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Article

Geochronological Evolution of the Safaga–Qena Transect, Northern Eastern Desert, Egypt: Implications of Zircon U-Pb Dating

by
Sherif Mansour
1,
Abdelghafar M. Abu-Elsaoud
2,
Faouzi Haouala
2,
Mohamed Zaki Khedr
3,*,
Akihiro Tamura
4 and
Noriko Hasebe
5
1
Geology Department, Faculty of Science, Port Said University, Port Said 42522, Egypt
2
Department of Biology, College of Science, Imam Mohammad ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia
3
Department of Geology, College of Science, Taibah University, Madinah 42353, Saudi Arabia
4
Department of Earth Sciences, Kanazawa University, Kanazawa 920-1192, Japan
5
Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa 920-1192, Japan
*
Author to whom correspondence should be addressed.
Minerals 2025, 15(5), 532; https://doi.org/10.3390/min15050532
Submission received: 18 April 2025 / Revised: 13 May 2025 / Accepted: 15 May 2025 / Published: 17 May 2025
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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Abstract

:
The granitic rocks and the Dokhan Volcanics at the transect between Safaga and Qena, the Egyptian Northern Eastern Desert represent the northern termination of the Arabian–Nubian Shield (ANS), which, in turn, represents the northern part of the East African Orogeny (EAO). The geochronological development of the magmatic activities that constructed the ANS is critical in understanding these orogenies. The ANS was constructed through pre-collisional, syn-collisional, and post-collisional magmatic phases. The transition between these magmatic phases marks tectonic shifting from subduction to compressional and extensional tectonic settings, respectively. The chronological constraints of these tectonic–magmatic phases are still questionable. Our study aims to refine these chronological constraints through the dating of four calc-alkaline granitic rocks (722 ± 5 Ma–561 ± 4 Ma), five alkaline granitic rocks (758 ± 5 Ma–555 ± 4 Ma), and three Dokhan Volcanic rocks (618 ± 5 Ma–606 ± 5 Ma). Our results suggest the absence of any pre-collisional rocks. The syn-collisional magmatism extended here from 758 ± 5 Ma to 653 ± 7 Ma, demonstrating the chronological domination of the syn-orogenic compressional regime in the NED. The Dokhan Volcanic activity marked the shifting of the tectonic setting from a compressional to an extensional regime at 618 ± 5 Ma. Post-collisional plutonism dominated between 583 ± 5 Ma and 555 ± 4 Ma in the studied region, suggesting that ANS magmatic activity was extended to the Phanerozoic edge. These findings refute the classical interpretations of older magmatism as calc-alkaline granitoids and younger magmatism as alkaline granitoids. Pre-Neoproterozoic (pre-ANS) xenocrysts with ages of 1879 ± 22, 1401 ± 25, 1385 ± 12, 1232 ± 27, 1210 ± 18, and 1130 ± 15 Ma were yielded, which might support a local reworked ancient magmatic source.

1. Introduction

The Egyptian Northern Eastern Desert (NED) covers a substantial portion of the Arabian–Nubian Shield (ANS), which represents the northern East African Orogeny (EAO). The EAO resulted in the development of juvenile crust, including the ANS, through island arcs and micro-continent accretion into an ancient Archean crust (Figure 1) between ca. 900 Ma and ca. 650 Ma [1]. The evolution of the ANS lasted for ca. 350 Ma, with crustal growth occurring through three main tectonic–magmatic stages: (1) pre-collisional intra-oceanic subduction-related magmatism (900–800 Ma), accompanying arc accretion during the closure of the Mozambique Ocean; (2) syn-collisional magmatism (750–630 Ma), during conversion between the East and West Gondwana; and (3) post-collisional magmatism (630–550 Ma), developed through the extensional collapse of the thickened lithosphere and thinning of the newly formed continental crust [2,3,4,5,6,7,8,9,10,11,12]. These magmatic events developed according to tectonic shifting in the ANS through time from subduction-related to compressional and extensional settings. These tectonic–magmatic stages are temporally framed. Therefore, the fine-tuning of chronological boundaries between each of these magmatic events is fundamental in understanding the tectonic development of the ANS and, consequently, the EAO.
The shortage of inclusive regional geochronological studies with reliable techniques might have partly compromised our attempts to reconstruct the geological and tectonic history of the ANS. Earlier research on the ANS supported pre-Neoproterozoic remnants (pre-EAO) represented by metamorphic exposures [27,28,29,30]. Nevertheless, modern geochronological research does not verify the presence of major pre-Neoproterozoic rock suites [15,18,23,24,31,32,33,34,35,36,37,38]. Traditionally, researchers classified the granitoid rocks of this region into (1) an earlier group named the older, Gray, or calc-alkaline granitoids, with ages ranging from ca. 800 Ma to 630 Ma., and (2) a later group named the younger, Red, or alkaline granitoids, with ages between ca. 630 Ma and 540 Ma [39,40,41]. However, modern studies have shown concurrent calc-alkaline and alkaline granitoids in the NED and other ANS regions [13,14,18,20,24,36]. Additionally, the Dokhan Volcanics’ timing of eruption and their tectonic setting remain a subject of debate in terms of whether they were triggered by (1) collision between the West and East Gondwana or (2) the changing of tectonic settings from a compressional to a tensional regime [13,21,24,42,43,44].
The granitoid ages reported from the NED and Sinai demonstrate extensive variability between earlier and recent studies, which poses challenges to the efforts of categorizing them into established classifications [21,22,35,45,46]. Additionally, subsequent tectonic events disturbed the northern ANS with uplift and erosion, which removed a substantial amount of its basement rocks [47,48,49,50,51,52,53], particularly the majority of earlier magmatic events [54].
Uncertainties persist regarding the ANS rocks’ sequence of development, especially in terms of the chronological boundaries between the different magmatic suites in the NED. Several critical questions remain unanswered, including the existence of pre-Neoproterozoic suites, the temporal margins of the magmatic suite, and the rationality of classical attempts to differentiate the major magmatic pulses chronologically into older and younger according to the rocks’ apparent geochemical composition of Gray and Red, respectively. This study presents zircon U-Pb data for basement rock samples collected from the NED, which were analysed using the laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) technique (Table 1). These data are presented to provide further insights into our understanding of the construction history of the northern ANS by discussing the aforementioned unresolved questions.

