Metal ◽  
Eastern Alps ◽  
High Grade ◽  
Metal Enrichment ◽  
Granitic Pegmatites

Unraveling sedimentary precursors and metal enrichment of high-grade metamorphosed manganese-rich rocks from the Borborema Province, northeastern Brazil

2021 ◽  
pp. 104283
Author(s):  
Felipe Holanda dos Santos ◽  
Wagner da Silva Amaral ◽  
Kurt Konhauser ◽  
Douglas Teixeira Martins ◽  
Marco Paulo de Castro ◽  
...  
Keyword(s):  
Northeastern Brazil ◽  
High Grade ◽  
Metal Enrichment ◽  
Borborema Province

EP-1025 RESCUE TREATMENT FOR HIGH GRADE GLIOMAS THROUGH HYPOFRACTIONATED RT+ BEVACIZUMAB. EXPERIMENTAL STUDY

2012 ◽  
Vol 103 ◽  
pp. S402
Author(s):  
V. González Vidal ◽  
A. Conde Moreno ◽  
P. Almendros ◽  
R. De Las Peñas Bataller ◽  
C. Ferrer Albiach
Keyword(s):  
Experimental Study ◽  
High Grade ◽  
Rescue Treatment ◽  
High Grade Gliomas

XX.—The Metamorphism of the Deeside Limestone, Aberdeenshire

1933 ◽  
Vol 57 (2) ◽  
pp. 557-592 ◽  
Author(s):  
Arthur G. Hutchison
Keyword(s):  
Regional Metamorphism ◽  
High Grade ◽  
Thermal Metamorphism

The limestone to be described occurs in two separate areas (fig. 1)—one in Lower Deeside around Banchory, another in Middle Deeside around Aboyne. The whole of the Banchory and a large part of the Aboyne outcrops provide limestone types in a high grade of regional metamorphism (the associated schists contain sillimanite). In the latter outcrop the limestone has undergone thermal metamorphism at the contacts with Newer Granite intrusions. Many of the resulting hornfelses have suffered hydrothermal alterations with development of prehnite and zeolites. Newer Granite pegmatites, intruded at the time of hornfelsing, share in this hornfelsing and later hydrothermal modifications. In addition, they exercise exopneumatolytic and exohydrothermal metamorphism. Quite local metamorphisms take place at hornblende-schist and Older Granite contacts.

Gneissic Alkalic Rocks and Carbonatites in the Frenchman's Cap Gneiss Dome, Shuswap Complex, British Columbia

1974 ◽  
Vol 11 (2) ◽  
pp. 304-318 ◽  
Author(s):  
W. J. McMillan ◽  
J. M. Moore Jr.
Keyword(s):  
Regional Metamorphism ◽  
Lava Flows ◽  
High Grade ◽  
Metamorphic Complex ◽  
Sedimentary Deposits ◽  
Gneiss Domes ◽  
The Core ◽  
Igneous Origin ◽  
Eastern Border ◽  
Shuswap Metamorphic Complex

Frenchman's Cap dome is one of a series of gneiss domes along the eastern border of the high-grade Shuswap metamorphic complex. The granitic gneisses which compose the core of the dome are enclosed in an envelope of metasedimentary rocks.Before Shuswap metamorphism and deformation, the rocks of the sedimentary envelope were intruded by concordant bodies of alkalic rocks and carbonatite. Other carbonatite bodies appear to have formed at or extruded onto the surface. It is not certain whether these are exhalative sedimentary deposits, lava flows, or pyroclastic deposits.Criteria which can be used to distinguish igneous alkalic rocks from those of metasomatic origin were almost entirely destroyed by regional metamorphism. A few relict igneous textures show that at least some of the alkalic gneisses are of igneous origin.

scholarly journals Magmatic evolution and controls on rare metal-enrichment of the Strange Lake A-type peralkaline granitic pluton, Québec-Labrador

Lithos ◽  
2018 ◽  
Vol 308-309 ◽  
pp. 34-52 ◽  
Author(s):  
Karin Siegel ◽  
Olga V. Vasyukova ◽  
Anthony E. Williams-Jones
Keyword(s):  
Rare Metal ◽  
Magmatic Evolution ◽  
Metal Enrichment ◽  
Granitic Pluton

Late Sillimanite in the Migmatites of Kildonan, Sutherland

1948 ◽  
Vol 85 (3) ◽  
pp. 149-162 ◽  
Author(s):  
Janet Watson
Keyword(s):  
Country Rock ◽  
Regional Metamorphism ◽  
High Grade ◽  
Direct Connection ◽  
North West ◽  
Feature Characteristic ◽  
History Of ◽  
The Common ◽  
The Village ◽  
Pelitic Rocks

A large part of Central Sutherland is occupied by an injection complex in which rocks of the Moine Series are associated with much granitic and pegmatitic material. These migmatitic Moinian rocks have reached a higher grade of metamorphism than those which occur outside the injection complex. One feature characteristic of the high-grade migmatites is the presence of sillimanite in many of the pelitic and semi-pelitic rocks. Near the village of Kildonan, ten miles north-west of Helmsdale, sillimanite is not only abundant in the country rock, but occurs also in many pegmatitic and aplitic veins. The field and microscopic evidence shows that this mineral was formed as a result of metasomatic activity at a late stage in the history of the injection complex, when the general metamorphism was already on the wane. The sillimanite seems to have no direct connection with the conditions of regional metamorphism. It was formed under the influence of pegmatitic solutions. In view of the common use of this mineral as an index of the grade of regional metamorphism, it is of interest to describe the evidence on which the above conclusions are based.

Compositional variation in högbomites from north Connemara, Ireland

1985 ◽  
Vol 49 (354) ◽  
pp. 649-654 ◽  
Author(s):  
N. S. Angus ◽  
R. Middleton
Keyword(s):  
Chemical Composition ◽  
Regional Metamorphism ◽  
The Other ◽  
Partial Substitution ◽  
Compositional Variation ◽  
Physical Parameters ◽  
Chemical Heterogeneity ◽  
High Grade ◽  
Thermal Metamorphism ◽  
Mineral Assemblages

AbstractHögbomite occurs in two contrasting mineral assemblages within the Currywongaun-Dough-ruagh intrusion of north Connemara: a cordierite-rich pelitic xenolith and an orthopyroxenite. In the latter, högbomite and green spinel form blebs within magnetite-ilmenite grains. The högbomite displays significant compositional variation from grain to grain: TiO2 (3.0–6.3%), FeO (21.6–21.3%), MgO (10.0–7.5%), ZnO (3.6–2.4%). This chemical heterogeneity appears to represent variable degrees of partial substitution of Mg and Zn by Ti, in the replacement of spinel by högbomite. By contrast, in the cordierite-hornfels, the högbomite compositions are more notably enriched in iron: TiO2 (4.7–7.0%), FeO (29.6–24.3%), MgO (4.2–6.2%), ZnO (2.7–2.1%). This iron-rich högbomite appears to have formed primarily by interaction between opaque ore and adjacent cordierite, rather than by replacement of spinel.Two high-grade metamorphic episodes appear to be necessary for högbomite growth, one determining chemical composition and the other appropriate physical parameters. In the Connemara occurrences thermal metamorphism and partial melting, coupled with contamination of the surrounding magma, controlled the formation of mineral assemblages rich in Fe, Mg, Al, Ti, and Zn. Emplacement of the intrusion was accompanied by amphibolite facies regional metamorphism and it is to this metamorphic event that the growth of högbomite may be attributed.

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