022625   Jetty J;Rao K S P;Satyanarayana K (Dep of Civ Engng, Osmania Univ, Hyderabad-500 007) : Geology and geochemistry of the Archaean meta basalts from the central part of Ramagiri schist belt, Andhra Pradesh, India. J appl Geochem 2005, 7(1), 90-9.

Archaean meta-basalts from the central part of Ramagiri schist belt are studied. The belt consists predominantly of meta-volcanics with thin sedimentary intercalations in a granitoid country rock. The meta-basics are represented by relatively high-grade schists and hydrothermally-altered varieties. Chemically, they represent low potassium tholeiite and follow an iron-enrichment trend, characteristic of non-calc-alkalic suites. Based on composition, an island-arc tectonic setting was inferred for these rocks. The data indicates that the volcanics were derived by partial melting of highly evolved Archaean mantle.

6 illus, 4 tables, 15 ref

022624   Jat M L;Singh R V;Balyan J K;Jain L K;Sharma S K (NO, Dryland Fmg Res Stn, Arjia, Bhilwara, Rajasthan) : Drought climatalogy of Western Rajasthan. Curr Agric 2005, 29(1-2), 29-35.

Frequency and intensity of drought of various categories in western Rajasthan for four stations were studied for 15 years period. Reference evapotranspiration, weekly water balance, departure of aridity index (Ia) from the median were computed. Results revealed that droughtiness factor increases with increase in mean aridity. One moderate drought year was experienced at Jodhpur whereas Fatehpur and Pali each had 2 moderate drought years and Sriganganagar experienced 3 moderate drought years. The maximum five large drought years were experienced at Jodhpur and minimum two large droughts experienced at Sriganganagar. The frequency of occurrence of severe drought years varied from one at Jodhpur and Fatehpur to two each at Sriganganagar and Pali. Year 1987 experienced severe drought at all the station expert at Fatehpur where it experienced moderate drought.

3 illus, 4 tables, 8 ref

022623   Hussain S M;Sunder Raju P V (Natn Geophys Res Inst, , Hyderabad-500 007, Email: pvsraju@ngri.res.in) : High chromium content in the ultramafic rocks, NW of Arsikere, Karnataka. J appl Geochem 2005, 7(1), 111-6.

Platinum group of elements and some noble metals occur in the Archaean mafic-ultramafic rocks containing chromite and occurring near shear zones. Unusual high concentrations of PGE in serpentine-talc-actinolite bearing chromitite were found in the linear detached ultramafic pods NW of Arsikere, east of a major lineament (Bababudan-Nallur). Distribution of chromite grains in amphibole and associated matrix is reported along with mineral analyses.

4 illus, 2 tables, 8 ref

022622   Hoque A;Aoki S I (Dep of Math, Univ of Rajshahi, Rajshahi-6205, Email: ashabulh@yahoo.com) : Air entrainment by breaking waves. Indian J Mar Sci 2006, 35(1), 17-23.

Variation of static pressure, density, potential energy and kinetic energy due to air bubble entratainment in the surf zone and their physical mechanisms have been studied theoretically. An averaging technique has been used to investigate the behavior of every single bubble in the bubble cloud. The above parameters have been found to be affected significantly by the entrained air bubbles.

7 illus, 12 ref

022621   Folk R L (Dep of Geosciences, Univ of Texas, Austin, Texas, USA) : Nannobacteria and the formation of framboidal pyrite: textural evidence. J Earth Syst Sci 2005, 114(3), 369-74.

Study of sedimentary pyrite in the form of framboids, euhedral crystals or metasomatic masses has revealed that their surfaces are commonly covered with spheroids of about 50 nm. This applies to all the examples studied, from modern to Proterozoic. These spheroids are interpreted as the pyritized corpses of nannobacterial cells; if correct, this indicates that precipitation of iron sulfide was performed by these dwarf forms of bacteria, often associated with decaying organic matter.

12 illus, 42 ref

022620   Dogra A S;Sharma J;Grewal S S (NO, Punjab Agric Univ Zonal Res Stn for Kandi Area, Ballowal Saunkhri, P.O. Takarla-144 521) : Participatory process development in watershed projects-An implementation experience of Punjab Shivaliks. Indian J Soil Conserv 2005, 33(3), 238-42.

The Shivalik foothills constitute one of the eight most degraded rainfed ecosystems of India, where an Integrated Watershed Development Project (IWDP) with financial outlay of Rs. 3.05 billion was launched during 1992. The main objective was to reverse the trend of environment degradation, improve productivity and alleviate poverty adopting watershed based conservation and production technologies. The package included afforestation, soil and water conservation, water resources development, forage production, livestock improvement, stabilizing rainfed agriculture and horticulture in priority watersheds. As usual, lack of sufficient community participation remained the weakest link in achieving project objectives when first phase concluded in four northern states in 1999. In the second phase (1999-2005), participatory process development was, therefore, given the topmost priority. The rural communities were mobilized by forming Village Development Communities (VDCs). Womens Self Help Groups (SHGs) and User Groups. Significant advances were made in generation of savings and enlisting participation of communities in the preparation of development plans and implementation of activities. The VDCs were encouraged to execute works themselves. The social funds generated by the VDCs were used to give loans to the fellow poors. The SHGs also started advancing loans to their members for income generating activities (IGA). As a part of horizontal linkage credit flow from rural development banks was started. The women gained confidence to start IGA and taking bold and innovative decisions. The project staff addressed the conflicts between the nomads and the poor residents. The needs of the poor dependent on natural resources were adequately addressed by promoting a range of livelihood activities. Most of the strategic tools like entry point activities, transparency, envisioning, cost sharing, community organization, capacity building, conflict resolution, gender sensitivity and equity were institutionalized to promote participatory process. Sharing the experience of this bold initiative of social mobilization, it is concluded that the project interventions are sustainable only if people are actively involved and put at the centre of the planning and implementation process.

2 tables, 12 ref

022619   Deb S P (Geol Stud Unit Indian Statistical Inst 203, , B.T. Road, Kolkata-700 108, Email: sarbani@isical.ac.in ) : Tidal shelf sedimentation in the Neoproterozoic Chhattisgarh succession of Central India. J Earth Syst Sci 2005, 114(3), 211-26.

