Late Neoproterozoic metamorphic assemblages along the Pan-African Hamisana Shear Zone, southeastern Egypt: Metamorphism, geochemistry and petrogenesis

Ali‐Bik, Mohamed W.; Sadek, Mohamed F.; Ghabrial, Doris Sadek

doi:10.1016/j.jafrearsci.2013.08.010

Cited by 20 publications

(18 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the given spider diagrams (Fig. 13), the patterns of both metavolcanics and gabbroic rocks exhibit a diagnostic subduction-related Ta-Nb trough (Pearce 1983;Condi 1989;Tepper 1996;Ali-Bik et al 2014) in contrast to the continental-rift, within-plate basalts. In terms of maturity, the pattern of the studied metavolcanics matches that of the gabbroic rocks (Fig.…”

Section: Metavolcanics and Gabbroic Rocksmentioning

confidence: 99%

“…It experienced polyphase deformations, metamorphism up to amphibolite facies, and magmatic activity during the Pan-African tectono-thermal event (900-450 Ma: Stern et al 1989;Abdelsalam et al 2003;Kusky et al 2003;Fowler and El Kalioubi 2004;Ali-Bik et al 2014). The ANS in the Central Eastern Desert of Egypt consists of extensive outcrops of metamorphosed gneiss domes, ophiolitic-related assemblages island arc metavolcanics and volcaniclastics association together with clastic molasse-type sediments.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Late Neoproterozoic basement rocks of Kadabora-Suwayqat area, Central Eastern Desert, Egypt: geochemical and remote sensing characterization

2015

Self Cite

View full text Add to dashboard Cite

Kadabora-Suwayqat area, in the Central Eastern Desert of Egypt, is built up by a wide variety of non-consanguineous, basement rock units, which represent a tectonostratigraphic suite within the frame of the Late Neoproterozoic, Pan-African Arabian-Nubian Shield. They were developed from different magma sources at varied tectonic settings through subsequent tectono-magmatic processes. They cover a wide compositional range of the Pan-African legend in the Eastern Desert of Egypt comprising ophiolitic, island-arc, and within-plate assemblages. The ophiolitic serpentinites were obducted onto arcrelated metavolcanics and intruded by gabbroic and syn-late to post tectonic granitoids. Geochemically, the precursor of the ophiolitic serpentinites seems to be peridotite (harzburgite). The basic, intermediate, and acidic metavolcanics imply a transitional stage between an island-arc and a proper active continental margin setting. They exhibit with the gabbroic rocks a diagnostic subduction-related island-arc, calc-alkaline affinity. The granitoids comprise both arc-related, calc-alkaline I-type and within-plate, anorogenic A-type varieties. These rocks have been successfully discriminated on Landsat 8 images including Minimum Noise Fraction (MNF; 4, 3, 7), Principal Component Analysis (PCA; PC6, PC2, PC7), and various band ratios (b6/ b2, b6/b7, b6/b5×b4b5) and (b7/b6, b7/b5, b5/b3). ASTER clay index (5×7/6) and silica index (10/13) discriminated the granitoid rocks, while the serpentinite-talc carbonate and metavolcanic rocks are distinguished on the ASTER images of amphibole index (6+9/7+8) and (6/8).

show abstract

Section: Metavolcanics and Gabbroic Rocksmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Late Neoproterozoic basement rocks of Kadabora-Suwayqat area, Central Eastern Desert, Egypt: geochemical and remote sensing characterization

2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The metapelite host rocks are peraluminous, have high major oxide contents such as Al 2 O 3 , TiO 2 , MnO, FeO, MgO, CaO and P 2 O 5 with low silica content, as well as notable enrichment in Cr, V, Sr, Rb, Zr, Y and Nb. These amphibolite facies rocks contain hornblende, biotite, muscovite, garnet, zircon and monazite (Ali-Bik et al, 2014), which are considered to be significant reservoirs of incompatible elements (REE and HFSE) in the metamorphic and magmatic systems (Bea, 1996). The abundance of these mineralogical phases in the metapelites, coupled with their geochemical characteristics, points to them likely being fertile enough to be a possible source for partial melting at depth, producing the pegmatite in the Wadi Ibib area (e.g., Bea and Montero, 1999).…”

Section: Mineralogical and Geochemical Constraintsmentioning

confidence: 99%

“…During the D3-tectonic event, the Wadi Ibib-HSZ area underwent an amphibolite facies metamorphism in response to intense collision (crustal thickening) and heat provided by terrain uplifting and shearing. The Wadi Ibib-HSZ rocks attained a peak temperature and pressure of about 600 ± 50°C and 5.0-6.5 kbar, during the retrogressive (cooling stage) reaching about 530°C (Ali-Bik et al, 2014). This syn-deformation thermal event supplied enough heat to create a local small-scale partial melting zone that had perhaps produced the pegmatites by the end of this event (e.g., Hibbard, 1987;Jamie et al, 2013).…”