2. Geologic Setting

Kennedy [55] introduced the term “Pan-African” to characterize extensive tectonic–thermal events spanning approximately 350 million years across the Gondwana supercontinent. The EAO represents the northern activities within the Pan-African framework, where the ANS was constructed by the accretion of oceanic plateaus, island arcs, and micro-continents into an Archean nucleus [3,56,57,58].
The Egyptian ANS consists of metamorphic rocks and igneous rocks with calc-alkaline-to-alkaline affinities, including metavolcanics, metasediments, schist, gneiss, ophiolite complexes, tonalite, diorite, granodiorite, and trondhjemite [59]. The Egyptian ANS of the Eastern Desert is broadly divided into three tectonically and chronologically different regions: the Northern Eastern Desert (NED), the Central Eastern Desert (CED), and the Southern Eastern Desert (SED) [21]. The NED basement rocks and the comparable Sinai regions are primarily characterized by vast granitoid occurrences accompanied by lesser metamorphosed and volcanic suites. These basement complexes are categorised broadly into the following: (1) Pre-collisional island arc-related highly deformed granitoids, metavolcanics, and metasediments, which originated in the earlier stages of the EAO (ca. 820–750 Ma) [14,16,60]; (2) Syn-collisional granitoids, marked by slightly deformed granitoids that developed through the subsequent compressional tectonic phases of the EAO, with formation ages ranging between ca. 750 Ma and ca. 630 Ma [21,24,61,62]. (3) Post-collisional undeformed granitoids, emplaced during the EAO late-extensional collapsing phase, with ages between ca. 630 Ma and ca. 560 Ma [14,63,64,65,66,67]. The Dokhan Volcanics eruption marked the initiation of the post-collisional stage between ca. 630 Ma and ca. 600 Ma, showing a geochemical composition ranging from basic to acidic rocks due to basaltic magma fractional crystallization and crustal contamination [13,43,68,69]. (4) Successive dike emplacement events occurred between ca. 590 Ma and ca. 550 Ma, indicating the continued dominance of the extensional tectonic processes until the conclusion of the EAO [14,38,70]. Despite these temporal classifications, there is still a debate about the chronological boundaries between each magmatic activity and, consequently, the transition between each tectonic setting. Additionally, there is a debate about whether these magmatic activities are synchronous or propagated from south to north [13,21,24,38].
Various attempts have been made to classify ANS granitoids in Egypt based on field observations and apparent geochemical compositions. The classical classification forms two main categories: (1) Earlier granitic rocks with ages of approximately 770–630 Ma that are classically constrained to granitoids with calc-alkaline affinities. Granitoids of this group are either called older [41], “Calc-alkaline or Gray” [71], syn- to late-orogenic [14,72], subduction-related G1 [73], Gα granites [74], or syn-collisional [24]. (2) Later granitic rocks with ages of approximately 610–560 Ma, which are classically limited to granitoids with alkaline affinities. Granitoids of this group are either called younger [41], “Alkaline or Red” [71], Gattarian [39], late-orogenic [14,75], suture-related G2 [73], Gβ granites [74], or post-collisional [24]. Most of these schemes do not offer inclusive geochronological or geochemical knowledge; therefore, they might mislead our regional tectonic assessment.
Geochemically, El-Bialy and Omar [2] have conducted detailed whole-rock major, trace, REE data, and petrographic studies on the Wadi Al-Baroud granitoids (on the northern border of the area of study). They concluded that the majority of the syn-collisional granitoids are calc-alkaline, granodiorite-to-tonalite, I-type granitoids. Post-collisional granitoids associated with regional transgression are affiliated mainly with peraluminous A-type granites [2]; however, massive I-type granitoids with high-K calc-alkaline are not uncommon [5]. The Dokhan Volcanics are high-K volcanic sequences frequently associated with A-type granites [2]. The Dokhan Volcanics represent transgression, escape, and crustal extension tectonism during the post-collisional phase [2,67,76,77].
The shortage of detailed dating studies and the imprecision of some earlier geochronological techniques complicate our ability to interpret the geological and tectonic history of the ANS. For example, earlier geochronological research on the ANS recommended the presence of pre-Neoproterozoic basement rocks, while recent studies suggest otherwise [13,18,23,24,31,32,33,34,35,36,37,38,70]. Granitoid ages from the region span the Neoproterozoic and post-Neoproterozoic periods. Generally, the oldest reported crystallization ages, ranging from ca. 1030 Ma to ca. 935 Ma, belong to the metamorphic complex of Sa’al and Solaf gneiss [6,15]. The youngest ages, ranging from ca. 580 Ma to ca. 560 Ma, belong to the younger granitic suite [7,14,18,20,23,78,79,80]. Subsequent Phanerozoic geological events—including the post-accretion erosional event (Cambrian), Variscan tectonism (Devonian–Carboniferous), Mid-Atlantic Ridge development (Cretaceous), and the Gulf of Suez rifting (Oligocene–Miocene)—provide additional difficulty to ANS evaluation due to having worn down an extensive amount of the ANS’s earlier suites [47,53,81,82].
Therefore, the chronological sequence of the igneous activities in the NED remains insufficiently addressed. Accordingly, we use the reliable zircon U-Pb technique to date the Safaga–Qena transect basement rocks, which represent the ANS exposures in the NED. These exposures are limited to granitic rocks and the Dokhan Volcanics (Figure 2).
The collected granitoids along the Safaga–Qena transect were plotted on the IUGS quartz (Q)–alkali feldspar (A)–plagioclase (P) diagram for plutonic rocks (Figure 3). Samples are plotted on the corresponding fields based on the apparent QAP percentage in hand specimens (Figure 3).

3. Methods and Techniques

Zircon crystals were separated using standard mineral concentration methods [14,35]. The U/Pb and Th/Pb isotopic ratios were revealed by employing the LA-ICP-MS system at Kanazawa University, Japan. The detailed specifications and operating conditions of the LA-ICP-MS setup can be found in the work of Tamura et al. [83]; these are described in brief in Table 2. Common issues encountered in the LA-ICP-MS methodology, such as instrumental mass bias, U-Th/ Pb dissociation, and elemental fractionation during the ablation process, were addressed using the following strategies: (1) employing a 213 nm wavelength for the laser [84,85]; (2) helium and argon gases were used to transport the post-ablated powder to the mass spectrometer; (3) restricting the ablation duration to ca. 30 s to avoid extreme heating [83,86,87,88]; and (4) frequent usage of reference materials such as Fish Canyon, GJ-1, AS3, and Plěsovice zircons to reduce mass bias and correct laser-induced fractionation [86,87].
Zircon references with well-documented ages were regularly analysed to ensure the reliability of our measurements. Our derived ages for the reference zircons—Fish Canyon tuff, GJ-1, AS-3, and Plěsovice—were 28.8 ± 0.3, 612 ± 2, 1099 ± 2, 341 ± 2 Ma, respectively. These values align closely with the reference ages of 28.4, 609, 1099, and 337.1 Ma [87,89,90,91]. To calibrate the 238U signal intensities, we used the SRM 610 standard material with a known uranium concentration of 456 ppm [92]. Additionally, the signal intensity of 29Si served as an inner identifier for tracking the geochemical configuration of zircons [92,93].
The LA-ICP-MS signals were inspected during all analyses to check that the signal intervals were steady and flat and contained no inclusions, variations between the core and rim of the crystal, high common Pb zones, or signal fractionation. After background correction, the average isotopic intensities were calculated to derive the isotopic ratios.
To address common Pb contamination in zircon ages, methods like measuring 204 Pb to be subtracted from the radiogenic Pb isotopes could be used [94]. During our analyses, counts of 204 Pb (and 204 Hg) were frequently below the detection limit (Table 3). Therefore, it was not feasible to determine 204 Pb with adequate precision in this study. As a result, all reported ages are not adjusted for 204 Pb contamination. The concordant ages, along with their 2σ uncertainties, are presented in the text, in Figure 2, and on Concordia diagrams, and were calculated using IsoplotR [95].

