Lineament Analysis Research Articles

Remote sensing and structural studies of the Central Asir Shear Zone, Western Arabian Shield: Implications for the late Neoproterozoic E-W Gondwana assembly

The Central Asir Shear Zone (CASZ) is a N- to NNE-oriented inhomogeneous strain zone parallel to the Nabitah shear belt in southern Saudi Arabia. It is ~200 km long and 20 km wide, and traverses the Asir terrane. The deformed terrains in the vicinity of the CASZ have experienced a prolonged history involving three successive phases of deformation: arc-collision, dextral transpression and sinistral strike-slip faulting. Remote-sensing data analysis and field investigation provide insights into the geological and structural features along the CASZ. Image transformation and enhancement reveal faults and folds, and discriminate between granitoids, metavolcanics, gabbros and younger (Ablah Group) sediments. The obtained evidence points to polyphase deformation of the area, characterized by narrow zones of high strain, folding and shearing enclosing slices of less deformed rocks. Lineament analysis shows predominantly NNE, NNW, N and NE trends of folds and shear zones, and NW, NE and E fracture trends. The CASZ has a >100 m.y. long deformation history, including a change from dextral to sinistral shearing. Both shearing senses are found on the older N-S and younger NW-SE fault systems. N-S oriented shearing was accompanied by intrusion of granitoids and localized hydrothermal alteration along N to NNE trending shear zones. Strain analysis shows low strain in the Ablah basin sediments, consistent with Ablah deposition after the tectonic climax in the region.

Statistical Analysis Of Lineaments Using Landsat 8 Data: A Case Study Of The Fergana Valley (East Uzbekistan)

This paper describes a statistical analysis of lineaments based on multi-temporal Landsat 8 imageries in the Fergana Valley (East Uzbekistan). The results of the statistical analysis showed that determined that the count of lineament structures changes by months. It was also noted that the Namangan region is more prone to the manifestation of lineament structures. The maximum count of lineament structures was in July. And in November, we observe a sharp decrease in lineament structures. According to the results of the rose diagrams, various orientations are observed for these months. There is a coincidence of directions.

Integration of remote-sensing data for mapping lithological and structural features in the Esh El-Mallaha area, west Gulf of Suez, Egypt

Esh El-Mallaha west of the Gulf of Suez is a potential area for hydrocarbon resources. In this article, Landsat-8 Operational Land Imager (OLI), Shuttle Radar Topography Mission (SRTM), and Advanced Land Observing Satellite (ALOS) Phased Array Type L‐band Synthetic Aperture Radar (PALSAR) data were utilized to identify the geological and structural features of this area which represents a part of the North Eastern Desert (NED), Egypt. The use of band ratios (BR) and principal component analysis (PCA) allowed characterizing the different varieties of rock units. These approaches allowed discriminating the various rock units e.g., metavolcanics, granitoids including the two phases of the older granites and younger granites along with the third phase which represented by elongated ridges cut the rocks and clearly allowed tracing the contacts of different lithological units of the Neoproterozoic basement and Phanerozoic sedimentary rocks. Applying the fused Landsat-8 OLI and ALOS/PALSAR data improved the structural elements that difficult to reveal by optical images. Combination of Landsat-8 OLI, ALOS/PALSAR, and SRTM data effectively display the structural and lithological contacts. The lineament extraction and interpretation indicated that the area is clearly shaped by the NW-SE graben and controlled by the Gulf of Suez tectonic trend. Such structures allowed the accumulation of thick sediments in the faulted basin that represents the promise area for oil, gas, and water resources. Lineament analysis revealed that the major tectonic trends controlling the area are NW-SE and NE-SW directions with less effect of N-S and E-W trends. The NW-SE sinistral and NE-SW dextral lateral movements are recognized. Overall results revealed that the integration of optical and radar remotely sensed data is an effective tool in deciphering geological and structural features in the arid regions.

