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\"This richly illustrated book provides an overview of the Neoproterozoic Pan-African Belt of Egypt (PABE), which represents the northwestern continuation of the Arabian-Nubian Shield (ANS) and the East African Orogen (EAO). The first chapter offers an introduction to the Turin Papyrus Map and the historical background of the PABE, while the second addresses how the PABE is related to the ANS and EAO. Rock succession of the PABE is dealt with in Chapter 3, while Chapter 4 focuses on Sinai Metamorphic Core Complexes and implications on the break-up of Rodinia. Subsequent chapters discuss a broad range of topics, e.g. ophiolite-dominated suprastructural rocks; volcanosedimentary succession, Neoproterozoic volcanism and volcanic rocks in Egypt; enigmatic issues concerning granite, Dokhan and Hammamat sediments; the lithospheric mantle beneath the Northeast African continent and the mantle section of Neoproterozoic ophiolites from the PABE; sutures, megashears and petrogenetic evolution of the Neoproterozoic rocks of Egypt; and metallic and non-metallic mineral deposits in the PABE, which are covered in extensive detail. The book's closing chapters discuss the application of remote sensing techniques and anisotropy of magnetic susceptibility (AMS) to decipher the tectonic evolution of the PABE, as well as the use of geophysical data to map structural features and hydrothermal alteration zones in the PABE\"--Back cover.

Combined petrographic and geochemical methods are utilized to investigate the provenance, tectonic setting, palaeo-weathering and climatic conditions of the Cambrian Araba clastic sediments of NE Egypt. The ~ 60 m thick Araba Formation consists predominantly of sandstone and mudstone interbedded with conglomerate. Petrographically the Araba sandstones are mostly sub-mature and classified as subarkoses with an average framework composition of Q80F14L6. The framework components are dominated by monocrystalline quartz with subordinate K-feldspar, together with volcanic and granitic rock fragments. XRD analysis demonstrated that clay minerals comprise mixed-layer illite/smectite (I/S), illite and smectite, with minor kaolinite. Diagenetic features of the sandstone include mechanical infiltration of clay, mechanical and chemical compaction, cementation, dissolution and replacement of feldspars by carbonate cements and clays. The modal composition and geochemical parameters (e.g. Cr/V, Y/Ni, Th/Co and Cr/Th ratios) of the sandstones and mudstones indicate that they were derived from felsic source rocks, probably from the crystalline basement of the northern fringe of the Arabian–Nubian Shield. The study reveals a collisional tectonic setting for the sediments of the Araba Formation. Palaeo-weathering indices such as the chemical index of alteration (CIA), chemical index of weathering (CIW) and plagioclase index of alteration (PIA) of the clastic sediments suggest that the source area was moderately chemically weathered. On the northern margin of Gondwana, early Palaeozoic weathering occurred under fluctuating climatic conditions.

The Arabian Nubian Shield (ANS) contains a variety of gold deposits in the form of veins and veinlets formed by hydrothermal fluids. Characterizing potential areas of hydrothermal alteration zones therefore provides a significant tool for prospecting for hydrothermal gold deposits. In this study, we develop a model of exploration for hydrothermal mineral resources in an area located in the ANS, Egypt, using multiple criteria derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Landsat-Operational Land Imager (OLI), and Sentinel-2 data and field work through GIS-based fuzzy logic approach. The hydrothermal alteration zones (HAZs) map extracted from combining mineral indices, spectral bands, and ratios is consistent with observed argillic alteration zones around the mineralized veins. Combining HAZs and lineament density led to identification of six zones based on their mineralization potential, and provides a tool for successful reconnaissance prospecting for future hydrothermal mineral deposits. The detected zones are labeled as excellent, very high, high, moderate, low, and very low, based on their potential for Au production, and the predictive excellent and very high zones cover about 1.6% of the study area. This model also shows that target prospective zones are quartz veins controlled by NNW-SSE trending fracture/fault zones all crosscutting Precambrian rocks of the ANS. Field observations and petrographic and X-ray diffraction analyses were performed to validate the mineral prospective map and revealed that quartz veins consist of gold–sulfide mineralization (e.g., gold, pyrite, chalcopyrite, and sphalerite). Consistency between the high potential hydrothermal alterations zones (HAZs) and the location of gold mineralization is achieved.

