012604   Sharma I N;Prakash D (Geology Dep, Banaras Hindu Univ, Varanasi-221 005) : Occurrence of kornerupine-bearing granulite form Karimnagar, Andhra Pradesh. Curr Sci 2006, 91(5), 72-7.

The occurrence of korneripine upine-bearing, quartz-free granulite from the Malial area of Karimna-gar district, Andhra Pradesh. It occurs as small enclaves and pods within the Granite-gneiss, associated with garnet-orthopyroxene-cordierite-biotite-gneiss. Its mineral assemblage includes kornerupine-cordierite-biotite-spinel, K-feldspar, ilmenite and magnetite. Kornerupine, a hydrated magnesium-aluminium silicate plots on the 4MgO-3Al_{2O3-4SiO2 (4:3:4) composition along the solid solution join between 4:3:4 and 1:1:1 (3.5 MgO 0.3.5 Al2O3 0.3.5 SiO2) compositions. The relative XMg values among various minerals are as follows: cordierite <62> biotite <62> kornerupine <62> spinel. The deduced post-peak metamorphic pressure-temperature conditions of 5-6 kbar and 650-750°C for the korne-rupine-spinel-bearing quartz-free granulites are consistent with the experimental work on stability of kornerupine in the MgO-Al2O3-SiO2-H2O system.}

5 illus, 1 table, 41 ref

012603   Semwal N;Akolkar P (NO, Central Pollution Control Board (Ministry of Environment & Forests, Go, Parivesh Bhawan, East Arjun Nagar, Delhi-110 032) : Water quality assessment of sacred Himalayan rivers of Uttaranchal. Curr Sci 2006, 91(4), 486-96.

Deals with water quality assessment of rivers in Uttaranchal, in view of their religious importance and ecological sustainability. Based on bio-monitoring assessment, biological water quality criteria have been evolved for rivers of Uttaranchal, indicating various beneficial uses of water quality and their respective levels of characteristics. Out of 60 stretches of 19 rivers, 41 stretches indicated clean water quality of Class 'A', five stretches were slightly polluted (class 'B'), six were moderately polluted (class 'C'), one stretch was highly polluted (class 'D') and there were altogether seven severely polluted (class 'E') stretches. The physico-chemical water quality in most of the rivers of Uttaranchal remained unchanged except of total dissolved solids, which ranged from 90.23 to 121.33 mg/l, total suspended solids varying from 126.5 to 236.5 mg/l and total alkalinity of 37.0 to 96.0 mg/l. Religious places have contributed significant levels of sulphates to water quality (1.66 to 20.0 mg/l). Traces of iron, zinc and copper metals in water and sediments have been observed in clean water quality stretches. Agricultural practices on the river bank may have considerable impact on contribution of pesticide residues such as total Endosulfan, Dieldrin and DDT. Open defecation is the most common activity on river banks, which has significant contribution towards the aesthetic water quality of rivers.

1 illus, 14 tables, 14 ref

012602   Satyanarayanan M;Balaram V;Roy P;Rao T G (NO, National Geophysical Research Institute, Hyderabad-500 007) : Interlaboratory collaborative analysis of rainwater reference material. Curr Sci 2006, 91(2), 235-8.

Results of an interlaboratory collaborative analysis of real-time rainwater sample obtained at the Geochemical Laboratory of National Geophysical Research Institute, Hyderabad, are presented. Estimation of eleven important toxic and trace metals (Al, V, Mn, Fe, Ni, Co, Cu, Zn, As, Cd and Pb) by inductively coupled plasma mass spectrometry (ICP-MS) is compared with reference and informative values provided by the organizer. Depending upon the Z-scores calculated, the fitness of the data for either 'pure geochemistry' or 'applied geochemistry' was assessed. An overview of Z-score results indicated that the data for Al, Mn, Ni, Co, Cu, Zn, Cd and Pb fell within the -2 <60> Z <60> 2 range, which included majority of the toxic and trace metals used in several problems dealing with atmospheric deposition. These results help to further investigate the analytical discrepancies observed in the data, optimize necessary aspects and minimize the interference effects caused during analysis.

1 illus, 4 tables, 21 ref

012601   Sarkar S;Banerjee S;Samanta P;Silambuchelvan J K (Geological Sciences Dep, Jadavpur University, Kolkata-700 032) : Microbial mat-induced sedimentary structures in siliciclastic sediments: examples from the 1.6 Ga chorhat sandstone, Vindhyan supergroup, M.P., India. J Earth Syst Sci 2006, 115(1), 49-60.

Paper addresses macroscopic signatures of microbial mat-related structures within the 1.6 Ga-old Chorhat Sandstone of the Semri Group - the basal stratigraphic unit of the Vindhyan succession in Son valley. The Chorhat Sandstone broadly represents a prograding succession of three depositional facies ranging from shallow shelf to coastal margin with aeolian sandsheet. The mat-mediated structures were generated because of plastic or brittle deformation of sand, turned cohesive and even thixotropic because of microbial mat growth. Mat growth also favoured abundant preservation of structures that usually have low presevation potential. Prolific growth of microbial mat in the subtidal to intertidal zone of the Chorhat sea was facilitated due to lack of grazing and burrowing activities of organisms in the Precambrian. It further indicates low rate of sedimentation between the storms, as also attested by frequent superposition of storm-beds, even near the storm wave base. It also reduces erosion and that, in turn, would imply low sediment concentration in flows leading to development of bedforms that are likely to be smaller in size and isolated from each other in a single train in contrast to those that form in mat-free sands.

14 illus, 52 ref

012600   Sanil Kumar V;Pathak K C;Pednekar P;Raju N S N;Gowthaman R (Ocean Engineering Division, National Institute of Oceanography, Dona Paula, Goa-403 004) : Coastal processes along the Indian coastline. Curr Sci 2006, 91(4), 530-5.

Based on the measured data, wave height and current speed at a few locations are presented along with the estimated sediment transport rates. The maximum significant wave height recorded during the passage of a cyclone along the west coast in a water depth of 27 m was 6 m. The current measurements show that the maximum currents vary from about 1.4 m/s in the open ocean to about 3.2 m/s in the Gulf of Khambhat. The gross longshore sediment transport rate was about 1 x 10^{6 m3 per year along south Kerala and south Orissa. The estimated longshore sediment transport rates show that net transport along the east coast of India is towards the north, whereas along the west coast it is mostly towards the south.}

2 illus, 6 tables, 28 ref

012599   Saini P;Shailendra Singh;Pandit M K (NO, Geological Survey of India, Jhalana Dungari, Jaipur-302 004, Email: geostranger1@yahoo.com) : Angular relationship between rocks of the Aravalli and Delhi supergroups in southeastern Rajasthan - a possible unconformity. Curr Sci 2006, 91(4), 432-4.

3 illus, 10 ref

012598   Sadhuram Y (NO, National Institute of Oceanography, Regional Centre, 176, Lawson's Bay Colony, Visakhapatnam-530 017, Email: sadhuram@.nio.org) : Long-range forecast of monthly rainfall over India during summer monsoon season using SST in the North Indian Ocean. Curr Sci 2006, 91(4), 425-8.

