Interpretation Of Lineaments Research Articles

Geological Mapping of Kaso, Tambaksari, Ciamis, West Java Province Using Lidar Images Interpretation

Abstract Remote sensing nowadays is used to quickly and effectively obtain information about an object, area or phenomenon and can be applied to large areas that are sometimes difficult to reach. Satellites with multispectral imagery are commonly used in geological mapping, but have drawbacks when used in tropical areas such as Indonesia, with dense vegetation, fast sedimentation rates and highly weathered that will cover fresh rocks making it difficult to interpret geological condition through aerial photo. Light Detection And Ranging (LiDAR) images using laser beams to produce elevation data (x,y,z) with high spatial resolution and can penetrate the surface of vegetation are expected to be a solution in areas with dense vegetation that are sometimes difficult to reach. The study was conducted by interpreting the morphometric aspects using Digital Terrain Model (DTM) data processed from LiDAR imagery with a spatial resolution of 1 m/pixel to display the topographical surface in detail. The morphometric aspects used include slope, surface roughness, aspect, hillshade, and stream pattern. Field data validation through surface mapping is carried out to correct the lithology interpretation by comparing the results of LiDAR image interpretation. Field data validation results show that interpretation using LiDAR imagery has good results (79%) through overall accuracy percentage, with the lithology units being sandstones, siltstone, breccias, and andesitic igneous rocks. The lineament interpretation of the DTM data indicates the existence of a geological structure in the form of a normal and strike-slip fault in the study area.

Digital topographic analysis and lineament interpretation south of the Lena Delta, North Siberia: Landscape expression of its tectonic activity

This study applies semi-automated techniques to analyze the landforms, morphostructure, and geology of the Kharaulakh and Chekanovsky sectors, south of the Lena Delta, northern Siberia. High-resolution data, including TanDEM-X 30 m spatial resolution Digital Elevation Models (DEM), 2 m spatial resolution ArcticDEM Digital Surface Models (DSM), and Sentinel-2 satellite imagery, serve as the basis for the analysis. Digital terrain classification and identification of tectonic lineaments are performed using the Benthic Terrain Modeler (BTM) and Linear Extraction (LINE) algorithm, respectively. Additionally, a hypsometric analysis is conducted to assess areas of potential neotectonic activity. 873 lineaments are identified, primarily in NE-SW and E-W orientations. NW-SE lineaments perpendicular to the lithological and fold belt strikes in the Kharaulakh Ridge suggest inheritance from original depositional settings or later compressional tectonics, now appearing as valleys and weak zones facilitating erosion and river incision. Longer N-S or NNW-SSE lineaments in the Kharaulakh Sector are associated with thrust sheets of the Verkhoyansk fold-and-thrust belt and Cenozoic graben structures linked to the formation of the Laptev Sea Rift System and ongoing regional deformation. The Chekanovsky Sector, marked by epiplatform blocks and hills, presents a dissected plateau with steep valleys. Here, high hypsometric integral values are attributed to compression and uplift near the southwestern boundary of the Laptev Sea Microplate.

Delineating geological structure utilizing integration of remote sensing and gravity data: a study from Halmahera, North Molucca, Indonesia

Halmahera Island is the result of the interaction between the Indo-Australian Plate, the Molucca Sea Plate, and the Philippine Plate, which gave rise to many active geological structures that are vulnerable to seismic activity around the island. The complexity of this geological structure makes Halmahera Island very interesting to study. This study aims to identify geological structures by integrating remote sensing and gravity satellite data. Surface lineament analysis using the remote sensing method was carried out based on Sentinel-1A imagery data. The gravity method uses GGMPlus satellite data to clarify the continuity of geological structures that cannot be clearly mapped on the surface. Lineament analysis on gravity data uses techniques such as fast sigmoid edge detection (FSED) and Euler deconvolution. The results of lineament interpretation based on integrating remote sensing and gravity satellite data show that the NE-SW structure controls the northern and northeastern arms of Halmahera.
 In contrast, the southern arm is dominated by the NW-SE structure. The Euler depth estimation shows that the Halmahera area contributes to having geological structures at various depths. Deep structures reach 4 km, while shallow structures are found at depths of up to 2 km. Earthquake hypocenter data strengthen the interpretation of this geological structure. This comprehensive study yields an excellent correlation between gravity and remote sensing techniques in describing the general structural framework of the area. The new finding is an NE-SW trending geological structure on the northern Halmahera arm, which may be caused by two different tectonics first, the subduction of the Molucca Sea Plate with the Halmahera Plate in the west. Second, the strike-slip movement is trending NE-SW, which cuts the northern and northeastern arms due to the rotational movement of the thrust fault with the Philippine Plate to the west.

