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Integration of potential field- and structural data make it possible to trace surface and subsurface large-scale geological structures of the Egyptian Nubian Shield (ENS). Obtained results indicate that the Northern Eastern Desert (NED) of the ENS is dominated by relatively younger (c. 580 Ma) E–W and NE–SW trending extensional structures that were controlled by the evolution and retreat of the Cadomian Arc. Density of such extensional structures increases with depth as displayed by the potential data. The prevailing structural trends in the Central Eastern Desert (CED) are NW–SE and WNW–ESE. Both trends are highly prompted by the timing of deformation upon the Najd Fault System, and are themselves dissected by a relatively younger NE–SW shearing trend. Lineament density in the CED is subordinate for both subsurface and near surface structures. The South Eastern Desert exhibits compressional and extrusion-related structures of two main prominent trends; WNW-to-NW (to the western part) and the N-, NNE- to NE (to the eastern part). The previously mentioned Neoproterozoic trends are remarkably influenced by the Oligocene–Miocene Red Sea-Gulf of Suez rift related fractures in the vicinity of the rift shoulder. The remarkable change in trends and densities of structural trends, especially in the NED, is interpreted in terms of concealing of the older structures by the younger extensional structures which in turns reflect an N-ward progressive deformation in the entire ENS. Gravity data are more appropriate in delineating the structural trends compared to the magnetic data which are largely affected by lithological variations and/or alteration zones and magnetic mineralogy.

This study delineated the Fe–Ti oxide deposit concurrencies on the layered mafic intrusion in Gabal Akab El-Negum (GAN), South Eastern Desert, Egypt, using aeromagnetic mapping and chemical analysis of the hosted mafic rocks and mineralogical studies. Aeromagnetic data was improved using the enhanced horizontal gradient amplitudeto detect the primary structures (edges/contacts/faults) that control the distribution of Fe–Ti ore deposit. GAN layered gabbros are differentiated into troctolite, olivine–, pyroxene–, and hornblende–gabbros. These mafic rocks primarily comprise plagioclase, olivine, pyroxene, and hornblende with Fe–Ti ores (magnetite and ilmenite). The significant variation in Mg# of clinopyroxene between 0.70 and 0.82 indicates the importance of fractional crystallization in developing layered mafic intrusion. Clinopyroxene and plagioclase thermometry yielded low temperatures similar to the fractionated primary basaltic magma. The pairs of magnetite–ilmenite minerals in gabbros provide equilibrium temperatures of 539.44–815.56, and highfO2, reflecting various cooling and subsolidus reequilibration phases of minerals. The enrichment of GAN gabbros in light rare–earth elements relative to heavy rare–earth elements indicates the interaction between the Fe–Ti rich mantle and the fractionated tholeiitic magmas in the back-arc setting, generating Fe–Ti oxide ores.

The LTHG and EHGA methods are enhancement versions of the gradient amplitude and can outline the edges of shallow and deep anomalous bodies simultaneously. Recently, these techniques have been used in approximating the edges of gravity and magnetic data. In this paper, we apply the LTHG and EHGA methods to the gravity dataset from the global gravity model WGM2012 to extract structural features of Northeastern Laos that appear as lineaments on transformed data maps. We also apply the tilt depth method to this dataset to estimate the depth of these lineaments. The findings showed that most of structures identified in Northeastern Laos are trending in the ENE-WSW, NE-SW, E-W, WNW-ESE and N-S directions with the depth ranging from 1.3 to 2.1 km.

The existing work deals with the structural analysis and detecting basement depth of G. Shilman area, South Eastern Desert (SED), Egypt. This work includes interpreting aeromagnetic data to map out structures within the study area and determine the depth of the magnetic basement which can be an aide to advance exploratory study. The first vertical derivative (1st VD) enhanced the short-wavelength and high-frequency features of the data. The analytic signal (AS) and horizontal gradient magnitude (HGM) maps well the structures of G. Shilman area. Statistical analysis of the delineated structures indicated that the NW, N_S, NNE and NE are the main structural trends controlling the study area. This suggests that the area was dominated by various stress regimes. The source parameter imaging (SPI) method which acts strongly at all magnetic latitudes was applied to the data to map the basement topography of G. Shilman area. The basement depths vary from about 0.1 km to about 1.5 km at the deepest part of the study area. The depth examination indicates that the recent deposits are not thick and reflect the shallow nature of the basement in G. Shilman area. The results of our study gives more accurate interpretation for the structural regime of the study area and can be applied for alike areas.

One major purpose of interpretation of magnetic data is to highlight edges of geology structures. In this paper, we applied the edge methods such as the enhancement of total gradient (ETG), normalized horizontal gradient (TDX), theta map (TM) and fast sigmoid (FSED) methods to delineate geological structures that appear as lineaments in transformed magnetic anomaly maps. Initially, these methods were estimated on a magnetic model for understanding their capability. Further, we applied these methods to real aeromagnetic data for determining lineaments of the Wadi Umm Dulfah area. Additionally, the depths of the magnetic sources in the area were also computed by the tilt depth method. The obtained results indicate the presence in the study area of three major lineament trends in NW–SE, N-S, and NE–SW directions, and most of the lineaments are in the depth range of 0.1 km to 1 km. These results bring a better understanding of the edge methods capability, as well as the geology structures of the Wadi Umm Dulfah area.

