002294   Singh K P (NO, Natn Geophys Res Inst, Hyderabad, Email: kps_ngri@yahoo.com) : P-wave signatures in VTI solid underlying a dipping plane. J Geophys 2005, 26(3), 167-72.

P-Wave phase, ray and CMP stacking velocities in transversely isotropic solid underlying a dipping plane depend on elastic parameters of solid, direction of propagation of wave from axis of symmetry, dip and depth of the reflector. The dependence of P-wave CMP stacking velocity on these parameters in transversely isotropic solids having vertical axis of symmetry (VTI) becomes very complex. To study the behavior of P-wave phase and ray velocities in VTI solids, mathematical expressions are also approximated in terms of Thomsen parameters e and d neglecting higher order terms involving e and d. Similar conditions and preassigned accuracy are applied to conventional and approximated (weak anisotropic) formulations to obtain P-wave reflection in common midpoint (CMP) array in all computations. Elastic parameters are also kept unchanged for various values of dip of the plane and depth of reflecting point. In case of weak anisotropic approximations, reflected phase and ray velocities increase with increase in angles and have no unique values corresponding to reflected phase and ray angles, both X²-T² and X-T plots are found highly nonlinear and fit with a polynomial of order greater than four. CMP stacking velocities abnormally increase with dip, and are almost twice of the velocities obtained without using any approximation. On the other hand CMP stacking velocities, computed without any approximation gradually increase with depth of reflection point and dip of the plane, phase and ray velocities smoothly increase with phase and ray angles, and X-T and X²-T² plots are hyperbolic and straight lines respectively. To obtain P-wave reflections under predefined conditions required maximum spread decreases and minimum spread increases with dip, and both increases with increase in depth. Thus, behavior of solids of small extent is not completely characterized in weak anisotropic approximations.

5 illus, 9 ref

002293   Sharma R;Verma P;Law R W (NO, Wadia Inst of Himalayan Geol, Dehra Dun-248 001, Email: rajesh_fluid@rediffmail.com) : Sulphur isotopic study on barite mineralization of the tons valley, Lesser Himalaya, India: implication for source and formation process. Curr Sci 2006, 90(3), 440-43.

Sulphur isotopic study on barite (BaSO₄) mineralization, located about 65 km NW of Dehra Dun in the Tons valley, Lesser Himalaya, has shown that δ³⁴ S values of barite vary from +26.5 to +29.5%. The data, coupled with earlier published abnormally high value of ⁸⁷Sr/⁸⁶Sr in barite (0.720448 to 0.728637), have demonstrated that sulphur was derived from Proterozoic sea water and Ba was obtained from the radiogenic crustal source. These isotopic signatures suggest mixing of sea water sulphate with Ba-carrying crustal fluid for barite formation, with its initial deposition linked to diagenesis of the host rocks.

3 illus, 2 tables, 20 ref

002292   Sharma M L (Dep of Earthq Engng, IIT Roorkee, Roorkee, Email: mukutfeq@iitr.ernet.in) : A new empirical attenuation relationship for peak ground horizontal accleration for Himalayan region using Indian and worldwide data set. J Geophys 2005, 26(3), 151-8.

In absence of recorded strong ground motion, the site specific earthquake parameter studies in India are based on a few attenuation relationships developed elsewhere in similar prevailing tectonic environments. An endeavor has been made to develop attenuation relationship for Himalayan region in India by collating worldwide data selected from those relationships which are in use for seismic hazard computation in Indian region. The data base consisting of 666 recordings of peak ground accelerations from 82 earthquakes with magnitude ranging between 5 to 8.1 and epicentral distances upto 200 km has been used. The closest distance to the zone of energy release is used as the distance measure. The analysis uses a two step stratified regression model. The proposed attenuation relationship is log₁₀(A)= 0.05974M - 0.9009log (X+e^0.2183M) where A is the peak ground horizontal acceleration (in cm/sec²), M is the magnitude and X is the hypocentral distance. The comparision is made of the proposed relationship with the earlier developed attenuation relationships using Indian data for the Himalayas. The relationship is considerd to be applicable for earthquake of magnutude ranging between 6.0 and 7.5 with least distance to the zone of energy release in the range of 10 to 200 km. Though the equation gives good results between magnitude 6.0 and 7.5, a larger data set from Indian side is required for accurate prediction of acceleration for all magnitudes to represent the prevailing tectonic environment for the region.