Neoproterozoic Kansapathar Sandstone of the Chattisgarh basin, a shallow marine shelf bar sequence, consists of mineralogically and texturally mature sandstones with subordinate siltstones, mudstones and conglomerates. The sediments were transported, reworked and deposited in subtidal environments by strong tidal currents of macrotidal regime as well as storms, and accumulated as discrete shoaling-upward features, separated from each other by muddy to low-energy sandy deposits. The sandbodies developed into shoaling up linear bars, often more than a kilometre in length, through accretion of thick cross-stratified units in transverse directions under the influence of ebb and flood tidal currents, as well as in longitudinal direction affected by southeasterly flowing along-shore currents. The aggrading upper surfaces of the bars experienced protracted reworking by strong oscillatory wave currents leading to extensive development of subaqueous 2D or 3D dunes mantled with lag pebble deposits at different points. With continued shoaling and progradation, the bars amalgamated into large sandstone sheets with the development of high energy beach deposits and coastal sand flats in the uppermost part of the sequence. The presence of rill marks, flat-topped ripples, wrinkle marks, desiccation cracks and adhesion warts point to intertidal conditions with intermittent exposure. The high energy sandstone bars overlie a thick mudstone-dominated shelf sequence across a sharp interface indicating rapid change in the sea-level, provenance, rate of sediment generation and sediment input, and circulation condition in the shelf. A quiet muddy shelf was replaced by a major sand-depositing environment with strong, open marine circulation. An interplay of tidal currents, oscillatory wave currents and storm currents generated a complex flow pattern that varied in time and space from bimodal-bipolar to strongly unimodal flows. Close parallelism of wave ripple crests, trend of linear bars and unidirectional flows suggest that the elongate bars were parallel to sub-parallel to the coastline, and were strongly influenced by along shore drift. The inferred coastline was broadly N-S. The large-scale structures in the bar sandstones, emplacement of vast amount of sand and migration of large bedforms under strong macrotidal currents collectively indicate that the Kansapathar shelf was intimately connected with an open ocean basin towards north-northwest.

16 illus, 1 table, 53 ref

022618   Datta B (NO, , 3, Bidhan Sarani, Kolkata-700 006) : Provenance, tectonics and plaeoclimate of proterozoic Chhandarpur sandstones, Chhattisgarh basin: a petrographic view. J Earth Syst Sci 2005, 114(3), 227-45.

Sandstones of early Neoproterozoic Chandarpur Group, Chattisgarh Supergroup, central India display progressive change towards greater textural and mineralogical maturity from base to top of the succession. The clay-silt matrix decreases, sorting of sand grains improves, frequency of rounded grains increases, monocrystalline quartz content increases with concomitant decrease in polycrystalline quartz, feldspar and rock fragments. The trend of variations in different mineralogical and textural attributes, however, exhibits inflections at different stratigraphic levels. The sandstones of the basal Lohardih Formation are alluvial fan deposits, characterized by high matrix and feldspar content, iron-oxide impregnated highly angular grains and poor sorting. Petrographic properties collectively indicate that the sandstones were derived from a weathered granitic crust under a humid climatic condition. Abundance of well rounded grains within the alluvial fan and overlying braided fluvial deposit indicates prolonged wind action during episodes of high aridity. The shallow marine deposit overlying the fluvial deposits in the upper part of the Lohardih Formation exhibits bed-to-bed variation in the frequency of angular grains, feldspar content and overall maturity suggesting environmentally controlled segregation of sediments. The abrupt appearance of coarse-grained immature sandstones with concomitant reappearance of iron-oxide impregnated/altered feldspar grains in the upper part of the shelf deposits of the Chaporadih Formation point to a phase of tectonic uplift that possibly triggered a regression. Continued regression and peneplanation heralded the deposition of supermature medium-grained purple quartzarenite of the upper shoreface Kansapathar Formation in the uppermost part of the Chandarpur succession under a hot desertic climatic condition. The provenance analysis revealed that the Chandarpur elastics were derived from granites and granite-gneisses of a continental block tectonic provenance. Petrographic studies further indicate that high grade metamorphic rocks did not make any perceptible contribution to the Chandarpur system. The Eastern Ghats Granulite Belt apparently did not emerge till the early Neoproterozoic.

17 illus, 4 tables, 67 ref

022617   Dass A;Patnaik U S;Sudhishri S (NO, Cent Soil and Wat Conserv Res and Training Inst Res Cent, P.B.No 12, Sunabeda-763 002) : Effective utilization of jhola water for crop diversification in Kokriguda watershed-A case study. Indian J Soil Conserv 2005, 33(3), 243-7.

In the Eastern Ghats of Orissa, 'Jhola' lands, the wide and stabilized gully beds transformed in to terraces hold vast potential for intensive cultivation due to perenniality of water supply but unexploited presently. In Kokriguda model watershed, a representative of the region, efforts were made to find out most promising crops and cropping systems jhola lands, saria lands and the adjoining medium lands by using jhola water to augment productivity and income, In Jhola lands, rice-rice system recorded the grain yield of 1 7.2 q ha^-1 during pre-project period, increased to 25.4 q ha^-1 during final year of the project with increase in net returns ot Rs.5001 to Rs. 10225 ha^-1. Traditional rice-fallow system with net returns of Rs. 4453 during pre-project increased to Rs. 7305 ha^-1 during the fourth year was considerably inferior to rice-rice sequence. In saria land, rice-cucumber gave higher paddy equivalent yield and net returns than rice-tomato sequence. Both of these systems, however, yielded six to seven folds more net returns than jhola's rice-rice sequence. In medium lands irrigated with diverted jhola water, chilli with net returns of Rs.65173 ha^-1 was most remunerative followed by brinjal (Rs. 43667 ha^-1).

4 tables, 5 ref

022616   Dasgupta P (Dep of Geol, Presidency Coll, 86/1 College Street, Kolkata-700 073, Email: pdggeopc@cal13.vsnl.net.in) : Facies pattern of the middle permian barren measures formation, Jharia basin, India: The sedimentary response to basin tectonics. J Earth Syst Sci 2005, 114(3), 287-302.

Lower Gondwana succession of the Jharia basin of eastern India, the Barren Measures Formation is characterized by the cyclic disposition of fine-grained lacustrine deposits and relatively coarse-grained fluvial deposits. The cyclic variation in the rate of coarse clastic input is attributed to the sedimentary response to basin tectonics. The sandstone-shale alternations of the Barren Measures succession can be correlated with the tectonic cyclothems developed on the hangingwall dip-slope and adjoining trough in a continental half-graben setting. Enhancement of the gradient of the hangingwall dip-slope during reactivation of the basin margin faults led to progradation of the existing fluvial system towards the half-graben trough and deposition of the coarser elastics on the fine-grained lacustrine deposits of the trough. Peneplanation of the hangingwall slope and slow increase in the lake level caused lacustrine transgression and retrogration of the fluvial system on the hangingwall block. The fluvial sediments were onlapped by the fine-grained lacustrine deposits. Episodic rejuvenation of the basin margin faults thus caused development of tectonic cyclothem on the hangingwall block. The paleocurrent pattern indicates that a persistent north ward paleoslope was maintained during Barren Measures sedimentation. The inferred depositional settings were much more extensive than the present limit of the outcrop. The faults, presently defining the northern limit of the Barren Measures Formation, were possibly emplaced after Barren Measures sedimentation. The final movement along these fault planes caused preservation of the downthrown hangingwall block and the Barren Measures sediments on the footwall block were eroded during subsequent denudation. The Southern Boundary Fault came into existence after the deposition of the Barren Measures sediments.

13 illus, 2 tables, 38 ref

022615   Das N K;Bhandari R K;Ghose D;Sen P;Sinha B (NO, Variable Energy Cyclotron Cent, l/AF, Bidhan Nagar, Kolkata-700 064) : Anomalous fluctuation of radon, gamma dose and helium emanating from a thermal spring prior to an earthquake. Curr Sci 2005, 89(8), 1399-1404.

