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BY 4.0 license Open Access Published by De Gruyter Open Access March 23, 2022

Statistical analysis on the radiological assessment and geochemical studies of granite rocks in the north of Um Taghir area, Eastern Desert, Egypt

  • Hamdy A. Awad EMAIL logo , Ibrahim Abu El-Leil , Aleksey V. Nastavkin , Abdellah Tolba , Mostafa Kamel , Refaey M. El-Wardany , Abdalla Rabie , Antoaneta Ene EMAIL logo , Huseyin O. Tekin , Shams A. M. Issa and Hesham M. H. Zakaly EMAIL logo
From the journal Open Chemistry

Abstract

Granite rocks are currently one of the foremost raw materials that can be used for various economic purposes such as ornamentation and building materials, because they do not possess radioactive concentrations and have good physical and mechanical properties. The granite rocks of north Um Taghir are connected to neoproterozoic rocks and integrated to the north Arabian-Nubian Shield (ANS), which lies in Northeast Africa. Inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence analysis, concurrent to some statistical analysis, have been carried for major oxides and some trace elements to extract much fundamental information by following certain mathematical methods. The exposed granite rock units in north Um Taghir are classified into four rock units represented by tonalite, granodiorite, monzogranite, and alkali-feldspar granite which are cut by different types of dikes. The magma of tonalite and granodiorite is low-to-medium K calc-alkaline affinity, while the magma of monzogranite and alkali-feldspar granite is medium-to-high K calc-alkaline affinity, and of metaluminous to peraluminous nature. Granite rocks show a slightly depletion of fractionated patterns from light rare earth elements (LREEs) to heavy rare earth elements (HREEs) with slightly positive to negative Eu anomalies from tonalite to monzogranite and alkali-feldspar granites. The statistical criteria have been achieved to explore the significant differences of radiological hazard parameters among samples. It is obvious that there is no homogeneity among samples; furthermore, in Kruskal–Wallis test, Mann–Whitney test, and Pearson correlation coefficient, it can be noticed that there are significant differences between each pair of samples: tonalite, monzogranite; tonalite, alkali-feldspar granite; granodiorite, monzogranite; and granodiorite, alkali-feldspar granite. There is a strong direct relationship among granodiorite and both tonalite and alkali-feldspar granite, and among alkali-feldspar granite and tonalite and granodiorite. There is a strong inverse relationship among monzogranite and tonalite, granodiorite, and alkali-feldspar granite. As stated by all results, it can be mentioned that the granite rocks have a worthy result of mechanical and physical properties. So that they can be used for various economic purposes.

1 Introduction

Granites constitute about 60% of exposures neoproterozoic basement rock in the Eastern desert and Sinai as a part of the Arabian-Nubian shield (ANS) related to the pan African orogenic belt [13]. Due to the widespread distribution of granite in Egyptian basement rock units, numerous studies and works have been conducted to classify the various granitic rocks in Egypt, based on their geologic context, petrographic, geochemical, and geochronological characteristics [4–8]. It can be concluded that the granite rock can be classified into two major types: the first type is older granite (880–610 Ma); can be mentioned as gray granite, shaitian granite, syn- to late-tectonic, and G1 granites. It comprises mainly trondhjemite, quartz diorites, tonalities, and granodiorites with calc-alkaline affinity of subduction origin. Quartz-diorite and tonalite always older than dokhan volcanic (Pre-dokhan). The second type is younger granite (620–540 Ma), it also referred to as Post-orogenic and anorogenic. The second type is younger granite (620–540 Ma), it also referred to as post-orogenic and anorogenic, Guattarian Granite, G2 and G3 granite, and red to pink granite usually alkaline to per-alkaline are formed by suture-related and intraplate granites, likewise, is classified into three phases: phase I comprises granodiorites and monzogranites, phase II comprises mainly monzogranites and syeno-granites, and phase III comprises mainly alkali feldspar granites. As well as, Monzogranite and Syanogranite always younger than dokhan volcanic. The two types of granite rocks are related to I-type granite, but some of the younger granite are A-type, rift-related granites. Granite rocks are currently one of the most essential raw materials for various economic reasons, such as decorative and construction materials, assuming they do not contain substantial radioactive concentrations and have excellent physical and mechanical capabilities [9–12]. Granite rocks of the north Um Taghir area are restricted in the southern extreme boundary of the northeastern Desert of Egypt on the Qena-Safaga road (Figure 1). It covers about 400 km2, between latitudes 26° 35′00″–26° 49′00″ and longitudes 33° 35′00″–33° 50′00″. It belongs to the North ANS, which constituent neoproterozoic evolution in northeast Africa [13–18]. Mostly, the ANS represents the largest area formed by the upper part of the mantle, with a length of 3,500 km and a width extending to 1,500 km; the African Orogen part (East African Orogeny) of ANS covers about 2.7 km2 × 106 km2 [7], as shown in Figure 2. Many researchers have been studied in the area along the road of Qena-Safaga [19,20–27]. Simultaneously, the statistical analysis is one of the most significant applications that appertain to scientific research, through which the researcher collects a set of factors that control his scientific research and assemble the critical analysis, subsequently, extracting the essential information from them by following certain mathematical methods, besides drawing his conclusion and recommendations from numerous sources, where these relationships are sensibly related to the content, thus emerging a new meaning of importance from the relationships that have no meaning if they exist individually. Statistical analysis is one of the types of analysis that is carried out when planning to do a specific project, or when conducting scientific research, Indeed the statistical analysis is one of the most important reasons for the success of the project or the scientific research presented by the researcher due to the great role that statistical analysis plays, from by providing important and valuable information that greatly helps the success of scientific research.

