Regional Structure Map Research Articles

The West African salt‐bearing rifted margin—Regional structural variability and salt tectonics between Gabon and Namibe

AbstractSalt‐bearing rifted margins comprise some of the most structurally complex and economically important sedimentary basin settings such as the South Atlantic and the Gulf of Mexico salt basins. They are also involved with some of the largest uncertainties regarding the crustal and syn‐rift basin architecture and supra‐salt tectonic evolution, as well as the link between rifted margin architecture with salt deposition and post‐rift gravity‐driven salt tectonics. We thus conduct a margin‐scale study along nearly the entire West African salt basin, from South Gabon to Namibe, combining a vast data set of 2D and 3D seismic and well data with gravimetric and magnetic data to analyse its along‐strike rift and salt tectonic structural variability. We construct regional structural and thickness maps of key salt and post‐salt intervals to depict the history of individual margin segments and to investigate (1) how rifting and rifted margin architecture influences post‐rift salt tectonics evolution, (2) how these vary through time and space and (3) what are the controls between their different salt tectonic styles. We show that rifting and rift structures controlled the salt basin geometry, thickness and base‐salt relief in different ways for the different margin segments, and drastically influenced their post‐rift salt tectonic evolution. Differences in post‐salt sediment supply and continental uplift also had a role in their salt tectonic evolution. The results also have general implications to understand the interplay between rifted margin architecture with post‐rift salt tectonics for salt‐bearing rifted margins.

Structural map of Sulawesi derives from gravity data and its implications for geothermal systems

Gravity satellites are one of the alternatives to conducting preliminary surveys because the cost of exploring a large area using conventional gravity methods is very expensive and takes a lot of time. Therefore, this study on Sulawesi Island uses a gravity satellite to identify fault contact boundaries. The methodology in this study consists of several steps, starting with a literature study, data collection through ICGEM, and then processing and analysis by compiling the gravity anomaly with the Sulawesi regional geological structure map, further interpreted using the classification of rock density variations from a geological perspective. The regional gravity anomaly values for Sulawesi Island and its surroundings range from -270.9 mgal to 320.8 mgal, averaging 78.99 mgal. High anomalies are estimated to be between 180 mgal and 360 mgal, dominated by land with a lithology predominance of igneous rocks, while low anomaly areas are identified in the Batui thrust subduction zone. This study concludes that the convergence of high and low gravity anomalies characterizes the fault contact boundary in the study area. This has implications for the geothermal system on Sulawesi Island, which has a significant impact as a medium for the release of hot fluids from the subsurface.

Seismogeological and structural characteristic of the Riphean sediments within Aldan-Maya petroleum region

The key features of the geological structure of the Riphean sedimentary cover within the Aldan-Maya petroleum region are considered. Using seismic and acoustic logging data, the velocity characteristics of the Riphean deposits were studied. It was shown that the main acoustic contrasts are associated with the formation of sustained intra-Riphean reflectors. They correlate with the boundaries of formations and series. Based on the results of generalization and interpretation of seismic data on 9 projects of regional prospecting, seismogeological sections and structural maps were constructed, which served as the basis for structural-tectonic zoning of the territory within the Aldan-Maya petroleum region. Tectonic maps are presented for two structural stages - Upper Karelian-Lower Riphean and Upper-Middle Riphean, their fundamental difference is shown, in particular, the large May inclined swell is developed only in the reliefs of the lower Riphean not in the Middle-Upper Riphean surfaces.

Integrated interpretation: Defining risk corridors by combining 3-D seismic interpretation with induced seismicity hypocenters

Development of a resource play is subject to intrinsic risks. These may include the risk of incurring unexpected costs or shutdowns due to anomalous induced seismicity, or risks associated with reservoir stimulation that differs from prior empirical or numerical models. These two risks may be related causally, as completion effectiveness could be adversely affected by loss of fracture fluids into fault systems and/or damage zones, irrespective of the occurrence of induced seismicity. We outline a novel strategy for pre-operational risk assessment that is guided by the interpretation of 3-D seismic data, principles of structural geology and available induced seismicity data from surrounding operations. We integrate regional seismic structural mapping with results of previous experimental studies to develop a corridor-based risk-assessment approach. This approach is illustrated by a case study from the Duvernay play in Alberta, Canada, where subtle basement-rooted strike-slip faults and associated Riedel shears have been activated during previous hydraulic-fracturing completion programs. Unlike previous case studies in this area, we combine analysis of several adjoining 3-D seismic and induced seismicity datasets in order to map regional risk corridors. Given the general infeasibility of exhaustive detection and mapping of all potentially seismogenic faults, our approach relies on established structural principles, analog settings (flower structures) and analysis of fault-slip potential to quantify the probability of activation within a defined corridor that contains interpreted faults.