Autochthonous origin of the Encruzilhada Block, Dom Feliciano Belt, southern Brazil, based on aerogeophysics, image analysis and PT-paths

The Encruzilhada Block lies between the eastern hinterland and western foreland of the Dom Feliciano Belt (southern Brazil) and its tectonic meaning in the orogenic evolution of the belt is still poorly understood. Its low magnetic signal is similar to that of the foreland supracrustal sequences, whereas the high gammaspectrometric signal appears due to the hinterland post-collisional granitoids. Satellite image lineament analysis points to tectonic similarities between the Encruzilhada Block and the foreland, as the structures in both domains show predominantly NNW and NNE trends, while the hinterland mostly presents NE-trending structures. The pre-orogenic connection between the Encruzilhada Block and the foreland is indicated by the correlation between the Várzea do Capivarita and Cerro da Árvore complexes. Both contain 800 – 780 Ma metaigneous rocks with arc-like geochemistry, and parametamorphic rocks with similar sedimentary provenance. Common syn-orogenic deformation history of both complexes is suggested by progressive to P-T o-th E-W transpressive deformation and similar peak metamorphic age (660 – 640 Ma). PT-paths suggest exhumation of the hinterland Várzea do Capivarita Complex from high-T/low-P conditions of 790–820 °C/4.4–4.8 kbar to 660–720 °C/2.5–3.4 kbar at ca. 630 Ma. On the other hand, the foreland Cerro da Árvore Complex was subject to progressive metamorphism from 555 to 565 °C/5.4–5.7 kbar to 560–580 °C/5.8–6.3 kbar, which is interpreted as a result of orogenic thickening. Evidence suggests that both complexes have originated in a similar, if not a single, basin on an attenuated lithosphere with high geothermal gradient, possibly a (back-arc?) rift. Oblique collision has caused basin inversion and thrusting of the lower crust over the rift margin, which may have been accompanied by lithosphere delamination. Progressive transpressional deformation and voluminous post-collisional magmatism (640 – 578 Ma) controlled by major lineaments have blurred the original tectonic contact and finally caused thermal metamorphism in both complexes at ca. 3 kbar, when the autochthonous Encruzilhada Block was stabilized in its present geological configuration. The intracontinental character of major shear zones limiting hinterland and foreland requires a review of the existing evolutionary model for the Dom Feliciano Belt in the context of Western Gondwana amalgamation.

Remote Sensing Analysis of Lineaments using Multidirectional Shaded Relief from Digital Elevation Model (DEM) in Olele Area, Gorontalo

The Gorontalo fault zone is an active fault that crosses Gorontalo Province with a movement of about 11 mm/year. The existence of this fault zone affects the morphological lineaments and offsets along its path and increases the potential of geological disaster hazards. The Olele area is located in the Gorontalo fault zone that makes it potential to landslide disaster. This study aims to analyze the lineaments of the Olele area and its surroundings. The results of this analysis will help to determine the geological structures distribution pattern that develops in the study area and its impact on the mitigation of landslide disasters in the study area. This study uses a spatial analysis method using Digital Elevation Model (DEM) image to analyze slope and lineaments data in the study area. The results of the analysis will be correlated with regional geological structures and give recommendations for geological disaster mitigation that can be implemented. The results showed that the slope class in the study area was dominated by the range of 16-35° and even in several places with a slope of 35-55°. The results of the extraction and processing of lineaments data get 203 data. The lineaments direction is relatively NNW - SSE. This direction indicates that mostly the morphologies are influenced by the existence of the Gorontalo fault zone. The existence of the Gorontalo fault zone makes this area prone to landslide disasters in the case of Gorontalo fault movement. Some prevention recommendations are to increase the slope stability level.

Геоактивные зоны и структура растительных сообществ в связи с новыми открытиями в космической геологии