4. Results

We obtained zircon U-Pb data from 170 grains separated from 12 ANS basement samples from the collected rocks. Grains with detectable levels of common lead, cracks, or inclusions were eliminated. As expected, the cathodoluminescence (CL) images revealed various internal zircon grain structures. Our study explored the crystallisation ages of the examined grains; therefore, we typically tried to analyse the core of each dated grain (Figure 4). Grains that did not exceed 90% concordance were excluded from the calculations.
For Sample SQ01 (Figure 2), a total of 13 zircon grains were analysed (Table 3). These grains exhibited varying degrees of transparency, ranging from clear to yellow, and were primarily prismatic in shape with well-formed euhedral faces. The average ratio between grain length and width was approximately 3:1. Most grains contained inclusions, and nearly 70% displayed prominent cracks. The isotopic ratios of Th/U varied between 0.19 and 0.64, with an average value of about 0.35 (Table 3). Grain A7, which showed discordance exceeding 10%, was excluded from the age determination and interpretation processes. All other grains were clustered on the Concordia, and grains C6 and D2 produced younger ages of concordance of 430 ± 6 Ma and 475 ± 14 Ma, respectively (Figure 5, Table 3). The remaining 10 crystals represented a unified population of an age of concordance of 563 ± 5 Ma (Figure 6), calculated using IsopltR [95]. The 563 ± 5 Ma age is interpreted as the formation age for the SQ01 syenogranitic sample (Figure 2; Table 1).
In Sample SQ03 (Figure 2), 15 zircon grains were analysed (Table 3). These grains exhibited varying degrees of transparency, ranging from translucent with minimal yellow to brown staining, and were primarily euhedral crystal form. The average ratio between grain length and width was approximately 2:1. Most grains contained inclusions, and nearly 60% displayed prominent cracks. The Th/U ratios varied between 0.3 and 1.13, averaging approximately 0.61. Grains B5 and D1 displayed discordance exceeding 10% and were excluded from further consideration. All other grains yielded concordant ages, with grains C7 and D3 producing pre-Pan-African ages of 1130 ± 15 Ma and 1210 ± 18 Ma, respectively (Figure 5). Grain D8 displayed a younger (compared to the total sample population) concordant age of 530 ± 10 Ma. The remaining 10 crystals represented a unified population of an age of concordance of 653 ± 7 Ma (Figure 7), representing the age of crystallization for the diorite rock (Figure 2; Table 1).
For Sample SQ05 (Figure 2), a total of 15 zircon grains were analysed (Table 3). These grains exhibited varying degrees of transparency, ranging from transparent to yellow appearance, and were primarily euhedral crystals. Their average length-to-width ratio was approximately 3:1. Most grains contained small inclusions, and nearly 70% displayed prominent cracks. The Th/U ratios varied between 0.24 and 0.54, averaging approximately 0.37 (Table 3). Grain C2, which showed discordance exceeding 10%, was excluded from the age determination and interpretation processes (Table 3). The remaining 14 grains demonstrated clustering on the Concordia (Figure 7), representing a unified population of an age of concordance of 569 ± 3 Ma. The 569 ± 3 Ma age is interpreted as the age of formation for the granodiorite rock under study (Table 1; Figure 2).
In Sample SQ06, a total of 15 zircon grains were analysed (Table 3). These grains exhibited a predominantly transparent appearance and were primarily euhedral crystals. The average ratio between grain length and width was approximately 3:1. Most grains contained small inclusions, and nearly 60% displayed prominent cracks. The isotopic ratios of Th/U varied between 0.02 and 0.67, with a mean ratio of about 0.37 (Table 3). Grain C5, which showed a discordance percentage surpassing 10%, was excluded from the age determination and interpretation processes (Table 3). The remaining 14 grains demonstrated clustering on the Concordia (Figure 6), indicating a unified population of an age of concordance of 675 ± 5 Ma. The 675 ± 5 Ma age is interpreted as the formation age for the syenite rock sample under investigation (Figure 2; Table 1).
For Sample SQ08 (Figure 2), a total of 11 zircon grains were analysed (Table 3). These grains exhibited varying degrees of transparency, ranging from transparent colours to occasional yellow-to-brown discolouration, and were primarily euhedral crystals. Their average length-to-width ratio was approximately 3:1. Most grains contained small inclusions, and nearly 70% displayed prominent cracks. The isotopic ratios of Th/U varied from 0.19 to 0.7, with a mean ratio of about 0.46 (Table 3). Grains B9 and C2 yielded pre-Pan-African ages of concordance of 1879 ± 22 Ma and 1401 ± 25 Ma (Figure 5), respectively. The remaining nine crystals represented a unified population of an age of concordance of 722 ± 5 Ma (Figure 7). This age is interpreted as the age of crystallization for the diorite rock under examination (Table 1; Figure 2).
In Sample SQ09, a total of 13 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from translucent to brown to yellow staining occasionally, and were primarily euhedral crystals. The average ratio between grain length and width was approximately 3:1. Most grains contained inclusions, and nearly 65% displayed prominent cracks. The isotopic ratios of Th/U varied from 0.29 to 0.8, with a mean ratio of about 0.49 (Table 3). All 13 crystals represented a unified population of an age of concordance of 561 ± 4 Ma (Figure 7). The 561 ± 4 Ma age is interpreted as the age of formation for the monzodiorite rock under study (Figure 2; Table 1).
In Sample SQ10, a total of 15 zircon grains were analysed (Table 3). These grains predominantly exhibited a transparent colour and primarily displayed euhedral crystal forms. The average ratio between grain length and width was approximately 3:1. Most grains contained small inclusions, and nearly 60% displayed prominent cracks. The Th/U ratios varied between 0.02 and 2.41, with a mean ratio of about 0.54 (Table 3). Grains B8, C5, and D3, which showed discordance exceeding 10%, were excluded from the age determination and interpretation processes (Table 3). The remaining 12 grains demonstrated clustering on the Concordia (Figure 6), indicating a unified population with an age of concordance age of 583 ± 5 Ma. The 583 ± 5 Ma age is represented as the crystallization age for the pegmatite rock under examination (Table 1; Figure 2).
In Sample SQ12, a total of 15 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from yellow to brown discolouration, and were primarily euhedral crystals. The average ratio between grain length and width was approximately 2:1. Most grains contained minor inclusions, and nearly 65% displayed prominent cracks. The isotopic ratios of Th/U varied from 0.17 to 0.55, with a mean ratio of about 0.39 (Table 3). Grains B2, C3, and C5, which showed discordance exceeding 10%, were excluded from the age determination and interpretation processes (Table 3). All other grains clustered around the Concordia, with grains C9 and D6 yielding pre-Pan-African ages of concordance of 1385 ± 12 Ma and 1232 ± 27 Ma, respectively (Figure 5). The remaining 10 crystals represented a unified population with an age of concordance of 758 ± 5 Ma (Figure 6). The 758 ± 5 Ma age was interpreted as the crystallization age for the granite rock under investigation (Figure 2; Table 1).
In Sample SQ13, a total of 12 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from yellow to brown discolouration, and were primarily euhedral crystals. The average ratio between grain length and width was approximately 2:1. Most grains contained minor inclusions, and nearly 65% displayed prominent cracks. The isotopic ratios Th/U varied between 0.02 and 0.59, with a mean ratio of about 0.28 (Table 3). Grains A3 and B9, which showed discordance exceeding 10%, were excluded from the age determination and interpretation processes (Table 3). The remaining 10 crystals exhibited clustering on the Concordia (Figure 8), forming a unified population with an age of concordance of 618 ± 5 Ma. The 618 ± 5 Ma age was interpreted as the crystallization age for the meta-andesite rock under analysis (Figure 2; Table 1).
In Sample SQ14, a total of 15 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from yellow to brown discolouration, and were primarily euhedral crystals. The average ratio between grain length and width was approximately 2:1. Most grains contained minor inclusions, and nearly 60% displayed prominent cracks. The isotopic ratios Th/U varied from 0.16 to 1.1, with an average value of about 0.4 (Table 3). Grains B4 and D1, which showed a discordance percentage surpassing 10%, were excluded from the age determination and interpretation processes (Table 3). The remaining 13 crystals demonstrated clustering on the Concordia (Figure 8), representing a unified population with an age of concordance of 606 ± 5 Ma. The 606 ± 5 Ma age is interpreted as the crystallization age for the andesite rock under examination (Table 1; Figure 2).
In Sample SQ15, a total of 15 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from transparent to occasional yellow discolouration, and were primarily euhedral crystals. Their average length-to-width ratio was approximately 3:1. Most grains contained small inclusions, and nearly 60% displayed prominent cracks. The isotopic ratios Th/U varied from 0.2 to 0.74, with a mean ratio of about 0.47 (Table 3). Grains C5, D8, and D9, which showed discordance exceeding 10%, were excluded from the age determination and interpretation processes (Table 3). All other grains yielded ages of concordance, and grain E1 showed an earlier age of concordance of 735 ± 7 Ma (Figure 2). The remaining 11 crystals represented a unified population with an age of concordance of 555 ± 4 Ma (Figure 6). The 555 ± 4 Ma age was interpreted as the crystallization age for the syenogranite rock under investigation (Table 1; Figure 2).
In Sample SQ16, a total of 15 zircon grains were analysed (Table 3). These grains exhibited varying transparency, ranging from yellow to brown discolouration, and were primarily euhedral crystals. The average ratio between grain length and width was approximately 2:1. Most grains contained minor inclusions, and nearly 60% displayed prominent cracks. The Th/U ratios varied between 0.09 and 1.13, with a mean ratio of about 0.38 (Table 3). Grains B2, B9, D3, and D9, which showed discordance exceeding 10%, were excluded from the age determination and interpretation processes (Table 3). The remaining 11 grains demonstrated clustering on the Concordia (Figure 8), representing a unified population with an age of concordance of 608 ± 3 Ma. The 608 ± 3 Ma age is interpreted as the age of formation for the andesite rock under examination (Table 1; Figure 2).