Figure 1 
               Sentinal-2B 421 in RGB image showing the location of the study area.
Figure 1

Sentinal-2B 421 in RGB image showing the location of the study area.

Figure 2 
               Geological map of Um Taghir area, created based on integrated processing of data from regional geological surveys, remote sensing, and field observations. Quaternary formations: 1 – (sand, pebbles, conglomerates). Neoproterozoic formations: 2 – schist; 3 – metagabbro; 4 – granodiorite; 5 – tonalite; 6 – gabbro; 7 – monzogranite, 8 – alkali-feldspar granite; 9 – Dokhan volcanics; (10) mafic dikes; 11 – felsic dikes; 12 – faults.
Figure 2

Geological map of Um Taghir area, created based on integrated processing of data from regional geological surveys, remote sensing, and field observations. Quaternary formations: 1 – (sand, pebbles, conglomerates). Neoproterozoic formations: 2 – schist; 3 – metagabbro; 4 – granodiorite; 5 – tonalite; 6 – gabbro; 7 – monzogranite, 8 – alkali-feldspar granite; 9 – Dokhan volcanics; (10) mafic dikes; 11 – felsic dikes; 12 – faults.

2 Materials and methods

About 28 samples of granite rocks have been collected from 20 sites in the north Um Taghir area. The samples (approximately 1 kg) were taken to the lab for sample preparation. Thin sections were performed at the Central Laboratory of Institute of the Earth Sciences, Southern Federal University, Russia. The mineral analyses were measured by microscopic modal analyses. The collected samples were dried and sieved through a fine mesh (<1 mm) (0.256 mm) for homologation. The samples were placed inside an oven for drying at 100°C for one day to completely remove moisture. The quantitative analyses were measured by ICP-MS, after digestion of the fused beads with HF + HNO3. The external of pure solution standers were selected for calibration. Measurements were performed on an ELAN-DRC-6100 ICP-MS at the Central Laboratory of Russian Geological Institute. Also, major oxides and some trace elements testing was carried out by X-ray fluorescence analysis at the Institute of Biology, Southern Federal University. The X-ray powder diffraction method works by collecting and analyzing the spectrum generated by exposing the test material to X-ray radiation. Set the voltage to 10 kV for light elements, 20–30 kV for medium components, and 40–50 kV for heavy elements.

2.1 Geological observations

The investigated granite rocks are affiliated with the Late Cryogenian-Ediacaran age magmatism of the East African Orogeny; they are represented by late to post-orogenic (Continental crust terrain) [7,28]. The granite rocks have a good result of mechanical and physical properties, so they can be used for various economic purposes [11]. We collected and prepared the representative samples from the different rock types from the investigated area in addition to using the QAP plutonic classification diagram [29]; the exposed rock units in the studied area have been classified into four distinct rock units represented by tonalite, granodiorite, monzogranite, and alkali-feldspar granite, which are traversed by different types of dikes as shown in Figures 2 and 4a. As Shown in Table 1 and Figure 2.

3 Results

3.1 Geological seating and petrographic description

3.1.1 Tonalite

It is located in the southeast of the study area, with distinguished gray color, jointed and low relief hills. It is intruded directly by monzogranite and crosscut in oldest rock (Figure 3a), on the other hand, monzogranite contains some xenolith of the tonalite rocks as big bodies (xenoliths; Figure 3b), nearby the contact with the quaternary rocks and monzogranite. Tonalite is represented essentially by plagioclase of andesine composition (∼50.3%), quartz (∼30%), and alkali-feldspar (∼3.15%), with some additional amount of biotite and hornblende, while sphene, zircon, and iron oxide occur as accessory minerals (Figure 4b).

Figure 3 
                     Photograph showing (a) Tonalitic rock (Tn) intruded in oldest rock (OR) at Gable Abu Furad (b) Monzogranite (Mz) contains on xenoliths from tonalitic rocks (Tn) at Wadi Um Taghir, (c) sharp contact between granodiorite (Gr) and monzogranite (Mz) at Gable Abu Hawiesand (d) sharp contact between granodiorite (Gr) and alkali-feldspar granite at Gable Abu Haweis.
Figure 3

Photograph showing (a) Tonalitic rock (Tn) intruded in oldest rock (OR) at Gable Abu Furad (b) Monzogranite (Mz) contains on xenoliths from tonalitic rocks (Tn) at Wadi Um Taghir, (c) sharp contact between granodiorite (Gr) and monzogranite (Mz) at Gable Abu Hawiesand (d) sharp contact between granodiorite (Gr) and alkali-feldspar granite at Gable Abu Haweis.

Figure 4 
                     (a) Plots of the investigated granites on QAP diagram [29] and (b) photomicrograph showing flaky crystals of biotite (Bt) associated with plagioclase (P) and quartz grains (Qz) in tonalite. (c) photomicrographs showing albite twin of plagioclase (P) associated with quartz grains (Qz) and crystal of orthoclase (Or) in granodiorite, (d) subhedral crystal of perthite (Pr) enclosing grains of quartz (Qz) to show poikilitic texture with very fine grain of biotite (Bt) and twin of plagioclase (P) in monzogranite and (e) orthoclase perthite (Or) with grains of quartz (Qz) and very fine grained of muscovite (Ms) in the alkali feldspar granite (CN).
Figure 4

(a) Plots of the investigated granites on QAP diagram [29] and (b) photomicrograph showing flaky crystals of biotite (Bt) associated with plagioclase (P) and quartz grains (Qz) in tonalite. (c) photomicrographs showing albite twin of plagioclase (P) associated with quartz grains (Qz) and crystal of orthoclase (Or) in granodiorite, (d) subhedral crystal of perthite (Pr) enclosing grains of quartz (Qz) to show poikilitic texture with very fine grain of biotite (Bt) and twin of plagioclase (P) in monzogranite and (e) orthoclase perthite (Or) with grains of quartz (Qz) and very fine grained of muscovite (Ms) in the alkali feldspar granite (CN).