The purpose of the work is to find out how plants react to such zones and whether their phytoindication is possible. Two territories of the Perm territory were studied: the Vishersky Nature Reserve and forests near Perm. The research methodology included lineament and geostructurometric analysis of space images and special maps using ring structures discovered on the Earth’s surface by Yu. I. Fivenskii, as well as phyto- and bioindication of small geoactive zones. It was found that in the forests near Perm favorable zones of such zones occupy 1.44% of the territory and within their limits the safety of common pine (Pinus sylvestris L.) is 29–42 times higher. Phytoindication of small geoactive zones of 1.0 and 3.0 m by common pine was shown in the zones of influence of these zones: 0–18 cm — the radius of inhibition with the absence of trees; 19–29 cm — the depression zone with small trees; 30–48 cm — the comfort zone with medium and large trees. Two types of networks formed by zones of 1.0 and 8.0 m in size near Perm (on the plain) and in the reserve (in the mountains) were compared. In the mountains, with high geodynamic activity of territories, the networks are oriented in one direction, while on the plain their orientation is misaligned by 30°. In the reserve, large trees of Siberian spruce (Picea obovata Ledeb.) were located on small geoactive zones of 1.0 and 8.0 m, and trees of Siberian pine (Pinus sibirica Du Tour) — on zones 1.0 and 3.0 m in combination with zones 16, 32 and 55 m. In the subgolets zone, ring structures of perennial plants were also found on the first two types of zones. In addition, along the edges of the swamps, chains of trees were found whose direction coincides with ring faults, and the chains themselves are similar to the structure of small geoactive zones networks, and this fractality requires field verification. The hypothesis recharge of plants within geoactive zones is proposed, which also explains the successful growth of trees on rocks, where the amount of available soil is minimal.

Lineament analysis of the dem in auminzatau mountains using the less a program

Lineament analysis is one of the main methods for automated decoding of satellite images. In this work, the lineament analysis was performed using the LESSA program. As a result, statistical data on lineaments were obtained, such as roses, elongation lines, lineaments density, and a map of lineaments of the Auminzatau mountains was compiled. This map allows a detailed study of faults in this region associated with the mineralization zone.

Influence of preexisting structures on the variation of neotectonic paleostress orientation in an area of the Southeastern Brazilian Margin

Abstract The Southeastern Brazilian Margin presents a NE-SW-striking structural framework, which is characteristic of the Neoproterozoic Ribeira Belt. Other important structural trends along the area are associated with E-W and NW-SE-striking structures, being most related to the Mesozoic-Cenozoic tectonic evolution. A succession of Cenozoic tectonic events has been described by many authors in the Southeastern Brazilian. Among those Cenozoic tectonic events, a Neogene to Quaternary E-W dextral strike-slip regime (EW-DT) shows a wide distribution, presenting some variations in the stress field orientation. This research investigates the influence of the preexisting structural framework on the variation of the paleostress field orientation associated with the EW-DT tectonic event in a selected area in the onshore continental margin of the Southeastern Brazil. The study was carried out in three main stages: lineament analysis, paleostress field analysis, and numerical mechanical modeling. The paleostress field related to the EW-DT tectonic event in the studied area presents: NNW-SSE-striking maximum horizontal stress, and counterclockwise rotation influenced by the structural framework. Regarding this, the regional variation of the paleostress field is influenced by a preferential reactivation of NE-SW-striking structures while sets of approximately E-W-striking structures are the main local control of counterclockwise rotation of the stress field.

ОСОБЕННОСТИ ТЕКТОНИЧЕСКОЙ ЭВОЛЮЦИИ ЗАПАДНО-ТИХООКЕАНСКОГО РЕГИОНА: ФОРМИРОВАНИЕ ЛИТОСФЕРНЫХ ВИХРЕЙ

Using the example of the West Pacific Segment of the Earth, the interrelation of vertical and horizontal tectonic movements is considered – the most important and far from being solved at present problem of geotectonics. An overview of the concept of the global ordering of various forms of the earth's surface as an end result of the action of geodynamic forces is given. The author's developments concern the issues of the origin of structures associated with the interaction and influence of endogenous forces on the formation of a regional relief. The main tools for its study were structural-geomorphological methods and lineament analysis. It has been established that: 1) all tectonic dislocations contain both horizontal and vertical components of the velocity of movement, and the former dominate in the structure formation of the region; 2) the end result of their interaction is vortex and other nonlinear (ring, spiral, arc, etc.) deformations of the lithosphere, which constitute the main type of structural elements of the region; 3) they are often accompanied by magmatic activation of the tectonosphere in the form of convective movements and / or «floating» of plumes; 4) the sea and oceanic depressions of the Western Pacific are, in essence, funnels of convective cells, which, under the conditions of shear velocities of the movement of interacting geoblocks of the lithosphere, were structured into the form of tectonospheric eddies. A model of convection of a three-layer tectonosphere is proposed, the movement of which in the gravity field is caused by local decompaction and a decrease in the viscosity of a piecewise inhomogeneous medium. The outlined concepts allow us to consider the tectonic evolution of the West Pacific region as the formation of a lithospheric mega-vortex in the continent-ocean junction zone. Its development is associated with the energy interaction of the mantle and the upper shells (tectonospheres) of the Earth, which is due to the unstable regime of the planet's rotational dynamics.