5. Discussion and Interpretation

Most of the Th/U isotopic values yielded from the concordant zircons ranged between 0.11 and 2.41, with an average value of 0.45 (Table 3). This range of ratios supports a magmatic origin for all zircon crystals based on countless analyses of magmatic and metamorphic zircons [96], and on studying low-temperature/high-pressure zircons [97]. We excluded three crystals that showed lower ratios: A10 from Sample SQ06, B1 from Sample SQ10, and B4 from Sample SQ13. These were magmatic samples, except for Sample SQ13, which was meta-andesite (Table 1). Still, the ages of all three grains were located within the representative single population of the corresponding sample’s age (Table 3).
The resulting U-Pb ages can be categorized into three distinct magmatic episodes: (1) Syn-collisional [14] magmatic events (ca. 758–653 Ma) are exemplified by the intrusion of both types of granitoid plutons, which are classically termed “Older, Gray, or Calc-alkaline” or “Younger, Red, or Alkaline” granitoids. Specifically, samples SQ12, SQ08, SQ06, and SQ03 yielded ages of concordance of 758 ± 5 Ma, 722 ± 5 Ma, 675 ± 5 Ma, and 653 ± 7 Ma, respectively (Table 1; Figure 2), overlapping with the previously documented ages of the “older” granites [22,24]. (2) Dokhan Volcanic activity (approximately 618–606 Ma) is illustrated by samples SQ13, SQ16, and SQ14, with ages of 618 ± 5 Ma, 608 ± 3 Ma, and 606 ± 5 Ma, respectively (Table 1; Figure 2), in agreement with the published ages of the Dokhan Volcanics [13,21,24,43,44,98]. The Dokhan Volcanics preceded the other post-collisional magmatism, likely marking the onset of the extensional tectonic stage in the studied region at 618 ± 5 Ma. (3) Post-collisional [14] magmatic events (ca. 583–555 Ma) are characterised by granitic intrusions that are classically termed “older, Gray, or calc-alkaline” or “younger, Red, or alkaline” granites, and are represented by samples SQ10, SQ05, SQ01, SQ09, and SQ15, yielding concordant ages of 583 ± 5 Ma, 569 ± 3 Ma, 563 ± 5 Ma, 561 ± 4 Ma, and 555 ± 4 Ma, respectively (Table 1; Figure 2). These results align with the published ages of the younger granites in different regions of the ANS [3,5,7,13,24,46,99,100]. The younger age here (i.e., 555 ± 4 Ma) emphasises the continuity of EAO magmatic activity in the NED up to the Pre-Cambrian/Palaeozoic boundary, as in southern Sinai [14]. The absence of representative ages of pre-collisional magmatic activity (i.e., the oldest phase) in the NED raises questions about its nonexistence or being constructed and wholly eroded, as indicated by Mansour et al. [54].
Granitoid rocks of both calc-alkaline or Gray and alkaline or Red granitoids, which are classically referred to as older and younger granitoids, respectively, coexist in both the syn-collisional and the post-collisional magmatic activities of our study. Therefore, the classical connection between calc-alkaline or Gray granites as the older rock suite and alkaline or Red granites as the younger rock suite is misleading.
Xenocrysts with pre-Pan-African ages (Paleo-Mesoproterozoic) were detected in three different samples (SQ03: grains C7 and D3; SQ08: grains B9 and C2; and SQ12: grains C9 and D6), yielding ages of concordance of 1130 ± 15 Ma, 1210 ± 18 Ma, 1879 ± 22 Ma, 1401 ± 25 Ma, 1385 ± 12 Ma, and 1232 ± 27 Ma, respectively (Table 3; Figure 9). Zircon grains with comparable ages are progressively identified in modern research on the magmatic rock suites of the juvenile ANS [7,14,18,22,25] and clastic sedimentary rocks [54]. These xenocrysts raise doubts concerning the probability of a former occurrence and removal of pre-Pan-African crust [54].
An inherited zircon grain was observed in Sample SQ15 (grain E1), yielding an age of concordance of 735 ± 7 Ma (Table 3), which is consistent with published studies suggesting a reworked nature of the ANS magmatic intrusions [7,14,18,22,23].
Zircon grains with younger ages (compared to the interpreted ages of crystallization populations) were identified in two different samples (SQ01: grains C6 and D2: and SQ03: grain D8), with ages of concordance of 430 ± 6 Ma, 475 ± 14 Ma, and 530 ± 10 Ma, respectively (Figure 5). These may represent new growth during magmatic differentiation or overgrowth during metamorphism. Their Th/U ratios indicate a magmatic source, especially since they were extracted from granitic samples (Table 1). However, grain D2 had an unexclusive ratio of 0.19 (Table 3). The age of 530 ± 10 Ma (SQ03: grain D8) could document a further extension of post-collisional magmatic activity [14]. While the ages of 475 ± 14 Ma and 430 ± 6 Ma (SQ01: grains C6 and D2) are of uncertain significance, dykes with consistent ages were documented in the Sharm El Sheikh area, South Sinai [19], as noted by Mansour et al. [14,54].