Detailed investigation of multi-scale fracture networks in glacially abraded crystalline bedrock at Åland Islands, Finland

Abstract. Using multiple scales of observation in studying the fractures of the bedrock increases the reliability and representativeness of the respective studies. This is because the discontinuities, i.e. the fractures, in the bedrock lack any characteristic length and instead occur within a large range of scales of approximately 10 orders of magnitude. Consequently, fracture models need to be constructed based on representative multi-scale datasets. In this paper, we combine a detailed bedrock fracture study from an extensive bedrock outcrop area with lineament interpretation using light detection and ranging (lidar) and geophysical data. Our study offers lineament data in an intermediary length range (100–500 m) missing from discrete fracture network modelling conducted at Olkiluoto, a nuclear spent-fuel facility in Finland. Our analysis provides insights into multi-scale length distributions of lineaments and fractures and into the effect of glaciations on lineament and fracture data. A common power-law model was fit to the lineament and fracture lengths with an exponent of −1.13. However, the fractures and lineaments might follow distinct power laws or other statistical distributions rather than a common one. When categorising data by orientation, we can highlight differences in length distributions possibly related to glaciations. Our analysis further includes the topological, scale-independent fracture network characteristics. For example, we noticed a trend of decreasing apparent connectivity of fracture networks as the scale of observation increases.

A study of faults in the Superior province of Ontario and Quebec using the random forest machine learning algorithm: Spatial relationship to gold mines

This paper uses the random forest (RF) algorithm to produce two maps of orogenic gold prospectivity (MPM) across the entire Superior geologic province of Ontario and Quebec, Canada. One MPM of this entire study area is based on a compilation of mapped faults while the other is based on a manual interpretation of lineaments from airborne magnetic data. In addition, we have created four MPMs over the Abitibi region as the MPM map of the entire Superior is characterized by a mapping bias due to more intense mapping of faults over the Abitibi portion of the study area with respect to the rest of the Superior province. There are three RF maps generated over the Abitibi region based on faults, fault density and fault intersection density, faults + magnetic data and faults + gravity + magnetic data. To reduce the effect of the fault mapping bias, we developed a fourth map based on a knowledge driven (weighted sum technique). Statistically the best MPM is based on the faults, gravity and magnetic data. The major predictors of gold are NW-SE, NE-SW, EW trending faults, fault intersection density between EW and NW trending faults and to a lesser extent fault density and a magnetic vertical gradient image. In addition, we compare two greenstone belts in three dimensions with respect to their potential for gold exploration. We conclude that the Larder Lake greenstone belt is more fertile with respect to gold mineralization than the Swayze greenstone belt due to deeper penetrating faults which have greater potential for tapping gold mineralized fluid from the mantle or lower crust. Our final MPM map has identified prospective areas that contain known gold mines as well as areas that do not contain any known gold mines. These prospective areas may be prime for orogenic gold exploration.

Comparative Studies on the Extraction of Lineaments and Its Variability Based on an Improved Line Segment Tracking Method—Taking the Gaosong Ore Field in the Gejiu Gejiu Tin Ore Deposit as an Example

Remote sensing technology is widely used in the application of the extraction of lineaments in geological research. However, most of the current traditional lineament extraction methods are based on edge detection technology using a digital filter to extract the mitochondrial features in the image. These previously used algorithms are generally unable to extract the mitochondrial features in the shadow area on the mountain and the area parallel to the direction of the solar incident angle. In this paper, we have improved the STA algorithm (Line Segment Tracking method). The line segmentation and connection methods were firstly proposed, and then 32 search directions were set with one pixel as the center to find the best continuity direction of the lineament. A threshold was then set in this direction to determine whether it was a line element. Finally, line elements were connected into lineaments for further lineament interpretation. The lineament data from three different directions were collected in the Gaosong ore field in the Gejiu mining area, namely at the first place the traditional Canny algorithm, then the improved line segment tracking method, and finally the field measurement. The coefficients of the three-type lineament variations were compared by calculating the lineaments’ strength and their density attributes. It shows that the lineament variability extracted based on the improved line segment tracking method is closer to the measured lineament variability. The results show that the lineaments extracted by the improved algorithm are closer to the measured data. The improved algorithm has higher precision than the traditional Canny algorithm. More realistic and comprehensive lineaments can be attained by using the improved method to extract lineaments in the mining area, which is helpful to the study of the geology of the mining area and helps to construct a more accurate structure model to serve the needs of the mine production.