Recent faulting along Gorontalo fault based on seismicity data analysis and lineament mapping

We focused our study to characterize the geometry and activity of Gorontalo fault. We analysed reviewed the ISC seismic catalogue and the BMKG relocated earthquake events available for the time period of 1960 to 2021, located along the expected location of this fault. In addition, we analysed continuous record from local seismic observatory available for the same period. Further, we mapped the lineaments using 8.3-m resolution DEMNAS data. Tens on shallow earthquakes occurred in the vicinity of this fault with a range magnitude of M 2 to 3. Our lineament analysis however does not reveal distinctive pattern that may indicate the fault manifestation at the surface. The NW-SE trending lineaments are coincidence with the mapped trace of Gorontalo Fault. The weak surface manifestation of the fault scarp may be related to the tropical climatic condition of the area which may obliterate the faulting topography. However, we observed alignment of the seismicity distribution with the mapped NW-SE lineament, indicating that the lineament is likely representing active fault and these earthquakes are associated with faulting along this fault. Our study provide indication that the Gorontalo Fault is active and further study is necessary to investigate subsurface geometry and mitigate its seismic hazards.

FIELD, PETROGRAPHIC AND STRUCTURAL CHARACTERIZATION OF MADA BASEMENT ROCKS, WONAKA SCHIST BELT, NORTHWESTERN NIGERIA

Geological mapping and petrological studies were carried out within the placer gold (Au) mineralized zones in the Wonaka Schist Belt in order to establish detailed petrographic and structural features. Thin sections were produced for petrographic and microstructural studies and lineament analysis was coupled with field structural observations for interpretation. The study area comprises of quartz-mica-schist, phyllite, metasandstone, medium to coarse grained porphyritic granite, granitic gneiss, and diorite as the five major rock types with aplite, quartz and quartzo-feldspathic veins representing minor rock occurrences. The structural pattern is dominated by regional scale, NE striking foliation, and N striking brittle lineament. However, the dominant tectonic fabric within the metasediments and the granite gneiss are the steeply dipping, N, NW and NE-trending phyllitic cleavage, schistose foliations (S1) and gneissocity respectively, formed from first phase of deformation (D1). The emplacement of brittle tectonic features, undulose extinction observed in the quartz crystals, inter- and intra-granular microfractures are evidences of the late stage deformation that occur toward the end of the Pan African. Similarities with other mineralized belts in term of structures provide weight to the possibility of the NW-SE, N-S and NE-SW trending lineaments and specifically the NW-SE quartz and quartz ± feldspar ± hematite ± mica ± sulphide veins to host Au within the study area.

ИССЛЕДОВАНИЕ ВЛИЯНИЯ ЗОН РАЗЛОМОВ ТЕРРИТОРИИ ЗАКАЗНИКА «ДОЛИНСКИЙ» (о. САХАЛИН) НА СОСТОЯНИЕ ЕГО РАСТИТЕЛЬНОГО ПОКРОВА С ИСПОЛЬЗОВАНИЕМ МАТЕРИАЛОВ ДИСТАНЦИОННОГО ЗОНДИРОВАНИЯ ЗЕМЛИ

