Lineament Map Research Articles

Rock discontinuities mapping with computer-based lineament extraction from satellite imagery

This study presents an approach for automatic lineaments analysis by using high-resolution digital images for mapping and delineating rock discontinuities. As a case study, we combine Landsat 8 images with 15 m resolution and shuttle radar topographic mission (SRTM) of a discovered gold mine in Nuba Mountains, Sudan. The satellite image contains band 7, band 4, and band 1 in red, blue, and green. In addition, band 5 is assigned to obtain the average of the three bands. The automatic extraction of lineaments approach was initially carried out with PCI Geomatica software, and then an accuracy assessment is performed to determine the most accurate parameters of extracted features. On the excellent reference of the output, the extracted lineaments are transferred to the Arc map software, and the coordinates of lines have been fixed. Finally, the attribute table of lineaments was imported to Rockware software to draw the rose diagram. Moreover, a manual lineament extraction process is carried out. For comparing automatic lineament extraction and manual lineament extraction, total length and number of lineaments and directional analyses are done by constructing the rose diagrams. Besides these two processes, field investigation in the study area is also applied to verify digitally extracted lineaments that the features represent true discontinuities. The final parameters of automatically extracted lineaments are determined. The produced lineament map in this study is proved to be very efficient in the discontinuities mapping for mining applications in terms of cost and time effectiveness.

Aeromagnetic and electrical resistivity mapping for groundwater development around Ilesha schist belt, southwestern Nigeria

Aeromagnetic and vertical electrical sounding around Ijano, southwestern Nigeria, was investigated for groundwater potential. Aeromagnetic dataset and vertical electrical sounding were acquired and used to investigate the study area. Oasis Montaj, Microsoft Excel and Arc GIS were used to present the results in maps, images and profiles. In order to map out the geological structures of the study area, magnetic image enhancing filters applied to the total magnetic intensity using Geosoft (Oasis Montaj) are reduction to equator, vertical derivative, total horizontal derivative and upward continuation. These filters helped define the lithological boundaries, geological structures, faults, folds and contacts. The lineament of aeromagnetic map was generated from derived field intensity gradients and solutions of Euler deconvolution carried out on the aeromagnetic data using structural index of 0.5 and 1. The processed image shows the lineaments trends majorly towards NE–SW directions. From these combined results of the study area, consistent aeromagnetic lineament map was generated showing the probable positions and trends of the suspected fractured/faulted zone as well as other basement structures. Hydro-lineament density maps based on lineament were produced from the generalized structure trends in the area. The result from the depth sounding data interpretation indicates three curve types which are H, HA and KH, where curve type H has the highest occurrence. The results from the vertical electrical sounding data revealed that the areas with the highest hydro-lineament density are good for groundwater prospect and development. The study has led to the delineation of areas where groundwater occurrences are most promising for sustainable supply, suggesting that an area with high concentrations of lineament density has a high tendency for groundwater prospecting. The results from the study show that the aeromagnetic technique is capable of extracting lineament trends in an inaccessible tropical forest.

Correction to: Lineament mapping for a part of the central Sulaiman fold–Thrust Belt (SFTB), Pakistan

Correction to: Lineament mapping for a part of the central Sulaiman fold–Thrust Belt (SFTB), Pakistan

The lineaments as one of the precursors of earthquakes: A case study of Tashkent geodynamical polygon in Uzbekistan

This work is to study earthquake precursors using lineament analysis of five MW3 earthquakes that occurred in 2018 on the territory of the Tashkent geodynamic polygon in Uzbekistan. The Landsat 8 satellite images were processed using the automated lineament detection method in the LEFA software. The processing steps included image preprocessing with graphic filters, edge detection using Canny's algorithm, the definition of a vector of linear elements based on the probabilistic Hough transform and combining collinear linear elements into lineaments. The analysis of the cyclicity of precursors before and after earthquakes was based on the study of the distribution of the lineaments trend in the study area using rose diagrams and lineaments density maps. The results showed a change in the dynamics of the lineament structure. The statistical analysis of lineaments revealed that the number and orientation of lineaments changed significantly about 2–4 months before an earthquake, and after 2–3 months, the system gradually returned to its initial state. The rapid increase in lineaments density began almost 20 days before the event, reaching a maximum about 4 days before the earthquake, and its decrease began 16 days after the earthquake. The main trends observed in the lineament map showed dominant trends in NS, EW, and the subdominant directions were in NW–SE, NE–SW, which coincided with main directions of the faults.

