Magnetic Susceptibility Technique Research Articles

Centennial scale temporal responses of soil magnetic susceptibility and spatial variation to human cultivation on hillslopes in Northeast China

Soil loss is a significant environmental issue that causes soil degradation and threatens national food security in the black soil region of Northeast China. The magnetic susceptibility (MS) technique is a promising method for evaluating soil loss and estimating soil redistribution. In this study, undisturbed soil samples were selected from four typical black soil cropland slopes with 110a, 60a, 30a, and 20a cultivated durations at 10 cm intervals from the surface to a depth of 50 cm to measure soil MS. Based on measurable magnetic indexes, a quantitative relationship between MS and cultivation duration was constructed. The results indicated that: (1) The MS showed an approximate trend, namely 110a < 60a < 20a < 30a < 0a, the longer the sloping land was cultivated, the smaller the MS. (2) The reduction rate of χlf on the surface and underlying soil ranged from 1.57 to 3.27 and was also enhanced in the topsoil. (3) The relative difference value of MS among cultivation durations were greater at the lower slope than at the upper and middle slopes for all selected slopes; however, all positions became nearly constant after 50a of cultivation; (4) MS values substantially correlated in power function with cultivation duration on the entire slope and on three slope positions with r2 values from 0.50 to 0.86 and root mean square error values from 0.21 to 0.41. Soil MS in croplands varied with cultivation duration and was directly proportional to the increase in cultivation duration, which was used to establish soil redistribution and erosion patterns. The results of this study demonstrate that MS is a credible index for quantifying soil loss during continuous tillage at the centennial scale.

Complex AC Magnetic Susceptibility as a Tool for Exploring Nonlinear Magnetic Phenomena and Pinning Properties in Superconductors.

The versatile AC magnetic susceptibility technique offers a detailed insight into the complex electrodynamic phenomena in superconductors. In the present study, we outline the key effects related to the temperature, AC field amplitude and frequency variations of the fundamental and harmonic components for an investigation of the vortex dynamics in a flux-grown FeSe crystal. By means of higher harmonic (nonlinear) analysis, we have explored certain atypical, asymmetric features in the AC magnetic response. These effects were identified through the detection of an even (second) harmonic and an unusual temperature shift in the odd (third) harmonic, possibly due to the complex interactions related to the composite superconducting/magnetic morphology of the crystal. Using the high-frequency sensitivity of the third harmonic, the basic functional dependencies of the pinning activation energy, as the main mixed state parameter, were determined with the implementation of the Kim-Anderson Arrhenius relation in the framework of the collective creep theory.

Evaluation of structural formation of granular materials using anisotropy of magnetic susceptibility

The structure of granular materials is one of the most important influential factors in mechanical behaviors. A few inevitable limitations exist in current optical measuring techniques, such as structure disturbance, operational complexity, and high cost. This study attempts to take a new application of the anisotropy of magnetic susceptibility (AMS) technique to investigate the structure of granular materials. To illustrate the feasibility of the AMS in detecting the structure, each of five different kinds of sand, including beach sand, river sand, aeolian sand, and calcareous sand, was reconstituted by moist tamping method and air pluviation method, respectively. Based on the structural features obtained from the optical and the AMS techniques, the validity and applicability of the AMS technique on granular materials with different magnetic mineral compositions were discussed systematically. It is found that the AMS technique is a feasible and efficient method to investigate the structure of granular materials both in laboratory tests and field sampling tests.