The debatable timing of India–Eurasia collision is based on geologic, stratigraphic, kinematic, and tectonic evidence. However, the collision event disturbed persistent processes, and the timing of disturbance in such processes could determine the onset of India–Eurasia collision precisely. We use the longevity of Southeast Indian Ridge (SEIR)—Kerguelen mantle plume (KMP) interaction cycles along the Ninetyeast ridge (NER) as a proxy to determine the commencement of India–Eurasia collision. The geochemical signature of the KMP tail along the NER is predominantly that of long-term coupling cycles, that was perturbed once by a short-term decoupling cycle. The long-term coupling cycles are mainly of enriched mid-ocean ridge basalts (E-MORBs). The short-term decoupling cycle is mostly derived from two distinct sources, MOR and plume separately, whereas the KMP is still being on-axis. The onset of India–Eurasia collision led to continental materials recycling into the mantle; hence the abrupt enrichment in incompatible elements at ca. 55 Ma, the MOR–plume on-axis decoupling, and the abrupt slowdown in the northward drift of the Indian plate was induced by the onset of India–Eurasia collision, thereafter MOR–plume recoupled.

The subsurface structures can be extracted from geophysical studies. This study deals with the detection of lineaments from gravity data that are related to the boundaries of the subsurface structures. The methods used in this study such as the horizontal gradient, total gradient, enhanced horizontal gradient, and improved logistic are tested on synthetic model prior to application to real gravity data. The results indicate that the improved logistic filter can be an effective method for boundary detection of gravity data.

Identification of lateral boundaries for the subsurface structures is a popular topic in many applications of geoscience. For this purpose, many edge detection and enhancement methods have been introduced to determine the lineaments of subsurface structures. In this study, the improved parabola-based method has been applied to reveal the lineaments of subsurface structures of Nam Dinh province. The obtained results have shown that there are NW–SE trending structures in this region and most of the lineaments are in the depth range of 2 km to 8 km. These results provide a new perspective to help us better understand the structural framework and tectonic settings of the study area.

The study area has a complex geological structure and is studied for mapping the density interfaces using geophysical techniques. However, it has not been studied for mapping geological structures, such as contacts and faults that appear as lineaments in gravity data. In this study, the lineaments in the area have been delineated using Bouguer gravity anomaly data, though some modern processing methods, such as horizontal gradient amplitude (HGA), tilt angle of horizontal gradient amplitude (THGA), and enhancement of horizontal gradient amplitude (EHGA). Most of the identified lineaments are trending in the NW–SE direction and some WE-trending lineaments in the southeastern region. This study provides new information for a better understanding of the structural framework and tectonic setting of the Thua Thien Hue area.

Determining the main structures that control sedimentary basins from magnetic and gravity data is an important step for hydrocarbon exploration. In this study, the structural features of the area, east of the Qattara Depression, was deduced utilizing the gravity and magnetic data. Regional-residual separation, lineament analysis, tilt derivative and spectral analysis techniques were utilized to realize this main goal. Fast Fourier transform (FFT) was used for regional and residual separation. The structural patterns of the area were outlined by lineament analysis. The bedrock depth was calculated by applying the spectral analysis method on twenty gravity and magnetic profiles. The coupled 2D and 2.5D modeling along the three gravity and magnetic profiles indicated that the region consists of horsts and grabens blocks, consisting of both acidic and basic rocks. Consequently, a structural map was made to identify the main basins and highs. Besides, it was observed that the thickness of the sedimentary cover varies between 2.5 and 5.5 km in the study area.

Amongst all the potential field methods, gravity data constitutes the frequently measured geophysical information for deep seated lithospheric structures. The present work aims to outline the structural pattern, the main basins of Sinai and the depths to both Conrad and Moho discontinuities (CMD) by utilizing the gravity data. Several basins were depicted based on high-pass filtered gravity map and much of them are in a close agreement with the former studies. Additionally, the dominant fault trends are NE, NW, EW and ENE. An empirical equation was applied to low-pass-filtered gravity data to estimate the depth of the CMD. However, the thickness of the sedimentary basins increases northwards, reaching approximately 8 km, the minimum depths of Conrad and Moho discontinuities were attained in the northern compartments to be about 18 and 31 km respectively. Meanwhile, far a way to the south, the maximum detectable depth of Conrad and Moho discontinuities are 21 and 37 km. Eventually, 2D gravity modeling was constructed and constrained by 15 drilled wells and the calculated depth of CMD to figure out the comprehensive lithospheric geometry beneath Sinai Peninsula.