TY  - JOUR
A1  - Zobir, Soraya Hadj
A1  - Altenberger, Uwe
A1  - Günter, Christina
T1  - Geochemistry and petrology of metamorphosed submarine basic ashes in the Edough Massif (Cap de Garde, Annaba, northeastern Algeria)
JF  - Comptes rendus geoscience
N2  - The study presents the first evidence of metamorphosed submarine ashes in the Edough Massif, in northeastern Algeria. It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust. The metamorphic complex consists of tectonically superposed units composed of gneisses (lower unit) and micaschists (upper unit). At the Cap de Garde, these units enclose an "intermediate unit" composed of micaschists and meter-thick layers of marbles, which are sometimes intercalated with amphibolites. The latter occur as discontinuous small lenses and layers. The amphibolites are parallel to the primary bedding of the marbles and the main foliation. Chemical markers and field observations indicate that they are metamorphic equivalents of basic igneous rocks. The lenticular character, low thickness and multiple intercalations with marine sediments and the unusual high lithium concentrations suggest subaqueous near-source basaltic ash-fall deposits in a marine environment. (C) 2014 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.
KW  - Amphibolites
KW  - Submarine sediments
KW  - Basaltic ash-fall deposits
KW  - Edough
KW  - Algeria
Y1  - 2014
U6  - https://doi.org/10.1016/j.crte.2014.09.002
SN  - 1631-0713
SN  - 1778-7025
VL  - 346
IS  - 9-10
SP  - 244
EP  - 254
PB  - Elsevier
CY  - Paris
ER  - 
TY  - JOUR
A1  - Zobir, Soraya Hadj
A1  - Oberhänsli, Roland
T1  - The sidi Mohamed peridotites (Edough Massif, NE Algeria) - evidence for an upper mantle origin
JF  - Journal of earth system science
N2  - The Hercynian Edough massif is the easternmost crystalline massif of the Algerian coast. It consists of two tectonically superposed units composed of micaschists, gneisses, and peridotite. This study concentrates on the small and isolated Sidi Mohamed peridotite outcrop area (0.03 km(2)). The Sidi Mohamed peridotite is composed mainly of harzburgites (Mg-rich olivine and orthopyroxene as major minerals). The Ni (2051-2920 ppm), Cr (2368-5514 ppm) and MgO (similar to 28-35 wt.%) whole-rock composition and the relative depletion in Nb make these harzburgites comparable to depleted peridotites related to a subduction zone. We suggest that the Sidi Mohamed ultramafic body was derived directly from the upper mantle and tectonically incorporated into the gneiss units of the Edough metamorphic core complex in a subduction environment.
KW  - Peridotites
KW  - upper mantle
KW  - Edough
KW  - Algeria
Y1  - 2013
U6  - https://doi.org/10.1007/s12040-013-0358-z
SN  - 0253-4126
SN  - 0973-774X
VL  - 122
IS  - 6
SP  - 1455
EP  - 1465
PB  - Indian Academy of Science
CY  - Bangalore
ER  - 
TY  - JOUR
A1  - Zobir, Soraya Hadj
A1  - Mocek, Beate
T1  - Determination of the source rocks for the diatexites from the Edough Massif, Annaba, NE Algeria
JF  - Journal of African earth sciences
N2  - The crystalline Edough Massif is located in the oriental part of the Algerian coastline. It consists of two tectonically superposed units of gneisses, augen-gneisses and migmatitic gneisses in the lower unit and micaschists in the upper unit. The crystalline rocks underwent a low to moderate degree of metamorphism; the gneisses suffered partial melting. They display migmatitic features such as nebulitic structures with contorted leucosome layers and K-feldspar porphyroblasts and thus can be classified as diatexites. The mineralogical composition of these rocks is very homogenous and consists of K-feldspar, micas and quartz. The feldspar-rich, arkosic nature of the outcrop implies a granitic source rock. High K2O/Na2O ratios and high A/CNK > 1.1 indicate an S-type granite source and a peraluminous composition of the protolith respectively. Chondrite normalized REE distribution patterns of the Edough diatexites show gently inclined patterns with a minor negative Eu anomaly (Eu/Eu* = 0.36-0.49), which points to a very slightly differentiated granitic source. The REE pattern and trace element data of the diatexites are similar to those of average Proterozoic upper continental crust, which suggests that they are derived mainly from upper continental crust and were deposited in continental margins.
KW  - Diatexites
KW  - Arkose
KW  - Protolith
KW  - S-type granite
KW  - Edough
KW  - Algeria
Y1  - 2012
U6  - https://doi.org/10.1016/j.jafrearsci.2012.04.004
SN  - 1464-343X
VL  - 69
IS  - 13
SP  - 26
EP  - 33
PB  - Elsevier
CY  - Oxford
ER  -