1 illus, 6 tables, 11 ref

012597   Roy A B (Geology Dep, Presidency College, Kolkata-700 073) : Seismicity in the peninsular Indian shield some - geological considerations. Curr Sci 2006, 91(4), 456-63.

Peninsular Indian Shield, traditionally considered , stable continental region, underwent significant change in its crustal character, first during the Jurassic break up of Gondwanaland, and then through the process of underplating as the cratonic block moved over the plume heads during its northward journey. The break up resulted in the development of a series of fracture appearing as lineaments on the surface, while the under plating caused subcrustal magmatism as well as surface volcanicity. The reconstituted Indian crust undergoes heterogeneous deformation responding to the north easterly stress presumably resulting from ocean opening along the Carlsberg Ridge-Rift system. The deformation is comparable to block tectonics, in which movements are restricted to the boundaries of the blocks while internally these remain rigid. In the context of the Peninsular Indian Shield, the relative movements: of rigid blocks trigger earthquakes. The presence of fluid in the deforming medium facilitates movement. There can be several sources of fluid release, influx from the subcrustal magma body or through some deep crustal processes like dehydration metamorphism. In some special instances, water leaking from a reservoir can help trigger earthquakes.

7 illus, 55 ref

012596   Ray J S (Physical Research Laboratory, , Navrangpura, Ahmedabad-380 009, Email: jsray@prl.res.in) : Age of the Vindhyan supergroup: a review of recent findings. J Earth Syst Sci 2006, 115(1), 149-60.

Vindhyan Supergroup of India is one of the lages and thickest sedimentary successions of the world. Deposited in an intra-cratonic basin, it is composed mostly of shallow marine deposits. It is believed to have recorded a substaintial portion of Proferozoic time and therefore, likely to contain valuable information of the evolution of the atmosphere, climate, and life on planet. It also contains some of the most disputed fossils of earliest animal life. Despite their importance, the absolute age of these rocks had remained unknown until recently. From the present findings it appears that the issues surrounding the age of the Lower Vindhyans in the Son valley are now resolved, whereas problems with the age of the Upper Vindhyans and that with the stratigraphic correlations remain to be answered.

^iia52 ref

012595   Ramkumar;Muralimohan K;Kiranmayi L;Srinivasa Y B (Agriculture Entomology Dep, Univ of Agricultural Sciences, GKVK, Bangalore-560 065, Email: yb@iwst.res.in) : Discrete generation cycles in the tropical moth Opisina arenosella. Curr Sci 2006, 91(6), 811-16.

Insect populations with discrete generation cycles (DGCs), have been rarely encountered in the tropics. Among the few known species, spatially segregated coastal populations of Opisina arenosella, the coconut caterpillar, have been shown to follow DGCs during outbreaks in Sri Lanka. Climatic parameters are known to be important in regulating generation cycles in insect populations. But, unlike temperate conditions, the tropics are characterized by high spatial heterogeneity in climate, which prompted the present investigation on generation cycles of populations of O. arenosella occurring in interior dry landscapes of the Indian peninsula. Two spatially isolated populations were regularly sampled for two years and data were subjected to time series analysis to determine periodicity, if any, in the occurrence of different developmental stages of the population. Results showed that populations followed DGC with a periodicity of approximately one generation, and further, correlations showed that there was a definite lead/lag in the peaks of different developmental stages, which closely correspond to the developmental period of different stages of the insect. The findings suggest that discrete cycles of O. arenosella may not be related to seasonality. The importance of generation cycles with respect to pest management has also been discussed.

3 illus, 12 ref

012594   Ramana M V;Ramprasad T;Desa M;Sathe A V;Sethi A K (NO, National Institute of Oceanography, Dona Paula, Goa-403 004) : Gas hydrate-related proxies inferred from multidisciplinary investigations in the Indian offshore areas. Curr Sci 2006, 91(2), 183-9.

Presence of gas hydrates along the Indian continental margins has been speculated by earlier workers based on the identification of Bottom Simulating Reflection (BSR) on the multichannel seismic reflection records and computed gas hydrate stability zone thickness map. The BSR alone is inadequate to infer gas hydrates as suggested by drilling results elsewhere. Therefore, to understand the subsurface distribution of gas hydrates along the continental margins of India, multi-disciplinary investigations have been undertaken. The observed geophysical anomalies (BSRs, pockmarks, gas upthrust zones, vents, blanking zones, etc.) in association with the geochemical (sulphate reduction trend and increase in methane flux with core depth) and microbiological proxy indicators (sulphate and nitrate-reducing bacteria, and fermenters) favour the presence of gas hydrates in some of the Indian offshore regions.

5 illus, 27 ref

012593   Rajendra Prasad B;Vijaya Rao V (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: rajbitragunta@yahoo.com) : Deep seismic reflection study over the Vindhyans of Rajasthan: implications for geophysical setting of the basin. J Earth Syst Sci 2006, 115(1), 135-47.

Paper presents results of high-resolution deep seismic reflection profiling of the Proterozoic Vindhyan basin of the Rajasthan area along the Chandli-Bundi-Kota-Kunjer profile. Seismic images have been used to estimate the thickness of Vindhyan strata as well as to understand the toctonic framework of the basin. The results are constrained by gravity, magnetic and magnetotellurid data. The study reveals gentle SE-dipping reflection bands representing the Vindhyan strate. The seismic sections depict gradual thickening of the Vindhyan succession towards south east from Bundi. The velocities fo the upper and lower Vindhyans are identifiecd as 4.6-4.8 km/s and 5.1-5.3 km/s. The NW limit of the Vindhyan basin is demarcated by the Great Boundary Fault (GBF) that manifests as a 30 km wide NW dipping thrust fault extending to a depth of 30 km.

11 illus, 32 ref

012592   Parvez I A;Vaccari F;Panza G F (CSIR Centre for Mathematical Modelling and Computer Simulation, NAL Belur Campus, Bangalore-560 037, Email: parvez@cmmacs.ernet.in) : Influence of source distance on site-effects in Delhi city. Curr Sci 2006, 91(6), 827-35.

The seismic ground motion along a geological cross-section from Tilak Bridge to Punjabi Bagh in Delhi city has been simulated at every 130 m with a hybrid technique (modal summation and finite differences). The authors use two earthquake source scenarios: (1) 27 August 1960, M = 6.0 at a distance of about 45 km (near source) and (2) a large (M = 8.0) earthquake due in the central seismic gap in the Himalayan region, at a distance of about 225 km (far source). Authors focus on the influence of the seismic source location and focal mechanism on site-response, which in general, is neglected in traditional site-effect studies. Also compare the Response Spectra Ratio (RSR) for frequency up to 3 Hz computed due to far and near sources. It is observe 6-7 times higher amplification in the radial component at around 2-2.5 Hz due to the far source as-compared to the near source. However, there is some amplification, of the order 2-3, at lower frequencies (less than 1 Hz) due to the near source, which is missing when the far source is considered. To validate our results, we compare the RSR, obtained from the signals at soft sites, namely CPCB, IHC and CSIR, normalized to the bedrock Ridge site, recorded during Chamoli earthquake of 1999, with that at similar sites theoretically computed along our 2D geological cross-sections.