High-resolution electrical resistivity tomography and seismic refraction for groundwater exploration in fracture hard rocks: A case study in Kanthan, Perak, Malaysia

• High-resolution ERT and seismic results were validated by tube-well drillings. • Sharp vertical boundary between high and low resistivity zones indicates fault zone. • Depression zone in seismic refraction depth profile indicates highly fractured rock. • DLS method of Wenner-Schlumberger + dipole–dipole arrays are the most effective. • Groundwater source is discovered at the intersection of major discontinuities . This research article describes the integration of high-resolution electrical resistivity tomography (ERT) and seismic refraction to explore potential groundwater in fracture carbonate hard rocks. Data Levels Synthesization (DLS) method is developed where the data levels of two different optimized arrays were merged to produce one final subsurface resistivity image to achieve high-resolution ERT. Numerical modeling was initially conducted on three different geoelectrical arrays. The results of before and after applied DLS method were compared to evaluate the effectiveness of each geoelectrical array to delineate fracture and anomalies accurately. Lineament map is constructed beforehand to map the major discontinuities which could possibly be the potential target for water-containing and water-conducting zones in the subsurface. Two geophysical survey lines were conducted where each survey line covered both ERT and seismic refraction methods. Two tube wells were successfully drilled exactly on the fracture zone with a flow rate around 1000 L/h. The potential water-containing zones within the subsurface limestone bedrock were identified as zones of low to moderate geoelectrical resistivity values ranging from 10 to 400 Ωm and V p velocities exceeding 2000 ms −1 . The fault zones were determined by sharp vertical boundary between the high and low resistivities zones in ERT image and lateral decrease in the V p velocities of the limestone bedrock and depressions along the overburden-bedrock interface. The DLS method of Wenner-Schlumberger and dipole–dipole arrays had been proven effective in enhancing the horizontal and vertical resolutions to produce high-resolution ERT image validated with seismic refraction, lineament map, and tube well drillings.

Mineralisation potential assessment using analytical hierarchy process (AHP) modeling technique: A case study of Ilesha schist belt, southwestern Nigeria

A mineralisation potential assessment in part of Ilesha Schist belt of southwestern Nigeria was carried out using multi criteria decision analysis (MCDA) in the context of analytical hierarchy process (AHP). Three parameters sourced from aeromagnetic, electrical resistivity and geological data were identified to favour gold mineralisation in the study area. These parameters include lineament density (Ld), lithology (Lt), and electrically derived coefficient of anisotropy (An). The application of data enhancement techniques such as total horizontal derivative, 3-D Euler deconvolution and source edge detection were employed in the production of lineament map of the study area. Two hundred and sixty-five (265) vertical electrical sounding (VES) points were investigated using Schlumberger configuration. Coefficient of anisotropy derived from the Dar-Zarouk parameters was obtained from the synthesized VES data. The lithologic information was obtained from the existing geological map of the area. The orientations of lineaments displayed on the aeromagnetic results suggest predominantly NE-SW trending structures, which are characteristic of the Pan African orogenic events in the area. However, few of the E-W trending lineaments are imprints of secondary structural alteration. Furthermore, the Euler deconvolution solutions revealed that the area is characterised by geological contacts with estimated depth of 94–600 m. The coefficient of anisotropy results obtained from the geo-electric parameters vary from 1.00–2.87. AHP weighting and ranking technique was used to develop a reliable mineralisation potential model (MPM). In line with the recommended lower limit of 10 %, the consistency ratio of the developed model is 9.61 %. The produced MPM was classified into low, moderate and high mineralisation potential zones. Preliminary validation of the MPM using the existing pits in the area showed 79 % success rate. The validation of the model using the existing geochemical information from the previous studies indicated 85 % agreement with the conceptual model; thus, confirming the reliability of the produced MPM. The developed model is therefore believed to serve as a future reference in the resource management of the study area.