3.1.2 Granodiorite

It is characterized by medium grained to coarse grained with greyish in color and moderate relief; it exhibits some foliation and joints. Nevertheless, monzogranite intruded in granodiorite with sharp contact, becomes visible especially at Abu Haweis granite (Figure 3c). Petrographically granodiorite occurs as medium-grained with a granular texture; it is composed mainly of plagioclase which ranges in composition between oligoclase and andesine (An16–An36) with an amount of 45.9%, quartz (∼30.4%), and alkali-feldspar (∼16.3%) as essential minerals. At the same time, apatite, biotite, and iron oxide represent the accessory minerals (Figure 4c).

3.1.3 Monzogranite

It covers about 30% of the investigation region and directly cuts granodiorite (Figure 3c), instead, monzogranite is intruded by alkali-feldspar granite by sharp contact. It is distinguished with white to pinkish in color, coarse-to-medium-grained massive rock, high relief, highly jointed in two trends E–W and N–S, and highly fractured due to the effect of numerous faults trends. On the other hand, cavernous cavity and exfoliation are very common. It often exhibits granite texture and consists predominantly of alkali-feldspar with an average ∼38.6% represented by microcline, orthoclase, and perthite, plagioclase of oligoclase in composition (∼29.7%), and anhedral grain quartz (∼27.8%). On the other hand, a negligible quantity of muscovite and biotite, while the accessory minerals are represented by zircon and iron oxides.

3.1.4 Alkali-feldspar granite

It represents the youngest unit of granite magma in the study area. The alkali-feldspar granite is characterized by an elongated NS belt extending from Abu Haweis in the north part of the study area to Wadi Um Taghir at the south (Figure 2). It shows high topographic relief up to ∼890 m in Abu Hawies. It is distinguished by massive, medium-to-coarse-grained pink to red color and less jointed. Moreover, it is intruded by the granodiorite and monzogranite with sharp contact between them (Figure 3d). Furthermore, it is composed mainly of alkali-feldspar minerals with an average ∼59.8% of perthite, microcline, and little amount of orthoclase, likewise quartz (∼33.2%) and noticeable amount as of plagioclase of albite in composition (∼3.4%), with addition small amounts of muscovite and iron oxide (Figure 4e).

3.2 Geochemistry of the investigated rock units

The results of the complete silicate analyses of the major oxides and trace elements of 28 samples were represented by 4 samples for tonalite, 6 samples for granodiorite, 13 samples for monzogranite, and 5 samples for alkali-feldspar granite (Tables 2 and 3).

Table 1

Geochronology of the basement rocks in the study area

Orogenic setting Rock units Age (Ma) Reference (age)
Late to post-orogenic Alkali-feldspar granite 650–542 Youngest Johnson et al. [7] and Johnson [28]
Monzogranite Oldest
Granodiorite-tonalite
Gabbro
Table 2

Major oxides, trace and REE of tonalite and granodiorite

Sample no. Tonalite Granodiorite
42 65 69a 79 23 26 31a 46 75 76
SiO2 60.7 64 63.2 64.5 69 67.7 68.5 69.2 68.4 69.3
Al2O3 14.8 13.2 14.4 14.4 14.9 14.5 13 13.1 13.4 14.3
Fe2O3 10 6.55 6 5.54 2.91 2.59 5.16 3.46 3.48 3.43
FeO 0.3 3.2 1.3 2.02 0.52 0.75 1.23 1 1.2 1.3
CaO 5 3.87 5.01 4.47 3.94 4.48 4.4 3.09 5.59 3.85
MgO 1.94 1.92 2.77 1.92 0.91 0.86 0.84 1.56 1.35 0.92
P2O5 0.8 0.25 0.33 0.23 0.3 0.16 0.14 0.2 0.17 0.16
TiO2 2.04 0.74 0.9 0.6 0.73 0.38 0.37 0.74 0.48 0.38
Na2O 2.6 3.4 2.9 3.6 4.3 4.4 3.2 4.1 3.9 4.03
K2O 0.91 2.04 1.54 1.01 1.07 1.57 1.83 1.95 1.69 1.49
LOI. 0.68 0.99 0.52 0.8 0.35 0.94 0.76 0.95 1.02 0.97
Av 99.7 99.7
Cr 16.1 56.6 123 42.2 28.3 17.6 13.3 26 33.6 14.3
Ni 14.6 35.8 105 33 24.9 10 28 24.7
Cu 1.59 28.4 90.8 23.3 18.5 4 3 21.2 16.8 0.1
Zn 186 80.4 87.5 64.2 60.2 68.4 34.2 66.8 57 52.7
Zr 25 30 27 32 51 62 43 56 47 40
Rb 12 23.5 11 14.4 12 84 75 52 66 73
Y 10 13.1 8 7.4 8.5 11.5 12 15.1 10.2 14
Ba 434 456 486 180 388 376 298 412 363 322
Pb 29.9 4.36 14.6 24.3 9.4 15 18 21 20 18.1
Sr 623 480 915 857 801 431 388 712 405 637
Ga 13 9 10 12 14 16 12 15 11 17
V 167 74.1 100 62.8 71.7 25 25.3 67.2 44 26.1
Nb 17 15 12 14 16 21 15 14 18 17
Co 104 33 52.9 31 21.4 15 18 24.8 19.3 12.3
U 1.05 1.5 1 0.7 1.2 1.4 1.06 1.45 1.23 1.02
Th 2.8 2.85 2.57 1.16 2.7 2.44 2.63 2.9 2.87 2.52
La 18 22 20 13 17 16 21 25 28 20
Ce 53 51 49 29 39 42 38 44 51 47
Pr 5 7 6 4 5 4 7 6 5 9
Nd 19 25 27 14 19 17 23 20 24 26
Sm 6 4 5 3 3.3 4 3.5 3.8 3.1 4.1
Eu 2 1 2 1 1.1 2 1.6 1.8 1.4 2.6
Gd 3 5 4 2 2.6 3 2.8 2.4 2.1 3.2
Tb 1 2 1 0.3 0.34 0.2 0.5 0.6 0.4 0.35
Dy 3 1 2 2 2 3 2 4 3 5
Ho 0.6 0.8 0.5 0.3 0.3 0.8 0.2 0.7 1 0.6
Er 2 1 1.3 1 1 3 1 2 4 2
Tm 0.4 0.5 0.2 0.13 0.13 0.2 0.3 0.1 0.16 0.2
Yb 1 1.2 1 0.6 0.8 1 1.2 1.8 1.6 1.3
Lu 0.3 0.4 0.2 0.1 0.13 0.5 0.4 0.5 0.6 0.3
∑REE 114 122 119 70.4 91.7 96.7 103 113 125 122
Eu\Sm 0.3 0.25 0.4 0.3 0.3 0.5 0.45 0.5 0.45 0.6
Av(Eu\Sm) 0.3 0.5
Table 3