7 illus, 30 ref

012591   Palanivelu K;Nisha Priya M;Muthamil Selvan A; Natesan U (Centre for Environmental Studies, Anna Univ, Chennai-600 025, Email: kpvelu@hotmail.com) : Water quality assessment in the tsunami-affected coastal areas of Chennai. Curr Sci 2006, 91(5), 583-4.

1 illus, 1 table, 3 ref

012590   Murali R M;Vethamony P;Saran A K;Jayakumar S (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: mmurali@nio.org) : Change detection studies in coastal zone features of Goa, India by remote sensing. Curr Sci 2006, 91(6), 816-20.

Digital remote sensing data of SPOT-1 (Nov. 1990),IRS- 1C (jan.2001)and IRS- 1D (Jan. 2003) have been subject to maximum likelihood classifier (MLC) to carry out change detection studies in the coastal zone of Goa. The classified images were evaluated on both homogeneous and heterogeneous regions in terms of confusion matrix as well as by field validation. The classification results of these multi-temporal data reveal that MLC gives an average accuracy of 85.69, 77.66, and 88.43% for 1990, 2001 and 2003 images respectively, and the corresponding kappa coefficients are 0.89, 0.84 and 0.86 respectively. Results of MLC indicate that there is an increase in urban land, vegetation and water body reduction in barren land and sandv beach along the coastal zone of Gon- The urbanization is attributed to tourism boom-related activities.

4 illus, 3 tables, 9 ref

012589   Majumdar T J;Bhattacharya R;Chatterjee S (NO, Earth Sciences and Hydrology Division, Space Applicants Centre (ISRO), Ahmedabad-380 015) : Generation of very high resolution gravity image over the Central Indian ridge and its tectonic implications. Curr Sci 2006, 91(5), 683-6.

Satellite altimetry can be used to infer subsurface geological structures analogous to gravity anomaly maps generated through ship-borne survey. In this study, free-air gravity image has been generated over the Central Indian Ridge using very high resolution database as obtained from Geosat GM, ERS-1, Seasat and TOPEX/ POSEIDON altimeter data. Isostatically compensated regions could be identified with all fracture zones clearly demarcated in this map.

4 illus, 11 ref

012588   Lopez S;Fernandez C;Castro A (Institutt for Geologi, Universitytet i Tromoso, 9037, Tromso, Norway, Email: Susana.Aparicio@ig.uit.no) : Evolution of the Archaean continental crust: insights form the experimental study of Archaean granitoids. Curr Sci 2006, 91(5), 607-21.

Experimental petrology is a valuable tool to test different models proposed to account for the origin of Archaean granitoids. However, a feasible petrogenetic model needs to be supported by studies from different disciplines. Therefore, the present article is a synthesis of experimental studies on the origin of Archaean granitoids (TTG and K-rich granites. Petrogenetic evolution of the Archaean crust was catalysed by progressive decrease in geothermal gradients. The thermal structure of the early Archaean down-going plates was favourable for melting the oceanic crust at low depths (P <60> 10 kbar) in subducting slabs to produce TTG magmas, without interaction with the mantle during ascent. The progressive cooling of the earth produced an increase in the dip of the subducting slab, favouring partial melting of the basaltic rocks at higher depths (P <62> 10 kbar) and the interaction of TTG magmas with the overlying mantle wedge. Crustal evolution at the Archaean-Proterozoic boundary was dominated by the generation of different sort of voluminous K-granite batholiths the origin of which is controversial. It is considerd an origin of K-granites by interaction between hydrous sanukitoids magma and tonalitic crust.

10 illus, 112 ref

012587   Likhar S;Kulkarni M N;Kayal J R (Geodesy and Remote Sensing Division, Department of Civil Engineering, Indian Institute of Technology, Mumbai-400 076) : Interpretation of post-geodetic and seismic data of the 2001 Bhuj earthquake Mw 7.7. Curr Sci 2006, 91(2), 225-9.

Devastating earthquake (M_w 7.7) struck Bhuj area, Gujarat, western India on 26 January 2001. Using Global Positioning System (GPS) data that were collected over three years (2001-03), displacement vectors in the Bhuj region were estimated. The local horizontal displacement vectors represent a general southwest-ward movement and the regional horizontal displacement vectors were in the northeast direction, parallel to the NE-SW trending major lineament and the major axis of the isoseismal of the 2001 earthquake. This observation is in conformity with the reverse faulting of the main shock and aftershocks due to the dominant compressional stress of the NNE-ward movement of the Indian plate. Some anomalous displacement vectors during the GPS epoch 2002-03 could be the result of a rebound of the southern block subsequent to the earthquake.

3 illus, 20 ref

012586   Kishor Kumar;Rautela K;Bisht K L;Joshi V D; Rautela A S;Dobriyal A K (Dep of Zoology, Govt Degree College, Dakpatthar, Dehradun) : Ecological studies on the biodiversity of river Khoh in the foot-hills of Garhwal Himalaya. I. Phytoplankton analysis. J Nat Conserv 2006, 18(1), 71-80.

Deals with the ecological study of phytoplankton community in the river Khoh of Garhwal Himalaya. Quanti-qualitative study of plankton is made and correlated with various ecological parameters like-temperature, dissolved oxygen, velocity of water current, total alkalinity and hardness.

5 illus, 4 tables, 15 ref

012585   Janardhana Raju N (Hydrogeology Lab, Geology Dep, Banaras Hindu University, Varanasi-221 005) : Seasonal evaluation of hydro-geochemical parameters using correlation and regression analysis. Curr Sci 2006, 91(6), 820-6.

Correlations and multiple linear regressions were used to develop models relating well water chemical quality parameters to a set of independent chemical variables in post- and pre-monsoon seasons in the upper Gunjanaeru river basin, Cuddapah district, Andhra Pradesh, South India. The correlation between the specific electrical conductance (SEC) and other parameters except potassium (K⁺) is significantly positive, whereas Ca²⁺ + Mg²⁺/Na⁺ K⁺ is significantly negative for both post-and pre-monsoon seasons. In predicting SEC for both post- and pre-monsoon, the independent variables, viz. HCO^-₃, SO^-₄ and Cl^- in the model had a significant effect (from 't' test for partial regression coefficient at the 5% level of probability). The multiple R² values 0.982 and 0.997 indicate that 98.2 and 99.7% of variability in the observed SEC could be ascribed to the combined effect of Na⁺, Cl^-, Ca²⁺ + Mg²⁺, HCO^-₃, and SO^-₄ for post- and pre-monsoon seasons, respectively. Out of the 98.2% variability in SEC due to the combined effect of Na⁺, Ca²⁺ + Mg²⁺, HCO^-₃, SO^2-₄ and Cl^- 44.8% is due to HCO^-₃, 44.4% is due to Cl^-, 9% is due to SO^2-₄ and 2% each is due to Na⁺ and Ca²⁺ + Mg²⁺ for post-monsoon season. Whereas in the pre-monsoon season, 99.7% variability in SEC is due to the combined effect of Na⁺, Ca²⁺ + Mg²⁺, HCO^-₃, SO^2-₄ and Cl^-; 38.8% is due to Cl^-, 36.9% is due to HCO^-₃, 12% is due to Na⁺, 7% is due to SO^2-₄ and 3% is due to Ca²⁺ + Mg²⁺. This shows that HCO^-₃, Cl^-, SO^2-₄: and Cl^-, HCO^-₃, Na⁺, SO^2-₄ are the most significant independent variables in predicting SEC for post- and pre-monsoon seasons respectively.

