Detrital zircon U–Pb geochronology of a Cenozoic foreland basin in Northeast India: Implications for zircon provenance during the collision of the Indian and Asian plates

Geochronology is useful for understanding provenance, and while it has been applied to the central and western Himalaya, very little data are available in the eastern Himalaya. This study presents detrital zircon U–Pb ages from the late Palaeocene–Eocene Yinkiong Group in NE India. The samples are from the late Palaeocene to early Eocene Lower Yinkiong Formation, and the Upper Yinkiong Formation deposited during the early to mid‐Eocene within the Himalayan foreland basin. The U–Pb ages of the detrital zircon within the Lower Yinkiong Formation are older than late Palaeozoic, with a cratonic and early Himalayan Thrust Belt affinity, whereas the Cenozoic grains in the Upper Yinkiong Formation indicate a Himalayan Thrust Belt source and possibly a granitic body within the Asian plate. The shift of the sources and the changes in the foreland basin system strongly suggest that the India–Asia collision in the Eastern Himalaya began before or immediately after the deposition of the Upper Yinkiong Formation, i.e., within the early Eocene (c. 56 to 50 Ma).     

Fuzzy inference system for identification of geological stratigraphy off Prydz Bay, East Antarctica

The analysis of well logging data plays key role in the exploration and development of hydrocarbon reservoirs. Various well log parameters such as porosity, gamma ray, density, transit time and resistivity, help in classification of strata and estimation of the physical, electrical and acoustical properties of the subsurface lithology. Strong and conspicuous changes in some of the log parameters associated with any particular geological stratigraphy formation are function of its composition, physical properties that help in classification. However some substrata show moderate values in respective log parameters and make difficult to identify the kind of strata, if we go by the standard variability ranges of any log parameters and visual inspection. The complexity increases further with more number of sensors involved. An attempt is made to identify the kinds of stratigraphy from well logs over Prydz bay basin, East Antarctica using fuzzy inference system. A model is built based on few data sets of known stratigraphy and further the network model is used as test model to infer the lithology of a borehole from their geophysical logs, not used in simulation. Initially the fuzzy based algorithm is trained, validated and tested on well log data and finally identifies the formation lithology of a hydrocarbon reservoir system of study area. The effectiveness of this technique is demonstrated by the analysis of the results for actual lithologs and coring data of ODP Leg 188. The fuzzy results show that the training performance equals to 82.95% while the prediction ability is 87.69%. The fuzzy results are very encouraging and the model is able to decipher even thin layer seams and other strata from geophysical logs. The result provides the significant sand formation of depth range 316.0- 341.0 m, where core recovery is incomplete.     

Shoreline Change Analysis at Chilika Lagoon Coast,India Using Digital Shoreline Analysis System

Shoreline is the dynamic interfaces of both terrestrial and marine environment, which constantly affected by natural coastal processes includes wave, tide, littoral drift and cyclonic storms as well as coastal development. Wave induced littoral drift and fluvial discharge causing the gradual inlet migration and has the concurrent impact on shoreline of Chilika lagoon. This study is to determine the long-term shoreline changes along the coast of Chilika lagoon. Historical satellite images were used to analyse the shoreline erosion and accretion based on statistical approach. The satellite data from 1975 to 2015 were processed by using ERDAS Imagine and the shorelines are extracted. The shoreline oscillation was analysed at an interval of 100 m along the coast of Chilika lagoon using DSAS software. Most commonly used statistical methods such as end point rate and linear regression rate are used. The shoreline change analysis for entire coast of the lagoon since 40 years (1975–2015) indicates that 62% is of accretion, 25% is under stable coast and erosion is 13%. The result reveals that the lagoon coast shows high accretion of 9.12 m/year at updrift side of the lagoon inlet whereas the downdrift side shows high erosion of ??10.73 m/year due to the wave induced northeasterly longshore sediment transport round the year and riverine discharge. This study would provide the potential erosion and accretion area at Chilika lagoon coast and would help in adaptive shoreline management plan.     