New Mixed Ni(II), Cu(II), and Co(II) Complexes derived from 2-((2-mercaptophenylimino)methyl)-4-methoxyphenol and 1,10-Phenanthroline: Synthesis and Characterization

Three new mixed Ni(II), Co(II) and Cu(II) complexes have been created using 2-((2-mercaptophenylimino)methyl)-4-methoxyphenol and 1,10-phenanthroline. FT-IR, Elemental analysis, magnetic susceptibility, UV-Vis and molar conductivity technique have all been used to explore the structural characterisation of these compounds. Magnetic susceptibility readings for the L-Cu, L-Ni, and L-Co complexes were 1.97 BM, 2.92 BM, and 2.84 BM, respectively. The L-Co complex is thought to be antiferromagnetic. The structures of the mixed ligand metal complexes are thought to be octahedral geometry. There are no conductivity properties in the complexes; however, they exhibit molar conductivities that range from 2.46 to 9.04 µS/cm.

Characterization of the magma flow direction in the Nandurbar-Dhule Deccan dyke swarm inferred from magnetic fabric analysis

The Deccan volcanic province (DVP; ~65 Ma old) of India is one of the classic examples of continental flood basalts. One of the most favoured hypotheses for DVP emplacement is “eruption through fissures” facilitated by major pre or syn-Deccan crustal extension. Determination of magma flow direction in its feeder dyke system provides clues on its possible association with a mantle plume, depth and number of the feeder chambers and other important geodynamic information on magma emplacement relevant in arguing about such hypotheses. In this paper, we have studied Dhule-Nandurbar Deccan (DND) dyke swarm (~210 mappable dykes) from Western India, that intruded compound basaltic (older than dykes) Deccan lava flows. Magnetic fabric which is commonly used as a proxy for magma flow fabric, was analysed in multiple oriented dyke samples using Anisotropy of Magnetic Susceptibility (AMS) technique. AMS analysis suggests that the studied dykes display dominantly subvertical to inclined flow and occasional sub-horizontal/lateral flow. The cumulative flow geometry further suggests the presence of multiple sub-surface magma centres (polycentric flow) from which magma pulses got injected through crustal fissures forming this magnificent dyke swarm that ultimately fed significant volume of the DVP.

Monitoring magnetic susceptibility and spatial distribution of soil attributes in different land uses: a case study in an arid and semi-arid region, southern Iran

The magnetic susceptibility (MS) technique could be used as an efficient tool for management, monitoring, and analysis of soil properties. This study was conducted to investigate the relationship among the magnetic parameters and soil surface properties as well as their spatial variation in different land uses in Fars Province, southern Iran. Three dominant land uses in the study area including cropland, barren, and pasture were selected, and a total of 72 samples were collected from the soil surface (0–15 cm). Physicochemical properties, total free (Fed) and amorphous (Feo) iron forms, and MS in both high (xhf) and low (xlf) frequencies were determined. The results showed a significant difference (p˂0.05) for xlf average values among different land uses which were decreased in the order of cropland (45.31× 10−8 m3 kg−1), barren (31.68 × 10−8 m3 kg−1), and pasture (17.84 × 10−8 m3 kg−1), respectively. There was a positive significant correlation (p <0.01) between the MS values and Fed and Fed-Feo, while a negative significant correlation was observed among xlf and EC, gypsum, and Feo/Fed. The spherical model suitably described the spatial behavior of magnetic parameters and soil properties. The spatial distribution maps represented an almost parallel pattern in the spatial variations of MS, Fed, Fed-Feo, and evolution index, but an inconsistent pattern for Feo, CaCO3, gypsum, and EC in the study area. This indicates the role of diamagnetic materials in decreasing the soil magnetic properties. Results of this study clearly revealed that the MS technique is of great potential in monitoring the spatial variations of soil properties.