Section: Source Controls On the Pegmatite Mineralizationmentioning

confidence: 99%

“…Ibrahim et al (2016) suggested that the HSZ represents a tectonic escape structure, according to a reconstructed paleostress configuration of the oblique shearing across a fold-thrust belt. Based on superimposed structures, the HSZ is suggested to have experienced a polyphase deformation history (Stern et al, 1989;Miller and Dixon, 1992;de Well., 2001;Johnson and Woldehaimanot, 2003;Ali-Bik et al, 2014;Ibrahim et al, 2014bIbrahim et al, , 2016.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Neoproterozoic U‐Th‐REE‐bearing Pegmatites in Wadi Ibib, South Eastern Desert, Egypt: Structural and Geochemical Measures for a Syn‐Tectonic Anatectic Model of Formation

Ibrahim

2021

Acta Geologica Sinica (Eng)

View full text Add to dashboard Cite

Pegmatites may form significant reservoirs of rare metals (Linnen et al., 2012;Dill, 2015), rare earth elements (REE) and radioactive metals (U and Th). Nevertheless, the origin of pegmatites and the associated mineralization is still a matter of debate (Černý and Ercit, 2005). Mineralized pegmatites can be classified into two suites (end-members): i) pegmatites with concentrations of niobium-yttrium-fluorine (referred to as the NYF suite); and ii) pegmatites with concentrations of lithium-cesiumtantalum (referred to as the LCT suite) (Černý et al., 2012). Two hypotheses are posited for the generation of pegmatitic melts: 1) continued fractionation of granitic magmas during plutonism and 2) limited partial melting of crustal sources, with inputs from circulating hydrothermal fluids (e.g., Martin and DeVito, 2005;London, 2005). These hypotheses can practically represent two endmembers of pegmatite formation. Generally, the host lithology, tectonic setting and geological setup of pegmatite swarms are important parameters that may control their formation and element budget.In the Egyptian Eastern Desert, most of the abundant pegmatite sets are spatially associated with post-tectonic Pan-African granites (e.g., Abd El-Naby and Saleh, 2003;Saleh et al., 2008;Ghazaly et al., 2015). Alternatively, the pegmatite sets associated with amphibolite facies gneissic and schistose rocks across the southern Eastern Desert are rarely recorded in some localities, e.g., Hafafit and Nugrus areas (e.g., Raslan and Ali, 2011;Ibrahim et al., 2015Ibrahim et al., , 2017.The structural pattern of Neoproterozoic rocks (e.g., propagation of thrusts and sutures) along the south Eastern Desert reveals a polyphase deformation history (Abd El-

show abstract

Volcanogenic talc‐copper deposits of Darhib‐Abu Jurdi area, Egypt: Petrogenesis and remote sensing characterization

2020

View full text Add to dashboard Cite

Economic talc deposits were developed as an integral part of a volcanogenic massive sulfide system in Darhib‐Abu Jurdi bimodal‐mafic type submarine volcanics in the South Eastern Desert of Egypt. These Pan‐African metavolcanics were erupted in a rift‐related environment and experienced low‐grade greenschist metamorphism. They host talc‐malachite mineralization, mainly within E–W trending alteration zones along the major latitudinal shear planes. These mineralized alteration zones contain economic talc deposits as well as averages of 1.7% Cu and 0.46% Zn; the maximum may exceed 11% Cu. Sentinel‐2, ASTER, and Landsat‐8 dataset in conjunction with a portable TerraSpec Halo mineral identifier device (ASD) were employed in detecting and mapping these mineralized alteration zones within the Darhib‐Abu Jurdi metavolcanics. Petrography, mineralogy, and geochemistry of these deposits and host volcanics enabled to put constraints on their petrogenesis and evolution as a submarine hydrothermal vent system. Mineralogical characteristics of pervasive chloritization stringer zone, hypogene primary sulfide ore zone, and supergene oxidized zone are addressed and discussed. Talc deposits were formed at Darhib‐Abu Jurdi area as the main gangue phase via (a) direct precipitation on seafloor by interaction of silica‐saturated hydrothermal fluids with Mg‐rich seawater, (b) precipitation with actinolite/tremolite at shallow depth beneath the sulfide ore lenses due to penetration of Mg‐rich seawater into hydrothermal conduit, and (c) replacement of pre‐existing tremolite, actinolite, chlorite, and septechlorite.

show abstract

Late Neoproterozoic metamorphic assemblages along the Pan-African Hamisana Shear Zone, southeastern Egypt: Metamorphism, geochemistry and petrogenesis

Cited by 20 publications

References 32 publications

Late Neoproterozoic basement rocks of Kadabora-Suwayqat area, Central Eastern Desert, Egypt: geochemical and remote sensing characterization

Late Neoproterozoic basement rocks of Kadabora-Suwayqat area, Central Eastern Desert, Egypt: geochemical and remote sensing characterization

Neoproterozoic U‐Th‐REE‐bearing Pegmatites in Wadi Ibib, South Eastern Desert, Egypt: Structural and Geochemical Measures for a Syn‐Tectonic Anatectic Model of Formation

Volcanogenic talc‐copper deposits of Darhib‐Abu Jurdi area, Egypt: Petrogenesis and remote sensing characterization

Contact Info

Product

Resources

About