10 illus, 2 tables, 17 ref

002291   Sharma H;Mukherjee J;Nath S (Engng Geol Div East Region Geol Surv of India, , Kolkata-700 091) : Lineament fabric of the area between Mahanadi and Vamsadhara rivers and its significance. Indian Miner 2004, 58(3-4), 197-204.

Area between Mahanadi river in Orissa and Vamsadhara river in Andhra Pradesh exposes mainly two suites of rocks viz. (i) khondalite and (ii) charnockite gneiss of Precambrian age. Anorthosite bodies are found as instrusives along regional fractures. Photointerpreted geological mapping (with limited ground checks) of the lineanents in the entire stretch straddling the Orissa-Andhra Pradesh border followed by detailed lineament analysis were carried out to decipher the structural pattern in the area. The lineaments depicted have been categorised into two groups as (1) major fracture system and (2) minor fracture system. The former comprises macro- and micro-lineaments and the latter comprises visible fracture patterns on satellite imagery. The directional behaviour of both major and minor fracture systems has been analysed keeping in view the lithological attributes and their differential competency in different sectors. The major fracture system has a general NE-SW trend in the northern part and NW-SE trend in the southern part of the study area, which is surmised to be related to the different tectonic episodes experienced by the belt from time to time. The minor fracture system depicts the prevailing joint system in the different sectors of the study area. The signature of the lineament fabrics has been corroborated with the geological set-up of the present belt.

3 illus, 10 ref

002290   Roonwal G S (Dep of Geol, Delhi Univ, Delhi-110 007) : Compatibility of Indian reserves and resources classification with UN framework classification. MGMI Trans 2004, 101(1-2), 99-109.

Establishment of a universal set of international standard reporting for universal reserves and resources, which can be undertaken by all countries; has moved a step closer following a major break through at meetings in Geneva (1997, 1999). The Council of Mining and Metallurgical Institutions (CMMI), International Definition Committee (led by Mr. Normal Miskelly) reached an agreement (1997) with the United Nation Economic Commission (UN-ECE) which virtually means that reporting definition put forward by CMMI and based on Australian user will be adopted worldwide. It has particular ramification for establishing guidelines for countries in transition to market economics (India-in this case). Now that the model has more or less been accepted (1999) and become the model for a recognized international code, it is important for every one concerned with the mineral industry, the academic, and user relating to geology, and mining, as well as industry has to become familiar with it. It is attempted to do this task.

3 illus, 6 tables, 3 ref

002289   Rathod V (NO, Natn Inst of Oceanography, Dona Paula, Goa-403 004, Email: rathod@darya.nio.org) : Distribution, abundance and vertical migration pattern of krill-Euphausia superba Dana at fishing area 58 of the Indian Ocean sector of Southern Ocean. Curr Sci 2005, 89(10), 1749-53.

First Indian Antarctic Krill Expedition (FIKEX) was an attempt to examine and obtain first-hand information pertaining to distribution, abundance and vertical migration pattern of krill - Euphausia superba Dana at fishing area 58 of the Indian Ocean sector of Southern Ocean. It has been ascertained that krill migrations occur between sea surface and a depth of about 100 m. Availability of food is the key factor affecting both seasonal and annual changes, and leads to krill migration. Under good feeding conditions the amplitude is maximal, and the migration cycle approaches 24 h. Adult individuals exhibit 24 h migration, whereas juveniles show lower migration, and their submergence is shallower. Water stratification may also affect krill distribution in the water column, and in certain conditions may lead to limitation of migration range.