Fault zones on the territory of Nature Sanctuary “Dolinsky” (Sakhalin Island), which are characterized by high geodynamic activity, are generally well distinguished when analyzing satellite imagery materials. In any territory, it is not difficult to identify the various plant communities that occupy it, as well as to determine their state by the content of phytomass determined by the vegetation index NDVI. The aim of the study is to test the validity of the hypothesis about the formation of abundant vegetation cover within the fault zones by analyzing the state of various plant communities by the volume of phytomass. Methods: decryption and analysis of Earth remote sensing data from Sentinel, Landsat and SRTM generation, geoinformation mapping on the ArcGIS platform. Results. In the course of the study, the state of the Nature Sanctuary “Dolinsky” analyzed by Landsat-8, Sentinel-2A satellite sur-veys, as well as SRTM data. Fault zones identified using the software systems ArcGIS, QGIS, and PyLEFA by lineament analysis, vegetation was classified by the maximum likelihood method, and its condition was determined by the values of the NDVI index, which reflects the content of phytomass in the study area. As result of the work carried out, an increase in phytomass revealed, and, consequently, good conditions for the growth of plant communities confined to the zones of distribution of faults of the earth's crust, and the reliability of the working hypothesis confirmed.

Aeromagnetic interpretation of basement structure and architecture of the Dahomey Basin, Southwestern Nigeria

ABSTRACT Significant yet untapped resources still abound in the Nigerian sector of the Dahomey Basin. Although the presence of an extensive Cretaceous Petroleum System has been confirmed following recent discoveries in Aje and Ogo Fields offshore Lagos, exploration outputs in the Dahomey Basin has so far not been encouraging. Proper understanding of the basement architectural framework and controls on tectonic development remains key to unlock the unrealised potentials in the basin. Hence, a geophysical interpretation of the basement structure and architecture of the Dahomey Basin southwestern Nigeria has been carried out in this study. Various edge enhancement techniques were applied to the high-resolution residual magnetic intensity (HRRMI) grid of the area. This includes first vertical derivative (FVD), total horizontal derivative (THDR), tilt derivative (TDR) and total horizontal derivative of upward continuation (10 km). Determination of the depth to magnetic sources and sedimentary thicknesses in the study area were achieved using standard Euler deconvolution and source parameter imaging (SPI) techniques, with depth range of 4.5–6.3 km attained in the two identified sub-basins located offshore of the study area. Lineament analysis gave insights on the tectonic trends and stress-field orientation in the basin with major trends in the NNE-SSW, NE-SW, NW-SE, and WNW-ESE directions. 2D forward modelling of some selected profiles was employed to characterise the basement pattern and architecture, which depicted a horst-graben architecture. The basement structure and architecture have a major control on the distribution of sub-basins, petroleum systems elements and trap styles in the basin. The study demonstrates the robust application of high-resolution aeromagnetic data in basin-wide mapping of regional subsurface geological features, basement architecture and determination of sedimentary thickness in a frontier basin.

Integrating of Remote Sensing and Airborne Magnetic Data to Outline the Geologic Structural Lineaments That Controlled Mineralization Deposits for the Area around Gabal El-Niteishat, Central Eastern Desert, Egypt

The Gabal (G.) El-Niteishat area lies in the Central Eastern Desert of Egypt which is known for various mineral resources and geological structures. Umm Gheig, Umm Naggat, Umm Shaddad, Wadi (W.) Zeidun and Sigdit represent some important regions that contain mineral deposits in the study area. Various filters such as first vertical derivative (FVD), horizontal gradient magnitude (HGM), tilt derivative (TDR) and near-surface were applied to the airborne magnetic data for the study area to deduce the structural lineaments and magnetic source edges which were controlled by the presence of mineral deposits. Processed Landsat ETM+ images are used for delineating the rock unit boundaries that are exposed in the study area such as serpentinite, metagabbro, metavolcanics and metasediments. Also, band ratios, principal component analysis (PCA) and false-color composite image (Crosta alteration image) were applied to get specific results about the alteration zones. The structural lineaments analysis illustrated that the common trends that affected the study area were NW-SE, NE-SW, E-W and N-S. Integration of remote sensing and airborne magnetic data exhibited the relation between mineralization and structural lineaments.