Application of anisotropy of magnetic susceptibility (AMS) fabrics to determine the kinematics of active tectonics: examples from the Betic Cordillera, Spain, and the Northern Apennines, Italy

Abstract. The anisotropy of magnetic susceptibility (AMS) technique provides an effective way to measure fabrics and, in the process, interpret the kinematics of actively deforming orogens. We collected rock fabric data of alluvial fan sediments surrounding the Sierra Nevada massif, Spain, and a broader range of Cenozoic sediments and rocks across the Northern Apennine foreland, Italy, to explore the deformation fabrics that contribute to the ongoing discussions of orogenic kinematics. The Sierra Nevada is a regional massif in the hinterland of the Betic Cordillera. We recovered nearly identical kinematics regardless of specimen magnetic mineralogy, structural position, crustal depth, or time. The principal elongation axes are NE–SW in agreement with mineral lineations, regional GPS geodesy, and seismicity results. The axes trends are consistent with the convergence history of the Africa–Eurasia plate boundary. In Italy, we measured AMS fabrics of specimens collected along a NE–SW corridor spanning the transition from crustal shortening to extension in the Northern Apennines. Samples have AMS fabrics compatible only with shortening in the Apennine wedge and have locked in penetrative contractional fabrics, even for those samples that were translated into the actively extending domain. In both regions, we found that specimens have a low degree of anisotropy and oblate susceptibility ellipsoids that are consistent with tectonic deformation superposed on compaction fabrics. Collectively, these studies demonstrate the novel ways that AMS can be combined with structural, seismic, and GPS geodetic data to resolve orogenic kinematics in space and time.

Evaluation of riverbed magnetic susceptibility for mapping biogeochemical hot spots in groundwater‐impacted rivers

AbstractRedox hot spots occurring as metal‐rich anoxic groundwater discharges through oxic wetland and river sediments commonly result in the formation of iron (Fe) oxide precipitates. These redox‐sensitive precipitates influence the release of nutrients and metals to surface water and can act as ‘contaminant sponges’ by absorbing toxic compounds. We explore the feasibility of a non‐invasive, high‐resolution magnetic susceptibility (MS) technique to efficiently map the spatial variations of magnetic Fe oxide precipitates in the shallow bed of three rivers impacted by anoxic groundwater discharge. Laboratory analyses on Mashpee River (MA, USA) sediments demonstrate the sensitivity of MS to sediment Fe concentrations. Field surveys in the Mashpee and Quashnet rivers (MA, USA) reveal several discrete high MS zones, which are associated with likely anoxic groundwater discharge as evaluated by riverbed temperature, vertical head gradient, and groundwater chemistry measurements. In the East River (CO, USA), widespread cobbles/rocks exhibit high background MS from geological ferrimagnetic minerals, thereby obscuring the relatively small enhancement of MS from groundwater induced Fe oxide precipitates. Our study suggests that, in settings with low geological sources of magnetic minerals such as lowland rivers and wetlands, MS may serve as a complementary tool to temperature methods for efficiently mapping Fe oxide accumulation zones due to anoxic groundwater discharges that may function as biogeochemical hot spots and water quality control points in gaining systems.

Strain partitioning across a subduction thrust fault near the deformation front of the Hikurangi subduction margin, New Zealand: A magnetic fabric study on IODP Expedition 375 Site U1518

Understanding the distribution of strain along thrust and splay faults in active accretionary systems is crucial to understand the mechanical properties of the sediments and the strength of the fault zone and its slip behavior. This paper investigates the distribution of strain through sediment compaction and texture development across the Pāpaku fault, a major splay fault near the deformation front of the Hikurangi subduction margin, New Zealand using the anisotropy of magnetic susceptibility technique (AMS). International Ocean Discovery Program Site U1518 penetrated hanging wall, fault zone and footwall sequences to a maximum depth of 484.9 meters below seafloor. A total of 330 discrete samples was subjected to AMS measurements and magnetic remanence data used to reconstruct the axial orientation of each sample in a geographic reference frame. The AMS display distinct fabric differences between hanging wall, through the fault zone and footwall domains, demonstrating that strain is partitioned across the fault zone. Hanging wall sequences show a strike-parallel northeasterly lineation of Kmax and weakly prolate shapes, typical for a component of northeast-southwest lateral shortening. In contrast, footwall sequences are more oblate and show a clustering of Kmax in northerly direction. This demonstrates that strain in the footwall is dominated by gravitational loading, however a component of sub-horizontal east-westerly strain, parallel to the convergence direction of the Pacific Plate exists. Strain decoupling between hanging- and footwall sequences occurs near the top of the Pāpaku fault zone. Differences in the degree of magnetic susceptibility between footwall sediments incorporated into the fault zone, and the underlying undeformed footwall sequences are indicative for the progressive dewatering of the underconsolidated footwall sequences.