^ssc3 illus, 19 ref

002288   Pruseth K L;Yadav S;Mehta P;Pandey D;Tripathi J K (NO, Sch of Envir Sci Jawaharlal Nehru Univ, New Delhi-110 067, Email: klpruseth@yahoo.com) : Problems in microwave digestion of high-Si and high-Al rocks. Curr Sci 2005, 89(10), 1668-71.

4 illus, 5 ref

002287   Pramanik K;Chakraborty D;Ghosh S S;Das D P (PGRS Div Cent Headquarters, Geol Surv of India, Kolkata-700 016) : Near-real-time evaluation of the impact of seismo-tsunami of December 26th 2004 over the Andaman-Nicobar Islands using IRS sensor data. Indian Miner 2004, 58(3-4), 215-22.

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002286   Neelakandan V N;Mohanan C N;Sakumar B (Cent for Earth Sci Stud P.B. No. 7250, , Akkulam, Thiruvananthapuram-695 031, Email: neelakdanvn@gmail.com) : Development of a biogeographical information system for conservation monitoring of biodiversity. Curr Sci 2006, 90(3), 444-50.

The need to document and conserve biodiversity has become a necessity in the wake of increased threats from deforestation, alteration in land use, soil degradation, pollution and climatic change. Developing technologies with more predictive capabilities could help the society address some of the concerns affecting nature and biodiversity. Current electronic inventories provide limited information on biodiversity, its environmental status, bioclimate, evolutionary history and management units of conservation. This communication explains a system that provides species-specific and site-specific information with improved data semantics to help conservation monitoring, eco-restoration and sustainable use of biological resources.

5 illus, 4 tables, 45 ref

002285   Nair R V G;Nair M M (NO, Geol Surv of India, Thiruvananthapuram-695 014) : Attapadi supracrustals - a probable greenstone belt in the southern granulite terrain. Indian Miner 2004, 58(3-4), 143-56.

Athapadi valley, located around the western termination of the Bhavani shear, is identified as one of the high strain areas within the Southern Granulite. Attapadi supracrustals (AS) comprising enclaves of metamorphosed ultramafic and basic, banded iron formation and metasedimentaries occur within charnockites and gneisses of the Peninsular Gneissic Complex. The ultramafic bodies of metapyroxenite and talc-tremolite schist exhibit pillow and ocelli structures suggestive of extrusive origin under submarine conditions. These rocks and the associated amphibolites show komatiitic chemistry and are also auriferous. BIF forms a distinct marker horizon separating these older litho assemblages from a younger amphibolite of tholeiitic parentage as well as the metasedimentary lithologies. REE geochemical characterisation assigns an Archaean age to the BIF. The extrusive nature of the ultrabasic bodies, komatiitic composition of the ultrabasics and amphibolites, chemogenic BIF and paucity of metasediments are all suggestive of the supracrustals to be classified as greenstone belt, yet hitherto unknown within the SGT. The auriferous potential of the Attapadi valley areas and their geographical obliterated by the high strain the area had been subjected to.

9 illus, 3 tables, 15 ref

002284   Mukhopadhyay P K;Ghosh S;Rath S C;Swain R B; Shome S (Geol Surv of India East Region, , Kolkata-700 091) : New find of lamproite dykes in Nawapara district, Orissa. Indian Miner 2004, 58(3-4), 183-96.

Diamondiferous kimberlitic province in the Bastar craton of Raipur district (Payalikhand-Berardih-Jangra-Kodamali belt) has long been established below the Chhattisgarh platform cover along its western fringe. Along the eastern fringe of the same platform cover a decade (1993-2002) of surveys and explorations conducted by GSI and subsequently by DGM, Orissa enabled the geoscientists to locate one kimberlitic lamproite body at Kalmidadar (DGM, Orissa) and two lamproite dykes at Sakri (AMSE, GSI), both in Nawapara district, Orissa. This work on the recent finds of ten new lamproite dykes in Nawapara district, Orissa by GSI, Eastern Region, substantiates the presence of diatreme-hypabyssal facies of the main kimberlitic crater facies of the Chhattisgarh-Orissa region. Volatile-rich lamproite magma exhibits igneous textures as well as effects of magmatic differentiation for which sharp distinction in mineralogy, minor accessories and nature of alteration between centrally located Darrimunda lamproite cluster vis-a-vis other radially distributed lamproite dykes (Amlidadar, Parkom, Sakri and Kalmidadar) around the former are noteworthy.