Major oxides, trace and REE of monzogranite and alkali-feldspar granites

Sample No. Monzogranite Alkali-feldspar granite
1 4 11 13 16 28B 33A 35 52A 54 61B 74B 78 14A 19A 33B 36 52B
SiO2 77 76 73.6 77.6 75.7 75 75.5 73.9 72.5 73 70.6 72.58 73.1 76.6 77.12 75.6 76.3 74
Fe2O3 2.34 1.9 1.8 1.9 2.46 2.04 2.44 2.97 3.22 3.3 4.7 3.7 2.62 1.9 1 1.92 1.43 2.6
FeO 0.12 0.04 1.4 0.87 1.05 1.2 1 0.84 0.91 0.8 1.3 0.48 0.91 0.23 0.3 0.16 0.13 0.4
CaO 0.43 0.2 2.2 0.5 1.6 1.61 0.8 1.6 1.8 1.03 1.6 1.7 1.9 1 0.2 0.76 0.83 1.35
MgO 0.23 0.09 0.7 0.3 0.25 1.5 1.2 1.13 1.5 0.4 0.64 1.73 1.4 0.14 0.14 0.24 0.29 0.85
TiO2 0.4 0.08 0.3 0.12 0.2 0.11 0.12 0.08 0.4 0.5 0.6 0.2 0.3 0.15 0.16 0.2 0.15 0.07
P2O5 0.07 0.06 0.11 0.07 0.16 0.06 0.07 0.16 0.1 0.08 0.14 0.6 0.12 0.06 0.06 0.07 0.06 0.06
Al2O3 10.6 12 11.4 10.2 11.4 11.3 10 10.8 11.44 13.2 12 12 11.3 10.9 10.9 11 11.54 11.7
Na2O 3.5 4.4 4.35 3.02 4.01 4.1 3.2 3.76 3.44 3.3 3.4 3.76 3.53 3.35 4.15 4 4.03 4.16
K2O 4.73 3.64 3.5 4.2 3.64 4.6 4.8 3.9 3.1 3.7 4.3 3.01 3.86 4.65 6.4 4.9 5 4.9
LOI. 0.67 1.06 0.85 0.65 0.54 0.42 0.27 0.84 0.86 0.75 0.7 0.69 0.88 0.35 0.92 0.48 0.24 0.72
Cr 7.6 7.91 16.5 3 6.5 10 7.8 6.6 16.2 4.6 9.8 9.9 7.6 10 7.4 8.6 7.2 6.4
Ni 9 10 12.2 9 11 11 11.5 15 11.3 10.3
Cu 0.8 6.05 5.2 8.8 4.3 8.4 7.6 0.5 4.9 7.8 8.3 1.4 1.3 0.4 8.3 1.4
Zn 283 41.3 42 26 50 22.4 73 10 58.8 93.6 121.7 88.1 64.2 17 7 67 17.5 31.2
Zr 122 130 133 141 132 145 151 142 127 128 134 150 128 122 134 146 126 158
Rb 50.2 98 115 125 156 162 175 87 23.4 194 186 191 162 216 232 254 242 66.1
Y 34.4 42 36 52 41 28 46 36 20.3 37 49 52 54 38 29 18 22 10
Ba 76.1 256 316 356 298 304 364 197 1240 235 214 216 322 256 303 385 246 93
Pb 23 0.08 14.6 24.5 11.4 27.7 11.8 7.9 25.6 3.7 14.5 25.3 25.6 0.4 11.6 3.4
Sr 45 17.9 393.4 89.3 32.7 44.6 66 47.5 175.3 167.5 156.7 303.7 214.6 82.5 33.5 74.6 46.2 41
Ga 14 12 22 16 18 15 24 28 13 11 15 23 25 28 18 16 32 22
V 9.9 12 19.1 19.8 26.3 46.6 9.2
Nb 20 18 24 32 41 17 26 28 17 24 19 21 20 18 42 30 52 54
As 8.5 3.9 3 6.8 10.3 6.7 6.1 10 9.8 4.2 6.2 4.5
Co 15.4 7.9 11 10.6 8.6 9.2 5.5 14.2 8.7 19.5 18.9 20.2 8.3 8.7 9.8 1.7 12 7.8
U 1.42 1.23 1.07 1.1 1.28 1.8 2.2 1.2 0.6 0.8 1.22 1.5 0.84 2.07 1.22 1.3 1.5 1.45
Th 7.9 4.23 6.02 4.02 4.2 5.23 3.4 2.56 4.11 4.3 5.2 3.4 3.2 1.71 1.44 1.25 1.85 1.25
La 134 50 62 56 55 49 53 61 50.3 45 42 51 58 23 32 30 25 20
Ce 275 110 98 102 106 115 90 114 109 93 96 102 116 62 50 36 42 40
Pr 31.6 15 16 14 12 17 15 19 13 20 15 18 20 2 3 1 2 3
Nd 119 42 40 36 32 35 43 55 53.4 62 48 51 50 31 36 32 40 26
Sm 17.3 10 12 13 9 10 14 11 9.19 17 8 9 7 4 4 5 4 3
Eu 1 1 3 2 1 3 2 4 3 2 3 2 1 1 0.8 1.1 0.6 0.8
Gd 15.8 10 9 8 6 7 8 6 7 9 8 12 10 8 6 7 6 5
Tb 1.6 2 1 2.2 1.2 2 1 1.8 0.9 1.5 3 1.6 2 1 2 2 1 1
Dy 8 5 7 9 6 7 10 9 4.8 4 6 5 8 2 3 3 1 2
Ho 1.5 1.6 1.5 1.2 2 1.8 1.7 1 0.8 1.1 1.6 1.7 1.3 1 1 1 2 1
Er 4 3 2 5 2 4 3 2 2.13 4 2 3 5 2 3 2 4 1
Tm .54 0.6 0.8 0.4 0.7 0.5 1 1.1 .31 0.8 1 1.2 0.3 1 2 3 4 3
Yb 4 3 4 1 2 1 3 2 2.05 2 2 3 2 2 2 1 3 1
Lu 1 0.6 0.2 0.5 0.8 0.7 0.6 0.4 0.3 0.9 1 0.5 0.3 0.8 2 1 1 2
∑REE 614.34 253.8 256.5 250.3 235.7 253 245.3 287.3 256.18 262.3 236.6 261 280.9 139.8 146.8 126.5 136 109
Eu\Sm 0.06 0.1 0.3 0.2 0.1 0.3 0.14 0.4 0.3 0.1 0.4 0.3 0.14 0.3 0.2 0.2 0.16 0.2
Table 4