Topsoil Magnetic Susceptibility and Heavy Metal Contamination: A Case Study in Al-Muthanna Province, Iraq

Due to rapid urbanization and industrialization that occurred in Al- Muthanna province in southeastern Iraq during the last decade, pollutants such as heavy metals were emitted into the environment and became a serious threat to human health. Environmental pollution could be caused by different types of pollutants, which come from different sources.&#x0D; This study aims to assess the environmental magnetism efficiency for heavy metal pollution assessment using the magnetic susceptibility technique which became a more rapid and cost-effective compared to conventional methods. Increasing heavy metal contents in soils causes an increase in the magnetic mineral concentration. The study area is located in Al- Muthanna province, southeast of Iraq, and contains three cement plants, an oil refinery, bricks factories, and power plants. Fifty topsoil and subsoil samples (0-50 cm depth) were collected from five sites; Al-Jinoob cement plant (one site), Samawa oil refinery (two sites) and Al- Muthanna cement plant (two sites). In this study, magnetic properties of samples in vertical sections and levels of heavy metal elements; of selected samples from regions with different geological settings were compared. The heavy metals analysis included chromium (Cu), iron (Fe), nickel (Ni), copper (Cu), Arsenic (As) and lead (Pb), which could give indications of heavy metal pollution in soil. The highest magnetic susceptibility value (65.23 x10-8 m3kg-1) was recorded in Al-Muthanna cement plant (TSL-4) and the highest Cu concentration (602.57 ppm) was also recorded in Al-Muthanna cement plant (TSL-5-3). The results of magnetic properties show the dominance of coarse magnetite, which is supposed to have originated from pedogenic particles in natural soils, causing the positive correlation between magnetic susceptibility (χ) and anhysteretic remanent magnetisation (ARM). According to the results of frequency dependent susceptibility ratio (κfd%), the magnetic particles showed an admixture of multi-domain and pseudo-single domain behaviour. Magnetic susceptibility and heavy metal analyses results indicated emissions from nearby industrial plants. X-ray fluorescence (XRF) was carried out for heavy metal analyses which supported our results. Results of this study demonstrate the suitability of applying magnetic techniques for assessing environmental situations.&#x0D;

Efficacy of magnetic susceptibility technique to estimate metal concentration in some igneous rocks

The present study was conducted to explore the relationships between magnetic measures and some heavy metals in some igneous rocks in north-western Iran. For this purpose, four major rocks including ultrabasic, basalt, granite and andesite were selected and totally 60 samples were collected. The collected samples were analyzed for magnetic measurements (\( \chi_{\text{lf}} \), \( \chi_{\text{hf}} \), \( \chi_{\text{fd}} \)) and heavy metals concentration (Fe, Cr, Cu, Zn, Co, Mn and Ni) by atomic absorption spectroscopy. Some samples were analyzed by XRD for iron mineral characterization. The results indicated that the highest and lowest \( \chi_{\text{lf}} \) and all measured heavy metals were found in ultrabasic (as a basic rock) and in granite (as an acidic rock), respectively. X-ray analysis confirmed the higher presence of magnetite/maghemite in basic rocks. Positive and significant correlations were found between magnetic susceptibility at low frequency and all heavy metals’ concentration except for Ni. Overall, magnetic susceptibility serves as a preliminary assessment of rock samples, providing rapid, non-destructive, economical and easy information about heavy metal concentration in igneous rocks in the study area.