The dismembered ophiolites in the Wadi Al-Barramiya area, Central Eastern Desert of Egypt, are one of a series of Neoproterozoic ophiolites present in the Arabian-Nubian Shield. Here we present new fieldwork, whole-rock geochemical data, and mineral chemistry of metapyroxenite and metagabbro associated with the Al-Barramiya ophiolite in order to constrain its nature and tectonic setting; in particular whether the ophiolite was formed in a subduction or non-subduction setting. The rocks selected were obtained from the mantle section (serpentinized peridotite), an ultramafic (pyroxenite) and the crustal section (metagabbro). The serpentinized peridotite is altered to talc carbonate and listvenite, and associated with magnesite. Pyroxenite occurs as irregular coarse-grained lenses of websterite and olivine websterite within the serpentinite and occurs adjacent to the ophiolitic metagabbro. The metagabbros form scattered allochthonous masses of various sizes that are distributed across the area. The ophiolitic rocks are metamorphosed from greenschist to lower amphibolite facies. Locally, fresh relicts of olivine and Cr-spinel can be found in the serpentinite, whereas pyroxenite has fresh relicts of olivine, clinopyroxene and Cr-spinel. Cr-spinel in the metapyroxenite is zoned, with Al 2 O 3 , Cr 2 O 3 and MgO decreasing and FeO t increasing from cores to rims, reflecting the effects of metamorphism that selectively removed the now-depleted components. The metagabbros are characterized by enrichment in large-ion lithophile elements (LILE) over high field strength elements (HFSE) and are tholeiitic with a calc-alkaline affinity. The high Cr# (0.63–0.75) of fresh Cr-spinel relicts in the metapyroxenite, together with their low TiO 2 contents (0.04–0.24 wt%), indicate that this rock is similar to highly refractory ultramafic rocks that evolved in a fore-arc setting. This is supported by the high forsterite content (Fo = 0.91–0.93) of fresh olivine and high Mg# (0.93–0.95) of fresh clinopyroxene. Clinopyroxenes in the metapyroxenite and metagabbro have the chemical characteristics of boninite, confirming the fore-arc setting. Graphical Abstract

Ultramafic rocks exposed at the Earth's surface generally record multiple stages of evolution that may include melt extraction, serpentinization, carbonatization, and metamorphism. When quantitative thermometry based on mineral chemistry is applied to such rocks, it is often unclear what stage of their evolution is being observed. Here, in peridotites with extensive replacement of silicate minerals by carbonates (listwaenites), we present a case study that addresses the timing of carbonate formation relative to closure of exchange reactions among relict primary minerals. Massive and schistose serpentinized peridotites of Neoproterozoic age outcrop at Gabal Sirsir, South Eastern Desert, Egypt (northwestern corner of the Arabian-Nubian Shield or ANS). Petrography, bulk composition, and mineral chemistry are all consistent with a strongly depleted mantle harzburgite protolith for the serpentinites. Bulk compositions are low in Al2O3 and CaO and high in Mg# [molar Mg/(Mg+Fe) = 0.89-0.93]. Relict spinel has high Cr# [molar Cr/(Cr+Al)] and low Ti, while relict olivine has high Mg# and NiO contents. Based on compositions of coexisting relict olivine and chromian spinel, the protolith experienced 19 to 21% partial melt extraction. Such high degrees of partial melting indicate a supra-subduction zone environment, possibly a forearc setting. Along thrust faults and shear zones, serpentinites are highly altered to form talc-carbonate rocks and weathering-resistant listwaenites that can be distinguished petrographically into Types I and II. The listwaenitization process took place through two metasomatic stages, associated first with formation of the oceanic crustal section and near-ridge processes (∼750-700 Ma) and subsequently during obduction associated with the collision of East and West Gondwana and escape tectonics (∼650-600 Ma). In the first stage, Mg# of chromian spinel in the serpentinites continuously changed due to subsolidus Mg-Fe2+ redistribution, while the Mg# of chromian spinel in the Type I listwaenites was frozen due to the absence of coexisting mafic silicates. During the second stage, the Type II listwaenites formed along shear zones accompanied by oxidation of relict chromian spinel to form ferritchromite and Cr-bearing magnetite in both serpentinites and listwaenites. The high Cr# of chromian spinel relics in both serpentinites and listwaenites preserves primary evidence of protolith melt extraction, but divalent cations are more easily mobilized at low temperature. Hence, relict chromian spinel in listwaenites shows significantly higher Mg# and lower MnO than that in serpentinite, suggesting that nearly complete alteration of ultramafic rocks to form listwaenite took place prior to re-equilibration between chromian spinel and the surrounding mafic minerals in serpentinites. Furthermore, the ferritchromite in the serpentinites has higher Mn content (1.1-2.1 wt%) than that in the listwaenites (0.6-0.9 wt%), indicating its formation after carbonatization since carbonate minerals are a favorable sink for Mn.