4 illus, 7 tables, 17 ref

012584   Gwal A K;Shrivastava A;Malhotra K (Department of Physics, Space Science Laboratory, Barkatullah University, Bhopal-462 026) : Observation of seismogenic ultra low frequency electric field fluctuations detected as a burst in the ionosphere during tsunamis over the Andaman and Nicobar Islands. Curr Sci 2006, 91(2), 229-34.

Natural ultra low frequency (ULF) geomagnetic pulsations are mainly caused by wave plasma processes in the terrestrial magnetosphereand ionosphere. Earth crust process may influence the parameters of geomagnetic noises and pulsations owing to the generation of additional noise or variation of local geo-electric properties. Electromagnetic disturbances of lithospheric origin observed before earthquakes are believed to become a physical background for short-term forecasting of seismic hazards. Among a large variety of seismo-electromagnetic phenomena, considerable interest has been paid recently to ULF frequency range. Here, electric field fluctuations recorded in the ULF frequency range on 25 and 26 December 2004, as a precursory effect to the series of seismic events that occurred after the disastrous tsunami hit the Andaman and Nicobar Islands, using DEMETER micro-satellite have been discussed. Since geomagnetic activity during the period was found to be moderate, the significant electric burst recorded in the early morning of 26 December 2004 around 04:05:00 UTC, could be attributed to the frequency of occurrence of earthquakes, including two major events (Mw=7.3, depth = 10 km and Mw = 7.1, depth = 39 km) that occurred a few minutes later around 04:21:00 UTC and 04:21:29.8 UTC on the same day. From the recorded observations, it is clear that the intensity of the electric fluctuations and diminishes as the number decreases. The pattern of electric field fluctuations recorded could be used for a precursory study of earthquake occurrences.

5 illus, 14 ref

012583   Gusain H S;Chandel C;Ganju A (Snow and Avalanche Study Establishment, Him Parisar, Plot No.1, Sector 37A, Chandigarh-160 036, Email: gusain_hs@yahoo.co.in) : Spatial variation of snow-cover properties on small uniform mountain slopes in the Greater Himalayan region. Curr Sci 2006, 91(5), 72-7.

Three small uniform mountain slopes were selected carefully for snow-pit observation in the Patsio bowl located in the higher latitudes of Himachal Pradesh in the Great Himalayan region. Totally 27 snow-pit observations were taken, with nine snow-pit observations in a study plot of each slope. At each observation point, 19 snow-pack parameters were recorded and analysed statistically. Analysis result of the snow-pack parameters shows a large spatial variation (up to 59%) in the snow-cover properties. Snow-pack parameters vary from one observation point to another point within the same slope as well as from one slope to another. The study reveals that in most cases, the snow-cover properties taken from a single snow-pit do not resemble the average snow-cover properties of the entire study plot with significant confidence level.

5 illus, 4 tables, 20 ref

012582   Dutta S;Steiner M;Banerjee S;Erdtmann B D; Jeevankumar;Mann U (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076) : Chuaria circularis from the early mesoproterozoic suket shale, Vindhyan supergroup, India: insights from light and electron microscopy and pyrolysis-gas chromatography. J Earth Syst Sci 2006, 115(1), 99-112.

Chuaria circularis (Walcott 1899) from the Suket Shale of the Vindhyan Supergroup (central India) has been reinvestigated for its morphology and chemical composition using biostatistics, electron microscopy and pyrolysis-gas chromatography. Morphology and microscopic investigations provide little clues on the specific biological affinity of Chuaria as numerous preservational artifacts seem to be incorporated. On the contrary, the predominance of n-aliphatic pyrolysates of presently studied Chuaria from India rather supports an algal affinity. Moreover, the reflectance of C. circularis can be used to obtain a comparative maturity parameter of the Preceambrian sediments. The review of the age and geographical distribution of C. circularis constrains that this species cannot be considered as an index fossil for the Proterozoic time.

7 illus, 78 ref

012581   Deshpande S M (Postgradute Geology Dep, Government Institute of Science, Caves road, Aurangabad-431 004) : Groundwater quality in and around Satara and Itkheda urban conglomerate of Aurangabad city area. Bioinfolet 2006, 3(4), 227-233.

Physiochemical characteristics of ground water have been studied in and around Satara and Itkheda Urban conglomerate of Aurangabad city area for assessment of their suitability for drinking purposes by collecting groundwater samples at 30 places. The temperature, pH, electrical conductivity, total dissolved solids, Ca, Mg, hardness, chloride and alkalinity were analyzed in the laboratory. The study revealed that the groundwater is contaminated due to domestic waste. The total hardness, Ca, Mg and Cl contents are well above Indian standards for drinking water.

2 tables, 8 ref

012580   Chalapathi Rao N V (EPMA Lab Mineral Sect, Ore Dressig Div, , Indian Bureau of Mines, Nagpur-440 016, Email: nucr100@gmail.com) : Mesoproterozoic diamondiferous ultramafic pipes at Majhgawan and Hinota, Panna area, central India: key to the nature of sub-continental lithospheric mantle beneath the Vindhyan basin. J Earth Syst Sci 2006, 115(1), 161-83.

9 illus, 137 ref

012579   Chakraborty P P (Applied Geology Dep, Indian School of Mines, Dhanbad-826 004, Email: partha_geology@yahoo.co.in ) : Outcrop signatures of relative sea level fall on a siliciclastic shelf: Examples from the rewa group of proterozoic Vindhyan basin. J Earth Syst Sci 2006, 115(1), 23-6.

Rewa Group of the Vindhyan Supergroup in the Son valley begins with a thick (<126> 200 m) dominantly shaly, shelfal succession, occurring between the Dhandraul Formation of the Kaimur Group (Fluvial sandstone) below and Drammondganj Formation of the Rewa Group (marginal marine sandstone) above. Such a stratigraphic disposition indicates a sharp rise in relative sea level at the onset of Rewa sedimentation, inducing a shelfal depth to the Vindhyan basin. However, a number of wedge-shaped, sandstone/conglomerate bodies (maximum thickness 23.5 m) occur at multiple stratigraphic levels within the aforesaid deeper water shale succession, which appear to be of much shallow water origin representing regressive deposite. Though these bodies do not define a single physically continuous unit, either vertically or laterally, they are still designated by a single term `Asan Sandstone' in the literature. On the other hand, the encasing shelfal shales are termed as Panna and Jhiri Shales, in accordance with their occurrence below or above the so-called `Asan Sandstone'. The present study reveals that in different sections spread over the Son valley, there are several discrete regressive wedges occurring vertically, and their depositional environment is also variable, ranging between braided fluvial, shoreface fan and braid delta.