Картографирование разломов на территории Cеверо-Cахалинской равнины по данным дистанционного зондирования земли

The article presents the results of the research of the fault zones of earth’s crust within the North Sakhalin plain using the lineament analysis of the SRTM model. The faults be identified in order to increase the information content of the maps of geological content. SRTM data was used as input. The analysis performed using the functionality of the LEFA software package. The use of SRTM data made it possible to assess disjunctive disorders in territory of the north of Sakhalin Island. The images of surface were analyzed using the binary-morphological erosion operation or using Canny mathematical algorithms with further digital processing by means of Hough Transform. The paper reveals the position of linear elements in different parts of the North Sakhalin plain. Excellent test of the quality of performed definitions was the results of earlier studies of the eastern part of the North Sakhalin Plain, which were carried out in connection with the development of hydrocarbon deposits and after the strong Neftegorsk earthquake. The data obtained served as the basis for drawing up a map of disjunctive disturbances of Sakhalin Island at scale of 1:500,000. Depending from scale, spatial resolution, and level of generalization of image, disjunctive disturbances of different lengths (transregional, regional, sub-regional, local) and ranks (1 rank from a few to hundred meters, 2 rank from a hundred meters to a kilometer, 3 rank from 1 km to 35 km, 4 rank from 35 to 100 km, 5 rank more than 100 km). The analysis of the SRTM model with the help of the LEFA toolkit allowed us to identify the zones where the earth’s crust fractures are located. The analysis of the SRTM model with the help of the LEFA toolkit allowed us to identify the zones where the earth’s crust fractures are located. As aresult of the analysis, the West Sakhalin, Central Sakhalin, Hokkaido-Sakhalin (Upper Piltun segment), Piltun, Garomai, Val-Langri, Gyrgylany-Daginsky, South Baikal, Udyl and many other faults of less than rank 2 were identified. The main results of the work will be useful in choosing places for the construction of economic and industrial facilities, as well as in the search and exploration of mineral deposits.

Depth Faults Along The Regmatic Network Of The Chatkalo-Kuramin Region And Their Relationship With Seismicity

Lineaments were identified using LANDSAT-8 satellite images and digital elevation models obtained from the ASTER GDEM satellite over the Chatkal-Kuramin region. Taking into account the stock materials and a comprehensive analysis of the results of processing remote sensing data, a map of lineaments of a 1: 100,000 regmatic network was compiled. Based on the automated visual lineament analysis in the Geomatica PCI program, lineaments of the regmatic network were obtained, which are located in the focal zones of strong earthquakes.

Investigação geotécnica de taludes rochosos por meio da análise estrutural: estudo de caso da BR-116, Rio Grande do Sul

A BR-116, localizada no nordeste do estado do Rio Grande do Sul, atravessa a Escarpa da Serra Geral, composta de derrames ácidos e básicos da Formação Serra Geral. Diversos movimentos de massa são observados na rodovia, relacionados com a queda e os deslizamentos de blocos dos taludes rochosos. Como hipótese, pretendeu-se verificar se as famílias de fraturas tectônicas regionais causam os movimentos de massa nos taludes da BR-116. O objetivo desta pesquisa foi aperfeiçoar os métodos de investigação geotécnica, correlacionando a Geologia Estrutural com a estabilidade de taludes rochosos. Entre os métodos utilizados estão o sensoriamento remoto e a análise de lineamentos estruturais, a análise estrutural geométrica e a análise geotécnica dos maciços rochosos (identificação de possíveis planos de ruptura e cálculo de seus fatores de segurança). Os resultados dos lineamentos estruturais regionais indicam o predomínio da direção ENE, seguida pelas direções subordinadas NE e WNW. Em relação às fraturas de alto ângulo analisadas em campo, caracterizou-se um máximo com direção N50-70E, similar ao observado regionalmente. A interpretação do diagrama de movimentos de massa indica que 75% dos movimentos que podem ocorrer na BR-116 seriam causados por deslizamentos em cunha, e o restante são planares, com predomínio de descontinuidades de alto ângulo. A direção máxima dos lineamentos (N70-90E) pode causar movimentos em seis dos sete taludes estudados, e o segundo máximo (N60-80W) condiciona deslizamentos em quatro dos sete pontos. Essa evidência mostra que as estruturas provenientes dos lineamentos regionais são as que mais podem gerar movimentos de massa.