Thrust duplexing and transpression in the Yanshan Mountains: Implications for early Mesozoic orogenesis and decratonization of the North China Craton

AbstractThe configuration and kinematics of fold‐thrust belts are essential for clarifying the plate boundary conditions through which ancient orogenic belts evolved. Temporal and spatial variations in extension versus contraction within convergent plate margins are related to changes in plate kinematics and subduction geometry. The Yanshan Mountains, located along the northeastern margin of the North China Craton and bounded by the Central Asian Orogenic Belt to the north and the Pacific subduction zone to the east, underwent multiple phases of intra‐continental deformation during the Mesozoic. The issue of whether early Mesozoic deformation was extensional or contractional has remained controversial. New regional structural mapping and detailed sedimentological investigations, coupled with age constraints provided by zircon U‐Pb geochronology, provide sufficient temporal and spatial resolution to show that shortening and thrust‐top basin systems dominated during the early Mesozoic. Our results show that the Dengzhangzi Basin within the Lingyuan fold‐thrust belt developed during the construction of a major Late Triassic Chapeng antiformal‐stack duplex system, with episodic, east‐vergent forward‐breaking thrusts and subsequent ‘beheading’ by out‐of‐sequence, top‐to‐east thrusting in the latest Triassic or earliest Jurassic. The neighbouring Guojiadian Basin in the east was generated during top‐to‐SSE sinistral transpression along the Niuyingzi thrust system in the Middle to earliest Late Jurassic. These results support a new model of early craton decratonization involving (a) thrusting along the northern margin of the North China Craton and (b) transpressional deformation in the east driven by the Central Asian Ocean collision and flat‐slab subduction of the Palaeo‐Pacific Plate beneath the East Asian continental margin. Our findings suggest that large‐scale shortening and crustal/lithospheric thickening, triggered by flat‐slab subduction in the North China Craton, were fundamental components of craton decratonization. Subsequent slab roll‐back during the Cretaceous led to lithospheric thinning and crustal extension in the North China Craton.

EVALUATING FOCAL MECHANISM OF SEPTEMBER 24, 2013 AWARAN EARTHQUAKE WITH GEOSPATIAL TECHNIQUES

Seismic records from IRIS (NIL, KBL, MSEY, KMI, QIZ, DGAR) were used to compute AWARAN September 24 2013 Earthquake's focal mechanism. Earthquakes are one of the most drastic threats that are likely to cause heavy human casualties and can destroy entire cities within minutes. We processed the waveform data from 6 separate stations for the computation of displacement. The issues related to attenuation have been overcome by the use of low frequencies (0.05-0.1). The crustacean model that determines the tensor PREM model's time is determined by minimizing the variance but produces a robust focal mechanism. Inverting the displacement data is applied to recover the moment tensor from the source, calculated the green feature with the reversal. GIS-based vectors of fault lines were abstracted by the digitization of regional tectonic lineaments and structural maps. We developed synthetic and observed surface shapes with a 100 percent dc correlation. Our understanding of the features of crustacean deformation and regional tectonics in the area will benefit from the resulting focus mechanisms. The measured earthquake focal mechanism is similar to a USGS agency hit, dip, and rake.

Relationship between gas reservoir distribution and structural system of upper Triassic Xujiahe Fm in the Sichuan Basin