The Suez Rift developed as a northern extension of the Red Sea rift during the Oligocene-Miocene, whose flanks were constructed from the Neoproterozoic basement rocks of the Arabian–Nubian Shield. These basement rocks are comprised of the whole tectonic history since their formation. The Suez Rift initiation model and proposed thermal overprint role in the rifting process and flank development remain uncertain. Additionally, the amplitude of different regional tectonic events’ effects on the region is still debatable. Integration of fission-track thermochronology data with modeling of the time-temperature history has demonstrated efficiency in addressing such issues. In the context of this study, eleven representative samples were collected from the different rock units in the Wadi El-Dahal area at the northern tip of the western flank of the Suez Rift. These samples revealed Carboniferous zircon fission-track cooling ages of 353 ± 9 Ma and 344 ± 11 Ma. Meanwhile, the apatite fission-track analysis provided two spatially separated age groups: Permian-Triassic and Late Cretaceous, with average ages of 249 ± 11 Ma and ca. 86 ± 10 Ma, respectively. The time-temperature modeling revealed four possible cooling pulses representing exhumation events, which were initiated as a response to four tectonic activities: the accretion-subsequent event of erosion during the Neoproterozoic, the Hercynian (Variscan) tectonic event during the Devonian-Carboniferous, the Mid-Atlantic opening during the Cretaceous, and the Suez Rift opening during the Oligocene-Miocene. The western flank of the Suez Rift suggests a passive mechanical type with no extra thermal overprint, as indicated by the dominance of older thermochronological ages, modest rift flank elevations, and a reduction in the heat flow.

A vast sequence of quartz-rich sandstone was deposited over North Africa and Arabia during Early Palaeozoic times, in the aftermath of Neoproterozoic Pan-African orogeny and the amalgamation of Gondwana. This rock sequence forms a relatively thin sheet (1–3 km thick) that was transported over a very gentle slope and deposited over a huge area. The sense of transport indicates unroofing of Gondwana terranes but the exact provenance of the siliciclastic deposit remains unclear. Detrital zircons from Cambrian arkoses that immediately overlie the Neoproterozoic Arabian–Nubian Shield in Israel and Jordan yielded Neoproterozoic U–Pb ages (900–530 Ma), suggesting derivation from a proximal source such as the Arabian–Nubian Shield. A minor fraction of earliest Neoproterozoic and older age zircons was also detected. Upward in the section, the proportion of old zircons increases and reaches a maximum (40%) in the Ordovician strata of Jordan. The major earliest Neoproterozoic and older age groups detected are 0.95–1.1, 1.8–1.9 and 2.65–2.7 Ga, among which the 0.95–1.1 Ga group is ubiquitous and makes up as much as 27% in the Ordovician of Jordan, indicating it is a prominent component of the detrital zircon age spectra of northeast Gondwana. The pattern of zircon ages obtained in the present work reflects progressive blanketing of the northern Arabian–Nubian Shield by Cambrian–Ordovician sediments and an increasing contribution from a more distal source, possibly south of the Arabian–Nubian Shield. The significant changes in the zircon age signal reflect many hundreds of kilometres of southward migration of the provenance.