11 illus, 29 ref

012578   Chakraborty C (Geological Studies Unit, Indian Statistical Institute, 203 B.T. Road, Kolkata-700 108, Email: chandan@isical.ac.in) : Proterozoic intracontinental basin: The vindhyan example. J Earth Syst Sci 2006, 115(1), 3-22.

Features of the Vindhyan succession clearly indicate a vast intracratonic basin that remained within tens of meters of sea level throughout its lifetime. Apparently, shallow water condition was maintained over a large area for a long period of time suggesting that the sub-Vindhyan lithosphere suffered susdence over a larger area for a long period of time suggesting that the sub-Vindhyan lithosphere suffered subsidence over a larger area producing a wide shallow ramp type basin. Hundreds of meters thick accumulation of peritidal strata in sequence 5 of the Vindhyan succession indicates that the subsidence rate was in perfect concert with the rate of sediment supply for a condiserably long period of time during the end phase of Vindhyan basin evolution - the hallmark of cratonic basins Sloss (1988a, b). It is inferred that during the terminal period of the Vindhyan sedimentation a self-regulating system of uplift, erosion, sedimentation and subsidence controlled the accumulation of strata.

9 illus, 2 tables, 53 ref

012577   Banerjee S;Dutta S;Paikaray S;Mann U (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Email: Santanu@iitb.ac.in) : Stratigraphy, sedimentology and bulk organic geochemistry of black shales from the proterozoic Vindhyan Supergroup (Central India). J Earth Syst Sci 2006, 115(1), 37-47.

Four organic-rich shale units of the Proterozoic Vindhyan sedimentary succession have been scanned to reveal their origin and hydrocarbon potential. The wavy-crinkly nature of the carbonaceous laminae is suggestive of microbial mat origin of the shales. These shales are thus different from Phanerozoic black shales which typically exhibit planar laminae. The hydrocarbon potential of the Phanerozoic black shales which typically exhibit planar laminae. The hydrocarbon potential of the black shale units has been evaluated by Rock-Eval pyrolysis. Total organic carbon content of many of the shales exceeds 1%. The mean T_max for the black shales translate to a vitrinite reflectance range of 2.05-2.40% Rm based on standard conversion techniques. These shales have reached the catagenetic stage near the beginning of anthracite formation.

7 illus, 44 ref

012576   Banerjee S;Bhattacharya S K;Sarkar S (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai-400 076) : Carbon and oxygen isotope compositions of the carbonate facies in the Vindhyan supergroup, central India. J Earth Syst Sci 2006, 115(1), 113-34.

Vindhyan sedimentary succession in central India spans a wide time bracket from the Paleoproterozoic to the Neoproterozoic period. Chronostratigraphic significance of stable carbon and oxygen isotope ratios of the carbonate phase in Vindhyan sedimdents has been discussed in some recent studies. However, the subtle controls of facies variation, depositional setting and post-depositional diagenesis on stable isotope compositions are not yet clearly understood. The Vindhyan Super group hosts four carbonate units, exhibiting a wide variability in depositional processes and paleogeography. A detailed facies-specific carbon and oxygen isotope study of the carbonate units was undertakden by us to investigate the effect of these processes and to identify the least altered isotope values. It is seen that both carbon and oxygen isotope compositions have been affected by early meteoric water diagnesis. The effect of diagnetic alteration is, however, more pronounced in case of oxygen isotopes than carbon isotopes. Stable isotope compositions remained insensitive to facies only wheh sediments accumulated in a shallow shelf setting without being exposed. Major alteration of original isotope ratios was observed in case of shallow marine carbonates, which became exposed to meteoric fluids during early diagenetic stage. Duration of exposure possibly determined the meagnitude of alteration and shift from the orginal values. Moreover, dolomitization is found to be accompanied by appreciable alteration of isotope compositions in some of the carbonates. The present study suggests that variations in sediment depositional settings, in particular the possibilit of subaerial exposure, need to be considered while extracting chronostratigraphic significance from δC data.

5 illus, 7 tables, 43 ref

012575   Ammanagi S;Poornima V;Sera A;Sunder R (NO, BiSS Research, 41A, 1A Cross, AECS 2nd Stage, RMV Extension, Bangalore-560 094) : Development of a digitally-controlled three-axis earthquake shake table. Curr Sci 2006, 91(2), 190-203.

Eight-actuator shake table was developed for evaluating specimen response under conditions that closely simulate actual earthquakes. The system contains a number of unique hardware and software features that considerably reduce the cost of earthquake simulation testing. These include single-ended actuator assemblies, contamination-insensitive servo-hydraulics and a robust DSP-based control and data acquisition system. Tests to simulate a number of three-axis earthquake time histories appear to suggest satisfactory table response.

11 illus, 3 tables, 9 ref

010526   Yadav S T;Dixit A J (Department of Agronomy, Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli 415 712) : Minimum temperature variation at Dapoli in Konkan region of Maharashtra. J Agrometeorol 2006, 8(1), 100-3.

Twenty years (1985-2004) daily data on minimum temperature of Dapoli, located in the Konkan region of Maharahstra at an altitude of 174 m above msl for the month December to January were collected and classified into various groups for interpretation. Result shows that the record of minimum temperature below 10°C occurred 93 times in the month of February and the minimum number (81) in December for the period of the study from 1985-2004. Among the extreme values, the lowest and highest minimum temperature were 3.4°C and 21.4°C recorded in January and February respectively. The CV varied from 22 to 44 per cent. Persistence in minimum temperature for one day was found to be maximum varied from 59.4 to 64.0 per cent. Analysis indicated that maximum numbers of cold wave occurred during December.

4 tables, 7 ref

010525   Thakur A K;Singh J K;Kumar A (Soil and Water Conservation Engineering Dep, College of Technology, G.B. Pant University of Agriculture and Technol, Pantnagar-263 145) : Optimal land use model to minimize soil loss in a Himalayan watershed. Indian J Soil Conserv 2006, 34(2), 114-7.

Attempt has been made to develop the optimal land use planning model to minimize soil loss in Chorgaliya watershed, balance on resource constraints such as land, water, labour opportunities and net return. The model was developed by using the linear programming technique considering only monsoon season. In order to make the model socially and economically acceptable to the people of the watershed, three alternative plans, viz., existing cropping pattern with restriction on crops preferred by farmers, existing cropping pattern with restriction on orchard trees, and existing cropping pattern with restriction on food grains were developed. The plan of existing cropping pattern with restriction on foodgrains was found to generate minimum soil loss.