Anomalous large-scale radon emission, striking high gamma dose rate and significant increase in He/CH₄ ratio have been observed in thermal spring emanations at Bakreswar, West Bengal prior to the recent major earthquake near the island of Sumatra, Indonesia. An attempt has been made to correlate the field observations as the precursory phenomena to the quake.

4 illus, 28 ref

022614   Chaudhuri A K (NO, Geol Stud Unit Indian Statistical Inst, Kolkata-700 108, Email: asru41@rediffmail.com) : Climbing ripple structure and associated storm-lamination from a Proterozoic carbonate platform succession: Their environmental and petrogenetic significance. J Earth Syst Sci 2005, 114(3), 199-209.

Mesoproterozoic Pandikunta Limestone, a shallow water carbonate platform succession in the Pranhita-Godavari Valley, south India, displays well developed climbing ripple lamination and storm deposited structures, such as HCS, wave ripple-lamination, combined-flow ripple-lamination and low angle trough cross-stratification. Different types of stratification developed in calcisiltite with minor amounts of very fine quartz sand and silt. The climbing ripple structures exhibit a complex pattern of superposition of different types (type A, B and S) within cosets pointing to a fluctuating rate of suspension deposition versus bedform migration, and an unsteady character of the flow. Close association of climbing ripple structures, HCS with anisotropic geometry, wavy lamination and combined-flow ripple-lamination suggest that the structures were formed by storm generated combined-flow in a mid-shelf area above the storm wave base. The combined-flow that deposited the climbing ripple structures had a strong unidirectional flow component of variable magnitude. The climbing ripple structure occurs as a constituent of graded stratified beds with an ordered vertical sequence of different types of lamination, reflecting flow deceleration and increased rate of suspension deposition. It is inferred that the beds were deposited from high-density waning flows in the relatively deeper part of the ancient shelf. The structures indicate that the Pandikunta platform was subjected to open marine circulation and intense storm activities. The storm deposited beds, intercalated with beds of lime-mudstone, consist primarily of fine sand and silt size carbonate particles that were hydrodynamically similar to quartz silt. Detrital carbonate particles are structureless and are of variable roundness. The particles were generated as primary carbonate clasts in coastal areas by mechanical disintegration of rapidly lithified beds, stromatolites or laminites, and the finest grade was transported to the offshore areas by storm-generated currents.

12 illus, 1 table, 49 ref

022613   Chakraborty T;Sarkar S (NO, Geol Stud Unit Indian Statistical Inst, 203 B.T. Road, Kolkata-700 108, Email: tapan@isical.ac.in) : Evidence of lacustrine sedimentation in the upper permian bijori formation, Satpura Gondwana basin: palaeogeographic and tectonic implications. J Earth Syst Sci 2005, 114(3), 303-23.

Upper Permian Bijori Formation of the Satpura Gondwana basin comprising fine- to coarsegrained sandstone, carbonaceous shale/mudstone and thin coal bands was previously interpreted as the deposits of meandering rivers. The study documents abundance of wave ripples, hummocky and swaley cross-stratification and combined flow bedforms in the Bijori Formation, suggesting that a significant part of the formation was deposited in a wave-agitated environment. Evidence of near-emergent depositional conditions provided by repeated occurrence of rootlet beds and hydromorphic paleosols, local flooding surfaces denoting rapid fluctuation of water level, occurrences of temnospondyl vertebrate fossils, and absence of tidal signatures and marine fossils suggest a lacustrine rather than marine depositional regime. Five facies associations recognised within the Bijori Formation are inferred to represent fluvial channels and associated floodplains (FA1), lake shorelines (FA2), subaqueous distributary channels and associated levees (FA3), wave- and storm-affected delta front (FA4), and open lacustrine/lower shoreface (FA5) deposits. The plano concave fluvial channel-fill sandbodies with unidirectional cross-beds are clearly distinguishable from the delta front bars that show a convexo-plan or bi-convex sandbody geometry and dominance of wave and combined flow bedforms. Some of the distributary channels record interaction of fluvial and wave-dominated basinal processes. Major distributary sandbodies show a north to northwest flow direction while wave-affected delta front sandbodies show very complex flow pat terns reflecting interaction between fluvial discharge and wave processes. Wave ripple crest trends show that the lake shoreline had an overall east-northeast to west-southwest orientation. The lack of documented contemporaneous lacustrine or marine sediments in the Satpura Gondwana basin posed a major problem of basin-scale palaeogeographic reconstruction. The existence of Bijori lake solves the problem and the lake is inferred to have acted as repository for the contemporaneous alluvial drainage. Development of the large Bijori lake body implies generation of accommodation space exceeding the rate of sediment supplied and thus represents locus of high tectonic subsidence. Transition of fluvial sediments with red mudstone and calcareous soil profile in the lower part of the succession to carbonaceous shale and coal-bearing lacustrine sediments in the upper part, denote a change from a warm semi-arid climate with seasonal rainfall to a more humid one.

18 illus, 3 tables, 63 ref

022612   Chakraborty C;Ghosh S K (NO, Geol Stud Unit Indian Statistical Inst, 203, B.T. Road, Kolkata-700 108, Email: chandan@isical.ac.in) : Pull- apart origin of the Satpura Gondwana basin, Central India. J Earth Syst Sci 2005, 114(3), 259-73.

Gondwana basins of peninsular India are traditionally considered as extensional-rift basins due to the overwhelming evidence of fault-controlled synsedimentary subsidence. These basins indeed originated under a bulk extensional tectonic regime, due to failure of the attenuated crust along pre-existing zones of weakness inherited from Precambrian structural fabrics. However, disposition of the basins and their structural architecture indicate that the kinematics of all the basins cannot be extensional. To maintain kinematic compatibility with other basins as well as the bulk lateral extension, some basins ought to be of strike-slip origin. The disposition, shape and structural architecture of the Satpura basin, central India suggest that the basin could be a pull-apart basin that developed above a releasing jog of a left-stepping strike-slip fault system defined by the Son-Narmada south fault and Tapti north fault in consequence to sinistral displacement along WSW-ENE. Development of a sedimentary basin under the above-mentioned kinematic condition was simulated in model experiments with sandpack. The shape, relative size, stratigraphic and structural architecture of the experimental basin tally with that of the Satpura basin. The experimental results also provide insights into the tectono-sedimentary evolution of the Satpura basin in particular and pull-apart basins in general.

9 illus, 1 table, 36 ref

022611   Chakrabarti A (NO, , 23A P.G. M. Shah Road, Kolkata-700 033, Email: tidalgobin@yahoo.co.uk) : Sedimentary structures of tidal flats: A journey from coast to inner estuarine region of Eastern India. J Earth Syst Sci 2005, 114(3), 353-68.

Sedimentary structures of some coastal tropical tidal flats of the east coast of India, and inner estuarine tidal point bars located at 30 to 50 kilometers inland from the coast, have been extensively studied under varying seasonal conditions. The results reveal that physical features such as flaser bedding, herringbone cross-bedding, lenticular bedding, and mud/silt couplets are common to both the environments. In fact, flaser bedding and lenticular bedding are more common in the point bar facies during the monsoon months than in the coastal tidal flat environments. Interference ripples, though common in both the environments, show different architectural patterns for different environmental domains. Interference ripples with thread-like secondary set overriding the earlier ripple-form, resembling wrinkle marks, are the typical features in estuarine point bars near the high water region. Because structures which are so far considered as key structures for near-coastal tidal flats are common to both the environments, caution should be exercised for deciphering palaeo-environments, particularly for Proterozoic rocks, where one has to depend only on physical sedimentary structures.

