Exotic thrust mass of the Padar area in Kashmir

To the south of the Great Himalaya Range in Kashmir, a group of metasedimentary rocks with altered ultrabasic rocks occur physically over the migmatitic complex, as a klippe. The best exposure of it is met with in the Kudi nala, west of Sumjam, where lensoid outcrops of basic and ultramafic rocks, comprising actinolite—tremolite rock intruded by garnetiferous amphibolite occur within the marble, calc-gneiss and graphitic schist-gneiss. These rocks occur at an altitude of 5000–5500 m and the underlying rocks comprise gneiss, migmatite, schist, etc.The klippe of the metasedimentaries with the basic and ultrabasic suite of rocks, shows a synclinal disposition with a sheared northern contact. The southern contact of this klippe is also sheared and a tectonic “melange” zone is exposed in certain outcrops. This unusual geological set up, along with the absence of a deep-seated fault in the area of investigation, had led the author to believe that this suite of metasedimentaries has no stratigraphic relation with the underlying rocks which they override. These are very much akin to some of the rock suites of the Indus ophiolitic zone outcropping far in the north, particularly those of the Suru valley (Kargil tehsil) and they appear to have been transported during post-Cretaceous times as a thrust mass. This is the first record of an exotic thrust nappe in the Kashmir Himalaya to the south of the Great Himalaya Range.     

Early Triassic palynomorphs from Kuraloi Block,Belphar area,Ib-River coalfield,Mahanadi basin,Odisha

A rich assemblage of palynomorphs including miospores and megaspores has been recorded from the bore core no. IBKAN-2 drilled at a depth of 17.80m in Kuraloi Block-A, south-west part of the Ib-River Coalfield, Jharsuguda district, Odisha. The miofloral assemblage recovered shows prominence of cingulate, zonate, taeniate, non-striate and non saccate palynotaxa which indicate an early Triassic age and is comparable with the palynoassemblages of the same age known from the Damodar basin, India. The megaspore assemblage includes eight genera and fifteen species namely, Banksisporites karanpuraensis, B. indicus, B. utkalensis, Banksisporites sp., Barakarella pantii, Barakarella sp., Biharisporites spinosus, Biharisporites sp., Erlansonisporites triassicus, Erlansonisporites cf. erlansonii, Erlansonisporites sp. Jhariatriletes sp., Singhisporites sp., Ramispinatispora sp. and Talchirella trivedii. Records of megaspores are sparse in the early Triassic of Gondwana basins of India. The present study records the first occurrence of miospores and megaspores from the early Triassic of Mahanadi basin besides substantiating the earlier data.     

The potential contribution of wildlife sanctuary to forest conservation: A case study from binsar wildlife sanctuary

Forest vegetation of a protected area(Binsar Wildlife Sanctuary) in Kumaun region(west Himalaya) was analysed for structure,composition and representativeness across three different altitudinal belts,lower(1,600-1,800 m a.s.l.),middle(1,900-2,100 m a.s.l.) and upper(2,200-2,400 m a.s.l.) during 2009-2011 using standard phytosociological methods.Four aspects(east,west,north and south) in each altitudinal belt were chosen for sampling to depict maximum representation of vegetation in the sanctuary.Population structure and regeneration behaviour was analysed seasonally for two years to show the establishment and growth of tree species.A total of 147 plant species were recorded from the entire region of which 27 tree species were selected for detailed study.Highest number was recorded at upper(18 species),and lowest at lower altitudinal belt(15 species).The relative proportion of species richness showed higher contribution of tree layer at each altitudinal belt.The population structure,based on the number of individuals,revealed a greater proportion of seedling layer at each altitudinal belt.The relative proportion of seedlings increases significantly along altitudinal belts(p<0.05) while opposite trends were observed in sapling and tree layers.The density of sapling and seedling species varied non-significantly across seasons(p>0.05).The density values decreased in summer and increased during rainy season.As far as the regeneration status is concerned,middle and upper altitudinal belts showed maximum number of species with fair regeneration as compared to lower altitudinal belt.Overall density diameter distribution of tree species showed highest species density and richness in the smallest girth class and decreased in the succeeding girth classes.This study suggests that patterns of regeneration behaviour would determine future structural and compositional changes in the forest communities.It is suggested that the compositional changes vis-à-vis role of ‘New’ and ‘Not regenerating’ species need priority attention while initiating conservation activities in the sanctuary.This study calls for exploring other less explored Wildlife Sanctuaries in the Himalaya and across the world,to achieve overall biodiversity status in these protected areas and thus to justify their role in conserving biodiversity in the region.     

