Petrologic and geochemical characterization and mineralization of the metavolcanic rocks of the Heib Formation, Kid Metamorphic Complex, Sinai, Egypt

Abstract

Metavolcanic rocks hosting base metal sulphide mineralization, and belonging to the Kid Metamorphic Complex, are exposed in the Samra-Tarr area, Southern Sinai. The rocks consist of slightly metamorphosed varicolored porphyritic lavas of rhyolite-to-andesite composition, and their equivalent pyroclastics. Geochemically, these metavolcanics are classified as high-K calc-alkaline, metaluminous andesites, trachyandesites, dacites, and rhyolites. The geochemical characteristics of these metavolcanics strongly point to their derivation from continental crust in an active continental margin. The sulphide mineralization in these metavolcanics occurs in two major ore zones, and is represented by four distinct styles of mineralization. The mineralization occurs either as low-grade disseminations or as small massive pockets. The associated hydrothermal alterations include carbonatization, silicification, sericitization and argillic alterations. The base metal sulphide mineralization is epigenetic and was formed by hydrothermal solutions associated with subduction-related volcanic activity. ª 2011, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. All rights reserved.

Petrogenetic evolution of the felsic and mafic volcanic suite in the Siang window of Eastern Himalaya, Northeast India

“…Variable volumes of felsic volcanics have been reported to occur associated with mafic volcanics, and diverse petrogenetic models have been proposed for such bimodal suites (Garland et al, 1995;Hooper, 1997;Riley et al, 2001;Xu et al, 2007;He et al, 2007;Thompson et al, 2007;Mahoney et al, 2008 and references therein; Diez Montes et al, 2010;Ball evre et al, 2011;Khalifa et al, 2011;Wang and Shu, 2012). Partial melting and fractional crystallization of crustal rocks accompanied by assimilation of the upper crust have been proposed for the rhyolites of Patagonia (Pankhurst and Rapela, 1995;Riley et al, 2001), Mesa central, Mexico (Orozco-Esquivel et al, 2002), St Francois mountains, Missouri (Menuge et al, 2002), felsic volcanics of the Cretaceous paresis ring complex, Namibia (Mingram et al, 2000), and the Malani Igneous Suite, northwestern India (Eby and Kochhar, 1990;Singh et al, 2006).…”

Mineralogical and geochemical changes due to hydrothermal alteration of the volcanic rocks at Acoculco geothermal system, Mexico

“…According to Khalifa, El‐Bialy, and Hassan (), REEs may be grouped into LREEs (La, Ce, Pr and Nd), MREEs (Sm, Eu, Gd, Tb, Dy and Ho) and HREEs (Er, Tm, Yb and Lu). The mean concentrations (normalised to the chondrite values; Mc Donough & Sun, McDonough, & Sun, S.‐s., ) of REEs in the rocks of this study (altered rocks) comparing to the precursor (relatively fresh rock; E‐7) suggest a general trend of gain in average mean concentrations of all LREEs and loss in those of MREEs and HREEs (Figures b and ).…”

Geochemical characterization of mineralized albitite from Paleoproterozoic Bhukia IOCG‐IOA deposit of Aravalli‐Delhi Fold Belt, Rajasthan, western India: Genetic linkage to the gold (±Cu ± U) mineralization

“…Despite extensive reporting of the several variants of the IOCG deposits across the continents, the gold‐bearing IOCG‐IOA deposits associated with albitite are rare. Some major occurrences are Wadi‐Tarr and Samra‐Tarr areas of southern Sinai, Egypt (Blasy, Baroudy, & Kharbish, ; Khalifa, El‐Bialy, & Hassan, ); Valhalla uranium deposit of Queensland, Australia (Polito et al, ); NE Sardinia of Italy (Costamagna, Cruciani, Franceschelli, & Puxeddu, ); Mlakawa and Penjween area of Kurdistan region, NE Iraq (Mohammad, Maekawa, & Lawa, ); Kitongo of northern Cameroon (Kouske, Suh, Ghogomu, & Ngako, ); Detour Lake gold deposit and Great Bear magmatic zone of Canada (Montreuil et al, ); Birmian Greenstone Belt of Burkina Faso (Béziat et al, ); and Carajas Mineral province of Brazil (Monteiro et al, ).…”