Low-potassium vaugnerites from Gu�ret (Massif Central, France). Mafic magma evolution influenced by contemporaneous granitoids

1997 ◽  
Vol 59 (3-4) ◽  
pp. 165-187 ◽  
Author(s):  
G. Gal�n ◽  
L. G. Corretg� ◽  
O. Laurent
Keyword(s):  
Mafic Magma ◽  
Magma Evolution ◽  
Massif Central ◽  
Low Potassium

Timescales of magma mixing in the magma plumbing system of Bezymianny volcano: insights from diffusion chronometry

2018 ◽  
pp. 52-58
Author(s):  
V. O. Davydova ◽  
V. D. Shcherbakov ◽  
P. Yu. Plechov
Keyword(s):  
Magma Mixing ◽  
Mafic Magma ◽  
Plumbing System ◽  
Magma Evolution ◽  
Bezymianny Volcano ◽  
Magma Plumbing System ◽  
Diffusion Chronometry ◽  
Shallow Magma Chamber ◽  
Trigger Mechanisms ◽  
Magma Plumbing

Zoned crystals record changes in magma evolution, such as injection of mafic magma into a shallow magma chamber, which often triggered to eruption of arc volcanoes. We applied diffusion chronometry for reverse zoned crystals of orthopyroxene from 6 eruptions of Bezymianny volcano during 2006–2012 years and showed correlation between time of injection of new magma and recorded seismicity. We descripted two type of Bezymianny volcano eruptions, which driven by different trigger mechanisms: 1) orthopyroxene rims formed during up to 3 years previous to eruption; 2) orthopyroxene rims formed during 0–2 months previous to eruption.

Field evidence for successive mixing and mingling between the Piolard Diorite and the Saint-Julien-la-Vêtre Monzogranite (Nord–Forez, Massif Central, France)

1988 ◽  
Vol 25 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Bernard Barbarin
Keyword(s):  
Large Volume ◽  
Mafic Magma ◽  
Complex Field ◽  
Massif Central ◽  
Field Evidence ◽  
Exchange Processes ◽  
Magmatic Enclaves

Recent mapping of the Nord–Forez region, Massif Central, France, reveals a variety of complex field relationships along contacts between a large enclave of diorite and its enclosing monzogranite. Field relations, hybrid rocks, and a wide variety of mafic magmatic enclaves can be explained by a succession of processes between coexisting mafic and felsic magmas that either prevent or promote exchanges. The large volume of mafic magma, and consequently the large amount of heat it brought with it, favored exchange processes. Because the distribution of heat varied with both time and place, the nature and intensity of the compositional exchange processes also varied.Most of the features attributed to exchange are related to processes that occurred at the level of emplacement and after the beginning of crystallization of the two magmas. These processes affected both the granitic and dioritic magmas already thoroughly hybridized by nearly similar processes that took place earlier at depth.

scholarly journals Origin of Talc and Fe-Ti-V Mineralization in the Kletno Deposit (the Śnieżnik Massif, SW Poland)

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Grzegorz Gil ◽  
Piotr Gunia ◽  
Jaime D. Barnes ◽  
Michał Szymański ◽  
Petras Jokubauskas ◽  
...  
Keyword(s):  
Mafic Magma ◽  
Bulk Rock ◽  
Massif Central ◽  
Δ13c Values ◽  
Oxygen And Carbon Isotope ◽  
Ore Bodies ◽  
Sw Poland ◽  
Fluid Interaction ◽  
Tectonic Slice ◽  
Δ18o And Δ13c

The Kletno deposit in the Śnieżnik Massif (Central Sudetes, SW Poland), mined for Fe, U, Ag, Cu, fluorite, and marble through the ages, developed at the contact of marbles and orthogneiss. Here, we present a new Fe-Ti-V-ore (containing up to 14.07 wt. % Fe, 2.05 wt. % Ti, and 2055 ppm V in bulk rock) and ornamental- to gem-quality talc prospect at the southwest margin of this deposit. This newly documented Fe-Ti-V mineralization is hosted in hornblendites, dolomite veins, and chlorite schists, which, along with talc, envelopes a tectonic slice of serpentinite. Hornblendites are interpreted as metamorphosed ferrogabbros, derived from the same mafic melts as adjacent barren metagabbros. The oxygen and carbon isotope compositions of metabasites and dolomite veins (amphibole δ18O values = 8.8–9.3‰; carbonate δ18O values = 12.8–16.0‰, and δ13C values = −8.3‰ to −7.2‰), in combination with those of the country marbles (carbonate δ18O and δ13C values = 23.2‰ and +0.1‰, respectively), suggest that mineralization-bearing hornblendites formed due to interaction of the mafic magma with CO2 released during the decarbonation of the sediments. The CO2-bearing fluid interaction with gabbros likely caused carbonation of the gabbros and formation of the dolomite veins, whereas talc formed due to Si-rich fluids, possibly derived from a mafic intrusion, interaction with serpentinite, or due to the metasomatism of the serpentinite–gabbro assemblage. Moreover, fluids leaching Fe and Ti from the adjacent sediments can mix with the mafic magma causing enrichment of the magma in Fe and Ti. Consequently, the mineralization-bearing ferrogabbros became even more enriched in Fe and Ti, which can be linked with the formation of Fe-Ti-V ore bodies.

The earliest ostracods from the Ordovician of the Prague Basin, Czech Republic

2014 ◽  
Vol 64 (4) ◽  
pp. 367-392 ◽  
Author(s):  
Karolína Lajblová ◽  
Petr Kraft
Keyword(s):  
Czech Republic ◽  
Bohemian Massif ◽  
Massif Central ◽  
Central European ◽  
Middle Ordovician ◽  
Prague Basin ◽  
Barrandian Area ◽  
Fossil Assemblages ◽  
European Variscides

Abstract The earliest ostracods from the Bohemian Massif (Central European Variscides) have been recorded from the Middle Ordovician of the Prague Basin (Barrandian area), in the upper Klabava Formation, and became an abundant component of fossil assemblages in the overlying Šarka Formation. Both early ostracod associations consist of eight species in total, representing mainly eridostracans, palaeocopids, and binodicopids. The revision, description, or redescription of all species and their distribution in the basin is provided. Their diversification patterns and palaeogeographical relationships to ostracod assemblages from other regions are discussed.

Muscle and meat characteristics from the main beef breeds of the Massif Central

2007 ◽  
Vol 27 (2) ◽  
pp. 168-180 ◽  
Author(s):  
B Picard ◽  
C Jurie ◽  
D Bauchart ◽  
E Dransfield ◽  
A Ouali ◽  
...  
Keyword(s):  
Massif Central
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