28 illus, 1 table, 37 ref

022610   Bhattacharya P M;Pujol J;Majumdar R K;Kayal J R (Cent Geophysics Div, Geol Surv of India, 27, J. L. Nehru Road, Kolkata- 700 016) : Relocation of earthquakes in the northeast India region using joint hypocentre determination method. Curr Sci 2005, 89(8), 1404-13.

A set of 1941 earthquake events recorded in the northeast region of India during January 1993 - December 1999 was used for relocation by the Joint Hypocentre Determination (JHD) technique. Utilized both P- and S-wave arrivals recorded by closely spaced 77 temporary and permanent seismic stations in the region. Results of this analysis shows that (a) the average root mean square travel time residual becomes smaller than the corresponding single event locations by the HYPO71; (b) station correction varies from -2.43 to 2.32 s for P- wave, and from -2.84 to 2.84 s for S-wave, indicating large crustal velocity variations in the region; (c) positive station corrections are obtained in the Shillong Plateau, Assam valley and in the Manipur fold belt, and negative station corrections are obtained in the Mikir hills, and (d) lateral variation of the velocity structure inferred from station corrections is comparable with that obtained by 3D velocity inversion using the local earthquake tomography method.

6 illus, 3 tables, 33 ref

022609   Bhattacharya H N;Chakraborty A;Bhattacharya B (Dep of Geol, Presidency Coll, Calcutta-700 073) : Significance of transition between Talchir formation and Karharbari formation in lower Gondwana basin evolution- a study in West Bokaro coal basin, Jharkhand, India. J Earth Syst Sci 2005, 114(3), 275-86.

Basal part of the Gondwana Supergroup represented by Talchir and Karharbari Formations (Permo-Carboniferous) records an abrupt change-over from glacio-marine to terrestrial fluviolacustrine depositional environment. The contact between the two is an unconformity. Facies analysis of the glacio-marine Talchir Formation reveals that basal glaciogenic and reworked glaciogenic sediments are buried under storm influenced inner and outer shelf sediments. Facies associations of the Karharbari Formation suggest deposition as fluvio-lacustrine deposits in fault-controlled troughs. An attempt has been made to explain the sedimentation pattern in Talchir and Karharbari basins, and the abrupt change-over from glacio-marine to terrestrial fluviolacustrine depositional environment in terms of glacio-isostacy.

17 illus, 38 ref

022608   Basu A (Dep of Geol Sci, Indiana Univ, 1001 East 10th Street, Bloomington, IN 47405, USA) : Nanophase Fe degree in lunar soils. J Earth Syst Sci 2005, 114(3), 375-80.

Back scattered electron and transmission electron imaging of lunar soil grains reveal an abundance of submicrometer-sized pure Fe<144> globules that occur in the rinds of many soil grains and in the submillimeter sized vesicular glass-cemented grains called agglutinates. Grain rinds are amorphous silicates that were deposited on grains exposed at the lunar surface from transient vapors produced by hypervelocity micrometeorite impacts. Fe<144> may have dissociated from Fe-compounds in a high temperature (<62>3000<144>C) vapor phase and then condensed as globules on grain surfaces. The agglutinitic glass is a quenched product of silicate melts, also produced by micrometeorite impacts on lunar soils. Reduction by solar wind hydrogen in agglutinitic melts may have produced immiscible droplets that solidified as globules. The exact mechanism of formation of such Fe<144> globules in lunar soils remains unresolved.

6 illus, 40 ref

022607   Balaram V;Mathur R;Banakar V K;Hein J R;Rao CRM;Rao T Ganeswara;Dasaram B (NO, Natn Geophys Res Inst, Hyderabad-500 007) : Determination of the platinum - group elements (PGE) and gold (Au) in manganese nodule reference samples by nickel sulfide fire-assay and Te coprecipitation with ICP-MS. Indian J Mar Sci 2006, 35(1), 7-16.

Platinum group elements (PGE) and Au data in polymetallic oceanic ferromanganese nodule reference samples and crust samples obtained by inductively coupled plasma mass spectrometry (ICP-MS), after separation and pre-concentration by nickel sulfide fire-assay and Te coprecipitation, are presented. By optimizing several critical parameters such as flux composition, matrix matching calibration, etc., best experimental conditions were established to develop a method suitable for routine analysis of manganese nodule samples for PGE and Au. Calibrations were performed using international PGE reference materials, WMG-1 and WMS-1. This improved procedure offers extremely low detection limits in the range of 0.004 to 0.016 ng/g. The results obtained in this study for the reference materials compare well with previously published data wherever available. New PGE data are also provided on some international manganese nodule reference materials. The analytical methodology described here can be used for the routine analysis of manganese nodule and crust samples in marine geochemical studies.

1 illus, 9 tables, 26 ref

022606   Alimohammadian H;Sahni A;Patnaik R;Rana R S; Hukam Singh (Centre of Advanced Study in Geol, Panjab Univ, Chandigarh-160 014, Email: ashok.sahni@gmail.com) : First record of an exceptionally adverse and well preserved amber embedded biota from lower Eocene (<126> 52 Ma) lignites. Curr Sci 2005, 89(8), 1328-30.

2 illus, 24 ref

022605   Ali S R;Rao L A K (Dep of Geol, Aligarh Muslim Univ, Aligarh-202 002, Email: srali_99@yahoo.com) : Trace element geochemistry of the precambrian stromatolitic phosphorites around Gandhra Panchmahals district, Gujarat. J appl Geochem 2005, 7(1), 36-42.

Trace elements in fifty phosphorite samples from the Champaner Group of rocks of the Precambrian Aravalli Super Group around Gandhra, Panchmahals district, Gujarat, have been determined. The phosphorites are enriched in Ni, Co, and Rb and depleted in Cu, Zn and Pb compared to the Matoon phosphorites of Rajasthan. The abundance, distribution and fixation of Cu, Ni, Co, Li and Zn are controlled by clay minerals, calcium phosphate minerals and biogenic activity.

2 illus, 3 tables, 18 ref

021694   Louis F I;Vafidis A P;Louis I F (Geophysics and Geothermic Dep Facult of Geol and Geo Environement, Univ of Athens, Panepistimiopolis, Ilissia, Athens 15784, Greece) : Constraining approaches in seismic tomography. Res J Chem Envir 2005, 9(4), 94-9.

Two ways of dealing with the problems of stability and uniqueness in travel time inversion are proposed. They involve constraining conditions in the form of damping and smoothing of the solution. A direct evaluation of these two proposed schemes is presented which is useful in the selection of optimum values. A synthetic cross-hole data set with intermediate noise level was used in the study. Data and model RMS misfits were plotted against damping/smoothing parameters. These diagrams indicate that the damped least squares method gives acceptable results for damping values which correspond to the region of local minimum for both types of error. First and second difference regularization methods performed in general better since noise was generally suppressed and better tomograms were obtained for distinctive values of the free parameter, although harsh smoothing recovered no observable velocity features.