6. Conclusions

  • The ANS basement rocks of the NED revealed two distinguishable temporal phases of igneous events: (a) the syn-collisional phase, characterized by the presence of calc-alkaline (Gray) and alkaline (Red) granitoids, developed between 758 ± 5 Ma and 653 ± 7 Ma, and (b) post-collisional activities, which were initiated by the eruption of the Dokhan Volcanics around 618 Ma, followed by the development of calc-alkaline (Gray) and alkaline (Red) granitoids from 583 ± 5 Ma to 555 ± 4 Ma.
  • The compressional tectonic regime dominated in the NED from 758 ± 5 Ma to ca. 618 Ma (at which point the transition from the compressional to the extensional regime began), and the extensional tectonic setting has dominated since ca. 583 ± 5 Ma.
  • EAO magmatic activity in the NED continued up to the Pre-Cambrian/Palaeozoic boundary, as indicated by the younger granitoid age of 555 ± 4 Ma.
  • Differentiating “older” and “younger” granitic magmatism according to their apparent compositional differences fails to adequately reflect the geological processes in the ANS, leading to inaccurate interpretations of temporal magmatic sequencing and tectonic evolution.
  • Although no pre-Neoproterozoic rock was identified in the studied region, the occurrence of xenocrystic zircons suggests the potential for older basement components, which are likely confined to specific localities or entirely eroded.
  • There is potential for post-Pan-African volcanic activity during the Late Ordovician period, indicating continued magmatic processes beyond the Pan-African orogeny.

Author Contributions

Conceptualization, S.M. and N.H.; methodology, S.M., A.T., and N.H.; validation, S.M., F.H., M.Z.K., A.M.A.-E., and N.H.; formal analysis, A.T., M.Z.K., F.H., and S.M.; investigation, S.M., F.H., A.M.A.-E., M.Z.K., and N.H.; resources, N.H., A.M.A.-E., and F.H.; data curation, S.M. and M.Z.K.; writing—original draft preparation, S.M.; writing—review and editing, N.H., F.H., A.T., M.Z.K., and A.M.A.-E.; visualization, S.M., F.H., A.M.A.-E., and M.Z.K.; supervision, N.H.; project administration, S.M., A.T., F.H., and A.M.A.-E.; funding acquisition, N.H., F.H., and A.M.A.-E. All authors have read and agreed to the published version of the manuscript.

Funding

This research work was supported and funded by the Deanship of Scientific Research at Imam Mohammad ibn Saud Islamic University (IMSIU) (grant number IMSIU-DDRSP2503).

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors without undue reservation.

Acknowledgments

We acknowledge the support and fund of the Deanship of Scientific Research at Imam Mohammad ibn Saud Islamic University (IMSIU) (grant number IMSIU-DDRSP2503).

Conflicts of Interest

The authors declare no conflicts of interest.