Kruskal–Wallis test for tonalite, granodiorite, monzogranite and alkali-feldspar granite

Mean rank Sig. (P-value) Test statistics
Tonalite Granodiorite Monzogranite Alkali-feldspar granite
53.88 61.14 97.08 104.32 0.000 28.017

3.2.1 Nomenclature of the investigated rock units

A lot of parameters are used to classify and follow up the chemical affinity of the investigated rocks. According to SiO2 vs (Na2O + K2O) diagram [30], the investigated samples of granites are falling in tonalite, granodiorite, monzogranite, and alkali-feldspar granite fields as shown in Figure 5a. The geochemical classifications of granites are well coexisting petrographic classifications as shown in Figure 4a.

Figure 5 
                     (a) Plots of the investigated granites on SiO2 vs (Na2O + K2O) diagram [30], (b) K2O–SiO2 showing the medium-to-high K nature of studied granites, calc-alkaline, shoshonitic, and ultrapotassic fields (modified from ref. [31]), (c) plots of the investigated granites [32]. A = Al2O3, C = CaO, N = Na2O, and K = K2O, (d) plots of the investigated granites on Nb versus Y diagram [33]. (e) ORG-normalization for study granite sand, and (f) chondrite-normalized REE diagram [34] of the study granites.
Figure 5

(a) Plots of the investigated granites on SiO2 vs (Na2O + K2O) diagram [30], (b) K2O–SiO2 showing the medium-to-high K nature of studied granites, calc-alkaline, shoshonitic, and ultrapotassic fields (modified from ref. [31]), (c) plots of the investigated granites [32]. A = Al2O3, C = CaO, N = Na2O, and K = K2O, (d) plots of the investigated granites on Nb versus Y diagram [33]. (e) ORG-normalization for study granite sand, and (f) chondrite-normalized REE diagram [34] of the study granites.

3.2.2 Magma type of the investigated rock units

The magma type of the studied rock units was discussed on the basis of the following proposed diagrams. According to Peccerillo and Taylor [31], K2O–SiO2 binary diagram shows the tonalite and granodiorite are low-to-medium K calc-alkaline, where monzogranite and alkali-feldspar granite are medium-to-high K calc-alkaline as shown in Figure 5b, as well as according to ref. [32] used ANK versus ACNK variation diagram to show quite a variation of the examined granites, from metaluminous to peraluminous nature, actually tonalite and granodiorite are metaluminous, while monzogranite and alkali-feldspar granite are metaluminous to peralkaline in nature (Figure 5c).

3.2.3 Tectonic setting of the investigated granites

Pearce et al. [33] used Nb versus Y diagram to show the tectonic setting of oceanic ridge granite (ORG), syn-collision granites (Syn-COLG), volcanic arc granite, and within plate granite (WPG) fields, particularly the tonalite and granodiorite samples are falling in the volcanic arc field, while the monzogranite and alkali-feldspar granite samples are related to WPG field (Figure 5d).