8 illus, 17 ref

020769   Sarkar P K;Lulla Y;Raut S D (Dep of Geol, Fergusson Coll, Pune-411 004) : Development of stalactitic forms of bacterial colonies (methanogenic organisms) by the seepage of leachate solutions along the fractures and flow contacts of an Abandoned basalt quarry at Urali Devachi, Pune dist., Maharashtra. Ecol Envir Conserv 2005, 11(3-4), 495-8.

Reports development of stalaclitic forms of bacterial colonies of methanogenic organisms formed by the leachate solutions.

2 illius, 1 ref

020768   Sarangi A;Madramootoo C A;Enright P;Prasher S O;Patel R M (Wat Technol Cent, Indian Agric Res Inst, New Delhi-110 012, Email: arjamadutta.sarangi@elf.mcgill.ca) : Performance evaluation of ANN and geomorphology-based models for runoff and sediment yield prediction for a Canadian watershed. Curr Sci 2005, 89(12), 2022-33.

Artificial Neural Network (ANN) and regression models were developed using watershed-scale geomorphologic parameters to predict surface runoff and sediment losses of the St. Esprit watershed, Quebec, Canada. Geomorphological parameters describing the land surface drainage characteristics and surface water flow behaviour were empirically associated with measured rainfall and runoff data and used as input to a three-layered back-propagation feed-forward neural network model. Morphological parameters such as bifurcation ratio, area ratio, channel length ratio, drainage factor and relief ratio were selected using the Multivariate Adaptive Regression Splines tool, based on their relative importance in prediction of runoff and sediment yield. Regression models were developed using the curve-fitting toolbox of MATLAB software and compared with the results obtained from ANN models. The coefficient of determination (R²) and model efficiency factor (E) were estimated to ascertain the model performance. Geomorphology-based ANN model validation statistics resulted in R² values ranging from 0.85 to 0.95 and E values from 0.74 to 0.82 for peak runoff rate and R² values from 0.78 to 0.93 and E values from 0.71 to 0.76 for sediment loss. Using geomorphology-based regression models, R² values for the same dataset varied from 0.78 to 0.88 (0.74<62>E<62>0.69) for peak runoff rate prediction and 0.39 to 0.54 (0.53<62>E<62>0.46) for sediment prediction. When morphological parameters were not associated with rainfall depth and peak runoff rate, prediction error statistical parameter values (R² and E) were less for both neural network and regression models. Thus, associating selected geomorphological parameters with rainfall depth and peak runoff rate enhances the accuracy of runoff rate and sediment loss predictions from the watershed. Furthermore, ANN models performed better than the regression equations.46) for sediment prediction. When morphological parameters were not associated with rainfall depth and peak runoff rate, prediction error statistical parameter values (R² and E) were less for both neural network and regression models. Thus, associating selected geomorphological parameters with rainfall depth and peak runoff rate enhances the accuracy of runoff rate and sediment loss predictions from the watershed. Furthermore, ANN models perormed better than the regression equations.

8 illus, 2 tables, 3 ref

020767   Pandey K;Dwivedi M M (Natn Cent of Expl Mineralogy and Petro, Univ of Allahabad, Allahabad-211 002, Email: kp542831@yahoomail.com) : High pressure-temperature viscosity study of an Indian natural rock. Asian J Chem 2006, 18(1), 299-306.

Viscosity measurement of the natural rocks is an important experimental tool for the knowledge of extrusive and intrusive igneous changes inside the earth. The viscosity is measured by the falling sphere technique. The chemical composition of the rock was analysed by EPMA.

5 illus, 2 tables, 12 ref

020766   Indra Bir Singh (Geol Dep, Lucknow Univ, Lucknow-226 007) : Climate change and human history in Ganga plan during late Pleistocene-Holocene. Palaeobotanist 2005, 54(1-3), 1-12.

The Ganga Plain exhibits a large variety of landforms produced essentially during last about 100 kyrs in response to base level, tectonic and climate change. Prominent changes in the monsoon rainfall in the Ganga Plain have been identified, namely, 45kyrs BP, humid climate; 20-13 kyrs BP, low rainfall; 13-11.5 kyrs BP, high rainfall; 11.5-10.5 kyrs BP, low rainfall; 10.5-5.8 kyrs BP, high rainfall; 5.8-2.0 kyrs BP, low rainfall; and 2.0-0 kyrs BP, high rainfall. Palaeo-vegetation studies indicate that the Ganga Plain was a grassland, at least, since 45 kyrs BP, where C-4 type vegetation dominated. The lakes supported C-3 type vegetation and they show changes in the water budget in response to the changes in rainfall. There is evidence of occupation of Ganga Plain by humans, at least, since 45 kyrs. They occupied the high grounds close to the water bodies, mostly lakes and ponds. Initially human population was hunter-gatherer depending on rich fauna and wild vegetation. Frequent climate changes in latest Pleistocene-Early Holocene probably led to adaptation of agricultural practices by humans. Large-scale occupation of the Ganga Plain took place between 3.5-3.0 kyrs BP. Study of oxygen isotopes in teeth enamel show century-scale rainfall changes in the last 3.5 kyrs BP which show some correlation to the cultural changes in the Ganga Plain. Climate change and human history in the Ganga Plain is closely related and need to be studied by high-resolution investigations.

6 illus, 45 ref

020765   Das S;Gupta V K;Gupta I D (Dep of Civ Engng, Indian Inst of Technol, Kanpur-208 016, Email: e-mail: vinaykg@iitk.ac.in) : Codal provisions of seismic hazard in northeast India. Curr Sci 2005, 89(12), 2004-8.

Seismic hazard maps have been prepared for Northeast India in the form of uniform hazard contours for pseudo-spectral acceleration at stiff sites. These maps are for the horizontal component of ground motion and for different values of exposure time, confidence level and natural period. A comparison with the codal provisions given by the Bureau of Indian Standards code (IS 1893 (Part 1): 2002) shows that the pseudo-spectral accelerations specified in the code for Northeast India are broadly consistent with the hazard level corresponding to 10% probability of exceedance and 50 years service life, and that the present practice of specifying seismic hazard through peak ground acceleration and a fixed spectral shape may be inappropriate for structures in most areas of the region.

ia4 illus, 2 tables, 8 ref

019661   Zamanian H (Geol Dep, Univ of Lorestan, POBox 465 Khorram Abad, Iran, Email: zamanian138@yahoo.com) : Petrography and mineral chemistry of Baba Ali magnetite Skarn deposit, Western Iran. Indian Mineralogist 2006, 40(1), 1-8.

The Almoughlagh granitoids, consisting chiefly of quartz-syenite and syenogranite rocks, belonging to the magnetite series granitoids, are mostly of I- type, metaluminous and calk-alkaline in nature. The Almoughlagh batholith which invaded both the Baba Ali diorite and Songhor Series culminated in development of thermal and hydrothermal metamorphic aureoles resulted in the formation of Baba Ali Magnetite deposit. Petrography and geochemistry of the host rocks and index minerals such as garnet, pyroxene and magnetite reveal a descending temperature regime, beginning at the peak of thermal metamorphism around 550°C and ending with the main phase of magnetite mineralisation around 350-400°C. Mineral chemistry of prograde minerals namely garnet and pyroxene have been utilized to classify the Baba Ali as a typical Fe-Skarn deposit.