3 tables, 7 ref

010524   Sudhishri S (NO, Central Soil and Water Conservation Research and Training Institute, R, PB 12, Sunabeda-763 002) : Development of station nomograph and intensity-duration frequency relations in eastern ghat high land zone of Orissa. J Agrometeorol 2006, 8(1), 72-6.

Rainfall data of 9 years of Semiliguda, Koraput (Orissa) of various durations were analyzed to develop rainfall intensity-duration-return period equation and nomograph for Eastern Ghat High Land Zone and discussed. The values of "a" and "b" were determined by using graphical method and those of "K" and "d" by least square method. The constants for this zone K, a, b and d were found to be 8.133, 0.1323, 0.54 and 1.2421 respectively.

3 illus, 1 table, 13 ref

010523   Selvi V;Singh D V;Sikka A K (Central Soil and Water Conseration Research and Training Institute, Re, , Udhagamandalam-643 004) : Utilities and limitations of remote sensing and GIS applications in micro-watershed planning: an experience in the Nilgiris. Indian J Soil Conserv 2006, 34(2), 123-8.

Integrated management of natural resources on watershed basis has been accepted as the most effective approach for sustainable production and development. Demonstrates the utilities and limitations of remote sensing and GIS applications for micro-watershed planning through the image map obtained on 1:12,500 scale, by processing and fusing the digital data from LISS-III and PAN sensors of IRS-ID for KG-4-1 Kuruthukuli watershed in Kundah basin of the Nilgiris district, Tamil Nadu. The geocoded image was subjected to visual interpretation. Slope map was generated from SOI toposheets (1:50,000) in GIS environment (ARC/INFO) and other thematic maps on land use, soils and cropping patterns were prepared in GIS after field verification. On the basis of these thematic maps together with information obtained from field visits and Participatory Rural Appraisal (PRA) exercises, watershed management plan was prepared for KG-4-1 watershed. The experience in using the image prepared on 1:12,500 scale has shown that precise spatial boundaries for different land uses could be obtained. However, this required large amount of field verification for micro-level planning, especially in a hilly watershed like that of the Nilgiris. In spite of the cost involved in procurement and processing of digital data, crucial factors apart from land use categories, which are needed for land use planning, like irrigation status, cropping status and land management conditions could not be obtained from the image map of KG-4-1 watershed processed at 1:12,500 scale. In order to generate water resource development plan for a micro-watershed in a hilly region, extensive field survey is required, especially for deciding the drainage line treatment measures as these are site specific. However, GIS is an ideal system to support watershed planning which is an integrative process, especially with the help of topological overlays of different thematic layers.

5 tables, 8 ref

010522   Sarma A A L N;Lakshmi Kumar T V (Department of Meteorlogy & Oceanography, Andhra University, Visakhapatanam, AP) : Studies on agroclimatic elements and soil wetness estimation using MSMR data. J Agrometeorol 2006, 8(1), 19-27.

Daily actual evapotranspiration, soil wetness and soil moisture adequacy are computed for the selected stations in Andhra Pradesh state for the monsoon period of 1999 to 2002 using the revised water balance model (Thronthwaite and Mather (1955)) from rainfall and potential evapotranspiration and are analysed in space and time. The daily brightness temperature data (BTD) is retrieved from the 6.6 GHz channel Multifrequency Scanning Microwave Radiometer (MSMR) of IRS-P4 satellite for the monsoon periods (June to August) of 1999 to 2001 and are compared with the soil wetness data. Correlation and regression analysis are made for the soil wetness and BTD for the footprints over Andhra Pradesh to point out the inverse relation between them.

5 illus, 1 table, 13 ref

010521   Sahoo D C;Sharda V N;Jayakumar M;Tripathi K P;Padmanabhan M V;Raghunath B;Mohanraj R;Chandran B (NO, Central Soil and Water Conservation Research and Training Institute, R, Udhagamandalam-643 004) : Hydrology of small watershed in high hills of Nilgiris. J Agrometeorol 2006, 8(2), 97-101.

Hydrological studies were conducted in three small watersheds viz., W₁, W₂A and W₂B having an area of 5.1, 5.7 and 19.8 ha under different management practices viz. with poor conservation measures (untreated), conservation measures (treated) and forest management, respectively to quantify the runoff, soil and nutrient losses. The results indicated that the land cover under perennial vegetation of shola forests reduced the runoff by 55%, and land cover under annual crops with proper soil and water conservation measures reduced runoff by 52.4% as compared to untreated watershed without any conservation measures. The base .flow component of total runoff was highest in the watershed under shola forest (73.6%) followed by watershed treated with soil and water conservation measures (68.5%) and lowest under untreated watershed (31.9%). The surface flow component reduced by 71% and 77% in the watershed W₂A and W₂B, respectively as compared to watershed W,. The soil loss was negligible in watershed W₂A and nil for W₂B. The loss of nutrients was higher under untreated watershed as compared to treated and forest watershed.

2 illus, 3 tables, 7 ref

010520   Saha R;Mishra V K (Division of Water Mangement, ICAR Research Complex for NEH Region, Umiam, Meghalaya-793 103) : Estimation of profile moisture status from surface moisture in hilly slopes of Meghalaya. J Agrometeorol 2006, 8(1), 81-6.

Water surplus and deficit periods were detected based on climatic water balance for 1993-2002 in upland terrain soil of Meghalaya state, India. Results indicated that June to October were the major part of water surplus periods contributing to 90.5 per cent of annual water surplus. The mean monthly water surplus (1016.6 mm) and deficit periods (311.8 mm) indicated that water surplus in this region is too high as compared to water deficit. The linear relationship between surface (0-15 cm) and profile (0-90 cm) water content has been drawn based on their differential behaviours under water surplus and deficit periods with high correlation coefficients (0.905 and 0.921, respectively).

2 illus, 1 table

010519   Ramesh Singh;Prasad S;Sharma H C;Ambrish Kumar (Irrigation and Drainage Engineering Dep, College of Technology, GBPUAT, Pantnagar-263 145) : Determination of station weights using GIS techniques. Indian J Soil Conserv 2006, 34(2), 170-1.

1 illus, 1 table, 3 ref

010518   Meshram D T;Bagle B G;Apparao V V (Central Horticultural Experiment Station, (CIAH-ICAR), , Vejalpur-389 340) : Estimation of surface runoff, using SCS model from micro watershed in semi arid region. J Agrometeorol 2006, 8(1), 77-80.

Soil Conservation Service model, has been applied for the estimation of surface run-off in a micro-watershed 3.38 Km² of semi-arid region located in the Mahi river basin in Panchmahals district of Gujarat state. The thematic map i.e. land use/cover, drainage and hydrological soil group have been prepared by actual ground truth to derive the modified run off curve number. The SCS model was then applied to estimate the surface run off and compare with the measured run off of five events of monsoon, year 2004. The deviation ranged between 4 to 7 per cent.

2 illus, 2 tables, 6 ref

010517   Karunakaran N;Ravichandran S (Centre Water Resources, Anna University, Chennai-600 025) : Estimation of soil erosion in Krishnagiri reservoir catchment of Ponnaiyar basin in Tamil Nadu. Indian J Soil Conserv 2006, 34(2), 110-3.