Heavy Oil Potentials in Central Sumatra Basin, Indonesia Using Remote Sensing, Gravity, and Petrophysics Data: From Literature Review to Interpretations and Analyses

Central Sumatra basin is located on Sumatra Island, Indonesia, and is considered an oil prolific basin that produces heavy oil. The basin is believed to have unexplored heavy oil potential. Therefore, this study aims to map the heavy oil potential distribution in the basin using surface and subsurface lineaments analyses interpreted from satellite imagery and gravity data, and assisted by well log/petrophysics analysis. A thorough basin analysis was conducted based on surface/subsurface structures’ control and source rock location settings to map all potential heavy oil traps. The gravity anomaly data interpretation identified the low areas and lineaments in NW – SE, and N – S directions. The interpretation of satellite imageries showed very similar lineament patterns with the same general direction. It was observed that there is continuity between subsurface and surface lineament features, which provide contact between reservoirs and surface water sources, thereby facilitating heavy oil generation. Overlapping the lineament interpretation of gravity and satellite imagery data, supported by petroleum system understanding and verification from wells data have confirmed 7 heavy oil trap potential areas within the sedimentary basin.

Convolutional neural networks applied to the interpretation of lineaments in aeromagnetic data

Parameter estimation in aeromagnetics is an important tool for geologic interpretation. Due to aeromagnetic data being highly prevalent around the world, it can often be used to assist in understanding the geology of an area as a whole or for locating potential areas of further investigation for mineral exploration. Methods that automatically provide information such as the location and depth to the source of anomalies are useful to the interpretation, particularly in areas where a large number of anomalies exist. Unfortunately, many current methods rely on high-order derivatives and are therefore susceptible to noise in the data. Convolutional neural networks (CNNs) are a subset of machine-learning methods that are well-suited to image processing tasks, and they have been shown to be effective at interpreting other geophysical data, such as seismic sections. Following several similar successful approaches, we have developed a CNN methodology for estimating the location and depth of lineament-type anomalies in aeromagnetic maps. To train the CNN model, we used a synthetic aeromagnetic data modeler to vary the relevant physical parameters, and we developed a representative data set of approximately 1.4 million images. These were then used for training classification CNNs, with each class representing a small range of depth values. We first applied the model to a series of difficult synthetic data sets with varying amounts of noise, comparing the results against the tilt-depth method. We then applied the CNN model to a data set from northeastern Ontario, Canada, that contained a dike with known depth that was correctly estimated. This method is shown to be robust to noise, and it can easily be applied to new data sets using the trained model, which has been made publicly available.

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.

Analysis and Interpretation of Lineaments for Evaluation of Groundwater Potential in Shendam and Environs, North Central Nigeria

This study was done to evaluate the groundwater potentials of Shendam and environs using lineaments analysis. The trends of field joints were measured during mapping and using satellite remote sensing to generate lineament. The area is underlain by crystalline basement rocks of biotite granite, medium grain granite, and syenite. Assessment was carried out to depict the possibility of groundwater occurrence in the area. LANDSAT ETM+ imagery was used, together with the geological map to investigate areas favorable for groundwater development. This was achieved by plotting the lineament trends, superimposing the lineament on the geological map, superimposing the lineament on the drainage map, furthermore by plotting density map to know the groundwater potentials of the area. Lineament was used in drawing the respective rose diagrams for each rock type. Structurally, the area is characterized by a predominant NE to SW trend which also affects or controls drainage and groundwater occurrence with major groundwater recharge areas trending NE- SW of the study area. Analyses have shown that the study area has numerous fractures whose major trends are mainly in NE-SW directions. Lineament density maps shows the cross-cutting lineaments to be relatively high in the areas around the northeastern to southwestern parts of the study area but low in the other areas. Zones of high lineament intersection density are feasible zones for groundwater prospecting.