4 illus, 3 tables, 15 ref

019660   Srivastava P K;Ajay Kumar (Geol Dep, Univ of Jammu, Jammu-180 006, Email: srivastava-pk@rediffmail.com) : Geochemical characteristics of magnesite minearalization at Panthal, Jammu & Kashmir. Indian Mineralogist 2006, 40(1), 59-72.

Stratabound magnesite mineralized body at Panthal (Udhampur district, J&K) is hosted witin the Riphean Sirban Limestone. Based on the crystallinity pattern the magnesite is classified into two categories as sparry magnesite and microcrystalline variety. It is further supported by the geochemical anomalies. It is observed that the sparry magnesite has very high MgO (41 to 49%) and low CaO (0.3 to 4%). In comparison the microcrystalline magnesite is characterized by a much lower MgO (25 to 34%) and anomalous higher CaO (16 to 27%). In the host rock dolomite the MgO content varies fro 19 to 23%, while CaO is between 23 to 29%. Mg/Ca ratio constantly increase from host dolomite (Avg. 0.65) to microcrystalline magnesite (Avg. 1.13) have maximum value for sparry magnesite (Avg. 63.53). The geochemical characteristics of Magnesite Mineralized Body (MMB) and host dolomite of Panthal are presented in order to understand chemical variation and origin of magnesite. Two stages for the formation of magnesiiten have been proposed for the Panthal magnesite deposit. In the first stage the microcrystalline magnesite is formed replacing the dolomite and at a latter stage this microcrystalline magnesite along with dolomite is converted to sparry magnesite and show further enrichment of MgO.

5 illus, 5 tables, 25 ref

019659   Srikantappa C;Fareeduddin;Malathi M N (Geol Dep, Univ of Mysore, Manasagangotri, Mysore-570 006) : Olivine-hosted melt inclusions in diamondiferous kimberlites from Wajrakarur, Andhra Pradesh, India. Indian Mineralogist 2006, 40(1), 73-6.

Primary, rounded to sub-rounded, globule-like melt inclusions occur in olivine macrocryst in diamondiferous kimberlites from Wajrakarur in Eastern Dharwar craton. They contain Co₂-rich liquid phase with a small vapour phase. Th of CO₂ vary from 26 to 29.5°C with density values of 0.65 to 0.55 g/cc. Th of melt inclusion vary from 950 to 1100°C. Presence of Co₂-rich volatile phase associated with melts in olivines and the presence of diamond in these rocks, indicate to their formation under high pressure conditions of around 50 kb, at depths of about 150 km.

^ssc2 illus, 8 ref

019658   Sabanayagam R;Jayakumar D (Geol Dep, Presidency Coll, Chennai, Tamil Nadu) : Geochemistry of retrograde charnockite-gneiss rocks from Toppur-Salem, Tamil Nadu, South India. Indian Mineralogist 2006, 40(1), 24-31.

Exposures in many quarries around Toppur exhibit evidence for retrogression of charnockite to produce hbl-biotite gneiss. The study relates to the effect of retrogression as well as the charnockite-gneiss relationship based on their petrography and geochemistry. Petrographic study reveals alteration of orthopyroxene, clinopyroxene and plagioclase to bluish green hornblende, biotite and epidote, indicating retrogressive metamorphism fo charnockites in the study area. Major element data of charnockite and gneiss shows low K₂O/SiO₂ ratio and high Na₂O relative to K₂O and CaO. Gneissic rocks show higher Co, Hf, Zn and La values relative to Sr. In addition, gneiss is enriched in Zn relative to Co, in Nb relative to Ta and in Hf relative to Zr. There is mobility of major, trace and rare earth elements when charnockite retrogressed to gneiss.

1 illus, 2 tables, 14 ref

019657   Esfahani M M;Kochhar N;Gupta L N (Min Engng Dep, Esfahan Univ of Technol, Esfhan, Iran, Email: mmansouri_2001@yahoo.com) : Morphological studies of zircons from the Hasan Robat granite and associated rocks, Esfahan, Iran. Indian Mineralogist 2006, 40(1), 49-58.

Zircons in the Hasan Robat granites (HRG) are mostly of pink, light brown and pale yellow in color. Most of the zircons are of idiomorphic shape and the overgrowths and outgrowths are of primary type. The elongation ratio (ER) frequency diagram of zircon from the granitic rocks shows one maximum between 2 and 2.5. It shows that HRG zircons are of magmatic orgin. Most zircons of the muscovite-quartz schist are of subidiomorphic shape. They are colorless, pink, pale yellow in color and indicate variable degree of clouding and corrosion. Cracks are common and at times have developed into microfaults. Majority fo outgrowths and overgrows are of secondary origin. It appears that they have developed under metamorphic conditions. The zircon lengths and breadths exhibit seven and three maxima respectively. The elongation ratio (ER) frequency diagran shows 3 maxima. These features suggest that the crystals have been derived from different sources.

3 illus, 19 ref

019656   Devaraju J;Srikantappa C (NO, , , Email: msimys@eth.net) : Geochemistry and fluid inclusion study of perumpunna alkali syenites, Kerala, India. Indian Mineralogist 2006, 40(1), 32-8.

Perumbpunna alkali syenites (PAS) occur as intrusive bodies within the enderbitic-charnockitic granulites towards northern part of Cannanore district, Kerala. They exhibit regional foliation trending E-W direction with steep dips towards SE. Alkali feldspar is the dominant mineral present in syenites, showing perthitic texture. Low density H₂O (0.62 to 0.72 g/cc) and medium to high density CO₂ inclusion (0.9 to 1.02 g/cc) are the prominent fluids in alkali syenite. The PAS show high alkali to peralkaline nature and higher concentration of K-Al-Ba. The lacation of PAS along the Bavali and Kabini shear lineament is significant, which represent a major shear zone. Generation and emplacement of these syenites are related to the formation and reactivation of major shear zone in south India.

2 illus, 3 tables, 20 ref

019655   Balayerikala Reddy N;Prasad K S S;Hanumanthu R C (Geol Dep, S.V. Univ, Tirupati-517 502) : Petrogenesis of amphibolites from Jallipalli, Anatapur district, Andhra Pradesh, India. Indian Mineralogist 2006, 40(1), 39-48.

The Jallipalli schist belt is composed of chlorite schists, banded ferruginous quartzites, amphibolites, granitoids and dolerite dykes. Amphibolites are massive and schistose exhibiting sharp contacts with other lithounits. Petrography and geochemical data show that the amphibolites are of tholeiitic basalts. They have been formed through fractional crystallisation of sub-alkalic tholeiitic magma and supposed to be evolved by the partial melting of primordial mantle in the island-arc environment.

8 illus, 1 table, 30 ref

018570   Vijay Kumari P;Hanumanthu R C;Sreedhar Babu C (Dep of Geol, Sri Venkateswara Univ, Tirupati-517 502) : Geology and geochemistry of the metavolcanics of Peddavuru schist belt in eastern Dharwar craton Andhra Pradesh, South India. J Indian Acad Geosci 2002, 45, 31-38.