14 illus, 5 tables, 17 ref

002283   Mukherjee A K;Singh S L;Sharma R;Babu Lal; Reger R L;Vinod Kumar;Om Prakash;Pandit M K (NO, Geol Surv of India, Jaipur) : Crustal evaluation and basement topography by gravity survey in the central part of Delhi fold belt, Rajasthan. J Geophys 2005, 26(3), 133-7.

The Delhi Fold Belt (DFB) of Central Rajasthan comprises of Proterozoic rocks disposed in a NE-SW direction. Major part of the present area is covered by alluvial tracts. Intrusive granites, pegmatite and ultramafic bodies are also reported from this area. Geophysical surveys comprising gravity method was carried out to establish the structural features of the crust and their continuity in the covered area. Gravity map of the area brought out low amplitude gravity high anomalies, trending in NE-SW direction over the DFB in the northern part. A significant E-W trending gravity discontnuity along Mangliawas -Nasirabad separates the southern gravity low anomaly from the northern gravity high. The discontinuity has been identified by a change in the trend of the contour pattern. The continuity of the northern gravity high could be traced in the SE part, near Masuda. The spectral analysis of the gravity data brought out three density interfaces at depths of 10.8, 6.13 and 1.33 km. The study suggests an eastward rise in basement, which slopes down towards west. 2D gravity model across the South Delhi Fold Belt (SDFB) indicated the Moho depth at 40 km and upwarp in the central part. One high-density body (+0.23 gm/cc) in the upper crust and another (+0.13 gm/cc) at 3 km depth were interpreted.

6 illus, 11 ref

002282   Mohapatra B K;Nayak B R (NO, Regional Res Lab, Bhubaneswar-751 013) : Phosphorus in the manganiferous rocks of gangpur group, Orissa. Indian Miner 2004, 58(3-4), 223-28.

^ssc4 illus, 1 table, 15 ref

002281   Mitra S;Bidyananda M;Samanta A K (Dep of Geol Sci, Jadavpur Univ, Kolkata-700 032, Email: bmaibam@yahoo.com) : Cation distribution in Cr-spinels from the Sittampundi layered complex and their intracrystalline thermodynamics. Curr Sci 2006, 90(3), 435-9.

High aluminium chromites occur as bands within anorthosite layered complex of Sittampundi (Tamil Nadu). Cation distribution of two chromite samples is determined by combined electron probe microanalysis and Mossbauer spectroscope. In the deconvolution of the Mossbauer spectra, the suitability of the best model of spectral fitting has been established with the observation that both Fe²⁺ and Fe³⁺ ions occur at tetrahedral (A) and octahedral (B) sites and Fe³⁺/ΣFe found to be ranging between 0.45 and 0.48. Oxygen fugacity (fO₂) has been determined to be about 10^-7.3. Thermodynamic parameters have been determined for the studied chromites using standard models.

2 illus, 3 tables, 32 ref

002280   Majumdar T J;Bhattacharyya R (Earth Sci and Hydrology Div Mar and Wat Resour Grp Remote Sens Applics, Space Applics Cent (Indian Space Res Organization), Ahmedabad-380 015, Email: tjmajumdar@sac.isro.gov.in) : Bathymetry prediction model from high-resolution satellite gravity as applied over a part of the eastern Indian offshore. Curr Sci 2005, 89(10), 1754-9.

Ship-borne bathymetry data collected over the Indian offsnore are quite sparse. With the advent of space technology, satellite altimetry has opened up a new vista for prediction of bathymetry using altimetric geoidal/gravity undulations over any particular region. This geoid/gravity-derived bathymetry model is fast and reliable in geologically unexplored offshore regions. ERS-1 high-resolution (168-day repeat) altimeter data of the eastern Indian offshore (6-12°N and 90-95°E) are used to generate satellite gravity. Using satellite gravity, bathymetry was predicted for the eastern Indian offshore region. The results were satisfactory on comparison with ship-borne bathymetry data.