The gas reservoir of Upper Triassic Xujiahe Fm in the Sichuan Basin is characterized by “accumulation in the early stage, entrapment in the middle stage and activation in the late stage”. In order to provide guidance for the prediction of hydrocarbon enrichment zone of Xujiahe Fm, we first plotted the regional structure map based on the 2D and 3D seismic merging data of the basin. Then, we displayed and described the structural characteristics by means of the 3D visualization technology of low-angle vertical backlight irradiation. In addition, the structural system was classified according to the dynamic direction of regional structure and the structural interrelationship, and the formation stages of the structure were confirmed. Finally, based on drilling and testing data, the hydrocarbon enrichment zone of Xujiahe Fm was predicted. And the following research results were obtained. First, five structural systems are developed in Xujiahe Fm in the Sichuan Basin, including EW-oriented arc structure, NE-oriented linear structure, NE-oriented arc structure, SN-oriented to NW-oriented brush structure and NW-oriented arc structure. Second, the EW-oriented arc structure is formed due to the uplift and extrusion of the northern section of Longmenshan thrust belt in the Indosinian period, successively developed in the Yanshanian and stabilized in the Himalayan period. And it is widely distributed in the basin. Third, the NE-oriented linear structure in the north of Western Sichuan Depression is resulted from the Anxian movement of Longmenshan thrust belt in the Indosinian period. Fourth, the NW-oriented arc structure before the Dabashan and the NE-oriented linear structure before the Huaying Mountain are stabilized in the Yanshanian and successively developed in the Himalayan period. Fifth, the SN-oriented structure in the Western Sichuan Depression is formed due to the extrusion of the southern section of Longmenshan thrust belt in the Himalayan period. Sixth, the combination of SN structure to the east of Longquanshan fold belt and NW-oriented linear structure in the basin is a brush structure belt with Jiangyou paleo-uplift as the mainstay, which is resulted from the extrusion of the southern section of Longmenshan thrust belt in the Himalayan period. Seventh, the high-yield wells are usually distributed in the arc anticlines of Indosinian–Yanshanian superimposed with the faults of Himalayan period. The structures of the Himalayan period are usually dry traps, and their fracture development zones are mostly water producing layers. The Indosinian synclines are also ineffective traps even though they are uplifted to anticlines in the Himalayan period. In conclusion, the confirmation of structural system stages can provide a technical support for the prediction and description of hydrocarbon enrichment zone of Xujiahe Fm in the Sichuan Basin.

Regional structural mapping using a combined geological and geophysical approach – A preliminary study at Cairo-Suez district, Egypt

Contrary to the usual application of individual geological and/or geophysical surveys, this paper represented a sequential use of surface structural mapping and DCR method to afford a sensible structural model in a cost effective way. Understanding the geological setting of a non-mapped area at the central part of Cairo-Suez District (CSD), Egypt, is an immediate engineering concern due to its complex deformation history. Field work is carried out to measure stratigraphic sections and establish structural characteristics of the rock units. Surface geophysical DCR sounding and electrical resistivity tomography (ERT) surveys are performed. To overcome the non-uniqueness problem of DCR interpretation, the available borehole data, detailed surface geological measurements and a sequential use of linear and non-linear inversion algorithms are applied. The practical benefits of detailed surface structural mapping are demonstrating in considering all geological parameters to a conceptual subsurface model, which would have not been identified or misinterpreted otherwise. In an integrative approach, such detailed surface data allow us to confirm the uncertain inferred regional subsurface structures based on DCR data inversion. For detailed subsurface structural characterization, the results of ERTs using coarse triangular mesh and iteratively reweighted algorithm show a good agreement with prior known surface and underground structural features. Additionally, ERTs significantly resolve the complex geological features, which constitute uncertain structures in the surface structural model. The main impact of presented integrative approach is to (i) constraint the DCR data interpretation and (ii) inform a preliminary study plan of regional structural investigation, which can be used as a platform for engineering decision–making and/or further detailed geophysical and geotechnical investigations.

Lineations and structural mapping of Io's paterae and mountains: Implications for internal stresses

The mountains of Jupiter's volcanic moon Io are tall, steep, and tectonic in origin, yet their precise modes of formation and their associations with volcanic paterae are not fully understood. Global spatial statistics of paterae and mountains and their associated lineations reveal that both types of features are more common at low latitudes and tectonic lineations have preferred orientations, whereas straight patera margins are randomly oriented. Additionally, structurally controlled lineations tend to cluster with each other, and in areas of high concentrations these tectonic lineations are shorter in length than their global average. These results indicate that global-scale (rather than local or regional) processes are involved in forming Io's tectonic structures, but that the diversity of mountain characteristics and the collapse of paterae adjacent to mountain complexes are more locally controlled. Regional structural mapping of the Hi'iaka, Shamshu, Tohil, and Zal regions reveals Io's mountains reside in large, fault-bounded crustal blocks that have undergone modification through local responses of subsurface structures to variable stresses. Strike-slip motion along reactivated faults led to the formation of transpressional and transtensional features, creating tall peaks and low basins, some of which are now occupied by paterae. We propose Io's mountains result from a combination of crustal stresses involving global and local-scale processes, dominantly volcanic loading and tidal flexing. These stresses sometimes are oriented at oblique angles to pre-existing faults, reactivating them as reverse, normal, or strike-slip faults, modifying the large, cohesive crustal blocks that many of Io's mountains reside in. Further degradation of mountains and burial of faults has occurred from extensive volcanism, mass wasting, gravitational collapse, and erosion by sublimation and sapping of sulfur-rich layers. This model of fault-bounded blocks being modified by global stresses and local structural response accounts for the variation and patterns of mountain sizes, shapes, and orientations, along with their isolation and interactions with other features. It also provides a context for the operation and extent of global and regional stresses in shaping Io's surface.

