Lineaments in the coastal zone of Goa

The paper decribes the lineaments in the coastal area of Goa identified on aerial photographs and their correlation with the lineaments reported from the adjoining areas. The majority of lineaments along the coastal part of Goa follows a NW-SE, NE-SW and a few ENE-WSW trends. The NW-SE direction is predominant and corresponds with the regional Dharwarian trend followed by NE-SW trending linears due to cross folding of Dharwar Orogeny.     

Geological and geomorphological studies of a part of Ganjam district,Orissa by remote sensing techniques

Geological and geomorphological mapping was carried out for a part of Ganjam district, Orissa through visual interpretation of IRS-IB LISS II flase colour composites. Various lithounits such as khondalites, charnockites and granites of Archaean age were mapped. The study area is traversed by two sets of vertical joints — one trending in NE-SW direction and the other in NW-SE direction. Three sets of lineaments in the study area trending in NE-SW, NW-SE and ENE-WSW suggest that the study area was subject to very high degree of deformation in the past. Major geomorphic units delineated are, Hills, Pediments, Valley Fills, New Flood Plains, Old Flood Plains, New Coastal Plains and Old Coastal Plains. Different landforms under each geomorphic unit are also mapped.     

Application of directional filtering in lineament mapping for groundwater prospecting around bhinmal — A semi arid part of thar desert

The significance of neotectonic lineaments for groundwater prospecting was studied for the area around Bhinmal — a semi-arid part of Thar desert. The application of Directional Filtering procedures on IRS LISS I Band 4 digital image of the study area revealed NE-SW, NW-SE and E-W trending lineaments which are very subtle and in two cases, even unnoticed otherwise. The use of exploratory borehole lithologs and field evidences indicated that the identified lineaments are long rectilinear buried and partly exposed channels and the intersection zones are characterised by thick lenses of coarse sand and gravel. These buried channels and zones of coarse sediments thus represent potential sites for the accumulation of freshwater during rain. The present work has highlighted the suitability of Directional Filtering procedures for lineament mapping and buried channel studies in a desertic terrain.     

Landsat analysis of Dhansiri valley

Detailed Landsat imagery interpretation was carried out in Dhansiri Valley, Lower Assam, employing the standard visual interpretation techniques. Optico-electronic analysis using 1²15 Video Image Processer was also carried out. Edge enhancement of the imagery using photographic methods was found to sharpen lineaments to a great extent. As many as fifteen localities have been identified as “anomalies” reflecting possible subsurface structures. The delineation is based on different factors including tone, texture, drainage etc. Prominent structural trends delineated are in NE-SW and ENE-WSW directions. The NE-SW trending Borholla-Mikir hills fault zone divided the valley into two distinct structural units, the relatively shallower northern sector dominated by the ENE-WSW trending faults and the southern sector comprising the Dhansiri-Diyung flood plains dominated by tne NE-SW trending faults.     

Interpretation of lineaments from precambrian rocks in Madaura and Sonrai area,Lalitpur dist., U.P.

Aerial photo-interpretation of the area underlain by Bandelkhand gneisses, Bijawars and Vindhyans, around Madaura and Sonrai in Lalitpur Dist. of U.P., revealed the presence of a number of lineaments. During fieldwork the lineaments were found to represent ultrabasic, basic and acidic intrusions, faultzones, lithological contacts and foliation. The drainage of the area was found to be grossly controlled by these elements. Three major trends viz. NW-SE, NE-SW and E-W are observed in the area. The first two represent shear joint system, while the latter represent release fractures. This setup is visualised to be due to N-S phase of compression.     