Automatic Extraction and Geospatial Analysis of Lineaments and their Tectonic Significance in South Cameroon Area using Remote Sensing Techniques and GIS

This study investigates the dominant orientations of lineament features and the relationship between these trends and the spatial orientation of tectonic structures in the transition zone of the Congo craton and the Pan African belt in South Cameroon area. Landsat 8 OLI/TIRS and hill-shaded images, constructed from 30 m-resolution SRTM-DEM data, were used for automatically extracting and mapping geological lineaments. Lineament features were analyzed by means of azimuth frequency and length density distributions. Three major sets of lineaments trending W–E, ENE-WSW and WNW-ESE are identified in the South Cameroon area. These trends are probably related to repeated reactivation of pre-existing crustal structures during Eburnean and Pan-African tectonic episodes. The lineaments were formed under the compressional tectonic stress regimes generated during these tectonic events.

An integrated structural and GPS study of the Jalpatagua fault, southeastern Guatemala

Abstract The Jalpatagua fault in Guatemala accommodates dextral movement of the Central America forearc. We present new global positioning system (GPS) data, minor fault analysis, geochronological analyses, and analysis of lineaments to characterize deformation along the fault and near its terminations. Our data indicate that the Jalpatagua fault terminates at both ends into extensional regions. The western termination occurs near the Amatitlan caldera and the southern extension of the Guatemala City graben, as no through-going structures were observed to continue west into the active volcanic arc. Along the Jalpatagua fault, new and updated GPS site velocities are consistent with a slip rate of 7.1 ± 1.8 mm yr−1. Minor faulting along the central section of the fault includes: (1) N-S–striking normal faults accommodating E-W elongation; and (2) four sets of strike-slip faults (oriented 330°, 020°, 055°, and 295°, parallel to the Jalpatagua fault trace). Minor fault arrays support dextral movement along a major fault in the orientation of the Jalpatagua fault. GPS and fault data indicate that the Jalpatagua fault terminates to the east near the Guatemala–El Salvador border. Data delineate a pull-apart basin southeast of the fault termination, which is undergoing transtension as the Jalpatagua fault transitions into the El Salvador fault system to the east. Within the basin, minor faulting and lineations trend to the NW and accommodate NE-directed elongation. This faulting differs from E-W elongation observed along the Jalpatagua fault and is more similar to minor faults within the El Salvador fault system.

Characteristics of Geological Lineaments Along the Eastern Coast of the Korean Peninsula: A Statistical Approach

Kim, T.; Kim, Y.-S., and Lee, H.-J., 2020. Characteristics of geological lineaments along the eastern coast of the Korean Peninsula: A statistical approach. In: Jung, H.-S.; Lee, S.; Ryu, J.-H., and Cui, T. (eds.), Advances in Geospatial Research of Coastal Environments. Journal of Coastal Research, Special Issue No. 102, pp. 88-100. Coconut Creek (Florida), ISSN 0749-0208.Lineament analysis is an essential method for evaluation of site safety in important facilities such as nuclear power plant and nuclear waste disposal site. However, in the case of coastal areas, if the same criteria used for inland is applied, large-scale lineament could be underestimated. Therefore, a different classification criterion is necessary to evaluate the characteristics of lineament pattern along coastal areas. Thus, here, a new statistical method focusing on zonal analysis is proposed. This method is applied for evaluating the characteristics of lineaments developed within 5 km from the eastern coastline of the Korean Peninsula. The most dominant direction of lineaments along the eastern coast lies in the N–S direction, followed by the NE–SW, and the E–W directions. Since the length distribution of the lineament shows the characteristics of the lognormal distribution, statistical analysis was performed using probability density functions (PDFs). The results indicate that the mode value of the lineament length is about 2 km, and lineaments shorter than 6 km account for 90 % of the total. To confirm the validity of the statistical distribution features, re-analyzing the study area by progressively increasing its width to 10 km, 15 km, 20 km, and 30 km was done. The analysis showed that the distribution characteristics were similar to those of the area with a width of 5 km. The statistical analysis using PDFs improved the existing classification criteria based on lineament length and provided three new quantitative classes of lineaments within coastal regions.