Harmonic AC magnetic susceptibility analysis of FeSe crystals with composite morphology

The AC magnetic response of multi-domain FeSe crystals has been explored by means of fundamental and third harmonic AC magnetic susceptibility (ACMS) analysis. Our previous studies have revealed a complex morphology which especially modifies the mixed state properties. The effects were expressed by an additional ‘pseudo’ peak feature of the magnetic hysteresis and in the present study we analyze its vortex dynamics nature and irreversibility behavior in the context of ACMS. We find that the effect is detectable mainly with the sensitive third harmonic component and especially at high AC field frequencies. From the analysis, the temperature dependence of the ‘pseudo’ peak effect at different DC fields ranges was determined, confirming the previously established superconductor–normal metal–superconductor type links between the domains in the crystal. The irreversibility line, the most important parameter for high power applications, shows a typical glass/liquid transition in the vortex matter. In addition we have observed surface barrier effects and vortex avalanche activity, the behavior of which appears to be influenced by the superconducting and magnetic nature coexistence and morphology. The presented results show the effective application of the harmonic AC magnetic susceptibility technique for a versatile analysis of complex nonlinear phenomena in materials with a sophisticated AC magnetic response.

High-temperature superconductivity in sulfur hydride evidenced by alternating-current magnetic susceptibility.

ABSTRACTThe search for high-temperature superconductivity is one of the research frontiers in physics. In the sulfur hydride system, an extremely high Tc (∼200 K) has been recently developed at pressure. However, the Meissner effect measurement above megabar pressures is still a great challenge. Here, we report the superconductivity identification of sulfur hydride at pressure, employing an in situ alternating-current magnetic susceptibility technique. We determine the superconducting phase diagram, finding that superconductivity suddenly appears at 117 GPa and Tc reaches 183 K at 149 GPa before decreasing monotonically with increasing pressure. By means of theoretical calculations, we elucidate the variation of Tc in the low-pressure region in terms of the changing stoichiometry of sulfur hydride and the further decrease in Tc owing to a drop in the electron–phonon interaction parameter λ. This work provides a new insight into clarifying superconducting phenomena and anchoring the superconducting phase diagram in the hydrides.

Magnetic freezing transition in a CoO/Permalloy bilayer revealed by transverse ac susceptibility

We utilize variable-temperature, variable-frequency magneto-optical transverse magnetic susceptibility technique to study the static and dynamical magnetic properties of a thin-film CoO/Permalloy bilayer. Our measurements demonstrate that in the studied system, the directional asymmetry of the hysteresis loop is associated mainly with the difference in the reversal mechanisms between the two reversed states of magnetization stabilized by the exchange-induced uniaxial anisotropy. The latter is found to be much larger than the exchange-induced unidirectional anisotropy of the ferromagnet. We also observe an abrupt variation of the frequency-dependent imaginary part of ac susceptibility near the exchange bias blocking temperature, consistent with the magnetic freezing transition inferred from the previous time-domain studies of magnetic aging in similar systems. The developed measurement approach enables precise characterization of the dynamical and static characteristics of thin-film magnetic heterostructures that can find applications in reconfigurable magnonic and neuromorphic circuits.

Estimating long-term erosion and sedimentation rate on farmland using magnetic susceptibility in northeast China