^ssc6 illus, 3 ref

002279   Kumaraguru A K;Jayakumar K;Wilson J J; Ramakritinam C M (Cent for Mar and Cstl Stud, Sch of Energy Envir and Nat Resour Madurai Kamaraj Univ, Madurai-625 021, Email: akkguru@eth.net) : Impact of the tsunami of 26 December-2004 on the coral reef environment of Gulf of Mannar and Palk Bay in the southeast coast of India. Curr Sci 2005, 89(10), 1729-41.

Live coral cover of 48.5% in the Gulf of Mannar was reduced to 36% after the tsunami of 26 December 2004. Corals showing partial bleaching, infestation with disease, silt-smothered live corals, recently killed corals, broken corals, upturned corals and sea grass damage were found in many places around the 21 islands. The coral cover under stress was 6.7%, which included corals showing partial bleaching and those infested with pink line disease syndrome. The silt-smothered coral cover was 30%. Damage to corals due to tsunami was 6.7% that included recently killed corals, upturned corals and broken corals. Sea grass damage was also found in low quantities. Landscape alterations revealed that Shingle, Mulli, Valai, Thalaiyari, Up-puthanni, Van, Kasuwar and Karaichalli islands experienced more shore erosion compared to the other islands. Uprooted trees were found in all the islands. Corals lying closer to the shore in all the islands were affected by sedimentation. The live coral cover of 26.7% in the Palk Bay was reduced to 19.2% after the tsunami. The coral cover under stress was 2.8%, which included those showing partial bleaching and those with infestation of pink line disease. Silt-smothered coral cover was 10.5%. Unlike the islands in the Gulf of Mannar, there was no change in landscape structure in the Palk Bay region. Only inundation of sea water was noticed in some places. There was substantial increase in sedimentation rate after the tsunami in the Palk Bay showing 12, 54 and 13 mg/cm²/d during Nov. 2004, Dec. 2004 and Jan. 2005 respectively.

7 illus, 1 table, 32 ref

002278   Ghosh S;Mujumdar P P (Dep of Civ Engng, Indian Inst of Sci, Bangalore-560 012, Email: pradeep@civil.iisc.ernet.in ) : Future rainfall scenario over Orissa with GCM projections by statistical downscaling. Curr Sci 2006, 90(3), 396-404.

The article presents a methodology for examining future rainfall scenario using fuzzy clustering technique from the General Circulation Model (GCM) projections. GCMs might capture large-scale circulation patterns and correctly model smoothly varying fields such as surface pressure, but it is extremely unlikely that these models properly reproduce nonsmooth fields such as precipitation. The model developed in the study is a linear regression model for estimation of rainfall, using GCM outputs of mean sea-level pressure and geopotential height as explanatory variables/regressors. To reduce the dimensionality of the dataset, the Principal Component Analysis (PCA) is used. Fuzzy clustering technique is applied to classify the principal components identified by the PCA and the fuzzy membership values are used in the regression model, with an assumption that the effects of circulation patterns on precipitation in different clusters are different. The regression model is then modified with an appropriate seasonality term. A major advantage of the proposed methodology is that while being computationally simple, it can model rainfall with a high goodness-of-fit (R²) value. The methodology is applied to forecast monthly rainfall over Orissa.

5 illus, 4 tables, 25 ref

002277   Dinesh Kumar (Dep of Earth Sci, Kurukshetra Univ, Kurukshetra, Email: Dineshk5@rediffmail.com) : Scenario hazard maps due to a moderate size earthquake in the Himalaya. J Geophys 2005, 26(3), 159-66.