Use of remote sensing in lineament analysis for tectonic evolution and resource study of a part of Vindhyan Basin,Jhalawar area,India

Synoptivity and the exemplified fracture systems exhibited by the space borne imagery data has helped in solving many of the geological enigma in various parts of the world. The study conducted, using such remotly sensed data, in Jhalawar anticline, part of Proterozoic Cratonic Vindhyan Basin, Rajasthan, India, led to infer the history of tectonic evolution of peribasinal deformation which has been a matter of controversy for a century and more. In Landsat MSS data the Jhalawar region displays a panorama of lineaments and their analysis through azimuthal frequency diagrams, isofracture, lineament incidence and lineament intersection incidence density maps shows that the mean orientation of the lineaments fall in NW-SE and NE-SW and the shape of the various lineament density contours also show NE-SW and NW-SE orientations. In aerial photographs the area exhibits four sets of lineaments in NE-SW, NW-SE, N-S and E-W directions. Amongst these the former two sets are expressed as wide open master fracture systems with prolific vegetation fills along them and the latter two sets are characteristically observed as thin vegetation linears with frequent strike slip faulting along them. The further analysis of these fracture/lineament systems derived from multi-level remote sensing data shows that the Jhalawar anticline, which followed the pattern of flexural slip fold mechanism, was evolved by horizontally disposed σ1 (greatest principal stress) and 3σ (least principal stress) with the former oriented in NE-SW and the latter aligned in NW-SE directions with vertically disposed 2σ. The inference of such palaeostress environment of the Jhalawar region lead in the identification of a buried rigid basement high southwest of Jhalawar anticline, beneath the Deccan pile and loci of ground water, silica sand and probable igneous plug.     

Geomorphic signatures of active tectonics in Bist Doab interfluvial tract of Punjab,NW India

Bist Doab interfluvial tract in the north-western part of Punjab, India, has been investigated for geomorphic signatures of active tectonics using remotely sensed data and geographical information system (GIS). The anomalous river flow, abrupt changes in flow direction, angular drainage, compressed meanders, asymmetry of river bends, high channel sinuosity, abandoned channels, water-logged and marshy areas observed along the courses of Beas and Sutlej rivers and their tributaries indicate tectonically active nature of the terrain. The strong control exercised by the NE-SW and NW-SE trending lineaments on the drainage network is well evident in the form of long straightened slope deviatory courses, definite changes in channel pattern and sharp knee bend turns taken by the seasonal rivulets. The asymmetric and elongated nature of watersheds and straight to curvilinear mountain fronts quantified through morphotectonic analysis are characteristic of tectonically active settings and further corroborate the evidence of active tectonics.     

Lineaments and seismicity of Kerala — a remote sensing based analysis

Seismically active lineaments of Kerala State were identified by correlating the lineaments mapped using IRS LISS-I data with the earthquake occurrences. There are 31 earthquake incidences in Kerala since 1821, out of which 22 are falling on/close to 9 major lineaments/faults (length more than 20 km) indicating the possible correlation between lineaments/faults and earthquakes. It was observed that the earthquake occurrences are mostly associated with the NNW-SSE to NW-SE trending lineaments (6 out of 9 lineaments), which are considered to be formed sympathetic to the West Coast Fault. Hence, there is a need to monitor these seismically active lineaments using advanced techniques such as GPS, SAR Interferometry etc. for better understanding of the influence of these lineaments on the seismic activities of Kerala.     

Geology amd drainage analysis of the area between peram-balur and padalur in the Trichinopoly District,Tamil Nadu

Photogeological studies of the area shows the presence of four major lithological groups as : 1. Precambrian basement made up of granitic gneisses and Charnockites, 2. The Utatur Group of rocks, 3. The Trichinopoly Group of rocks and 4. The Ariyalur Group of rocks. Some prominant lineaments roughly trending in NE-SW direction are seen. These lineaments represent the traces of the reactivated faults in the basemeht. The photogeological studies were supplemented by morphometric analyses. It is seen that the drainage in lower order basins is controlled by structure, i.e. by the strike of the rocks and faults in the basement. The higher order streams apparently follow the direction of regional gradient.     

Remote sensing as applied to mineral exploration in the Chalkidiki peninsula, northern Greece

Landsat (TM) imagery studies combined with photogeology, heliborne EM-radiometric interpretations and field data provided the fracture pattern in the eastern Chalkidiki peninsula, northern Greece. Processing of the respective data revealed the following four main directions of lineaments trending 070°–080°, 120°–130°, N-S and E-W. This fracture pattern is persistent in all geological units including the Tertiary basins and may represent reactivated older or even Tertiary fractures superimposed on all units. The control and the distribution of the major mineralization such as Pb---Zn (Au---Ag) massive sulphides, Mn (Fe) oxides, and porphyry Cu (Au) are of similar orientation to the deduced fracture pattern.These findings support the remote sensing is an important mineral exploration tool which can become quite effective when combined with ore deposit type, geochemical and geophysical data in partly explored areas.     