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Minerals 15 00532 g001
Figure 1. (A) The EAO and the ANS within the framework of the Gondwana assemblage (modified from [13]), where SF is the São Francisco craton and RP is the Rio de la Plata craton. (B) The location of the northern ANS (represented in (C)) is within the frame of Africa, Arabia, and Eurasia. (C) Location map for the Egyptian ANS with previous key dating results (modified from [14]). OG is Older Granites, YG is Younger Granites, DV is Dokhan Volcanics, and PD is Phanerozoic dyke. G. Samra [14], Feiran area [6,15,16], Wadi Kid [17], Wadi Nasib and Wadi Ghazalla [18], Wadi Lithi [19], Taba area [20], Gabal Gharib [21], Marsa Alam–Idfu [13], Gabal Dara, Gabal Zeit, Gabal Abu Harba, and Gabal Qattar [22,23], Qift–Quseir [24], Fawakhir, Ghadir, Gerf Nappe, and Haimur [25], and Wadi Allaqi [26].
Figure 1. (A) The EAO and the ANS within the framework of the Gondwana assemblage (modified from [13]), where SF is the São Francisco craton and RP is the Rio de la Plata craton. (B) The location of the northern ANS (represented in (C)) is within the frame of Africa, Arabia, and Eurasia. (C) Location map for the Egyptian ANS with previous key dating results (modified from [14]). OG is Older Granites, YG is Younger Granites, DV is Dokhan Volcanics, and PD is Phanerozoic dyke. G. Samra [14], Feiran area [6,15,16], Wadi Kid [17], Wadi Nasib and Wadi Ghazalla [18], Wadi Lithi [19], Taba area [20], Gabal Gharib [21], Marsa Alam–Idfu [13], Gabal Dara, Gabal Zeit, Gabal Abu Harba, and Gabal Qattar [22,23], Qift–Quseir [24], Fawakhir, Ghadir, Gerf Nappe, and Haimur [25], and Wadi Allaqi [26].
Minerals 15 00532 g001
Minerals 15 00532 g002
Figure 2. Location map for analysed samples along the Safaga–Qena transect area where zircon U-Pb ages are represented. Sample numbers 1, 2, 3, …., 16 correspond to sample codes SQ01, SQ02, SQ03, ……, SQ16 in Table 1.
Figure 2. Location map for analysed samples along the Safaga–Qena transect area where zircon U-Pb ages are represented. Sample numbers 1, 2, 3, …., 16 correspond to sample codes SQ01, SQ02, SQ03, ……, SQ16 in Table 1.
Minerals 15 00532 g002
Minerals 15 00532 g003
Figure 3. IUGS quartz–alkali feldspar–plagioclase diagram with the collected granitoid rocks of the study area plotted.
Figure 3. IUGS quartz–alkali feldspar–plagioclase diagram with the collected granitoid rocks of the study area plotted.
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Minerals 15 00532 g004
Figure 4. Cathodoluminescence (CL) images for some of the analysed zircons, representing location and ages of analysed spots.
Figure 4. Cathodoluminescence (CL) images for some of the analysed zircons, representing location and ages of analysed spots.
Minerals 15 00532 g004
Minerals 15 00532 g005
Figure 5. Single-crystal zircon U-Pb ages for samples with un-Pan-African (older and younger) ages, where mean ages and MSWD values were determined from concordant grains after excluding older and younger crystals.
Figure 5. Single-crystal zircon U-Pb ages for samples with un-Pan-African (older and younger) ages, where mean ages and MSWD values were determined from concordant grains after excluding older and younger crystals.
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Minerals 15 00532 g006
Figure 6. Concordia diagram for all zircon grains with discordance percent ≤10% for all alkaline granitic samples, plotted using IsopltR [95].
Figure 6. Concordia diagram for all zircon grains with discordance percent ≤10% for all alkaline granitic samples, plotted using IsopltR [95].
Minerals 15 00532 g006
Minerals 15 00532 g007
Figure 7. Concordia diagram for all zircon crystals with discordance percent ≤10% for all calc-alkaline (older) granitic samples, plotted using IsopltR [95].
Figure 7. Concordia diagram for all zircon crystals with discordance percent ≤10% for all calc-alkaline (older) granitic samples, plotted using IsopltR [95].
Minerals 15 00532 g007
Minerals 15 00532 g008
Figure 8. Concordia diagram for zircon grains from the Dokhan Volcanics rock samples with ≤10% discordance, plotted with 2σ error using IsopltR [95].
Figure 8. Concordia diagram for zircon grains from the Dokhan Volcanics rock samples with ≤10% discordance, plotted with 2σ error using IsopltR [95].
Minerals 15 00532 g008
Minerals 15 00532 g009
Figure 9. Distribution chart of the analysed single-zircon U-Pb concordant ages of all samples.
Figure 9. Distribution chart of the analysed single-zircon U-Pb concordant ages of all samples.
Minerals 15 00532 g009
Table 1. The samples examined for this study.
Table 1. The samples examined for this study.
SampleLocationElev.
m.a.s.l.		Th/URock TypeTraditional Suite ClassificationConcordant
LatitudeLongitudeAge (Ma)±2σ
(Ma)
Syn-orogenic
SQ1226 33 11.733 18 58.54990.390GraniteRed or Younger Granite7585
SQ0826 42 36.833 36 08.06230.463DioriteGray or Older Granite7225
SQ0626 42 08.333 41 12.84530.373SyeniteRed or Younger Granite6755
SQ0326 43 13.833 47 52.22510.657DioriteGray or Older Granite6537
Post-orogenic/Dokhan eruptions
SQ1326 30 2.033 43 20.76400.308Meta-AndesiteDokhan Volcanics6185
SQ1626 38 25.433 53 31.12230.393DaciteDokhan Volcanics6083
SQ1426 25 58.533 50 25.33900.399AndesiteDokhan Volcanics6065
Post-orogenic/Magmatic emplacement
SQ1026 41 07.133 31 20.56750.547PegmatiteRed or Younger Granite5835
SQ0526 41 26.533 43 53.43670.373GranodioriteGray or Older Granite5693
SQ0126 45 59.233 51 38.62090.345SyenograniteRed or Younger Granite5635
SQ0926 42 36.833 36 08.06230.498MonzodioriteGray or Older Granite5614
SQ1526 32 40.033 50 35.23560.469SyenograniteRed or Younger Granite5554
Elev. (m.a.s.l.) means elevation in meters above sea level.
Table 2. Operating conditions for LA-ICP-MS.
Table 2. Operating conditions for LA-ICP-MS.
ICP-MS
ModelAgilent 7850
Forward power1200 W
Plasma gas flow15 L min−1
Carrier gas flow1.10 L min−1 (Ar), 0.3 L min−1 (He)
InterfaceNi sampler/Ni skimmer
Laser
ModelUP-213 (New Wave Research)
Wavelength213 nm (Nd-YAG)
Spot size25 μm
Repetition rate5 Hz
Energy density7 J cm−2 (Attenuater: 50%–60%)
Warming up10 s
Table 3. LA-ICP-MS U-Th-Pb zircon data for the studied samples.
Table 3. LA-ICP-MS U-Th-Pb zircon data for the studied samples.
Gr.Intensities
and 3σ D. L.		Conce. (µg/g) and 2σ ErrorsIsotopic Ratios and 2σ ErrorsAge (Ma) and 2σ Errors %Discordance
204Pb3σ238U2σTh/U2σ206Pb/
238U		2σ207Pb/
235U		2σ208Pb/
232Th		2σ206Pb/
238U		2σ207Pb/
235U		2σ207Pb/
206Pb		2σConc.2σ
Sample SQ01
A20.0240.004263420.3830.0460.090850.009740.732230.008420.031050.002005611255810546145559-0.5
A40.170.03470980.2840.0440.086820.012410.695510.010580.028110.0020853715536135331853612−0.1
A50.0870.013398800.2730.0390.096640.012770.788040.011320.030130.0020159515590135711858612−0.8
* A70.0030.0009680.3310.0330.069860.004480.675320.004620.037540.00158435552469317247516.9
B30.0050.0017360.6380.0440.088780.004990.731500.004420.027750.0012154865575594756651.6
C11.1110.1675111100.2020.0320.086460.012880.697260.011060.028030.00183535155371354719540130.5
** C60.0000.000174200.6080.0640.072500.006270.544240.004810.023800.0015745184416388114306−2.3
C100.0010.000117120.3510.0280.087260.006230.732490.005620.029720.0012253975587634957373.4
** D20.670.108462200.1950.0390.075810.014470.592980.011730.024410.00201471174731548023475140.4
D80.760.11315530.2020.0250.085280.009980.700300.008730.029330.00150528125391058715551102.1
E30.0960.014176230.4370.0440.088710.007770.750080.007100.028730.00162548956886501158683.6
E50.0940.014194260.390.040.087210.008020.717410.007060.029130.001625391054985901255981.8
E758.48.85471250.190.030.089720.013850.711480.011720.030790.0019955416546145112053713−1.5
Sample SQ03
A8−0.0140.002108350.9050.0820.963810.088770.109820.000650.033390.002126856672572976825−2.0
A10−0.0090.001159610.7780.0830.924690.102300.110880.000790.034460.00246665166781462018668131.9
B40.0070.001153580.7390.0760.943660.102930.110760.000780.034960.0023967596778666967580.4
* B5−0.0030.000107330.2980.0220.916650.082950.085480.000500.034790.000006611052971140175917−24.9
B6−0.0070.001161640.6510.0670.982760.110970.114080.000820.033850.00223695146961269015695110.2
C30.0020.000132450.4440.0390.860620.085430.104870.000680.031960.0015763156435585263461.9
** C70.0050.001170320.6960.0750.194510.017512.038020.024920.061100.004331128171146151094181130151.5
C8−0.0010.0004252600.3030.0450.883910.158120.103770.001210.031260.002286439637866696418−1.0
*D10.0050.00195260.2950.0210.809930.067280.075640.000410.038420.000006021147071137195268−28.2
** D30.0040.001134240.5950.0550.215630.017382.276170.025650.065020.003781205211259191109201210184.3
D5−0.0090.001196840.380.040.933090.114860.106510.000840.034760.0019466919652167252266516−2.6
** D80.0090.001143450.6970.0690.687130.067450.085500.000570.029400.0018853112529115401453010−0.4
E40.0120.00297280.630.050.851090.072120.101290.000560.032590.0016362518622156362162415−0.5
E70.0050.00183220.5920.0430.834070.064910.100350.000520.031510.0014261611617106131361690.1
E80.0090.0012621261.1280.1690.886480.124700.103640.000950.034610.0038364522636196752464218−1.4
Sample SQ05
A10.0120.0028070.4670.0320.095550.005650.760090.004850.030590.001205887574651785595−2.5
A30.0070.0014330.3160.0150.091990.003960.729670.003370.030650.000725675556451155434−2.0
A90.0060.0013020.3000.0120.093680.003410.777270.003070.031510.0006157745844609558931.1
B20.0040.001144170.3100.0270.095980.007620.822460.007170.031850.00136591960986781062683.1
B70.0010.000154190.2380.0210.091310.007480.765890.006800.030600.00119563957786321159082.4
B100.0020.0005540.530.030.094260.004620.762190.004030.029760.001025815575555375704−0.9
* C20.0100.001162160.2950.0270.055380.004580.515120.004350.039220.00000348642268518173517.6
C8−0.0030.000107110.2980.0220.094850.006490.800490.005980.031330.0011358485977646960872.2
C90.0040.0015840.5440.0320.092150.004620.771310.004190.029330.0010556855815628659252.1
D2−0.0040.001192260.3470.0350.092180.008450.743760.007340.029860.00157568105659548125618−0.7
D40.060.01152180.3880.0360.088420.007180.710640.006160.030980.0015354695457540115447−0.2
D6−0.0050.001110110.4820.0390.088970.006150.727590.005400.028310.0013254975556578956161.0
E10.0030.001131150.4410.0380.092540.007000.794810.006560.030490.00149571859476831061583.9
E70.0050.0019590.2950.0210.090330.005820.752060.005230.030590.0010455875696616957962.1
E90.0050.0014330.2650.0120.091750.003980.724270.003360.028220.000615665553450055384−2.3
Sample SQ06
A60.0120.0025140.5850.0330.109280.005180.946470.005060.033450.0011766966765701768351.1
A10−0.0040.001343690.0220.0030.112440.013890.932410.012930.035140.0006268716669146081765112−2.7
B10.0160.002122150.2100.0160.111020.008170.968380.008080.034170.001116791068887161069681.3
B9−0.0030.001138170.4260.0380.106230.008300.927920.008150.033700.001666511066797191168092.4
C20.0060.001248410.5450.0670.105790.011080.900680.010530.034520.00258648136521166515656110.6
* C50.0050.0014330.2650.0120.091750.003981.141260.005900.052770.000005665773614295229226.8
C80.0000.000152200.6260.0620.107500.008830.914490.008410.035160.002216581065996631166190.2
D1−0.0050.001126150.3170.0260.108810.008130.950570.008020.034610.00141666967887191069081.9
D20.0010.000194290.6740.0770.109850.010190.975550.010280.032890.00242672126911175413710112.8