Structural mapping and interpretation of lineaments related to the In Teria volcanism (southeastern Algeria) using Landsat 8 OLI TIRS images and aeromagnetic data

The In Teria region is located South-East of Algeria, in the North-East of the Illizi basin. Generally, this area is recognized as a volcanic region with circular craters controlled by faults. In this research, structural lineaments were extracted using aeromagnetic data and satellite images (Landsat 8 OLI TIRS), and the direction of distribution of volcanic craters was analyzed by the center-to-center method. The mains observations show, at different structural levels, the following results: 1- the directions of the surface lineaments are E-W, WNW-ESE and ENE-WSW while those of crustal scale are N–S, E-W, NNW-SSE to NW-SE. 2- The volcanic craters are located at the intersection of these two directions (E-W and NW-SE) with the N–S lineaments. Some of these directions are linked to a reactivation of Pan-African mega-shear zones (N–S, NW-SE to NNW-SSE) during the Cenozoic, and some others (NW-SE and NNW-SSE) had already been reactivated during the Cretaceous rifting. 3- The depth estimation methods used thanks to Euler deconvolution and Tilt derivative showed, for the first time, the presence of magnetic anomalies related to magmatic bodies at a shallow depth of 2.5–3 km. The spectral analysis method gave a depth of more than 11 km for the deep sources. 4- The depth of the basement estimated by 2D forward modeling according to an N–S profile which passes through the outcrop zone of the craters, varies from 200 to 6000 m. All these data and new results presented in this work helped to highlight on the dynamics of In Teria's volcanism and to derive an updated structural mapping of this volcanic region.

A Robust SAR Speckle Tracking Workflow for Measuring and Interpreting the 3D Surface Displacement of Landslides

We present a workflow for investigating large, slow-moving landslides which combines the synthetic aperture radar (SAR) technique, GIS post-processing, and airborne laser scanning (ALS), and apply it to Fels landslide in Alaska, US. First, we exploit a speckle tracking (ST) approach to derive the easting, northing, and vertical components of the displacement vectors across the rock slope for two five-year windows, 2010–2015 and 2015–2020. Then, we perform post-processing in a GIS environment to derive displacement magnitude, trend, and plunge maps of the landslide area. Finally, we compare the ST-derived displacement data with structural lineament maps and profiles extracted from the ALS dataset. Relying on remotely sensed data, we estimate that the thickness of the slide mass is more than 100 m and displacements occur through a combination of slumping at the toe and planar sliding in the central and upper slope. Our approach provides information and interpretations that can assist in optimizing and planning fieldwork activities and site investigations at landslides in remote locations.

Lineament mapping in the Ikniouen area (Eastern Anti-Atlas, Morocco) using Landsat-8 Oli and SRTM data

The present work focuses on the use of remote sensing techniques and Geographical Information Systems (GIS), to Automatic extraction and geospatial analysis of lineaments, in the district of Ikniouen located in the eastern Moroccan Anti Atlas. To achieve this objective, we relied on the processing of Landsat-8 OLI spectral bands and SRTM data covering the study site. In the first instance, essential pre-processing was carried out on our spatial data for the automatic extraction of lineaments by applying the mathematical algorithm Line Module from PCI's Geomatica 2016 software. Some of the treatments used included Principal Component Analysis, Shaded relief of SRTM data from different angles, 7 × 7 matrix directional filters, and finally the automatic extraction of lineaments. The results obtained from lineament extraction from the PC1 image, the seven spectral bands with a spatial resolution of 30 m, and the digital elevation models (DEM) SRTM proved that each map produced had a strong similarity in terms of density and orientation with two major directions – NE-SW and E-W – with high densities in areas well known to be fractured, namely the Oussilkane granites in the northeast, the Ikniouen granites in the west, and the rhyolites and ignimbrites of the Amtatouch-Yadawdane formations in the south of the study area. The results from the automatic extraction of the lineaments revealed 2680 lineaments, whose size varied from a few metres to 3.4 km, with an average length of 534 m. The lineaments of small extensions were the most numerous, as they had an interval comprising almost between 30 and 1158 m. The projection of these lineaments on a Rose diagram showed a predominance of the NE-SW direction. Multi-source data, such as lithological factors, slope factors, and calibrated, high-resolution ESRI field imagery basemap, were used to validate potential results of this automatic lineament mapping. The automatic extraction allowed a better mapping of the structural lineaments; it add information to geological data, but the geological meaning of the linear feature have to be investigated. This technique is usefull to preliminary identify areas with a probable difference in potential lineament density together with their main directions.