Regional tectonic controls on basement architecture and oil accumulation within the Muglad basin, Sudan

SummaryThe Muglad basin, Sudan, is a good example of polyphase rifting with at least three major phases of basin development. Each phase has resulted in the generation of source rock, reservoir and seal geology with structural traps often closely linked to basement highs. In this contribution we investigate the tectonic processes that have contributed to basin development at both macro and micro scales.The macro perspective investigates the basin’s evolution as part of an Africa wide rift system and how it is intimately linked to global plate tectonics and to changes in plate interactions. These changes in plate interactions have caused significant modifications in the orientation and magnitude of the African stress field which in turn has controlled the development of the rift system. On the micro basin scale, the methods used to investigate structure include the compilation of structural maps for different time periods of the individual rift basins into regional structural maps, the role and importance of stratigraphic unconformities within basins and geophysical mapping of the basement morphology of the Muglad basin using an integrated interpretation approach.

Structural architecture and a new tectonic perspective of Ovda Regio, Venus

The structural architecture of the Ovda Regio, Venus, derived from regional and detailed structural mapping of several key segments, reveals a new tectonic perspective, for the first time that varies from most of the existing tectonic models. The interpreted structural features include folds of different styles and scales, mega shear zones, ribbon structures, and other kinematic indicators. While concentric folding is predominant in the western Ovda, the eastern Ovda is characterized by shear folding. Two mega shear zones are recognised: dextral NW–SE trending GMSZ and a complimentary sinistral NE–SW trending KKSZ. Two tectonic stages are identified in a coherent and continuous strain history involving initial N-S compression that gave rise to regional east–west folding providing the fundamental tectonic architecture of a mountain fold-thrust belt. Ribbon structures in a broad radial pattern were developed contemporaneously with this folding. The second tectonic stage saw the development of a conjugate pair of mega shear zones and a range of kinematic indicators, consistent with continued N-S compression and the pre-existing fold pattern was modified resulting in the development of new fold structures, particularly in the eastern Ovda. The structural characteristics of Ovda Regio are analogous to those of Himalaya–Tibet collision front and also the Precambrian mobile belts of southern India.

Aeromagnetic and Landsat TM structural interpretation for identifying regional groundwater exploration targets, south-central Zimbabwe Craton

Aeromagnetic (AM) and Landsat Thematic Mapper (TM) data from the south-central Zimbabwe Craton have been processed for the purpose of regional structural mapping and thereby to develop strategic models for groundwater exploration in hard-rock areas. The lineament density is greater on TM than on AM images, partly due to the resolution of the different datasets, and also because not all TM lineaments have a magnetic signature. The derived maps reveal several previously undetected lineaments corresponding to dykes, faults, shear zones and/or tectonically-related joints, striking predominantly NNE, NNW and WNW. We suggest the possible hydrogeological significance of some of these patterns as follows: the aeromagnetic data can be used to map faults and fractures of considerable depth which are likely to be open groundwater conduits at depth (typically under tension), while TM lineaments, although not necessarily open (mostly under compression), represent recharge areas. The interpreted persistent lineation and well developed fracture patterns are correlated with existing boreholes and indicate a spatial relationship between regional structures and high borehole yields (> 3 m 3/h). This relationship is combined with other lithological and hydrogeological information to identify potential regional groundwater sites for detailed ground investigations. These are defined as dyke margins, faults, fractures/joints or intersections of any combination of these structures. Priority should be given to coincident AM/TM lineaments (e.g., NNW and NNE fractures) and continuous structures with large catchment areas (e.g., NNE and WNW faults). The late Archaean (2.6 Ga) granites are considered the most favourable unit because of their associated long and deep brittle fractures between numerous bornhardts (inselbergs) and kopjes. Several small-scale TM lineaments also form important local sources of groundwater for hand-dug wells. Based on measured rock susceptibilities from the area, we present a model of the typical magnetic responses from the possible groundwater exploration targets. The developed magnetic model could be applicable to similar terrains in other Archaean Cratons.