R-mode factor analysis of lithologic variables from cyclically deposited Late Paleozoic Barakar sediments in Singrauli Gondwana sub-basin,Peninsular India

The quantitative relationships between lithological variables from the Late Paleozoic coal bearing cycles have been investigated using factor analysis in an attempt to analyze net subsidence during the deposition of these cycles. The results suggest that there are only two non-zero eigenvalues in varimax matrix which indicate that the hyper ellipsoid enclosing the data points have seven axes of zero length and exists an ordinary two dimensional ellipsoid. The data points can be located with reference to two mutually perpendicular axes. Loading on thickness of sandstones, thickness of shale, number of sandstone beds and number of shale beds are extremely high on RF-I and low on the other factor. This would lead to the interpretation that a balance was maintained throughout the Barakar sedimentation between the rate of deposition and the rate of subsidence. On the other hand, loading on number of coal beds is high on ‘ suggesting that the development of peat swamps (coal beds) is not a normal feature during the Late Paleozoic Barakar sedimentation in this Gondwana sub-basin.     

Heating of the intracluster medium by quasar outflows

We study the possibility of quasar outflows in clusters and groups of galaxies heating the intracluster gas in order to explain the recent observation of excess entropy in this gas. We show that radio galaxies alone cannot provide the energy required to explain the observations but the inclusion of Broad Absorption Line (BAL) outflows can do so, and that in this scenario most of the heating takes place atz ∼ 1–4, the “preheating” epoch being at a lower redshift for lower mass clusters.     

Cyclicity in early Permian fluviatile Gondwana coal measures: An example from Giridih and Saharjuri basins,Bihar, India

The Karharbari and Barakar coal measures of Giridih and Saharjuri basins of Bihar, eastern India, comprise an interbedded assemblage of sandstone, shale and coal in variable abundance. The lithofacies composition records a progressive decrease in sandstone and enrichment of shale and coal from Karharbari up to Barakar. Application of first-order embedded Markov-chain statistics to subsurface data of Karharbari (52 borehole logs) and Barakar (10 borehole logs) reveals that deposition in both the coal measures followed a Markovian mechanism with variable probability, to yield a sequence of upward transition from sandstone through shale to coal. The repetitive fining-upward cycles are asymmetrical, i.e. sandstone → shale → coal → sandstone in the case of Karharbari, but symmetrical as sandstone → shale → coal → shale in Barakar.The abundance of sandstone and the asymmetrical nature of Karharbari cycles are attributed to abrupt shifting of channel bars in low-sinuosity anabranching streams. By contrast, the subequal amount of sandstone, shale and coal forming symmetrical cycles in the overlying Barakar Formation is due perhaps to a slow and gradual shift of the stream channels over and across the adjacent subenvironments of the flood plain.     

Crustal thickening under the palaeo-meso-Proterozoic Delhi Fold Belt in northwestern India: evidence from deep reflection profiling

The results of deep reflection profiling studies carried out across the palaeo-meso-Proterozoic Delhi Fold Belt (DFB) and the Archaean Bhilwara Gneissic Complex (BGC) in the northwest Indian platform are discussed in this paper. This region is a zone of Proterozoic collision. The collision appears to be responsible for listric faults in the upper crust, which represent the boundaries of the Delhi exposures. In these blocks the lower crust appears to lie NW of the respective surface exposures and the reflectivity pattern does not correspond to the exposed blocks. A fairly reflective lower crust northwest of the DFB exposures appears to be the downward continuation of the DFB upper crust. The poorly reflective lower crust under the exposed DFB may be the westward extension of the BGC upper crust at depth. Thus, the lower crust in this region can be divided into the fairly reflective Marwar Basin (MB)-DFB crust and a poorly reflective BGC crust. Vertically oriented igneous intrusions may have disturbed the lamellar lower-crustal structure of the BGC, resulting in a dome-shaped poorly reflective lower crust whose base, not traceable in the reflection data, may have a maximum depth of about 50 km, as indicated by the gravity modelling.
The DFB appears to be a zone of thick (45-50 km) crust where the lower crust has doubled in width. This has resulted in three Moho reflection bands, two of which are dipping SE from 12.5 to 15.0 s two-way time (TWT) and from 14.5 to 16.0 s TWT. Another band of subhorizontal Moho reflections, at ≈ 12.5 s TWT, may have developed during the crustal perturbations related to a post-Delhi tectonic orogeny. The signatures of the Proterozoic collision, in the form of strong SE-dipping reflections in the lower crust and Moho, have been preserved in the DFB, indicating that the crust here has not undergone any significant ductile deformation since at least after the Delhi rifting event.