Peddavuru schist belt has predominantly mafic volcanics followed by minor acid volcanics. The basic volcanics are tholeiite and the acid volcanics.are calc-alkaline in nature. This association refers to the higher stratigraphic level. It can be suggested that the Peddavuru volcanic suite has been derived from an initial tholeiitic magma which has iven rise to both early basaltic suite and later calc-alkaline suite of rocks. Geochemical signatures of the schist belt litho-units suggest an island are and active continental margin tectonic setting for the rocks of Peddavuru schist belt have undergone greenschist facies metamorphism.

8 illus, 2 table

018569   Vidyasagara Chary D;Bala Kotaiah G (Dep of Geol, Osmania Univ, Hyderabad-500 007) : Cadmium, lead and chromium contamination of vegetables grown in urban sewage sludge along river Musi, Hyderabad, India. J Indian Acad Geosci 2000, 43, 13-14.

Paper reports level of metal contamination of vegetables grown on urban sewage sludge. Common vegetables. common vegetables such as Spinahc (palak, Amaranthus (leafy vegetables) and Tomatos were collected along the contaminated sites. Pb, Cd, Cr were analyzed in vegetables along with sludge. Cd, pb, Cr were quite high envegetables than permitted levels of WHO which is hazardous to human beings.

1 table, 7 ref

018568   Vansutre S;Sahu G R;Diwan P;Mishra D K (Dep of Geol, Govt Coll of Sci, Raipur) : Remote sensing & geographical information system (RS-GIS) - An indispensible tool in optimal mine planning for corundum (ruby) mining in Bhopal Pattanam area, Bastar cratpm, India. Indian Min Engng J 2005, 44(11-12), 34-7.

Application of RS-GIS has brought a revolutionary change in utility of technology because, depth is a fundamental consideration in mining activities. Ruby mining in Bhopalpattnam area (Kuchnoor 80%25'E and 18%51'N) was in operation until 1997. The mining activities of the MPSMC (M.P State Mining Corporation now known as Chhattisgarh State Mineral Development Corporation) were proceeding in the direction of dip of beds i.e. SW as, ruby bearing veins were going deeper in the direction of dip. Study, with satellite data of IRS ID LISS - III)Feb 2000) and multilayered map produced with the help of software MAP INFO 7.0, aims at the possible optimal mine planning for the mining activity to be resumed in near future.

3 illus, 7 ref

018567   Reddy M R K;Venkatarami Reddy Y;Bala Yerikala Reddy (NO, , Cuddapah-516 003) : Management of water resources for Cuddapah municipal water supply, Andhra Pradesh. J Indian Acad Geosci 2001, 44, 23-26.

Public Health Engineering Department and the municipalities undertake the responsibility to provide water to urban areas. An outline of the problems encountered in the supply of water to the rapidly growing Cuddapah Municipality is now described. At present 47 Lakh gallons/day ofwater is required for the entire Cuddapah public in the municipal limits. Out of this 39 Lakh gallons/day of water only is supplying from Bugga water works, Gandi water works, lingampalli water works and Borewells from town, for supply of which the electrical energy is required approximately 600H.P. From all the sourceswater is pumped to Ground level service reservoir, which is constructed at Cuddapah Municipal office and from there the water is distributing to all the parts of Cuddapah town. The Buggavanka river passes right across the Cuddapah town and pollution is getting increased at a tremendous pace with increase of population in the town Gandhi water works located in the downstream of the buggavanka river, posses a serious threat on the quality of water and thereby on the health of Cuddapah people. Buggavanka Irrigation Reservoir is constructed across the Buggavanka river in the upstream of the Cuddapah town. A portion of the water can be diverted to quench thurst of Cuddapah people through Reddypalli tank by gravity.

1 illus, 5 ref

018566   Reddy K S N;Varma D D;Rao N B;Lakshmi Prasad T (Dep of Geol, Andhra Univ, Visakhapatnam-530 003) : Surface microtextures of heavy minerals from pudimadaka to pentakota nearshore and innershelf sediments, eastcoast of India. J Indian Acad Geosci 2001, 44, 15-22.

Scanning electron microscopic studies of placer heavy minerals, such as sillimanite, ilmenite, garnet, zircon, monazite and rutile from nearshore and innershelf sediments of Pudimadaka - Pentakota, indicate numerous micro features. The mechanical impacts and chemical action result breakage in blocks; steplike features, 'V' shaped pits and etch marks, solution channels and precipitation features respectively. The surface microtextures are the result of chemical and mechanical processes as well as nature of minerals and also the environment. The study is made to identify the common grain microtextures of placer minerals and the processes responsible for their formation.

4 illus, 1 table, 15 ref

018565   Ramanaiah S;Srinivasarao K (Dep of Geol, S V Univ, Tirupati-517 502) : Geomorphological parameters of the Boggeru river basin, Nellore district, Andhra Pradesh. J Indian Acad Geosci 2002, 45, 51-4.

Geomorphologic studies of Boggeru river basin have been carried out to understand the morphological features like geometry of the drainage basin, drainage network, textural analysis and relief characteristics. Boggeru River isVI order and very coarse-grained stream. it obeys the Horton's laws relating to linear and areal aspects. Hypsometric analysis and bifurcation ratio reveals that the basin has reached mature stage of development.

2 illus, 2 table, 5 ref

018564   Prabhakara Rao A;Panda N K;Subrahmanyam A V; Ravi G S;Desmukh R D (Atom Miner Directorate For Explor and Res, , Madhavadhara, Visakhapatnam-530 018) : Textural charecteristics of sands in the interpretation of depositional environments between river varaha and mulapeta creek east coast of india. J Indian Acad Geosci 2000, 43, 1-8.

Wide variations are observed in textural characters along different geomorphic domains viz., the course of river and across the coast i.e., berm, fore, inter and rear dune along 60-km stretch between Varaha River and Mulapeta creek due to the varying geomorphic processes. River sediments from upstream towards confluence are coarse to medium, moderately to poorly sorted, negatively skewed and meso kurtic to very lepto kurtic whereas in mid-stream they are medium grained, well sorted, coarse to fine skewed and platy kurtic in nature. Berm zone sands are medium to fine, moderately well sorted, negatively skewed and leptokurtic. Dunal sands are characterised by medium to fine sand moderately well sorted, finely skewed (+ve) and meso kurtic. Scatter plot of standard deviation vs mean size plot clearly distinguishes between river and dune environment. The negatively skewed characteristics of river, berm and creek sediments pertain to high-energy environments involving multidirectional flow, while positively skewed dune areas correspond to relatively low energy environment. the linear discriminant function (Y) and the vectors (V₁&V₂) reflect that the river, bermand dune samples belong to the fluvial, beach and dune environments respectively.

3 illus, 2 table, 10 ref

018563   Madhusudan Rao B;Shashidhar D;Narsaiah R; Murthy B V C (Cent of Explor Geophysics, Osmania Univ, Hyderabad-500 007) : Geological significance of magnetic signatures over the granitic region in Osmania university campus, Hyderabad, India. J Indian Acad Geosci 2002, 45, 39-44.