3.2.4 Trace and rare earth elements of the investigated rock units

Based on the ORG normalizing diagram [33], the tonalite and granodiorite are enriched in some trace elements content (Figure 5e) particularly, K, Rb, Sr, Th, Ce, and Sm compared to Nb, Hf, Zr, Y, and Yb with distinct troughs at Nb and Zr, like the I-type granites from subduction zones. Monzogranite and alkali-feldspar granite are enriched in Rb and Th relative to Nb and Ta, and Ce and Sm are enriched relative to their adjacent elements, like Sabaloka within plate granites. Rare earth element patterns [34] of granite rocks show slight depletion of fractionated patterns from LREEs to HREEs with slight positive to negative Eu anomalies from tonalite to monzogranite and alkali-feldspar granites as shown in Figure 5f.

3.3 Statistical study of measuring values of clark value, K, Ra226, TH232, and U238

Here, we present some statistical criteria to investigate the significant differences among sample results obtained for Th-234, Pb-212, Pb-214, and K-40 at 93, 239, 352, and 1,460 kV for uranium, thorium, radium, and potassium, respectively. By studying the results, we found that there is no homogeneity or normality among sample results, so we shall use Kruskal–Wallis test for checking the differences among samples (Table 4). The test results of the test are listed below:

We note that P-value <5%; hence there is a significant difference between tonalite, granodiorite, monzogranite, and alkali feldspar granite. We performed Mann–Whitney test between every two samples together to determine the difference. The results are listed in:

From Table 5, there is no significant difference between both tonalite, granodiorite and monzogranite, alkali-feldspar granite; this is clear of mean ranks for every two samples together. Also, this decision can be taken by comparing P-values with significance level of 5%, where P-value of 0.415 > 0.05 for tonalite and granodiorite and P-value of 0.367 > 0.05 for monzogranite and alkali-feldspar granite. While comparing P-values and mean rank of the remaining samples, we can notice that there are significant differences between each pair of samples [(tonalite, monzogranite), (tonalite, alkali feldspar granite), (granodiorite, monzogranite), and (granodiorite, alkali-feldspar granite)].

Table 5

Mann–Whitney test for tonalite, granodiorite, monzogranite, and alkali-feldspar granite

Mean rank Test statistics (Z) Sig. (P-value) Notice
Tonalite Granodiorite −0.815 0.415 P-value >5%, that is, there is no significant difference between tonalite and granodiorite
28.25 32.00
Tonalite Monzogranite −3.795 0.000 P-value <5%, that is, there is a significant difference between tonalite and monzogranite
31.46 57.67
Tonalite Alkali-feldspar granite −3.482 0.000 P-value <5%, that is, there is a significant difference between tonalite and alkali-feldspar granite
19.17 34.17
Granodiorite Monzogranite −3.853 0.000 P-value <5%, that is there is a significant difference between granodiorite and monzogranite
39.94 65.60
Granodiorite Alkali-feldspar granite −3.387 0.001 P-value <5%, that is, here is a significant difference between granodiorite and alkali-feldspar granite
26.19 42.27
Monzogranite Alkali-feldspar granite −0.902 0.367 P-value >5%, that is, there is not a significant difference between monzogranite and alkali-feldspar granite
52.81 58.88

Table 6 shows the Pearson correlation among samples (tonalite, granodiorite, monzogranite, and alkali-feldspar granite). We can notice that there is a strong direct relationship between tonalite and both granodiorite, monzogranite, and alkali-feldspar granite with Pearson correlation coefficient (0.603**, 0.752**, 0.573**) significant at the 0.01, respectively. Also, there is a strong direct relationship among granodiorite and both tonalite and alkali-feldspar granite with Pearson correlation coefficients (0.603** and 0.723**) significant at the 0.01, respectively. Moreover, a strong direct relationship among alkali-feldspar granite and tonalite and granodiorite with 0.573** and 0.723** Pearson correlation coefficient significant at the 0.01, respectively. Also, one can see that there is a strong inverse relationship among monzogranite and tonalite, granodiorite, and alkali-feldspar granite with Pearson correlation coefficients (−0.752**, −0.485** and −0.598**) significant at the 0.01.

Table 6

Pearson correlation among (tonalite, granodiorite, monzogranite, and alkali-feldspar granite)

Sig (2-tailed) Tonalite Granodiorite Monzogranite Alkali-feldspar granite
Tonalite 1 0.603** −0.752** 0.573**
Granodiorite 0.603** 1 −0.485** 0.723**
Monzogranite 0.752** −0.485** 1 −0.**598
Alkali feldspar granite 0.573** 0.723** −0.598** 1

**Correlation is significant at 0.01.

4 Conclusion

Granite rocks are currently one of the chief row materials that can be subjugated for various economic purposes such as ornamentation and building materials. They do not include radioactive concentrations and have good physical and mechanical properties. Granite rocks of north Um Taghir are appropriate to Neoproterozoic rocks related to the north ANS, which occurs in northeast Africa. The exposed rock units in the investigated area are classified into four rock units represented by tonalite, granodiorite, monzogranite, and alkali-feldspar granite, which are cut by different dikes. The magma of tonalite and granodiorite is low-to-medium K calc-alkaline affinity, while the magma of monzogranite and alkali-feldspar granite is medium-to-high K calc-alkaline affinity, metaluminous to peraluminous nature, and related to ORG, Syn-COLG, and WPG fields. The normalization of trace elements such as K, Rb, Sr, Th, Ce, and Sm compared to Nb, Hf, Zr, Y, and Yb with distinct troughs at Nb and Zr, reffered to the I-type granites that resulting from the subduction zones. However, monzogranite and alkali feldspar granite are enriched in Rb and Th relative to Nb and Ta; in addition, Ce and Sm are enriched relative to their adjacent elements. Granite rocks show a slight depletion of fractionated patterns from LREEs to HREEs with slightly positive to negative Eu anomalies from tonalite to monzogranite and alkali-feldspar granite. In contrast, the statistical criteria have been functioned to explore the significant differences among the sample. By probing the results, we establish that there is no homogeneity or normality among sample results. Furthermore, with Kruskal–Wallis test, Mann–Whitney test, and by comparing P-value with a significance level of 5%, we can notice that there are significant differences between each pair of samples [(tonalite, monzogranite), (tonalite, alkali-feldspar granite), (granodiorite, monzogranite), and (granodiorite, alkali-feldspar granite)]. With Pearson correlation coefficient, we can notice a strong direct relationship among granodiorite and both tonalite and alkali-feldspar granite, among alkali-feldspar granite and tonalite and granodiorite, there is a strong inverse relationship among monzogranite and tonalite, granodiorite and alkali-feldspar granite. Granitic rocks have outstanding mechanical and physical properties, as stated in all of the results, allowing them to be used as a raw material for a variety of economic purposes.