Application of remote sensing data and geographic information system for identifying potential areas of groundwater storage in middle Moulouya Basin of Morocco

The main objective of this study is to identify the groundwater storage areas in the middle Moulouya Basin by using Geographic Information System (GIS) and Remote Sensing (RS) methods which are the prominent supports of groundwater modeling. Five thematic maps of lithology, rainfall, drainage, lineaments, and slope; which were respectively categorized as they were weighed. Capaciously, they have been used to generate the map of potential groundwater storage zones. The results have shown that the area of very low to low potential surfaces represents approximately 10% of the total area, indicating that the middle Moulouya Basin is rich in groundwater, where more than 2200 wells and boreholes have been drilled. The obtained results have been validated with specific yield of springs in the study area. It indicates a clear correlation between the groundwater potential zones and the specific yield, this correlation is particularly obvious in light of yield of water points and their locations, indeed, most of water points with high yield are located in excellent potential zones, while poor potential zone includes the majority of water points with low yield.

Identification of Deep Tectonic Structures of the Pho Lu area, northwestern Vietnam using Digital Elevation Model and Earth focal mechanism

The digital elevation model and the earthquake focal mechanism are utilized to define the geological structure of the Pho Lu area, northwestern Vietnam. The results allow the identification of lineaments and recognition of the correlation between the lineaments and geological structures directed in the study area. The digital elevation model (DEM) was used in the methodology of interpretation trends of lineaments derived from various enhancing techniques to show that the most lineament trend in the NW‒ SE direction. Further more, the interpreted lineament map demonstrates the NW‒SE system is correlated with the Red River fault zone, which is interpreted as a positive flower structure combined with the focal mechanism of earthquake. The results also demonstrate the capacity to used the digital elevation model and focal mechanism of the earthquake to identify deep geological structures.

Directional analysis of drainage network and morphotectonic features in the south-eastern part of Bükk Region

The fracture deformations often result in linear morphological elements (lineaments, valleys) on the surface. In many cases, the direction of the lineaments and valleys can be well followed by the strike of the geological structural elements. Therefore, conclusions can be drawn from these directions for regional tectonic processes. Our work aimed to analyse the relationship between the valley and lineament network and the structural elements in the south-eastern part of Bükk Region. We prepared the theoretical drainage network map and lineament map of the area. The direction of the linear elements was examined separately on the eastern part of South-Eastern Bükk that is built up mainly by Mesozoic limestone and the eastern side of Bükkalja area covered by Neogene and Quaternary sediments. Structural geological surveys were also performed on seven sites to measure the strike of joint sets. These results were compared with the valleys’ direction in the 2 km wide area of the measurement sites. Based on our results, it can be stated that the development of the drainage network was influenced by the geological elements; however, there are local differences in the characteristics of the South-Eastern Bükk and Bükkalja. Our study confirmed that the study of linear morphological elements has great importance in the exploration of geological structural elements.

INTERPRETATION OF AEROMAGNETIC DATA AND LANDSAT IMAGERY OVER THE NIGERIAN YOUNGER GRANITES IN AND AROUND KAFANCHAN AREA, NORTH-CENTRAL NIGERIA