Soil loss is a global environmental issue. Increasing amounts of attention have been paid to assessing soil erosion and its distribution on cultivated slopes using magnetic susceptibility (MS), which is a rapid, reliable, economic and nondestructive method. However, the MS technique provides incomplete estimates of soil loss. The objective of this study is to employ MS as a tracer to estimate soil loss on cultivated slopes in northeast China. A typical degraded sloping farmland area with a 40-year history of cultivation and a reference forest site were selected. The eroded and deposition regions were distinguished and the tillage homogenization model was used to predict variations in MS with erosion depth. The soil erosion depth, deposition thickness, soil loss, and soil erosion rate were calculated by matching the MS profile measured in the farmland sites to the reference forest site. The results showed that nearly 64% of the area of the selected slope had been eroded, and sediment produced by erosion had been deposited on 36% of the slope as a whole. The largest MS values occurred on the lower portion of the slope (a deposition area), whereas the smallest values occurred on the middle portion of the slope (an eroded area). The average eroded soil depth was 44.5 cm or 1.1 cm·yr-1, and the average deposition thickness was 35.5 cm or 0.9 cm·yr-1. The total amount of soil loss from the sampling slope was 29,338.4 t, which corresponded to a rate of soil loss of 4,630.5 t·km-2·yr-1 over the 40-year cultivation period. This result was similar to those obtained by previous studies conducted in the same region using other methods and techniques. Thus, soil MS was demonstrated to be a reliable tool that can be used to quantify soil erosion on cultivated slopes in northeast China.

Soil great groups discrimination using magnetic susceptibility technique in a semi-arid region, central Iran

This study was performed to determine the variability of magnetic susceptibility to discriminant soil great groups in an arid region including six soil great groups in the Borujen Region, Chaharmahal-Va-Bakhtiari Province, central Iran. Seventy-three soil profiles were described and classified in six soil great groups (i.e., Calcixerepts, Haploxerepts, Haploxeralfs, Xerorthents, Calcixerolls, and Haploxerolls) according to the Soil Survey Staff. Soil organic carbon (OC), calcium carbonate equivalent (CaCO3), pH, electrical conductivity (EC), dithionite extractable iron (Fed), oxalate extractable iron (Feo), iron pyrophosphate (Fep), magnetic susceptibility at low and high frequencies (χlf and χhf), and frequency-dependent (χfd) were measured in the laboratory for the soils selected from control sections. Among the six soil great groups, Haploxerolls showed the highest χlf and χhf values, lowest Feo, highest Fed and Fed-Feo, as well as the highest Fep. However, all stated features showed an inverse trend for Haploxeralfs great group. The results of discriminant analysis indicated that the accuracy of 54.11% was achieved to discriminant soil great group for the combination of magnetic measures, different form of Fe, and soil physicochemical properties in the control section. Therefore, it can be concluded that magnetic susceptibility could be used as a fast and nondestructive technique for discrimination of soil great groups in the present case.

Soil drainage assessment by magnetic susceptibility measures in western Iran

The objective of the present study was to evaluate the efficiency of soil magnetic parameters for assessment of soil drainage classes in Juneqan district, Charmahal and Bakhtiari province, western Iran. Four soil drainage classes including well drained (WD), moderately well drained (MWD), intermittent poor drained (IPD) and poorly drainage (PD) were selected. A total of 89 soil pedons were described and soil samples were collected within the moisture control section. Magnetic susceptibility (MS) at high (χhf) and low (χlf) frequencies and frequency-dependent MS (χfd) were evaluated in the laboratory. Poorly crystalline iron (Feo) and pedogenic iron (Fed) values of all soil samples were also measured. The results revealed that among the four drainage classes, PD class showed the lowest χlf and χhf values, greatest of Feo and Feo/Fed, lowest contents of Fed, as well as the highest average increase of χlf on heating (at 500 °C). However, all mentioned features showed an inverse trend in the WD class as compared to PD. The results of discriminant analysis demonstrated that magnetic measures could prosperously discriminate between the selected drainage classes in this study area (average accuracy = 83.1%). Therefore, it can be concluded that MS technique could be used as a powerful, nondestructive and fast technique for separation of soil drainage classes in the present case.