D50.0060.001194280.290.030.102710.009510.886890.009150.033100.00161630116451069412658102.2
D90.0240.0045091230.1700.0260.107110.016080.918210.015450.035130.00211656196611667921667160.8
D100.0070.001344690.3150.0420.109810.013570.931870.012940.034300.0023067216669146581766613−0.4
E20.0390.0065061190.190.030.103850.015520.868000.014370.033600.0021263718635166252163215−0.4
E60.0070.001202310.540.060.111890.010610.945770.010100.045960.0031168412676116491366910−1.2
E100.070.017081960.3050.0590.101700.017970.867720.017000.033750.00319624216341966924644181.6
Sample SQ08
A10.0470.0077992550.6830.1580.120260.022751.045170.022750.037440.0056373226727237082772917−0.8
A20.0430.006271500.2780.0330.120040.013231.035810.013110.037790.0021173115722136931672610−1.2
A70.0030.000126160.4970.0430.113670.008520.980430.008350.035070.001796941069496921069470.0
B10.0450.007348740.5170.0750.120990.015101.083970.015710.038460.00332736177461577318742121.2
B40.0020.00092100.4030.0290.116380.007451.027080.007540.036540.0014371097188741971461.1
** B90.0050.001167420.6960.0740.333110.031465.530420.098460.100400.007191853311905311962181879222.7
** C20.0040.0014091340.3030.0440.240870.034333.006800.065580.071610.005221391361409331436251401251.3
C40.0060.0018080.450.030.115380.006881.037920.007120.039440.0015170487237781871452.6
C80.0030.0015472880.190.032.124650.55551229.78043.972523.90717.59125734522955253874893826228142−32.9
D40.0050.0016860.5390.0350.117410.006471.057080.006730.038350.0015071687327783872552.3
D80.0170.002207330.5490.0620.118840.011431.078160.012030.037590.0025872413743127991373492.5
Sample SQ09
A70.0000.000174230.6080.0640.091050.007940.742230.006960.030410.00201562956485711156680.4
A90.0010.000117120.3510.0280.088800.006350.737190.005670.029450.0012154885617610957172.2
B3−0.0050.001194260.6740.0770.090760.008350.759310.007550.030110.002215601057496271258592.4
B60.0100.001162200.2950.0270.092420.007770.744990.006750.028740.0012757095658546115617−0.8
B80.0960.014177230.4370.0440.088820.007790.752260.007130.030640.00173549957086531158893.7
C10.0010.000154180.3860.0360.086400.007080.747480.006610.031200.00155534856786991059395.8
C30.0040.001188250.8040.0940.091590.008300.719210.006970.045630.00363565105508489125347−2.7
C50.0010.000113110.4670.0380.085820.006000.713330.005340.028300.0013253175476613956262.9
C60.0270.004194270.390.040.092410.008510.743940.007370.030370.00169570105659543125608−0.9
D2−0.0100.001143160.6970.0690.085500.006730.687130.005740.029400.00188529853175401053370.4
D8−0.0030.000110110.4820.0390.089460.006190.738520.005500.030030.0014055275626598957161.6
E10.0030.001131150.4410.0380.092540.007000.794810.006560.030490.00149571859476831061583.9
E60.0030.0009690.4440.0330.087540.005660.689660.004730.030500.001285417533649695245−1.6
Sample SQ10
A10.0120.0025140.5850.0330.093470.004400.810170.004180.033450.0011757656035703662454.4
A30.0080.0015181160.1510.0230.092210.013870.740140.011970.033950.0019356916563145371955613−1.1
A40.0040.001248380.4700.0570.089260.009280.769700.008690.031320.00217551115801069213604114.9
B1−0.0040.001343630.0220.0030.092030.011260.771600.010240.035140.00062568135811263215594112.3
B20.0030.000115120.2240.0170.089930.006360.738260.005610.031280.0010255575616586956861.1
* B80.0000.0004791050.7070.1280.091940.013301.158370.020060.042600.000015671578119145416226727.4
C40.0040.001134152.4090.3260.090640.006930.744640.006140.027770.00320559856575881057071.0
* C50.0020.000142190.440.040.113580.009051.229150.011800.046140.000006941081411115810410814.8
C70.0010.00098100.6790.0550.091720.005990.743420.005220.031550.001655667564655885636−0.2
* D30.0080.001287500.3780.0480.098410.011051.127130.015000.051940.000016051376614127013285721.0
D60.0160.002122130.2100.0160.086400.006290.742130.005820.033000.0010753475647683958975.2
D70.0070.001381730.4040.0590.091200.011760.755800.010530.029210.00233563145721260616580121.6
E4−0.0030.001138160.4260.0380.090260.007000.767840.006460.029450.00145557857976631059883.7
E70.0080.001176230.4370.0440.090490.007940.772780.007360.029110.00164558958186711160194.0
E100.0020.000153190.5460.0530.096450.007900.817030.007340.031190.00183594960686541061982.1
Sample SQ12
A50.0060.001248450.5450.0670.121930.012861.123190.013880.038960.00292742157651383115754103.0
A60.0070.001344720.3150.0420.118530.014701.072190.015420.037990.00255722177401579317732112.4
A80.0070.001202330.540.060.122120.011631.068640.011770.038630.002607431373811723147409−0.6
A90.090.016121690.3260.0590.117200.019381.043530.019870.039280.00358714227261976023721151.6
* B20.0960.014176230.4370.0440.088710.007771.610380.018610.066890.0000054899741421199631843.8
B3−0.0070.001232410.5420.0650.127400.013031.155850.013930.039360.00285773157801379914777100.9
B70.0130.0026001650.3210.0570.118080.019341.027640.019300.037460.0033572022718197112371914−0.3
* C30.0010.000116120.480.040.089460.006360.926940.007470.037590.000005527666810728604617.1
* C50.0010.000339610.2810.0370.088710.010770.914730.012540.028200.000005481366013106214599916.9
** C90.0060.001115200.5110.0430.244390.018522.842490.032230.073650.00371141019136717130013138512−3.1
D10.0030.000102120.4660.0360.121060.008201.097260.008660.037780.0016873797528797974562.0
D30.140.024931210.1680.0250.114530.016980.976020.016400.036090.0021169919692176662069513−1.1
** D60.070.017082860.3050.0590.213250.039532.327960.060870.064280.00617124641122136117631123227−2.1
E30.0320.0058772900.3480.0760.116550.023071.040030.023700.037310.00420711267242376427718171.8
E70.180.037082090.2940.0560.115510.020531.051040.021570.036510.00339705237292180524718163.4
Sample SQ13
A20.0120.0025140.5850.0330.103350.004880.891950.004700.033750.0011863466475693666152.1
* A30.670.108461900.1950.0390.056910.010760.348610.006340.024110.00000357103049532443158−17.5
A60.0080.0015181200.1510.0230.097040.014630.829480.013750.033950.00193597176131567320627152.7
B10.0040.001248400.4700.0570.097320.010150.858650.009930.033030.00229599126291174014652124.9
B4−0.0040.001343650.0220.0030.097860.012010.771600.010240.032470.0005760214581124981756010−3.7
B70.0030.000115130.2240.0170.103010.007330.822420.006400.031280.0010263286097525105876−3.7
* B90.760.1111303150.0560.0120.064490.014150.573500.013030.040320.000004031746017757233703112.5
C40.0160.002122140.2100.0160.101170.007410.855260.006930.033000.00107621962876491063371.0
C50.0070.001381760.4040.0590.099080.012820.828200.011770.034400.00275609156131362517616120.6
D7−0.0030.001138160.4260.0380.097520.007590.797860.006760.033910.0016760095968579105917−0.7
D90.0080.001176240.4370.0440.097970.008620.804030.007730.033000.00186603105999585115968−0.6
E60.290.046861840.1550.0280.099480.017270.834350.015940.033620.00223611206161763223620170.7
Sample SQ14
A10.0060.001248400.5450.0670.097320.010150.789420.008950.030080.002245996591556075835−1.3
A60.0020.000153190.5460.0530.096450.007900.817030.007340.033580.0019759456064654561942.1
A90.0240.0045091160.1700.0260.095910.014330.818000.013400.036290.00218590860776681062282.7
B20.0050.0015821430.180.030.098550.015760.814100.014250.031050.0020360696058599116048−0.2
* B4−0.0070.001149190.2860.0250.095510.007721.520130.015870.043070.000005885939618865213137.3
B70.0010.0009391.0980.0970.099210.006330.793790.005510.030220.001966104593353045753−2.8
B9−0.0080.001154200.5450.0530.099840.008220.833910.007550.030040.0017761356164623561840.4
C20.0030.0004631020.4090.0660.098990.014120.825110.012920.032850.00290608861176191061370.4
* D10.0000.000116120.480.040.089460.006360.926940.007470.037590.000005524666410724305317.1
D2−0.0020.000393790.2520.0350.096600.012680.809620.011630.032430.0020859476027630961061.3
D40.0000.0004721050.2410.0370.098940.014250.799250.012540.034150.0023460885967551105856−2.0
D80.0070.001344650.3150.0420.098180.012070.831640.011240.032460.0021760476156654862561.8
E1−0.0140.002158200.5360.0530.097160.008080.782610.007070.030310.001795985587454565764−1.8
E50.0390.0065061150.190.030.096730.014410.821640.013430.033600.00212595860976591062272.3
E80.0000.0004821080.1590.0240.097660.014200.826740.013210.034530.0019560186127652962371.8
Sample SQ15
A9−0.0060.001136150.3720.0320.089930.006930.732890.006060.029140.0013355585587570955750.6
B10.0030.0008932600.5620.1330.089160.017580.773290.016570.034630.00499551205821970425567145.3
B2−0.0030.001154180.5450.0530.086860.007110.726520.006380.030040.00177537855576261054763.2
B6−0.0030.000116120.480.040.089460.006360.689340.005200.028830.001385527532644795405−3.7
C21.090.164991070.2020.0310.086460.012740.752260.011990.032280.00208535155701471118553106.1
* C51.110.175111280.2020.0320.086460.012885.044620.150950.454900.00000535151827503993155521570.7
C80.0030.000256400.3830.0460.090850.009600.777190.008930.031760.0020256111584106751457384.0
D20.0010.000107110.5340.0430.086290.005870.683650.004930.028910.001405347529650885314−0.9
D70.0010.000105100.4540.0350.084230.005680.675820.004830.025610.0011352175246536852340.6
* D80.0010.0004931170.1680.0250.106420.015721.087940.018800.036090.0000065218748181045196981312.8
* D90.0030.00097102.240.250.093360.006071.222560.009650.036520.000005757811915277656629.0
** E10.0060.001134170.7390.0710.118210.009161.087830.009800.036730.002357201074798291073573.6
E30.0020.000339600.2510.0330.088710.010770.751820.009860.031520.0018754813569116551556083.8
E70.0080.00199100.5680.0450.089420.005880.760560.005420.032640.0015855275746662856453.9
E90.0030.0009390.540.040.090560.005750.770070.005310.032320.0014655975806662857153.6
Sample SQ16
A60.0130.0025741410.3360.0590.099000.015720.852800.014980.032840.00293609186261669021641162.8
A70.140.024931120.1680.0250.098740.014530.858500.013990.097840.00589607176291570919647163.5
* B20.0240.004263420.3830.0460.090850.009741.046440.013080.041960.000005611172713128112249622.9
B40.070.017081900.3340.0650.096050.016920.770370.014690.029150.0028859120580175352356815−1.9
B50.0320.0058772670.3480.0760.099460.019540.882890.019330.040580.00458611226432075325667234.9
B80.390.067742180.2800.0560.096610.017800.857390.017510.034430.00326595216291975323655215.4
* B90.090.01398590.2730.0390.049380.006380.788040.011320.056400.0000031185901318911065247.3
C10.3020.0459102860.1580.0320.101680.020360.893690.019980.114330.00915624236482173226669223.7
C60.0140.00210493410.0890.0190.095200.020410.749720.017300.029380.0019258624568204952854918−3.2
C80.0020.0005531310.2600.0430.095560.014870.780760.013190.029360.0022658817586155762058414−0.4
* D30.0010.000116120.480.040.089460.006360.926940.007470.037590.000005527666810728305617.1
* D90.0020.000339610.2810.0370.088710.010770.914730.012540.028200.0000054813660131062143051016.9
E10.0120.00297100.630.050.101290.006620.851090.006140.032590.0016362286257636862960.5
E30.0050.0018380.5920.0430.100350.006050.800660.005260.030490.001376177597652485795−3.2
E60.0090.001262451.1280.1690.103640.011150.886480.010620.035630.00394636136451167514653111.4
Gr = grains, A1 grain symbol; * A7 = grains with %Discordance ˃10; ** C6 = older or younger grains, which were excluded from age calculations; intensities represent background-corrected signal intensities; 3σ calculated for signal background to represent the detection limit of our system; Conc. = concentration by µg/g, ±2σ error; %discordance = percent of discordance between 206Pb/238U and 207Pb/235U ages.
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MDPI and ACS Style