In this research the lineaments of the Kafanchan area in North-central Nigeria were investigated in order to explore the mineralization zones of the area. Aeromagnetic data over Kafanchan and environs within the Younger Granite Province, in the North-Central Nigeria were collated and analyzed. The aeromagnetic map of the area was interpreted both qualitatively and quantitatively so as to identify the nature of the magnetic sources and the trends direction in the study area. The trend of the Total Magnetic Intensity (TMI) map is predominantly in NE-SW. The First Vertical Derivative (FVD) Lineaments Map was also correlated with LADSAT lineaments map and both maps agreed in most areas. The study area is characterized by predominant magnetic lineament trend in NE-SW direction and subordinate E-W direction. The result also shows that the most significant structural trends affecting the distribution of these magnetic anomalies in the study area is in NE-SW direction. The TMI map indicates that there are three major mineralization zones in the study area. The high magnetization contrast in the NE and SE parts of the study area correlates with the migmatite-gneiss, biotite-granites, granites and basalts which are associated with high magnetic contrasts. Also, the high magnetization contrast in the NW part of the area correlates with basalt and the biotite-granite. However, the predominant low magnetization contrast observed in the western half does not correlate with the basic igneous rock

Structural interpretation of the south-western flank of the Anambra Basin (Nigeria) using satellite-derived WGM 2012 gravity data

The Anambra Basin in the west of the lower Benue Trough is one of Nigeria's most petroliferous provinces. The subsurface structure has been extensively studied using various geophysical methods except for the mapping of structural lineaments. For the present study, the satellite-derived World Gravity Map 2012 (WGM 2012) global gravity model was utilized to study structural features located at different depths. Upward continuation at the height of 30 km was used to extract the regional anomaly from the Bouguer anomaly. The residual anomaly was determined after the deduction of the regional gravity anomaly from the Bouguer anomaly. The total horizontal derivative (THD) of the complete Bouguer, regional, and residual anomalies was used to map the lineaments. The Bouguer gravity anomaly ranges from −58 to more than +28 mGal and presents two generic trends in the E-W and NNE-SSW directions. The regional Bouguer anomaly reveals a Moho depth of 38.0 km from the CRUST1.0 model. The amplitude pattern of the residual gravity anomaly was used to distinguish seven high residual anomalies (HR1-HR7) and four low residual anomalies (HL1-HL4). The residual anomalies of HR1-HR7 are inferred to be hypabyssal igneous rocks. The low residual anomalies of HL1-HL4 are interpreted to be Paleogene and Cretaceous deposits of the Niger Delta complex, and the Bende-Ameki, Imo, Nsukka, Ajali, Mamu, and Nkporo formations. Based on THD analysis, the major structural trends are found to be in NE-SW and NW-SE directions. In addition, 2.5-dimensional forward modelling using the residual Bouguer anomaly along profile CD was performed, providing a variation of the basement depth between 3.5 km and 6.5 km. Therefore, the sedimentary thickness is adequate for the recommended minimum depth for source rock formation and petroleum accumulation with respect to the other petroleum system elements.

Contribution of remote sensing and GIS to mapping groundwater vulnerability in arid zone: Case from Amour Mountains- Algerian Saharan Atlas

Protecting groundwater resource from pollution in arid zone is coming an important act for sensing development in this region calling for geomatics tools to characterize the geological and hydrogeological environment. The present work gives a new way to combine remote sensing and geographic information systems to elaborate vulnerability map of Deffa watershed (in Amour Mountains). This region is a good example of arid zones how know an important growth of agriculture, but there is under gap of geological, hydrogeological and soil knowledge. In the first time, we analyzed the Landsat 8-OLI image data with bands combination, ratios composition in RGB and filters to cartography the lithology's contours and lineament map. The false color composition of bands (765, 753, and 543) in RGB given the primary lithological delimitation. Supported by band rationing technique, we produced of 1/50000 geological map. The filter treatments given the lineament map superposed to the first one to realize geo-structural map. In addition, these images served to elaborate pedology map, using Decision Tree (Slope, Redness Index and Lithology parameters). Secondly, we established a GIS including the result map of RS treatment (lithology, lineament and soil maps) and additional spatial information (aquifer type and deep of groundwater surface and precipitations …). In GIS, the vulnerability index are calculated using GOD and PI methods. Both of maps displayed four classes of vulnerability: between Low and Extreme in the first map, and Very low to High vulnerability in the second one. In the some areas, we have controversial values of vulnerability; this leads us to validate these maps using pollution indicators (NO3−, NH4+ and SO42−). The validation displayed that the PI coincides better with special concentrations of pollutants.