The Synthesis and Characterization of Novel Pd and Cu vic-dioxime precursors for Their Supercritical Deposition on Multiwalled Carbon Nanotubes

Novel precursors were developed for deposition of Cu and Pd nanoparticles on multiwalled carbon nanotubes for supercritical carbon dioxide deposition technique. 3-(heptadecafluorooctyl)aniline-vic-dioxime and phenanthrenequinonedioxime were used as ligands in synthesis of the palladium and copper precursors. All synthesized ligands and complexes were characterized with elemental analysis, 1H and 19F NMR, FT-IR and magnetic susceptibility technique. Deposition of these precursors in supercritical carbon dioxide was performed at 363ºK in the pressure 0.69 MPa H2 and 27.6 MPa CO2. Surface morphology of metal deposited multiwalled carbon nanotubes has been investigated with X-ray diffraction, high-resolution transmission electron microscopy and scanning electron microscopy with EDX. TEM micrographs showed homogenous distributions of Cu and Pd nanoparticles on the multiwalled carbon nanotubes. The nature and crystallinity of the nanoparticles were confirmed using XRD. This study showed that these novel vic-dioxime complexes are suitable precursors for the preparation of supported metal nanoparticles in supercritical carbon dioxide.

Preliminary Magnetic Susceptibility Results from the Northwestern Part of Madinah, Saudi Arabia: Environmental Degradation of Wadi Aqiq

Recent advances in environmental magnetism have led to new applications in understanding soil pollutions from anthropogenic sources. The utility of environmental magnetic techniques varies widely depending on biological, chemical and physical processes that create and transform soils and sediments. Researchers in some European and Asian countries have successfully studied heavy metals in top soils using magnetic susceptibility technique. Accelerated urbanization in the past two decades has significantly altered the environmental landscape of Madinah. A famous wadi Aqiq in the heart of Madinah, an important conduit for groundwater recharge, is one of the most affected. This study thus focuses on magnetic susceptibility application as environmental magnetic technique to map heavy metal concentrations in top soils along wadi Aqiq, northwestern part of Madinah. Higher values of magnetic susceptibility from soil cover than those from parent igneous rocks indicate anthropogenic origin metallic contamination in the study area. The trucks/tankers parking area reveal highest values of magnetic susceptibility. The areas close to heavy vehicular traffic along two major roads also indicate higher magnetic susceptibilities because of enhanced metallic contaminations. The areas covered by residential and commercial buildings reveal medium level of magnetic susceptibilities. The left over asphalted materials at various places in the area is another source of high magnetic susceptibilities. Widely distributed metallic objects in the area, such as hangers, cans, and construction materials also contribute to enhanced soil contamination as evident from high magnetic susceptibilities.

Neoproterozoic Evolution and Najd‒Related Transpressive Shear Deformations Along Nugrus Shear Zone, South Eastern Desert, Egypt (Implications from Field‒Structural Data and AMS‒Technique)

The tectonometamorphic evolution of Nugrus Shear Zone (NSZ) in the south Eastern Desert of Egypt was reevaluated through an integrated study including field-structural work and magnetofabric analysis using Anisotropy of Magnetic Susceptibility (AMS) technique, complemented by detailed microstructural investigation. Several lines of evidence indicate that the Neoproterozoic juvenile crust within this high strain zone suffered an impressive tectonic event of left-lateral transpressional regime, transposed the majority of the earlier formed structures into a NNW to NW-directed wrench corridor depicts the northwestern extension of the Najd Shear System (NSS) along the Eastern Desert of Egypt. The core of the southern Hafafit dome underwent a high metamorphic event (M1) developed during the end of the main collisional orogeny in the Arabian-Nubian Shield (ANS). The subsequent M2 metamorphic event was retrogressive and depicts the tectonic evolution and exhumation of the Nugrus-Hafafit area including the Hafafit gneissic domes, during the origination of the left-lateral transpressive wrench corridor of the NSS. The early tectonic fabric within the NSZ and associated highly deformed rocks was successfully detected by the integration of AMS-technique and microstructural observations. Such fabric grain was checked through a field-structural work. The outcomes of the present contribution advocate a complex tectonic evolution with successive and overlapped deformation events for the NSZ.