Comments on the papers by Bailie et al. concerning the age and deposition of the Bushmanland Group (South African Journal of Geology, 110, 59-86) and single zircon ages of the Aggeneys Granite Suite (South African Journal of Geology, 110, 87-110)

The authors of the two papers fulfill a long-felt need for accurate isotopic data on the Bushmanland Group and the contiguous granitic gneisses, not to mention a wealth of new geochemical analyses. The samples that were used, were collected in the eighties by Lipson (reported in a thesis, 1990) and by Duncan et al . (provided in an unpublished report, 1985). We much appreciate the new data but believe that the stratigraphic sampling context is fundamentally flawed, constraining the interpretation of analytical results. The stratigraphic framework that we prefer is based on detailed as well as regional sequence and structural mapping, elucidated in several previous publications (Strydom et al. , 1987; Colliston et al. , 1986; 1989 …

Strain pattern and deformational history in the eastern part of the Cauvery shear zone, southern India

Regional structural mapping, guided by remote sensing interpretation, in the eastern part of the Cauvery shear zone (CSZ), southern Granulite Terrain, reveals a structural framework of two major boundary shear zones interlinked by a set of sigmoidal shear belts. The strain pattern and deformational history are manifest in terms of two major episodes; D1 and D2. While D1 structures are well preserved in low strain areas, the D2 fabrics are well reflected in high strain belts enveloping the low strain domains. Our multiscale structural observations can be modelled in terms of a plan view duplex showing a cross sectional flower structure related to regional transpression resulting from late Neoproterozoic collisional processes in the eastern Gondwana.

The Piermont allochthon revisited and redefined at its type locality

Regional lithostratigraphic and structural mapping of the Piermont allochthon of northwestern New England at its type locality indicates that the Foster Hill fault, the supposed sole thrust, is a stratigraphic boundary. Rather, the allochthon lies above the Bean Brook fault, covers a much smaller area than suggested previously, and is limited to the vicinity of Piermont, western New Hampshire. The allochthon, which primarily consists of rocks correlated with the Silurian age Rangeley Formation of Maine, has horizons of metamorphosed polymictic conglomerate at its base. Rocks directly below the allochthon are correlated with the metasedimentary, Ordovician-aged Albee Formation and contain abundant metamorphosed dykes and sills that do not cross the sole detachment of the allochthon. Analysis of macro- and mesoscale structures indicates local preservation of fold hinges and overprinting foliations oblique to and later than those previously described and has allowed the deformation history to be significantly extended by several events. Emplacement of the allochthon early in the deformation history at metamorphic conditions caused NW-SE elongation lineations of clasts in conglomerate at the base of the allochthon. The relict foliations and fold hinges are commonly preserved below the allochthon, suggesting that these rocks have had a more protracted deformation history relative to rocks in the allochthon. The new interpretation of the Piermont area provides a framework to build a more thorough tectonic history for this part of the New England Appalachians.

Subglacial bedrock structure in the Transantarctic Mountains and its influence on ice sheet flow: insights from RADARSAT SAR imagery

The Transantarctic Mountains represent a major Cenozoic rift-flank uplift that crosses the interior of Antarctica. On one side of the mountains lies the Ross embayment, a submarine portion of the West Antarctic rift system. The East Antarctic Ice Sheet overlies the cratonic margin of the mountains. The Transantarctic Mountains restrict flow of the ice sheet to lower elevations within the Ross embayment. Using RADARSAT imagery, radio-echo sounding data and field-based structural data, we demonstrate that RADARSAT imagery can be used for regional structural mapping of the Transantarctic Mountains and, in particular, that bedrock structures can be traced subglacially beneath the ice-covered mountain flanks. Our analysis shows that regional structures in the mountains have provided preferred pathways for ice flow from the East Antarctic Ice Sheet across the Transantarctic Mountains barrier to the Ross embayment in West Antarctica. Further regional mapping using RADARSAT imagery has the potential to delineate the regional structural architecture of the Transantarctic Mountains and to establish the degree of spatial coupling between structures associated with mountain uplift and regional drainage patterns of the Antarctic ice sheets.