THE CONTRIBUTION OF REMOTE SENSING AND AEROMAGNETISM TO GOLD PROSPECTING: THE CASE OF THE MEIGANGA ZONE, CAMEROON

In order to optimize gold prospecting in the Meiganga zone located in the Adamaoua region of Cameroon, aeromagnetic and remote sensing prospecting was carried out in the eastern and southern parts. The remote sensing approach on a Landsat 8 OLI/TIRS image highlighted areas of maximum gold concentration. Thus, ferric ion bearing minerals are located in the North-West, silicate minerals bearing ferrous ions are in the Centre while clay minerals are in the North-East and East. The principal component analysis revealed important structural information. The PCA Spatial Map (PC1, PC2, PC3) showed the plutonic formations composed of anatexis and anatexis granites, vegetation cover (at the date of image acquisition: February 22, 2019), areas of permanent water circulation or accumulation, and metamorphic and sedimentary formations namely gneisses, quartzites, schists and superficial clay formations. A Landsat SRTM (Shuttle Radar Topography Mission) image was also used to enhance the lineaments through the Sobel filter to highlight the geomorphological (cliffs, valleys, ...) and topographic (river network, ridge and drainage segment) structures. The aeromagnetic approach was also important. The study of the modified magnetic field (CM) showed 4 ranges: very high, high, medium and low. The Total Magnetic Anomalies (TMI) of the area are subdivided into 2 ranges large positive anomalies (221.1-103.0 nT) located in the lower part of NE-SW orientation, small positive anomalies (103.0-(-)89.7 nT) located in the upper part of NE-SW orientation. The reduced total magnetic anomaly at the equator shows a fairly similar distribution to the total magnetic anomaly with the large positive anomalies in almost the entire lower part. Superimposed on the geological map, Neoproterozoic pre- to syn-tectonic granitoids (C) are superimposed on the large positive anomalies and Neoproterozoic conglomerates, quartzites, sedimentary shales and volcanosedimentary rocks (A) and Neoproterozoic syn-tectonic granitoids (B) are superimposed on the large and small positive anomalies. The grid of the reduced residual equatorial anomaly (ARRE) confirms that the local geology is strongly magnetic (gneiss and quartzite). The filters of the derivatives allowed to establish a map of magnetic lineaments of major orientation N045° and minor orientation N130°. The horizontal gadient superimposed on the local maxima showed the presence of deep structures oriented NE-SW. The analytical signal superimposed on the local maxima highlights the metamorphic basement consisting of rocks with strong magnetism. The application of Euler deconvolution localizes the depth of the sources of linear anomalies.

Assessing the accuracy of combined DEM-based lineament mapping and the normalised SL-index as a tool for active fault mapping

Satellite image-based lineament mapping in combination with the normalised Stream Length Gradient Index (SL/K-index) is one of the most widely used methods to identify active faults in areas where other verification methods, such as faulted strata, geophysical subsurface data, or seismic activity in the upper crust, are unavailable, and to classify their degree of activity. The accuracy of this approach, however, has not yet been assessed rigorously. We assess its accuracy by comparing the results against 27 thrust fault segments that were identified from six seismic reflection profiles with a total length of 340 km. Over 106,000 SL/K points were calculated from 815 river profiles on basis of the SRTM v.3.0 DEM. Standard deviations (SD) of < -2SD (class 1) to > +2SD (class 5) were calculated from the lognormalised SL/K data and five SL/K classes were made and assigned to the nearby lineaments. A comparison with the fault segments from the seismic profiles showed a good coincidence between the presence of knickpoints, SL/K classes 4 and 5 and to a lesser extent class 3. Lineaments with SL/K classes 1 and 2 never corresponded to actual faults. We identified seven master thrusts of which three are very active to highly active, likely older, structures with important amounts of accumulated slip. The other thrusts are probably younger faults with relatively little accumulated slip, yet they are also active to highly active faults. Minor strike-slip faults were identified as very active to highly active structures. Published slip rates shows that at least some of the SL/K class 4 faults experience slip rates of ~1 to ~4 mm a−1 and the SL/K class 5 strike-slip faults may experience slip rates as high as one metre over the course of several months. Most active faults occur where the basal evaporite layer is abnormally thick.