The Arabian–Nubian Shield envelops the entire regional tectonic history from its formation during the Ediacaran to the Red Sea/Gulf of Suez rifting in the Oligocene–Miocene. The occurrence and extent of the expected successive tectonic events on Sinai basement rocks remain uncertain. Integration of thermochronological techniques with time–temperature modelling has proven to be a powerful tool for thermal-tectonic history reconstruction. Therefore, we collected representative samples from the Arabian–Nubian Shield basement rocks of the Wadi Agar area at the eastern flank of the Suez rift. Zircon fission-track data show two cooling age possibilities of Ediacaran and Devonian ages. Meanwhile, apatite fission-track data represent three cooling age spans of Carboniferous, Triassic, and Cretaceous. The integration of these data with the modelled time–temperature histories reveals four different cooling events synchronous with the regional events; (1) the Neoproterozoic post-accretion erosional event that causes near-surface rock uplift, (2) the Devonian–Carboniferous Hercynian tectonic event which affected the region with rocks exhumation of ca. 4.2 ± 1.4 km, (3) the Triassic Gondwana breakup initiation, and (4) the Oligocene–Miocene Gulf of Suez rifting which caused flanks uplift in the studied region of ca. 1.2 ± 0.4 km. The Gulf of Suez is a passive rift with a dominant mechanical component that is divided into two differently exhumed northern and southern segments, where an additional far-field thermal overprint was restricted to the southern segment.

Multi-isotope study including whole-rock Nd–Sr, single zircon Hf, and SIMS δ 18 O analyses of zircons sheds light on magma sources in the northernmost Arabian–Nubian Shield (ANS) during ~820–570 Ma. Reconnaissance initial Nd and Sr isotope data for the older rocks (~820–740 Ma) reaffirms previous estimates that early crustal evolution in this part of the shield involved some crustal contamination by pre-ANS material. Prominent isotope provinciality is displayed by post-collisional calc-alkaline and alkaline igneous rocks of ~635–570 Ma across a NW-SE transect across basement of the Sinai Peninsula (Egypt) and southern Israel. Silicic rocks of the NW-region are characterized by lower εNd(T)–εHf(T) and higher Sr i and δ 18 O compared with rocks of the SE-region, and the transition between the regions is gradual. Within each region isotope ratios are independent of the extent of magma fractionation, and zircon cores and rims yield similar δ 18 O values. Comparison with southern segments of the ANS shows that the source for most ~635–570 Ma rocks can be modeled as the isotopically aged lower-intermediate crust in the ANS core (SE-region) and its northern, more contaminated ANS margins (NW-region). Nevertheless, Nd–Sr isotope enrichment of the lithospheric mantle is indicated by some basic magmas of the NW-region displaying the most enriched Nd–Sr isotope compositions. Comparison of Nd and Hf depleted mantle model ages for rocks of the SE-region may indicate that crustal formation events in the ANS geographical core took place at 1.1–1.2 Ga and were followed by crustal differentiation starting at ~0.9 Ga.

The Egyptian Nubian Shield (ENS), the northwestern continuation of the East African Orogen (EAO), comprises a variety of three lithologically and structurally different tectonic provinces—southern compressional-, central transpressional/wrench-, and northern extensional- provinces. The extensional tectonic province (ETP) extends from Qena‒Safaga shear belt up to the northern tip of the ENS. Several lines of evidence indicate extensional regime in the ETP, such as mantle delamination-induced post-orogenic magmatism and bimodal Dokhan Volcanics, together with the pervasive E‒W dyke swarms and the E‒W (to ENE‒WSW) oriented extensional fractures. The present work is devoted to carry out the fault striae analysis and paleostress reconstruction of the northern tectonic province (ENS) in attempt to add more contribution to the brittle deformation history of the northern EAO. Field measurements collected from six areas (I‒VI) have been processed using Win-Tensor Software. Analysis of fault-slip data revealed four paleostress tensor stages (groups or regimes) that prevailed in the ENS. The stress states and related tectonic regimes are characterized by the stress regime index R' and the horizontal stress axes as follows: 1st stage: transpression (R' = 1.91), E‒W compression (SH max = N090°‒270° E); 2nd stage: transtension (R' = 1.16), N‒S compression (SH max = 174°‒354° E); 3rd stage: transpression (R' = 1.81), NE‒SW compression (SH max = N053°‒233° E); 4th stage: extension (R' = 0.31), E‒W extension (Sh min = N074°‒254° E). The 1st stage can be related to the oblique convergence between E and W Gondwanalands. The 2nd stage was probably concurrent with the N- to NNW-ward migration of the Central Eastern Desert syn-collisional delamination (triggering orogen-parallel extensional collapse) to the North Eastern Desert post-collisional delamination. The 3rd stage was controlled by the generally N‒S shortening which affected the northern and central ENS, post-dating the formation of volcanosedimentary Hammamat Basins. The 4th stage is akin to retreat of the Cadomian arc and the Red Sea rifting.