Structural Interpretation of Lineament from Nlonako Area and Surroundings: Contribution to Pan-African Tectonic Reconstruction

The Nlonako anorogenic complex (NAC) is located in the south western part of the Cameroon Line and is superposed on the N50E section of the central Cameroon shear zone. It is suggested to be a ring complex of 10 km diameter which was emplaced as sill intrusive body during the Tertiary. In order to do characterize the Nlonako complex shape and characterize the tectonic history in the study area and surrounding, spatial technology (Landsat 8 ETM+ and SRTM images) were used for geological mapping and structural reconstruction based on lineament analysis.
 Data extracted from Landsat 8 ETM and SRTM images show a sub-circular shape for the NAC and the superposition of field and petrographic data from our previous research works confirm the fact that the NAC is a ring or annular complex slightly elongated NNE-SSW, thus it is known as the Nlonako ring complex (NRC). Map of lineament synthesis and the SRTM image of the study area display NE-SW, NW-SE and N-S trend structures. (1) The dominant NE-SW trend mostly displayed by the NRC and its basement rock is parallel to (i) the main metamorphic foliation trend and (ii) to the central Cameroon shear zone regional fault, corresponds to the trending of the regional foliation, structures and the Ngondo pluton elongated shape. (2) The secondary N-S direction may correspond to the late deformational phase in the area because, the N-S-related structures transposing NE-SW structures towards a meridional direction in the NRC basement rock. (3) The NW-SE trend corresponds to the direction of NW-SE fault cross cutting the NRC.
 Field data and synthetic lineament map enable to identify: (1) a Compressive deformational phase D1 whose main markers are NNW-SSE to NW-SE S1 foliation; (2) an early left-lateral deformational phase D2 characterized by anticlockwise rotation of clasts and NE-SW sinistral transposition of early structures; (3) a NE-SW right-lateral deformational phase D3 marked by clockwise rotation and dextral transposition of preexisting structures as well as the NE-SW S3 foliation and (4) a late left-lateral deformational phase D4 marked by the N-S transposition of NE-SW dextral D3-related structures by late sinistral shear movement. This suggests a more complex tectonic history for the Pan-African Belt in Cameroon showing at least three shear phases, that is a right-lateral phase, sandwich by two left-lateral phases.

Lineament Trend Analysis for Designing of Fault Deformation Monitoring Network in the Sermo Reservoir Area, Yogyakarta, Indonesia

The Sermo Reservoir plays a vital role in the livelihood of the surrounding community. However, based on the geological map, a fault crosses the reservoir and possibly through the dam body. Therefore, disaster needs to be mitigated by monitoring the deformation of both the fault and the dam body. Deformation monitoring network design needs to consider the accuracy, reliability, and sensitivity in detecting and measuring any displacement. Geological conditions affect the sensitivity of the network. This research aims to analyze the geological structure based on the lineament interpretation of the deformation monitoring network design of the fault. The study was conducted by interpreting lineaments using the Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) image with 30 m resolution and then representing the lineament patterns with a rose diagram. The lineament analysis was related to the rock formation of areas surrounding the Sermo Reservoir. Furthermore, the deformation monitoring network will be designed considering the geological phenomenon resulting from lineament analysis and other factors used in previous research, such as the distance and direction of the control point from the fault. From the lineament analysis, initial information showed that the fault was estimated in the direction of northwest-southeast and may be active. Deformation monitoring stations should be established along the fault plane, in both the right and left sides, and within various distances. The stations should be evenly distributed to cover the areas around the reservoir, the area outside the reservoir but still within the fault area, and the area outside the reservoir and the fault. The distribution of the stations should also form a transverse baseline to the fault.

Airborne geophysical data interpretation of the southeast portion of Parnaíba Basin, Brazil

Airborne geophysical surveys are widely used in geological prospecting for hydrocarbon reservoirs. The efficiency and fast acquisition of these methods covering large areas, recognize them as a key tool for any prospecting project located in frontier basins, such as Parnaiba Basin, where there is a large amount of technical data. Among the airborne geophysical methods, gravity and magnetic methods, usually called potential field methods, are the most propagated in Oil and Gas projects of this nature. Such methods are used to support the generation of regional geological knowledge, detailed approaches, integrated with seismic, geochemical, and well data. Specifically, in the case of magnetometry, its use in more detailed specifications has been available in the Brazilian market since 1988 with the release of the GPS signal to the market and mainly after the replacement of the proton precession magnetometers by the cesium vapor (1991–1994), which is much more accurate in determining the anomalous magnetic field. In terms of airborne gravity, applications in detailed survey approach were not available to the Brazilian market until 2006. Investments in hydrocarbon prospecting in Brazil were concentrated in the promising Campos Basin, leading to few and almost no investments in other Brazilian sedimentary basins. The Parnaiba Basin is one of the Brazilian sedimentary basins with almost no prospecting investment. The aims of this work is a qualitative interpretation of magnetic lineaments and high gravity and structural lows, to suggest a map of the integrated structural context and of geological and geophysical methods of the southeast portion of Parnaiba basin. Using filters like the First Vertical Derivative and the Analytic Signal maps was possible to highlight the structural magnetic lineaments interpreted and a qualitative interpretation of geological intrusions and sills. On results, the data interpretation showed an important structural complexity and identified graben and horst structures usually favorable to the hydrocarbon trap occurrence, as well as an intrusive rock occurrence usually associated to organic matter maturation, in a higher concentration in the center region of the study area.