Acknowledgements

The researchers (H.A.A and H.M.H.Z.) are funded by a scholarship under the Joint (Executive Program between Egypt and Russia).

  1. Funding information: Authors expresses their thanks to “Dunarea de Jos” University of Galati, Romania for APC support.

  2. Author contributions: H.A., I.A., A.N. – conception of the study; A.T, M.K. – experiment; R.E., A.R. – analysis and manuscript preparation; H.Z., H.A., H.T. – data analysis and writing the manuscript; S.I., H.Z. – analysis with constructive discussions.

  3. Conflict of interest: The authors declare they have no conflict of interests.

  4. Ethical approval: The conducted research is not related to either human or animal use.

  5. Data availability statement: All data generated or analyzed during this study are included in this published article.

References

[1] El Bahariya GA. An overview on the classification and tectonic setting of neoproterozoic granites of the Nubian shield. Eastern Desert Egypt: Geochemistry; 2021.10.5772/intechopen.95904Search in Google Scholar

[2] Hussein AA, Ali MM, El, Ramly MF. A proposed new classification of the granites of Egypt. J Volcanol Geotherm Res. 1982;14(1–2):187–98.10.1016/0377-0273(82)90048-8Search in Google Scholar

[3] El Mezayen AM, Heikal MA, El-Feky MG, Shahin HA, Abu Zeid IK, Lasheen SR. Petrology, geochemistry, radioactivity, and M–W type rare earth element tetrads of El Sela altered granites, south eastern desert, Egypt. Acta Geochimica. 2019;38(1):95–119.10.1007/s11631-018-0274-7Search in Google Scholar

[4] Akaad M. Geology and petrochemistry of the granite association of the Arabian Desert Orogenic Belt of Egypt between latitudes 25°35′ and 26° 30′. Delta J Sci. 1979;3:107–50.Search in Google Scholar

[5] Stern RJ, Gottfried D, Hedge CE. Late Precambrian rifting and crustal evolution in the Northeastern Desert of Egypt. Geology. 1984;12(3):168–72.10.1130/0091-7613(1984)12<168:LPRACE>2.0.CO;2Search in Google Scholar

[6] Ghoneim MF, Lebda EM, Anbar MM, Abd El-Wahed MA. Toward a new concept for the classification of granite rocks of the Eastern Desert, Egypt: geothermobarometry constraints. Fifth Int Conf Geol Africa. Assiut Egypt: Assiut Univ Fac Sci Geol Depart; 2007. p. 131–42.Search in Google Scholar

[7] Johnson PR, Andresen A, Collins AS, Fowler AR, Fritz H, Ghebreab W, et al. Late Cryogenian-Ediacaran history of the Arabian-Nubian Shield: A review of depositional, plutonic, structural, and tectonic events in the closing stages of the northern East African Orogen. J Afr Earth Sci. 2011;61(3):167–232.10.1016/j.jafrearsci.2011.07.003Search in Google Scholar

[8] Fawzy KM. Characterization of a post orogenic A-type granite, Gabal El Atawi, Central Eastern Desert, Egypt: geochemical and radioactive perspectives. Open J Geol. 2017;7(1):93–117.10.4236/ojg.2017.71007Search in Google Scholar

[9] Zakaly HM, Uosif MA, Madkour H, Tammam M, Issa S, Elsaman R, et al. Assessment of natural radionuclides and heavy metal concentrations in marine sediments in view of tourism activities in Hurghada city, northern Red Sea. Egypt J Physiol Sci. 2019;30(3):21–47.10.21315/jps2019.30.3.3Search in Google Scholar

[10] El-Taher A, Zakaly HM, Elsaman R. Environmental implications and spatial distribution of natural radionuclides and heavy metals in sediments from four harbours in the Egyptian Red Sea coast. Appl Radiat Isot. 2018 Jan;131:13–22.10.1016/j.apradiso.2017.09.024Search in Google Scholar

[11] Awad HA, Nastavkin AV. Some mechanical and physical studies of granite rocks in Um Taghir, Eastern Desert, Egypt. J Phys Conf Ser IOP Publishing. 2021;1945(1):12012.10.1088/1742-6596/1945/1/012012Search in Google Scholar

[12] Zakaly HM, Uosif MA, Issa SA, Tekin HO, Madkour H, Tammam M, et al. An extended assessment of natural radioactivity in the sediments of the mid-region of the Egyptian Red Sea coast. Mar Pollut Bull. 2021 Oct;171:112658.10.1016/j.marpolbul.2021.112658Search in Google Scholar

[13] Gass IG. Upper Proterozoic (Pan-African) calc-alkaline magmatism in north-eastern Africa and Arabia. Andesites: Orogenic Andesites and Related Rocks. 1982;1:591–609.Search in Google Scholar