Multi-sensor Assessment of Geological Lineament Detection

The advances in remote sensing technologies and geographical information sciences are applicable in various branches of geosciences. The high availability of remote sensing data provides a wide range of spatial and spectral resolutions that can be utilized for lineament mapping purposes, especially in detecting geological linear features in remote areas. The aim of this study is to compare multi-sensors active and passive remote sensing technologies in lineament mapping, based on automatic image processing tools. Landsat 8, Sentinel 1 and Sentinel 2 satellite data will be processed to detect lineaments between the state boundaries of Selangor and Pahang in the Peninsular Malaysia, with reference to the published geological map. In detail, lineaments will be automatically extracted after image enhancement processes. Then, the output will be imported in a geo-graphical information system to further analyze the extracted lineaments. Overall, statistics descriptions, density, and orientations analysis indicate a correlation between the extracted lineaments and the geology of the area. Furthermore, lineaments extracted from Sentinel 1 radar images show the most significant result. Sentinel 1 data indicated about 6396 extracted of lineaments with 2465.93km total length as compared to Sentinel 2 with only 2637 lineaments extracted and total length of 1045.92km. The accuracy assessment of matching lineaments provides the Sentinel 1 as the best sensor compared to both the Sentinel 2 and the Landsat 8, with root mean square errors (RMSE) equal to 1.660, 1.743 and 2.757, respectively. Therefore, both remote sensing technologies and geographical information sciences can be effectively integrated within the field of the structural geology, thus allowing the mapping of lineaments in a more practical, cost and time effective way.

Landsat-8 Lineament Analysis for Detection of Epigenetic Mineralization Zones in Parts of Igarra Schist Belt, Southwestern Nigeria

The study of lineaments derived from optical imagery provides insights to the location of mineral deposits as they reflect geologic structures. The present study employs lineament extraction from Landsat-8 Operational Land Imager (OLI) to identify possible areas of epigenetic mineralization in the rocks of Dagbala-Atte District. Fifty-one (51) geologically significant lineaments of varying lengths and directions were extracted. Lineament map revealed three promising zones of epigenetic mineralization. These zones are those in the northeastern, central, and southwestern parts of the district. Previous reconnaissance stream sediment geochemical survey in the larger region comprising the district had selected areas that correlate well with these zones as the more prospective for metallic mineralization. Also, pedogeochemical surveys in the district revealed plausible areas underlain by rocks most likely contain different metallic mineralizations that synchronize well with these promising zones. Geological mapping and preliminary lithogeochemical survey in these zones have unveiled uranium bearing pegmatite in the northeastern zone; gold bearing marble deposit and iron oxide-copper-gold-silver mineralized silicified sheared rock along the central zone; and lead-zinc mineralized metaconglomerate in the southwestern zone. Ample geological studies of these mineralized rocks are recommended.

Lineament Extraction using Gravity Data in the Citarum Watershed

Lineament is one of the most important features showing subsurface elements or structural weakness such as faults. This study aims to identify subsurface lineament patterns using automatic lineament in Citarum watershed with gravity data. Satellite gravity data were used to generate a sub-surface lineament. Satellite gravity data corrected using Bouguer and terrain correction to obtain a complete Bouguer anomaly value. Butterworth filters were used to separate regional and residual anomaly from the complete Bouguer anomaly value. Residual anomaly gravity data used to analyze sub-surface lineament. Lineament generated using Line module in PCI Geomatica to obtain sub-surface lineament from gravity residual value. The orientations of lineaments and fault lines were created by using rose diagrams. The main trends observed in the lineament map could be recognized in these diagrams, showing a strongly major trend in NW-SE, and the subdominant directions were in N-S. Area with a high density of lineament located at the Southern part of the study area. High-density lineament might be correlated with fractured volcanic rock upstream of the Citarum watershed, meanwhile, low-density lineament is associated with low-density sediment. The high-density fracture might be associated with intensive tectonics and volcanism.