渭河盆地深大断裂处构造应力特征及其活动特性

利用渭河盆地2001~2010年高精度GPS监测资料,采用有限元数值分析法,分析了渭河盆地内深大断裂处的构造应力特征及断裂活动特性。结果表明,盆地西部断裂处均呈现出明显的近E-W（east-west）向挤压应力特征,而盆地中部断裂处则均呈现出显著的NW-SE（northwest-southeast）向拉张应力特征,东部断裂处呈现出一定的NW-SE向拉张应力,但该部量值较中部断裂处小;走向各异的同一条深大断裂不同区段,呈现出的应力特征、量值以及活动速率也存在差异性;跨断裂剖线显示沿断裂走向的速度分量在断裂两侧均发生了一定量值的变化,构造断裂具有一定的扭动特性。模拟计算结果进一步显示盆地中部较东、西部受NW-SE向拉张应力作用显著,且在中部这些具有拉张应力特征的深大断裂交汇处,特别是断裂活动速率较大的区段,正是盆地内地裂缝灾害最为集中发育的区域。     

Integrated remote sensing data utilization for investigating structural and tectonic history of the Ghadames Basin,Libya

This study was initiated to constrain the geological structure of the Ghadames Basin in northwest Libya. Detailed analysis was based on digital integration of surface data, including SRTM DEM, ETM+ and geologic maps with subsurface data, including well logs and potential field data. Integrated analysis of remotely sensed data of the SRTM and ETM+ were utilized to identify geologic lineaments in the area. Ground-based verification of the remote sensing data was achieved with field work. Interpretation and analysis of the lineaments indicate that the Ghadames Basin is controlled by four main fault systems that trend WNW, NNW, NW and ENE. Well logs and potential field data were used to delineate a detailed picture of the subsurface structure. The potential field data reveal two NE and NNE trending sedimentary basins. The depth of the basement inside the main basin ranges from 2 to 6 km. A two-dimensional (2-D) schematic model shows that the basin gradually deepens towards the southwest. The applied data integration gave new insight into the tectonic and structure patterns of the Ghadames Basin and the adjacent areas of northwest Libya.     

Geological and geomorphological significance of a few mega-lineaments of Northeastern Rajasthan

The Precambrian metamorphites of Northeastern Rajasthan belonging to Pre-Aravalli, Aravalli and Delhi Supergroups exhibit a mature topography where the physiography has faithfully depicted the major structures of area. Few important megalineaments demarcated on the imagery either represent major fault zones or the zones of intense granitic activity. Some of these are oblique to the regional strike of rocks and support drainage running in diagonally opposite direction within the same lineament, indicating thereby upheavels subsequent to the lineament formation. The lineaments fall broadly in two sets which are correlatable to the two major phases of Delhi orogeny. The lineaments of the first set trend NE-SW and are more prominent: than the NW-SE and WNW-ESE running lineaments. The major lineaments such as Sabi-Sota, Mendha and Kakor-Lalsot lineament together with other regional lineaments depict appreciable geomorphological expressions and significant geological evidences.     