[14] Stern RJ. Arc assembly and continental collision in the Neoproterozoic East African Orogen: implications for the consolidation of Gondwanaland. Annu Rev Earth Planet Sci. 1994;22(1):319–51.10.1146/annurev.ea.22.050194.001535Search in Google Scholar

[15] Kröner A, Krüger JA, Rashwan E-AA. Age and tectonic setting of granitoid gneisses in the Eastern Desert of Egypt and south-west Sinai. Geol Rundsch. 1994;83:502–13.10.1007/BF01083223Search in Google Scholar

[16] Abdelsalam MG, Stern RJ. Sutures and shear zones in the Arabian-Nubian Shield. J Afr Earth Sci. 1996;23(3):289–310.10.1016/S0899-5362(97)00003-1Search in Google Scholar

[17] Collins AS, Pisarevsky SA. Amalgamating eastern Gondwana: the evolution of the Circum-Indian Orogens. Earth Sci Rev. 2005;71(3–4):229–70.10.1016/j.earscirev.2005.02.004Search in Google Scholar

[18] Hamimi Z, Zoheir BA, Younis MH. Polyphase deformation history of the Eastern Desert tectonic terrane in northeastern Africa. XII Int Conf “new Ideas Earth Sci. Muscow; 2015.Search in Google Scholar

[19] Hume WF, Lyons HG. Geology of Egypt: the fundamental pre-cambrian rocks of Egypt and the Sudan; Their Distribution, Age and Character. The Later Plutonic and Minor Intrusive Rocks, with a Special Chapter Dealing with Dynamical Geology (cataract Sturcture and Contact Metamor. Egypt: Government Press; 1935.Search in Google Scholar

[20] Akaad MK, El-Gaby S, Habib ME. The Barud gneisses and the origin of grey granite. Bull Fac Sci Assiut Univ. 1973;2:55–69.Search in Google Scholar

[21] Habib ME. Microplate accretion model for the Pan-African basement between Qena-Safaga and Qift-Quseir roads. Egypt Bull Fac Sci Assiut Univ C Biol Geol. 1987;16:199–239.Search in Google Scholar

[22] El-Gaby S, List FK, Tehrani R. Geology, evolution and metallogenesis of the Pan-African belt in Egypt. Pan-African Belt Northeast Africa Adjac Areas Tecton Evol Econ Asp a Late Proterozoic Oregon; 1988;1:17–68.Search in Google Scholar

[23] Fowler AR, Ali KG, Omar SM, Eliwa HA. The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt. J Afr Earth Sci. 2006;46(3):201–20.10.1016/j.jafrearsci.2006.04.011Search in Google Scholar

[24] Awad HA, Zakaly HM, Nastavkin AV, El-Taher A. Radiological implication of the granitoid rocks and their associated jasperoid veins, El-Missikat area, Central Eastern Desert, Egypt. Int J Environ Anal Chem. 2020;1–14.10.1080/03067319.2020.1845666Search in Google Scholar

[25] Zoheir BA, Johnson PR, Goldfarb RJ, Klemm DD. Orogenic gold in the Egyptian Eastern Desert: widespread gold mineralization in the late stages of Neoproterozoic orogeny. Gondwana Res. 2019;75:184–217.10.1016/j.gr.2019.06.002Search in Google Scholar

[26] El-Bialy MZ, Omar MM. Spatial association of Neoproterozoic continental arc I-type and post-collision A-type granitoids in the Arabian–Nubian Shield: the Wadi Al-Baroud older and younger granites, north eastern desert, Egypt. J Afr Earth Sci. 2015;103:1–29.10.1016/j.jafrearsci.2014.11.013Search in Google Scholar

[27] Abed NS, Monsif MA, Zakaly HM, Awad HA, Hessien MM, Yap CK. Assessing the radiological risks associated with high natural radioactivity of microgranite rocks: a case study in a Northeastern Desert of Egypt. Int J Environ Res Public Health. 2022 Jan;19(1):473.10.3390/ijerph19010473Search in Google Scholar PubMed PubMed Central

[28] Johnson PR. An expanding Arabian-Nubian Shield geochronologic and isotopic dataset: defining limits and confirming the tectonic setting of a Neoproterozoic accretionary orogen. Open Geol J. 2014;8(1).10.2174/1874262901408010003Search in Google Scholar

[29] Streckeisen A. Plutonic rocks: classification and nomenclature recommended by the IVGS sub-commission on the systematic of igneous rocks. Geotims. 18. 26-30. Classification nomenclature plutonic rocks. Geol Rundsch. 1976;63:773–85.10.1007/BF01820841Search in Google Scholar

[30] Middlemost EA. Magmas and magmatic rocks. New York: Longham; 1985.Search in Google Scholar

[31] Peccerillo A, Taylor SR. Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, northern Turkey. Contrib Mineral Petrol. 1976;58(1):63–81.10.1007/BF00384745Search in Google Scholar

[32] Maniar PD, Piccoli PM. Tectonic discrimination of granitoids. Geol Soc Am Bull. 1989;101(5):635–43.10.1130/0016-7606(1989)101<0635:TDOG>2.3.CO;2Search in Google Scholar

[33] Pearce JA, Harris NB, Tindle AG. Trace element discrimination diagrams for the tectonic interpretation of granite rocks. J Petrol. 1984;25(4):956–83.10.1093/petrology/25.4.956Search in Google Scholar

[34] Boynton WV. Cosmochemistry of the rare earth elements: meteorite studies. Dev Geochemistry. vol. 2, Elsevier; 1984. p. 63–114.10.1016/B978-0-444-42148-7.50008-3Search in Google Scholar

Received: 2022-01-12
Revised: 2022-01-22
Accepted: 2022-01-26
Published Online: 2022-03-23

© 2022 Hamdy A. Awad et al., published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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