Abstract
Tremendous quantities of practically untapped talc-carbonate rocks are distributed in Barramiya area in intimate - spatially and genetically - association with the ophiolitic serpentinites. These deposits could serve as an important potential source of magnesia which is used in a broad spectrum of strategic industries. Barramiya ophiolitic serpentinites represent obducted
oceanic slices onto island-arc successions. They occur as elongated mountainous ranges in the form of anticlinal-synclinal sheets demarcating the general ENE-WSW brittle-ductile shear zone of the area. The serpentinite-hosted talc-carbonate deposits of Barramiya area are located: a) either along major faults that cut the serpentinite slices or b) at thrust contacts between abducted serpentinites and other melange components (more siliceous country rocks of island-arc affinity). The latter were regionally metamorphosed in greenschist up to middle amphibolite facies. Barramiya talc-carbonate rocks represent in situ fissure-fed metasomatic products of serpentinite precursors via extensive rock-fluid interactions. The main fluids that involved in transformation processes of serpentinites to talecarbonates were SiO2 acqueous and CO2. In general, the deposits located along fault system that cut the serpentinites host are magnesite-rich, whereas those located at the contacts between serpentinites and the more siliceous country rocks are typically talc-rich. Talc and magnesite as the main constituents of Barramiya talc-carbonate rocks occur in variable proportions. Hence, the rocks were distinguished into assemblages according to the predominance of these phases in conjunction with the other accessories such as dolomite, quartz and serpentine minerals. In the present work, petrogenesis of Barramiya talc carbonate rocks and their evolution courses from serpentinite precursors are elaborated in the light of their petrography, mineralogy, mineral chemistry and geochemistry, using remote sensing and GIS techniques, the Barramiya talc-carbonate rocks were reasonably mapped as separate layers and their reserve estimations (possible and proved) were accomplished.
oceanic slices onto island-arc successions. They occur as elongated mountainous ranges in the form of anticlinal-synclinal sheets demarcating the general ENE-WSW brittle-ductile shear zone of the area. The serpentinite-hosted talc-carbonate deposits of Barramiya area are located: a) either along major faults that cut the serpentinite slices or b) at thrust contacts between abducted serpentinites and other melange components (more siliceous country rocks of island-arc affinity). The latter were regionally metamorphosed in greenschist up to middle amphibolite facies. Barramiya talc-carbonate rocks represent in situ fissure-fed metasomatic products of serpentinite precursors via extensive rock-fluid interactions. The main fluids that involved in transformation processes of serpentinites to talecarbonates were SiO2 acqueous and CO2. In general, the deposits located along fault system that cut the serpentinites host are magnesite-rich, whereas those located at the contacts between serpentinites and the more siliceous country rocks are typically talc-rich. Talc and magnesite as the main constituents of Barramiya talc-carbonate rocks occur in variable proportions. Hence, the rocks were distinguished into assemblages according to the predominance of these phases in conjunction with the other accessories such as dolomite, quartz and serpentine minerals. In the present work, petrogenesis of Barramiya talc carbonate rocks and their evolution courses from serpentinite precursors are elaborated in the light of their petrography, mineralogy, mineral chemistry and geochemistry, using remote sensing and GIS techniques, the Barramiya talc-carbonate rocks were reasonably mapped as separate layers and their reserve estimations (possible and proved) were accomplished.
| Original language | English |
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| Title of host publication | Sinai International Conference for Geology and Development (SICGD) |
| Publication status | Published - 2010 |