Gondwana-Derived Terranes Structural Mapping Using PALSAR Remote Sensing Data

Gondwana-derived terranes are now separated by major faults or suture zone, which are rarely simple and easily recognizable lineaments. Different association of ore mineral systems such as deposits of sediment-hosted/orogenic gold and granite-related minerals is discovered in collision and subduction zones of the Gondwana-derived terranes. They are associated with large-scale, terrane-bounding fault systems and broad areas of deformation. Mineralization mostly associated with structurally-controlled complex lodes, veins, sheeted veins and veinlets in diverse orientations. Recognizing the structural significance of lineaments and curvilinear is very difficult in tropical, arid and Antarctic regions due to environmental obstacles. Remote sensing data could be used to detect geological structures associated with suture zones between Gondwana-derived terranes especially for large inaccessible regions where fieldwork is limited or nonexistent. In this investigation, the Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to map major geological structures in the Bentong-Raub Suture Zone of Peninsular Malaysia. It is one of the major structural zones in Sundaland, Southeast Asia, which forms the boundary between the Gondwana-derived the Sibumasu terrane and Sukhothai-Indochina arc. Structural features associated with sediment-hosted/orogenic gold deposits in the Central Gold Belt and tin mineralization in S-type granites in the Main Range were investigated using PALSAR data and comprehensive fieldwork. Results indicate that main faults strike along 340° to 350° that are intersected by many shear or lateral fault zones are high potential zone for gold mineralization in the Central Gold Belt. Hydrothermally alteration mineral zones and cataclastic rocks are also the other indicators of gold mineralized veins in the gold belt. High potential zones for tin mineralization are N–S strike-slip faults, fault zones and shear zones trending E–W, NE–SW and WNW–ESE in dissected crystalline granitic rocks that are associated with hydrothermal alteration zones in the Western Tin Belt. Lineament analysis using PALSAR satellite remote sensing data is a useful tool for mapping major geological structural features and detection of the boundary between the Gondwana-derived terranes and detailed structural analysis of fault systems and deformation with high potential for a variety of mineral resources, especially in tropical, arid and Antarctic regions.     

Tectonic evolution of early precambrian south indian shield (rocks) using remotely sensed data

The interpretation of satellite imagery of part of South India falling South of 15 degree North latitude shows that the regional anticlines, synclines, domes and basins of the Precambrian group of metamorphites are aligned in three major hill ranges/domains such as Chitra-durga domain in the north, the Mangalore-Ootacamund-Bangalore domain in the centre and the Cochin-Cape Comorin-Madurai-Chittoor domain in the south. These hills are crescent shaped with their axes of elongation oriented in NNW-SSE direction. The lineaments with ENE-WSW, NE-SW/WNW-ESE and NNW-SSE azimuthal frequencies respectively exhibit extensional, shear and release geometries. Such deformational fabric shows that the tectonic evolution of South India was controlled by two major compressive forces, the first one aligned in N-S direction and the second in ENE-WSW direction.     

Geology in parts of Sainj Valley,Kulu district,Himachal Pradesh

The paper highlights the findings of photogeological studies, with selective field checks, carried out in Sainj Valley. For the first time, a photogeological map of the area has been prepared using large scale aerial photographs Structurally the area forms‘Window in a Window’ structure as the oldest rocks of Kulu formation are thrusted over the younger rocks of Larji Group (Larji and Banjar formations) and further Banjars are thrusted over Larjis. Thus, Larjis being stratigraphically youngest, occupy the lowest tectonic position. The Kulu formation mainly consists of Central Crystalline, schists and gneisses. Banjar is composed of quartzite, metabasics, slate and phyllite. Larji predominantly consists of dolomite and quartzite with slate and phyllite. The photogeological studies have helped to bring out the lineament pattern, landslide zones, major structural trends and main geological formations. The lineaments mainly trend in NNE-SSW, NW-SE, NE-SW and NNW-SSE directions. A key for photo-characters of different litho units and terrain elements of the area is established.     

Fracture zones in the Deccan Traps of Western and Central India: A study based on remote sensing techniques

Deccan Trap lavas (Cretaceous to Tertiary), which cover a large area in the Western and the Central India, are generally regarded as structurally undisturbed save for certain areas along the west-coast and the Narmada Valley in Central India. Remote Sensing techniques have given a new dimension to the problem of locating such disturbed areas by virtue of the capacity of aerospace imagery to delineate lineaments, many of which represent structural geological features. Studies carried out in the areas west and north west of Pune, (above and below the western ghat scrap), the Narmada valley region north of Barwah and the Ramakona area of Central India, reveal that these areas are riddled with fractures. The fractures have generally given rise to narrow valley or escarpments. Some of the fractures show displacement along them, while some show intrusive dykes filling them. The fractures in Central India were sometimes found to the extensions of faults traversing the basement. Hence, in the regoins, where the basement is not exposed, they may be suggestive of the structural trends of the concealed basement.     