Regional-Scale Extensional Tectonic Pattern of Ultrahigh-Pressure and High-Pressure Metamorphic Belts from the Dabie Massif, China

Recently, regional structural studies and detailed mapping at a scale of 1:10,000 in several key areas in the Dabie massif have revealed that the present regional tectonic pattern of ultrahigh-pressure and high-pressure metamorphic belts was formed mainly by extensional processes that postdate the Triassic collision between the Sino-Korean and Yangtze cratons. The tectonic pattern is characterized by an ancient metamorphic core complex, in which the most prominent feature is the development of multilayered extensional detachment zones on a crustal scale. This pattern controls the present spatial distribution of the ultrahigh-pressure metamorphic (UHPM) and high-pressure metamorphic (HPM) rocks, and obviously records large-scale subhorizontal extensional flow under amphibolite-facies conditions when the UHPM and HPM rocks were returned to lower-middle crustal levels. Based mainly on the crustal-scale tectonic scenario and combined with previous petrological and geochronological studies, the Dabie Mountains can be subdivided into six main tectonometamorphic units—the Northern Huaiyang (NHY) tectonic belt, Dabie complex, UHPM unit, HPM unit, epidote-blueschist (EBM) unit, and weakly metamorphosed sedimentary cover (SC). All units are tectonically separated by detachment ductile shear or fault zones. The Balifan-Mozi-tan-Xiaotian fault (BMXF), separating the NHY tectonic belt to the north from the Dabie massif (DM) to the south, is considered as the suture zone between the Sino-Korean and Yangtze cratons during the Triassic intracontinental collision. The geodynamic implications of this extensional tectonic pattern for the exhumation process of the UHPM and HPM rocks also are briefly discussed. It appears that recognition of the extensional tectonic pattern is of paramount importance for an understanding of the kinematics and dynamics of the Dabie-Sulu collisional orogen.

Barents Sea tectonic structures visualized by ERS1 satellite gravity data with indications of an offshore Baikalian trend

Free air gravity maps can be generated using satellite radar altimetry for all offshore areas between 828 S and 828 N. Such maps are especially useful for regional structural mapping as all structural features yielding density contrasts will contribute to the gravity field at both regional and local scales. However, the gravity maps will often be dominated by major regional features which can overshadow relatively minor local features, e.g. small basins, basement highs and fault zones. Nevertheless, these minor features are describable provided that the shorter wave length gravity anomalies can be enhanced. The aim of this paper is to demonstrate that satellite gravity data, carefully processed by image enhancement techniques, may be used as a suitable basis for fast regional structural mapping. The Barents Sea, which contains a number of structural features of different ages, styles and trends provides an example. The well-known south-western part was used to investigate the limitation of the method, while the data in the poorly investigated eastern areas were used to search for previously unrecognized structures. The first part of the paper focuses on data quality and image enhancement techniques. In the second part, the processed gravity image is evaluated by comparing it with a structural map of the Barents Sea (Johansen et al. 1993). Finally, a previously unknown, large, SE±NW trend observed in the eastern Barents Sea is further investigated with the aid of regional gravity modelling.

Demarcation of geological and geomorphological features of parts of Dharwar Craton, Karnataka, using IRS LISS-II data

Abstract To demonstrate the capabilities of Indian Remote Sensing Satellite (IRS) Linear Imaging Self-scanning Sensor-II (LISS-II) data in preparation of regional level geological, structural and geomorphological maps of 1:500000 scale and to understand the interrelation between lithology, structures, landforms and drainage details in diverse geologic environs, a study has been carried out. The area chosen for the study is a strip of terrain in Karnataka between latitudes 13° N and 14° N. Different rock types such as peninsular gneisses, granites, schists and laterites were mapped based on their distinctive image characteristics like colour and textural variations, typical landforms, soil cover and drainage networks. The satellite images have exhibited more clearly the Bababudan ‘horse shoe’ fold, Doddaguni fold, Chikanayanakanahalli fold, Kolar schist belt. bounding lineaments of Closepet granite, regional scale NNW-SSE trending lineament located to the west of Bababudan schist belt, N-S trending lineame...

Facies Relationships and Depositional Environments of Lower Tuscaloosa Formation Reservoir Sandstones in McComb and Little Creek Field Areas, Southwest Mississippi: ABSTRACT

Facies Relationships and Depositional Environments of Lower Tuscaloosa Formation Reservoir Sandstones in McComb and Little Creek Field Areas, Southwest Mississippi: ABSTRACT