Soil erosion in the Krishnagiri reservoir catchment of Ponnaiyar basin in Tamil Nadu was estimated using Revised Universal Soil Loss equation (RUSLE). Soil loss was estimated spatially at sub-watershed level and different classes of erosion zones in the catchment were mapped in the Maplnfo environment with Vertical Mapper. The severely eroded zones in the catchment comprised of 40% area, but accounted for 80% of the total soil loss (5328000 t). The middle and lower part of Markandanadhi (68 t ha^-1yr^-1), the Veppanapalli watershed (62 t ha^-1yr^-1) and Nachikuppam watershed (64 t ha^-1yr^-1) were found to be most severely eroding zones of the catchment where the maximum rate of erosion was observed upto 149 t ha^-1yr^-1.

3 illus, 3 tables, 18 ref

010516   Chakraborty P B;Majhi D;Das S (NO, Bidhan Chandra Krishi Viswavidyalaya, Regional Research Station (CSZ), Kakdwip-743 347) : Estimation of weekly runoff for Sundarban delta. Indian J Soil Conserv 2006, 34(2), 106-9.

Daily rainfall data of Sundar ban delta for the period of 1986-2001 were used to estimate weekly runoff using curve number method. The relationship between weekly runoff and rainfall for 23rd-45th weeks were analysed and found significantly linear. Further, analysis revealed the similBttrend at 5.88,17.64,47.05,76.47 and 88.23% levels of probability. However, the best fit linear regression equations were emerged to predict runoff successfully from weekly total rainfall and most of the equations were found to explain more than 90% of the variables. Ultimately a nomograph to predict weekly runoff has been developed for Sundarban delta.

3 illus, 3 tables, 7 ref

009554   Srivastava G P;Shukla M;Prabhat Kumar;Madhav Kumar;Anand Prakash (NO, Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow-226 007) : Record of pillbug Armadillidium and millipede (Polyxenus) remains from the resin lumps of Warkalli formation (Upper tertiary), Kerala coast. J Geol Soc India 2006, 67(6), 715-9.

Remains of Pillbug and millipede from the resin lumps associated with the Tertiary sediments, Kerala coast arc reported for the first time. These remains have been described as Armadillidium payangadensis sp. nov. and Polyxenus miocenica sp. nov. The resin lumps containing Arthropod remains are found associated with the Tertiary deposits (Warkalli Formation) exposed at several places along Kerala Coast. The fossil bearing resin lumps have been collected from Payangadi China Clay mine, Cannanore, Kerala.

^ssc4 illus, 15 ref

009553   Sriniwas;De Lima O A L (Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee-247 667) : Correlating electrical and hydraulic conductivity of a general aquifer model: concept and applicant. J Geol Soc India 2006, 67(6), 730-6.

There are physical similarities between hydraulic conductivity and electrical conductivity in a porous and permeable medium. In the study mathematical equations are developed to estimate hydraulic aquifer property from surface electrical measurements. A general three-layer aquifer model is proposed to show that on macro scale if the third (basement) layer is highly resistive in comparison to second (aquifer) layer there would be direct relationship between hydraulic and electrical conductance whereas in case of relatively conducting third layer there would exist a direct relation between hydraulic conductance and electrical resistance. A method is suggested to reliably estimate the electrical conductance or electrical resistance, as the case may be of the aquifer layer directly from VES data. Two numerical examples are also included. It is shown with field examples that in case of conducting substratum the hydraulic conductance can be approximated with electrical resistance. However, if hydraulic conductivity is known at few points, this estimation may be improved considerably. An example of this type is included to prove our point.

2 tables, 50 ref

009552   Singh M P;Singh A K (Department of Geology, Banaras Hindu University, Varanasi-221 005, Email: mpsingh02@yahoo.co.in) : Morphology, maceral association and distribution of pyrite in the tertiary coals of Northeast India: a proposal for the classification of high sulphur coals. J Geol Soc India 2006, 67(6), 783-801.

This paper is an attempt to focus on the micro-morphological characterization of pyrite and its quantitative distribution in the Tertiary coal deposits of Northeast India with the help of improved incident light microscopic techniques. The coal deposits of this region occur in the states of Meghalaya, Assam, Arunachal Pradesh and Nagaland, and are known to have originated in two distinct tectono-sedimentary settings. The coal bearing sequences of Meghalaya are Eocene in age and have evolved over platform areas under stable shelf conditions. On the other hand, the coal deposits of Assam, Arunachal Pradesh and Nagaland are Oligocene in age and have originated in the foreland basins. Pillar coal samples from all the coal seams (Measuring a metre or more in thickness), either exposed as outcrops or in mine workings, have been subjected to the study. A classification scheme for the pyrite rich coals has been framed using size of pyrite forms (irrespective of type) and their quantitative occurrence as parameters. This classification would be helpful in characterizing coals with high pyrite content and can be used as a tool to decide the optimum particle size of a particular coal for the efficient liberation of pyrite.

10 illus, 9 tables, 28 ref

009551   Sahu P C;Sahoo H (PG Department of Geology, Khallikote Autonomous College, Berhampur-760 001) : Targeting ground water in tribal dominated bonai area of drought-prone Sundargarh district, Orissa, India - a combined geophysical and remote sensing approach. J hum Ecol 2006, 20(2), 109-15.

Remote Sensing technique is being utilized presently as an indispensable tool for ground water exploration, which is both time and cost effective in contrast to conventional costly and tedious methods. The study has been for targeting ground water in hard rock terrain by adopting Geophysical and Remote Sensing techniques. Information on geomorphology and lineaments were generated and integrated to prepare the hydro-geomorphological and lineament map of the study area. The hydro-geomorphic units like alluvial plains, intermontane valleys and deeply weathered buried pediplains have good ground water potential; and shallow weathered buried pedipiains and pediments have moderate to poor groundwater potential. The structural hills, denudational hills, residual hills and inselbergs are indicated as runoff zone. Fracture trace analysis of the area further strengthens the fact that the better yields are expected in the areas traversed by NE - SW trending lineaments. Further, the areas of intersection points of lineaments in pediplain, alluvial plain and intermontane valleys are important loci for ground water occurrence. Vertical Electrical Sounding (VES) studies reveal that the thickness of the aquifer (i.e. water bearing and yielding formation) ranges from 30 to 60m in hydro-geomorphic units like alluvial plain, Intermontane valleys and deeply weathered buried pediplain. The weathered, semi-weathered and fractured zone constitute the aquifer system in the area. The prominent fractures zone are restricted within a depth range of 60 to 70 m below the ground level. Depending upon the depth to massive bedrock, suitable ground water structures have been suggested to harness ground water for sustainable growth of agriculture and mitigating drinking water problem in tribal dominated drought - prone Bonai area of Sundargarh District, Orissa, India.

3 illus, 4 tables, 17 ref

009550   S Chandra;S Atal;Murthy N S K;Subrahmanyam K; Rangarajan R;Reddy D V;Nagbhushanam;Dimri V P (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: shakeelahmed@ngri.res.in) : Oozing of water in parts of Andhra Pradesh, India. Curr Sci 2006, 90(11), 1555-60.

