Geochemical Pattern and the Evolution of the Mafic Rocks of Southwest Obudu Plateau, Bamenda Massif, Nigeria

2016 ◽  
Vol 6 (4) ◽  
pp. 1-12
Author(s):  
E Ukwang ◽  
V Ukaegbu
Keyword(s):  
Mafic Rocks ◽  
Geochemical Pattern

scholarly journals Evidence of active magmatic rifting at the Ma’Alalta volcanic field (Afar, Ethiopia)

2021 ◽  
Vol 83 (6) ◽  
Author(s):  
Gianmaria Tortelli ◽  
Anna Gioncada ◽  
Carolina Pagli ◽  
Mauro Rosi ◽  
Laura De Dosso ◽  
...  
Keyword(s):  
Seismic Data ◽  
Volcanic Field ◽  
Lava Flows ◽  
Magmatic Activity ◽  
Magma Storage ◽  
Plumbing System ◽  
Mafic Lava ◽  
Cinder Cones ◽  
Mafic Rocks ◽  
Seismic Networks

AbstractDuring continental rifting, strain and magmatism are believed to localize to narrow magmatic segments, while the rift margin is progressively abandoned. We integrate volcanological, geochemical, petrological and seismic data from the Ma’Alalta volcanic field (MVF) near the western margin of Afar, to show that the MVF is an active magmatic segment. Magmatism in MVF initiated with lava flows and large-volume, caldera-forming ignimbrites from a central edifice. However, the most recent magmatic activity shifted towards mafic lava fields, cinder cones and obsidian-rich silicic domes erupted from vents aligned NNW-SSE, defining a ~ 35-km-long magmatic segment. Along the same area, a NNW-SSE alignment of earthquakes was recorded by two local seismic networks (2005–2009 and 2011–2013). The geochemistry of the mafic rocks is similar to those of nearby axial volcanoes. Inferred magma storage depth from mineral geobarometry shows that a shallow, silicic chamber existed at ~ 5-km depth below the stratovolcano, while a stacked plumbing system with at least three magma storage levels between 9 and 24 km depth fed the recent basalts. We interpret the wide set of observations from the MVF as evidence that the area is an active magmatic segment, showing that localised axial extension can be heavily offset towards the rift margin.

Opening of the West Paleo-Tethys Ocean: New insights from earliest Devonian meta-mafic rocks in the Saualpe crystalline basement, Eastern Alps

2021 ◽  
Author(s):  
Qingbin Guan ◽  
Yongjiang Liu ◽  
Franz Neubauer ◽  
Sanzhong Li ◽  
Johann Genser ◽  
...  
Keyword(s):  
Eastern Alps ◽  
Crystalline Basement ◽  
The West ◽  
Mafic Rocks ◽  
Tethys Ocean

Using the isotope dating of endocontact hybrid rocks for the age determination of mafic rocks (southern Siberian craton)

2013 ◽  
Vol 54 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
D.P. Gladkochub ◽  
T.V. Donskaya ◽  
M.T.D. Wingate ◽  
A.M. Mazukabzov ◽  
S.A. Pisarevsky ◽  
...  
Keyword(s):  
Siberian Craton ◽  
Age Determination ◽  
Mafic Rocks ◽  
Isotope Dating

Reconstruction of multiple P-T-t stages from retrogressed mafic rocks: Subduction versus collision in the Southern Brasília orogen (SE Brazil)

Lithos ◽  
2017 ◽  
Vol 294-295 ◽  
pp. 283-303 ◽  
Author(s):  
Mahyra Tedeschi ◽  
Pierre Lanari ◽  
Daniela Rubatto ◽  
Antônio Pedrosa-Soares ◽  
Jörg Hermann ◽  
...  
Keyword(s):  
Mafic Rocks ◽  
Se Brazil

Petrochemical characterization of mafic rocks from the Ligurian ophiolites, southern Apennines

2009 ◽  
Vol 53 (1) ◽  
pp. 130-156 ◽  
Author(s):  
Maria T. Cristi Sansone ◽  
Giovanna Rizzo ◽  
Giovanni Mongelli
Keyword(s):  
Southern Apennines ◽  
Mafic Rocks

The Weathering of Mafic Rocks by Lichens

1993 ◽  
Vol 25 (3) ◽  
pp. 285-297 ◽  
Author(s):  
P. Adamo ◽  
A. Marchetiello ◽  
P. Violante
Keyword(s):  
Oxalic Acid ◽  
Chemical Substance ◽  
Mineral Surfaces ◽  
Secondary Products ◽  
Mafic Rocks ◽  
Crustose Lichens ◽  
Parmelia Conspersa

AbstractThe weathering phenomena resulting from the growth of six foliose and crustose lichens (Parmelia subrudecta, Xanthoria ectaneoides, Parmelia conspersa, Aspicilia radiosa, Caloplaca sp. and Ochrolechia parella) on three mafic rocks have been studied. The bioweathering results in more or less extensive fragmentation and corrosion of the mineral surfaces immediately beneath the lichen thalli and in the formation, in the thallus or at the rock-lichen interface, of secondary products. The significant amounts of whewellite found in all interfaces, and the bipiramids of weddellite detected at the serpentine rock-Ochrolechia parella interface, suggest that the oxalic acid secreted by the mycobiont is the chemical substance principally involved. The capacity of the lichens to alter their rock substrata does not appear to be related to their thallus morphology.

Sign in / Sign up

Export Citation Format

Share Document