Semi-detailed total field magnetic survey has been conducted in the northern half of the Osmania University campus setting up about six hundred observations. The magnetic anomaly map brought out reflections of prominent lithological and structural features and in general found to corroborate with those from gravity survey. Fourier spectra along two traverses projected along an east west and north-south gave broadly two effective magnetic interfaces - a shallowerone indicating the weathering thickness and the second one suggesting the fractured and fissured granitic zones. The depths to these interfaces appear to be in agreement with those reported by earlier researchers. Gravity vertical gradient and the horizontal component magnetic anomaly show close correspondence and therefore suggest that significant part of magnetization is due to induction. The magnetic anomaly thus found, helped in better understanding of the surface and sub-surface geological description of the Osmania University Campus.

4 illus, 1 table, 10 ref

018562   Madan D K;Kuldip Singh;Aggarwal R;Gupta A (Dep of Math, Technol Inst of Text and Sci, Bhiwani-127 021) : Displacements and stresses in an anisotropic medium due to non-uniform slip along a very long strike-slip fault. ISET J Earthquake Technol 2005, 42(1), 1-11.

The problem of static deformation of a homogeneous, orthotropic elastic uniform half-space due to non-uniform slip along a vertical strike-slip fault of infinite length and finite width has ben studied. Closed-form analytical expressions of displacements and stresses for different slip profiles - parabolic, linear, elliptic, and cubic are obtained. The results obtained here are the generalization of the results for an isotropic medium (Singh et al., 1994) in the sense that medium of the work is orthotropic which is more realistic than isotropic and results for an isotropic case can be derived from the results. The variations of the horizontal displacements and stresses with distance fromthe fault due to various slip-profiles at the surface have been studied to examine the effect of anisotropy on the deformation. Numerically, it has been found that for parabolic elastic medium are greater than that for an orthotropic elastic medium while in case of cubic slip, the surface displacements in magnitude for orthotropic elastic medium is greater than that for the isotropic medium.

9 illus, 24 ref

018561   Kedareswarudu U;Lakshmipati Raju a (Dep of Geophysics, Andhra Univ, Visakhapatnam-530 003) : Geochemistry, density and magnetic properties of manganese ores of Vizianagram district Andhra Pradesh. J Indian Acad Geosci 2000, 43, 9-12.

Manganese content, bulk density, NRM intensity and magnetic susceptibility of manganese protores and ores of Vizianagaram district, Andhra Pradeshwere determined to study the effect of supergene oxidation and enrichment on magnetic properties. The bulk density of protores and ores is in the ranges 2.6-3.7g/cc and 2.7-4.1 g/cc. The concentration MnO₂ (wt%) in the two types ores is 20-23 22-55. Fe₂O₃ is 5-27 and 1-23. The concentration of MnO₂ is fairly constant over the range fo densities in protores and increases in ores. A diadochial relationship between Mn and Fe was observed. increase of MnO₂ and the associated decreade of Fe₂O₃ correlate with decrease in NRM intensity and volume magnetic susceptibility. Thus, the ore enrichment by supergene oxidation is found to weaken the magnetic properties.

3 illus, 1 table, 13 ref

018560   Johnson M E C (Dep of Bot, Osmania Univ Coll for Women, Koti, Hyderabad-500 195) : Fluoride distribution in the groundwater of Hyderabad city, Andhra Pradesh. J Indian Acad Geosci 2001, 44, 27-29.

Fluoride concentration in the groundwater around Hyderabad City varied between 0.25 mg/l to 2.0 mg/l. The groundwater of these locations are being used for drinking purposes. It is evident that more than 0.5 mg/l of Fluoride indrinking water causes yellowing of teeth, dental cavities and joint pains in the consumer.

2 illus, 2 table, 7 ref

018559   Jaya Rama Rao K;Bala Kotaiah G;Ravinder R; Chandrakala V (Geol Dep, Osmania Univ, Hyderabad, Andhra Pradesh) : Morphometric analysis of Kanga river sub-basin, Andhra Pradesh, India. J Indian Acad Geosci 2002, 45, 45-9.

Attempt is made to study the basin characteristics of Kagna sub-basin of the Krishna basin through morphometric analysis. The drainage is mainly sub-parallel to parallel. Most of the higher order streams are structurally controlled and the area is designated as sixth order basin. The lower values of bifurcation ratios are mainly due to gently sloping flows of basaltic lavas and indicative of favourable hydrogeological conditions. The denudatinal and fluvio - denudational processes control the formation of slopes and is one of the important parameters in the groundwater prospecting.

5 illus, 3 table, 5 ref

018558   Dey M R (Anthrop Surv of India East Regional Cent, , 2, Ripon Street, Kolkata-700 016) : Painted rock shelters of Jharkhand. J Anthrop Surv India 2004, 53(1), 55-8.

A first hand but chance find of the remote past of early human being is the expression of his thoughts and feelings that was recorded unintentionally on the rock walls in the form of painting or engraving. India is one of the richest preserved rock art centres of the world. In eastern India, Chhotanagpur Plateau is a very potential zone in yield of this earliest document of mankind. Gives a brief account of some important rock art sites of this region.

9 ref

018557    (NO, , ) : Tsunami : 20 - feet wall of water hits coasts : one of the worst tragedy in a century in Asia. Bionotes 2005, 7(1), 37-9.

017603   Tiwari A;Dube V S;Ojha P (Geol Dep, B.N. Coll Patna Univ, Patna-800 004) : Petrography and geochemistry of the lower Vindhyan shales from Bhawnathpur, Panda valley, Garhwa, Jharkhand. Indian J Geochem 2005, 20, 63-76.

The shales collected from the Porcellanite Formation of Semri Group in the eastern margin of the Vindhyan Basin in the Son calley were examined for finding the petrographic and geochemical basis for determining the nature of provenance, and to understand the environment of weathering, sedimentation and the tectonic condition at the time of their deposition. The geochemistry of all the shale samples indicates the prevalence of an arid climatic condition in the source region during the deposition of these sediments, while a low to moderately weathered provenance terrain is indicated from the study of the detrital clastic samples. The chemical Index of Alteration (CIA) of the studied shales ranges from 52 to 71, which indicates that the source rocks had under gone low to moderate chemical weathering before their sedimentation. The major elements data indicate an overall taphrogeosynclinal continental rift related depositional basin having a plate interior setting. The higher ratios of SiO₂/Al₂O₃ in shales indicate a largely felsic character of the provenance.

9 illus, 2 tables, 41 ref

017602   Subba Reddy N;Darga Reddy N (Geol Dep, S.V. Univ, Tirupati-517 502, Email: nsr161950@yahoo.com) : Rare earth element distribution in banded iron formation (BIF) of Aroli-Donimalai, Karnataka greenstone belt. Indian J Geochem 2005, 20, 151-6.

The Rare Earth Element (REE) distribution in 5 samples of banded iron formations (BIF) of Aroli-Donimalai area of Greenstone belts of Karnataka suggest that the iron and silica in BIF are derived from hydrothermal source. The BIF thus formed together with associated litho units metamorphosed to greenschist to amphibolite facies conditions of metamorphism.

1 illus, 1 table, 23 ref