Oozing of water and rise in water level were reported by villagers and media during the third week of January 2005, in parts of Rangareddy, Nalgonda and Mahboobnagar districts of Andhra Pradesh. The event also coincided with the aftermath of the 9.3 magnitude earthquake in Sumatra, Indonesia and the tsunami in the Indian Ocean. The villagers and State and Central agencies were baffled by the unusual phenomenon. After a general reconnaissance, an integrated study comprising water-level monitoring, water quality analyses, topography survey, isotopic analyses, mise-a-la-masse survey and electrical resistivity imaging (ERI) was carried out at two sites near Mukindapur and Devanur of Yalal mandal in Ranga Reddy district, where the phenomenon of water-oozing was observed. The integrated study revealed that the oozing of water at the studied location is purely hydrological/hydro-geological and a shallow phenomenon. Scientific data could not attribute any strong connection to the deeper tectonics nor to the impact of the Sumatra earthquake and aftershocks. However, investigations form a prelude to any such geogenic activity in the region, suggesting monitoring of water level and further studies during the current hydrological year for any definite conclusion.

5 illus, 1 table, 14 ref

009549   Pant R K;Juyal N;Basavaiah N;Singhvi A K (Physical Research Laboratory, , Navrangpura, Ahmedabad-380 009, Email: navin@prl.ernet.in) : Late quaternary glaciation and seismicity in the higher central Himalaya: evidence from Shalang basin (Goriganga), Uttaranchal. Curr Sci 2006, 90(11), 1500-5.

Shalang basin, which is a tributary basin of the Goriganga in the higher central Himalaya, is endowed with record of late Quaternary glaciation and seismicity. Three distinct glaciation events in the form of lateral moraines have been identified and are used to reconstruct the palaeo-Equilibrium Line Altitudes (ELA). Maximum ELA depression (<126> 600 m) was associated with the oldest and longest Stage-I glaciation. Subsequent glacial advancements were limited in extent and remained above 3500 m. Luminescence dating of glaciogenic sediments suggests that the oldest Stage-I glacial event is equitable to Marine Isotopic Stage-4 (MIS-4), whereas stages-II and III are assigned MIS-2 and little ice age respectively. Morphology of the moraines and presence of seismites in a lake sequence suggest tectonic activity along the Trans-Himadri Fault during the late Quaternary.

9 illus, 1 table, 23 ref

009548   Paliwal B S (Department of Geology, Jai Narain Vyas University, Jodhpur-342 005, Email: paliwalbhawani@yahoo.co.in ) : Magnetic spherules with metallic shine in the recent alluvium of Rajasthan. J Geol Soc India 2006, 67(6), 709-14.

Magnetic spherules with metallic shine ranging from a fraction of millimeter to one millimeter in size have been discovered from red coloured ferruginous soils of Quaternary period at a large number of places in western Rajasthan. Occurrence of these magnetic spherules at far away places, in the red coloured ferruginous sandy loam that overlies the Mesoproterozoic metasediments of Delhi Supergroup, the Neoproterozoic rocks of Malani Igneous Suite and sediments of Marwar Supergroup, is quite significant, especially, in view of the inferred association of magnetic spherules with the intense volcanic activity, melting of inter planetary dust, ablation of meteorites and impact of extra terrestrial bodies like the one that possibly hit the earth and caused the mass extinction at K-T boundary.

^ssc9 illus, 2 tables, 16 ref

009547   Nath S;Bhattacharyya C (Department of Geology, University of Calcutta, Kolkata-700 019, Email: cbbhattacharyya@yahoo.com) : Petrology and geochemistry of amphibolites around Kuilapal, West Bengal, Eastern India. J Geol Soc India 2006, 67(6), 748-58.

Abundant small lenses and bands of different types of amphibolites belonging to amphibolite facies occur within Proterozoic (1638±38 Ma) Kuilapal granitoid gneiss body (12.8 Km x 6.4 Km) and outside it in the metapelitic country. The different petrographic types are: (A) Pl-hb-Mc amphibolite, (B) Ap-mt-hb-M amphibolite, (C) Monomineralic hb-UM amphibolite, (D) Tr-act-UM amphibolite and (E) Mi-hb-MC amphibolite. Petrographic and geochemical studies suggest that all these types of amphibolites except (E) are orthoamphibolites which are similar in chemical composition to tholeiitic ferrobasalt and exhibit trace element characters corresponding to ocean floor basalt. The parent basaltic magma for these amphibolites appears to show signature of a magmatic history connected with Dalma basalts derived from iron-enriched mantle source. However, the parent basaltic magma of the Kuilapal area, in all probability represents an earlier phase of basic magmatism than Dalma basalt (1547±20 Ma). The age of emplacement of ferrotholeiitic magma in the present area should be earlier than 1638±38 Ma, which is the age of Kuilapal granitoid rocks. The chemical composition of tractinolite amphibolite, ap-mt-hb amphibolite and pl-ap-mt-hb amphibolite have similarity with such igneous rocks as pyroxenite, ap-mt pyroxenite and gabbroic rocks respectively. The type (E) amphibolite represents metamorphosed impure marly sediment. EPMA data of hornblendes show systematic increase of Si and Mg and decrease of Fe from almandine zone to sillimanite zone metamorphism. Hornblende-plagioclase geothermometry suggests the variation of temperature from about 730°C to 795°C from garnet/staurolite to sillimanite zone.

10 illus, 6 tables, 25 ref

009546   Murthy K S R;Subrahmanyam A S;Murty G P S; Sarma K V L N S;Subrahmanyam V;Mohana Rao K;Suneetha Rani P;Anuradha A;Adilakshmi B;Sri Devi T (NO, National Institute of Oceanography, Regional Centre, 176, Lawsons Bay, Visakhapatnam-530 017, Email: ksr@nio.org) : Factors guiding tsunami surge at the Nagapattinam-Cuddalore shelf, Tamil Nadu, east coast of India. Curr Sci 2006, 90(11), 1535-8.

Tamil Nadu margin, in particular the Nagapattinam-Cuddalore shelf was the worst affected by the tsunami surge and inundation caused by the great Sumatra earthquake of 26 December 2004 (M_w 9.3). Surge heights in this part were of the order of 2 to 5 m, with inundation of the order of few hundred metres into the interior coast, thus causing huge loss of human life and property. Several reasons were attributed to the unusual surge in this part of the Tamil Nadu margin, the main reason being its relative proximity to the origin of the event, apart from the concave nature of the shelf with a gentle gradient. A detailed analysis of geophysical data of the Nagapattinam-Cuddalore shelf is presented. The results indicate that the structure of the underlying basement, the morphology and the land-ocean tectonics are the main guiding factors for the run-up heights in case of the Nagapattinam-Cuddalore shelf. The fault-controlled basement structure, and a straight coastline with narrow and gentle shelf have helped in rapid transgression of the surge inundating the coastal area.

3 illus, 18 ref