Spatial variation in elephant impact on the Zambezi teak forest in the Chobe national park,Botswana

Abstract

Tectonic mapping and geologic evolution of a region were historically conducted on the basis of field observations. After the advent of remote sensing technology, tectonic mapping became much easier and structural mapping through imagery has gained credibility and suitability in regional mapping, tectonic evolution and modeling. In this regard, an attempt has been made to make use of the satellite technology to bring out the structural trends and the fracture/lineament pattern in Biligirirangan region of Northern Tamil Nadu through satellite remote sensing. The folded architecture in Biligirirangan region has evolved from structural trends. The subsurface structures of the region were derived through resistivity contours and resistivity images created by GIS software.

The surficial information derived from the satellite imagery and subsurface structures derived from the resistivity contours and images were integrated with field observations. This integration has given a clear tectonic picture of the Biligirirangan region and the tectonic structures were then analysed for tectonic forces, evolution and modeling.

The study determined that the Structural trends were mostly in a N‐S direction and the folds were of isoclinal type with alternating synclinal and anticlinal folds of an easterly dipping nature. These folds in conjunction with the lineaments have brought out the palaeostress pattern of the Biligirirangan region. The study further suggests that the regional compressive force trending in ENE‐WSW direction was responsible for the present configuration of folds. In addition, the study also focuses the efficacy of the satellite imagery in tectonic analysis and the resistivity contours and images for the subsurface structural analysis.     

Geomorphology and Petroleum Prospects of Cauvery Basin,Tamilnadu, Based on Interpretation of Indian Remote Sensing Satellite (IRS) Data

Geomorphological studies of the Cauvery basin, Tamilnadu were carried out using IRS images with special emphasis on identification of zones of hydrocarbon occurrences. The basin exhibits landforms of fluvial and fluvio-marine plains. Two major trends of lineaments and 15 circular anomalies have been identified. The NW-SE trend appears to be younger and might have played an important role in migration and entrapment of hydrocarbons. Six circular anomalies are associated with known oil/gas wells. The study has identified probable zones of hydrocarbon occurrences.     

Impact of Climate Change on Runoff of the Major River Basins of India Using Global Circulation Model (HadCM3) Projected Data

The effects of climate change on hydrological regimes have become a priority area for water and catchment management strategies. The terrestrial hydrology driven by monsoon rainfall plays a crucial role in shaping the agriculture, surface and ground water scenario in India. Thus, it is imperative to assess the impact of the changing climatic scenario projected under various climate change scenario towards the hydrological aspects for India. Runoff is one of the key parameters used as an indicator of hydrological process. A study was taken up to analyse the climate change impact on the runoff of river basins of India. The global circulation model output of Hadley centre (HADCM3) projected climate change data was used. Scenario for 2080 (A2 scenario indicating more industrial growth) was selected. The runoff was modeled using the curve number method in spatial domain using satellite derived current landuse/cover map. The derived runoff was compared with the runoff using normal climatic data (1951–1980). The results showed that there is a decline in the future climatic runoff in most of the river basins of India compared to normal climatic runoff. However, significant reduction was observed for the river basins in the eastern region viz: lower part of Ganga, Bahamani-Baitrani, Subarnrekha and upper parts of the Mahanadi. The mean projected runoff reduction during monsoon season (June–September) were 18 Billion Cubic Meter (BCM), 3.2 BCM, 3.5 BCM and 5.9 BCM for Brahmaputra-Barak Subarnrekha, Subarnarekha and Brahmini-Baitrani basin, respectively in comparison to normal climatic runoff. Overall reduction in seasonal runoff was high for Subarnrekha basin (54.1%). Rainfall to runoff conversion was high for Brahmaputra-Barak basin (72%), whereas coefficient of variation for runoff was more for Mahanadi basin (1.88) considering the monsoon season. Study indicates that eastern India agriculture may be affected due to shortage of surface water availability.