Comparison of Fusion Techniques for Very High Resolution Data for Extraction of Urban Land-Cover

This paper aims in presenting a thorough comparison of performance of pan sharpening techniques, belonging to spatial, spectral, scale-space and spatial-frequency domain, for Very High Resolution Satellite Data. With the availability of new Very High Resolution sensors, especially, World View-2 sensor, which provides data at sub-meter level, the need for fusion of Panchromatic (PAN) and Multispectral (MS) images has to be further investigated. Pan-sharpening techniques namely, Hue-Saturation-Intensity, Brovey Transform, Principal Components Analysis, Discrete Wavelet Transform, Stationary Wavelet Transform, Non Sub-sampled contourlet Transform and Pseudo Wigner Distribution (PWD) fusion method have been selected for the fusion of PAN and MS images of World View-2 sensor. Further, the comparison of performance of each of the techniques have been carried out by using various evaluation indicators, such as, Root Mean Square Error, Peak Signal-to-Noise Ratio, Correlation Coefficient, Universal Image Quality Index. It is found that PWD based fusion technique gives good result with a good trade-off between the preservation of spectral information and enhancement of spatial resolution.     

Mineralogical composition and ash geochemistry of raw and beneficiated high sulfur coals

Coal is one of the most available energy sources on earth. The mineralogical and geo-chemical aspects of coals are of prime importance for their utilization. The mineralogical composition, ash chemistry, and ash fusion temperature (AFT) ranges of raw and beneficiated coals are investigated in this paper. Further, the mineral matter transformation during the beneficiation processes viz. by oxidative desulfurization; alkali extraction and ultrasonication along with the relationship of the ash fusion temperature (AFT) ranges with the ash components in the coal are discussed. The major oxides present in the coal and beneficiated coal ashes include Fe₂O₃, Al₂O₃, SiO₂, CaO, and MgO, which significantly affect the ash fusion temperature ranges. Initial deformation temperature (IDT) changes with the ash components and, increases with the increase in the Fe₂O₃ content in coal ash. With increasing concentrations of both Al₂O₃ and SiO₂, the initial deformation temperature (IDT) also increases. The increasing and decreasing nature of the initial deformation temperature (IDT) observed is also dependent upon the CaO and MgO contents. XRD analysis of the coal samples revealed significant changes in mineral matter contents with the types of beneficiation processes adopted for coal. The minerals like chlorite, illite, montmorillonite, pyrite, calcite, aragonite, and alumina have been removed during the beneficiation processes. The FTIR spectra also indicate the presence of minerals like gypsum (G), calcite (C) aragonite (Ar), quartz (Q) and kaolinite (K) in the raw coal and their subsequent removal after the beneficiation processes.     

Ground deformational studies using ALOS-PALSAR data between 2007 and 2010 of the central Kutch area,Gujarat, India

The central Kutch region of Gujarat, India, experienced a M7.7 earthquake on January 26, 2001, causing large-scale ground deformations including a huge loss of lives and infrastructure. The rupture of a hidden reverse fault was the reason for this intense tectonic activity. The post-seismic ground deformations, attributed to the relaxation phase of a stressed crustal layer, have been analyzed using a pair of Advanced Land Observation Satellite-Phased Array type L-band Synthetic Aperture Radar interferometric synthetic aperture radar (InSAR) images. The InSAR images were obtained in 2007 and 2010, covering an area around Bhuj. It falls on the Kutch Mainland Fault and Katrol Bhuj Fault. Using the ADORE-DORIS software, interferometric imagery has successfully been generated, covering the study area. This allowed making interesting geological inferences. Three different regions in the study area elicited countable visible colored fringes, indicating different amounts of positive and negative ground deformations (surface motion with respect to the satellite). They occurred within the InSAR data acquisition dates. The region around Bhuj and to the north and east of Bhuj showed top surface deformations of about 35, 35, and 24 cm, respectively. The synoptic view of the interferometric image of the study area suggests two crustal fault lines running to the north and south of Bhuj city. The Institute of Seismological Research, geophysical and Global Positioning System data, indicates that huge seismic events occurred during the year 2007–2010 and supports the observational inference of clustering of interferometric fringes to the E and NE of the study area.