Integration of field mapping, lineament interpretation and electrical resistivity tomography survey to characterize granitic rock mass lining by shotcrete

Integration of field mapping, lineament interpretation and electrical resistivity tomography survey to characterize granitic rock mass lining by shotcrete

Interpretation of lineaments and faults near Summerville, South Carolina, USA, using LiDAR data: implications for the cause of the 1886 Charleston, South Carolina, earthquake

LiDAR (light detection and ranging) data acquired near Summerville, South Carolina, reveal numerous lineaments trending in various directions across the Middleton Place-Summerville seismic zone (MPSSZ) and surrounding area. These lineaments are defined by linear depressions and stream valleys that are developed within late Eocene to Holocene marine, marginal marine, and fluvial sediments of the Atlantic Coastal Plain. The 40-kmlong, ENE-WSW-oriented Deer Park lineament coincides with the Woodstock epicenter of the 1886 Charleston earthquake, suggesting that the main shock may have occurred along a fault associated with this lineament. The proximity of the 17-km-long, ENE-WSW-oriented Middleton Place lineament to the Middleton Place epicenter suggests that it too may have ruptured in 1886. Several E-W-oriented topographic scarps are also located near the area of modern seismicity, including the 3- to 5-km-long, south-facing McChune and Summerwood scarps. The McChune scarp is aligned with the E-W-trending portion of the Summerville scarp to the west, suggesting that both scarps may be from uplift to the north along the same fault. The McChune scarp and the Otranto and Middleton Place lineaments coincide with faults interpreted from previously acquired seismic-reflection profiles, suggesting that these features are surface expressions of Quaternary faults. Other lineaments east of the MPSSZ are associated with Neogene structural domes, indicating that the interpreted faults along these lineaments have been active during the late Cenozoic. The LiDAR data also revealed a ~350-m dextral offset of a middle Pleistocene beach ridge along the Woodstock fault and a ~20-km-long, NW-SE-oriented lineament to the east (Canterhilllineament) that appears to be the surface expression of the Charleston fault.

Geospatial and statistical interpretation of lineaments: salinity intrusion in the Kribi-Campo coastland of Cameroon

This study detected, mapped and analysed lineaments from Landsat-8 satellite images of the coastal area of Kribi-Campo, Cameroon. Kribi, a fast-growing coastal city with a youthful population whose main industry is agriculture, is currently under great pressure due to the influx of internally displaced persons, victims of the current socio-political crisis in the western part of Cameroon. With the growing demand for food and water resources, it has been reported that saline soils and groundwater are affecting the agricultural productivity and domestic water supply of the area. This paper investigates the lineaments network in this area to understand its spatial distribution, its extent and the potential effect on inland intrusion of saline water. The datasets, including Landsat-8 imagery, geological data and a digital elevation model were processed using principal component analysis and filtering techniques. Linear features were enhanced based on textural changes of false colour composite images to describe fractures, faults and hydrology features. 390 effective lineaments were extracted automatically and manually from those images and analysed based on length, density and orientation using statistical analysis. But before this processing, non-effective lineaments that may correspond to terraces, linear valleys, cliffs, or tonal contrast as well as to human activities have been deleted. The effective lineaments range in length from 95 to 4910 m with an average of 1171 m. Although the lineaments are not isotropic, their perpendicular orientations to the coast suggest potential intrusion of saline water into regional groundwater resources and farmlands. The paper presents a combined technique of geospatial and statistical analysis in the interpretation of lineament effects which have the potential to inform on salinity intrusion in coastlands. The electrical conductivity of 50 groundwater samples collected in the study area are used to validate the impact of lineaments on seawater intrusion.