Mansour, S.; Abu-Elsaoud, A.M.; Haouala, F.; Khedr, M.Z.; Tamura, A.; Hasebe, N. Geochronological Evolution of the Safaga–Qena Transect, Northern Eastern Desert, Egypt: Implications of Zircon U-Pb Dating. Minerals 2025, 15, 532. https://doi.org/10.3390/min15050532

AMA Style

Mansour S, Abu-Elsaoud AM, Haouala F, Khedr MZ, Tamura A, Hasebe N. Geochronological Evolution of the Safaga–Qena Transect, Northern Eastern Desert, Egypt: Implications of Zircon U-Pb Dating. Minerals. 2025; 15(5):532. https://doi.org/10.3390/min15050532

Chicago/Turabian Style

Mansour, Sherif, Abdelghafar M. Abu-Elsaoud, Faouzi Haouala, Mohamed Zaki Khedr, Akihiro Tamura, and Noriko Hasebe. 2025. "Geochronological Evolution of the Safaga–Qena Transect, Northern Eastern Desert, Egypt: Implications of Zircon U-Pb Dating" Minerals 15, no. 5: 532. https://doi.org/10.3390/min15050532

APA Style

Mansour, S., Abu-Elsaoud, A. M., Haouala, F., Khedr, M. Z., Tamura, A., & Hasebe, N. (2025). Geochronological Evolution of the Safaga–Qena Transect, Northern Eastern Desert, Egypt: Implications of Zircon U-Pb Dating. Minerals, 15(5), 532. https://doi.org/10.3390/min15050532

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