Structural interpretation of lineaments using satellite image processing: A case study in the vicinity of the Charvak reservoir

This work presents the results of lineaments interpretation using the automated method of the satellite images in the territory of the Charvak water reservoir in Uzbekistan. Tectonic and local (water impoundment in Charvak reservoir) features of the region deformation were determined on base LINE algorithm in software PCI Geomatica. The thematic map with the geospatial arrangement of lineaments was constructed on base of satellite images LANDSAT-8 processing. We concluded that water level fluctuations have a greater influence on the appearance of the lineaments structure than periods of water filling and downstream in the reservoir. Lineament density maps showed dominantly increased density towards the north-southern direction is due to tectonic features of the region and the west-eastern direction is due to water level fluctuations in the reservoir. The lineaments density maps for summer-autumn periods showed the faults arising from water level fluctuations only. Winter-spring period affected with high influence of the seasonal (snow pack, rainfall) processes as well.

Insights into tectonic reactivation and landscape development processes at the Paraná Basin border using integrated geomorphometric and radiometric analyses

In the Bom Jardim de Goiás region, the Transbrasiliano Lineament shows evidence of a fault reactivation along NE-SW structures (main direction) and secondary directions related to subsequent events. To study the structural framework and reactivation inputs toward tectonic events, distinctive features of the northern Paraná Basin border were analyzed by integrating gamma spectrometry and radar data, both supported by field research. The remote sensing database obtained by the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) sensor allowed detecting lineaments and morphometric derivatives. Besides, the developed morphogenetic process images attest to the importance of structural control on relief evolution while concentrating lineaments as a function of lithological and geomorphological domains. Airborne gamma-ray spectrometry data processing focused on Kd (Anomalous Potassium) and F-Parameter indices. In this context, the fuzzy logic and Index Overlay Method allowed multivalued integration that indicated hydrothermal products and weathering processes correlated with Kd and F-Parameter anomalies. Thus, the joint interpretation of lineaments, geomorphological domains, and Kd/F-Parameter anomalies allowed differentiating primary geological elements and products from surface dynamics, directly or indirectly related to tectonic reactivation processes.

Applicability of Developed Algorithm for Semi-automated Extraction and Morphotectonic Interpretation of Lineaments Using Remotely Sensed Data, Southwestern Tunisia

In this study, we performed semi-automatic extraction of lineaments using satellite imagery of Landsat-8 OLI (Operational Land Imager) and digital elevation model of SRTM (Shuttle Radar Topography Mission). The developed algorithm used for this purpose combines STA (Segment Tracing Algorithm), ALEGHT (Automatic Lineament Extraction by Generalized Hough Transform) and AERA (Alluvial Effect Reducing Algorithm) to achieve maximum precision in the output results. To evaluate the spatial distribution of lineaments, we performed multicriteria statistical analysis and mapping of the density and length. This methodology was applied to Segui region located in the southwestern part of Tunisia. It is characterized by folds made up by carbonate formations. The statistical analysis shows emergence of two major general lineament trends that represent extrados faults and has the same direction of folds axis. Density measurements of the spatial lineaments distribution indicate a high density in the centre of structures. High density is also observed along fold hinges and structural gaps. Measurements of lineaments lengths show that directional families with the same fold axis are the longest. The proposed approach is useful in other similar case studies for the morphotectonic and lineament interpretation.

Watersheds Morphometry and Structural Interpretation of Lineaments Extracted from SRTM Data in the Mayo-Kani Division Far-Nord Region, (Cameroon)

In the Far-North Region of Cameroon, the high rate of weathering and erosion of rocks do not allow to map the hydrological and geological structures in the field. This paper aims to test the combined use of field topographic data and Shuttler Radar Topography Mission (SRTM) data to define watershed morphometry, highlight the different erosion factors, and characterize the structural lineaments of the Mayo-Kani Division, within the Far-North Region of Cameroon. All these are done using; watersheds, hydrographic network, slopes, manual lineaments and automatic lineaments maps. These treatment techniques used (filtering, enhancement and slope analyses) allows: to morphologically characterize the ten identified Mayo-Kani watersheds, to measure the erodibility rate of the watersheds using the Universal Soil Loss Equation (USLE) and to compute the fracture maps. This last operation was validated using ground truth field observations and the literature review. Fracture networks were analyzed using statistical analysis techniques by studying fracture length distribution laws.