The scenario hazard maps due to a moderate size earthquake (Ms 7) in the Himalaya have been presented. For this purpose, the accelerograms have been synthesized at large number of points using a fast semi-emperical technique. These scenario hazard maps show the spatial distribution of peak ground acceleration values, modified Mercallli Intensity and spectral accelerations for the periods T= 0.4s, 0.75s, 1.25s. These maps may be used to augment the information available in the probabilistic seismic hazard maps of the region. These maps are useful for the agencies involved in the planning of mitigation of seismic risk in the region.

7 illus, 1 table, 23 ref

002276   Choudhary P;Kumar A;Laskar S K (NO, Tezpur Univ, Tezpur, Assam, Email: skl@tezu.ernet.in) : Identification of EW trending faults and determination of sedimentary thickness in Shillong-Mawlong area by analysis of magnetic data. J Geophys 2005, 26(3), 139-50.

Gradient analysis and downward continuation of aeromagnetic data and harmonic analysis of a ground magnetic profile are carried out for delineation of EW-trending basement faults and determination of sedimentary thickness in the Proterozoic basin of Shillong-Nongpoh area of Meghalaya. The analysis reveals that there exists a 40 km long E-W trending hidden basement fault at about 7 km north of Umsning under about 2.5 km thick pile of apparently non-magnetic Shillong group of sediments. Starting from north of Umsaw reserve forest, the fault runs eastward along upstream of the west flowing tributary of river Umsaw and meets the NE-SW trending Barapani shear at a distance of about 30 km east of the reserve forest. Thereafter it extends further east taking a SEW trend. The analysis further reveals that there exists a SEW trending fault at Umsning meeting the Barapani shear at about 5 km east of Umsning. In all probability, the hidden 40 km long E-W trending fault appears to be the Oldham fault predicted by Bilham and England (2001).

10 illus, 19 ref

002275   Bose M K;Sarkar S S;Banerjee P P (Dep of Geol, Presidency Coll, Kolkata-700 073) : Quantitative evaluation of compostional characteristics of alkaline complexes of Koraput and Khariar, Orissa-a numerical approach. Indian Miner 2004, 58(3-4), 115-42.

Alkaline intrusive complexes of Koraput and Khariar in Orissa have been compared through numerical analyses of their major-element compositional data. The alkalinity of the two complexes are compared quantitatively. Khariar complex has feeble agpaitic stamp whereas the Koraput suite is nonagpaitic. Correlation matrices for major-element oxides of both the two plutons signify a history of fractional ion dominated by mafic silicate phases. Correlation patterns between the compositional variables in the two complexes has also presented graphically. The correlation behaviour of some oxide pairs found to be controlled by the scale of compositional domains as observed in subsets within the total data structure. It also appears that finer domain size in the scale of mineral lattices may control the correlation behaviour of the major elements. The spread of data for individual component (major-element oxide) in general shows a curvilinear inverse relation to its mean value. Weaker element correlation observed in the syenites of both the complexes reflects limited control of fractionation process in these domains being close to relevant system-minimum. Khariar complex does not bear any distinct imprint of postmagmatic chemical disorder. Qantitative study reveals distinguishing magma chemistry and crystallisation behaviour of the two alkaline complexes manifesting independent magmatic impulses.

16 illus, 8 tables, 22 ref

002274   Bhaduri S K;Banerjee D;Roy N K (Chem Div, East Region Geol Surv of India, Kolkata-700 016) : Application of X-ray fluorescence spectrometry (xrfs) in complete analysis of iron ore. Indian Miner 2004, 58(3-4), 209-14.

Method was developed for analysis of iron ore by pressed pellet XRF technique. In this method 2.5 g finely powdered and homogenised sample is pressed as a uniform disk of 30 mm diameter. This pellet is irradiated and fluorescence is measured on a Philips WD PW 1400 spectrophotometer using Rh target X-ray tube. Five international iron ore standard samples, MW-I (Canada), ERCM 679-1, ERCM-601-1, ERCM-603-1 and ERCM-609-1 (all France) are used for calibration line. Two iron ore samples of International Standard, SCH-1 (Canadian) and 800-2 (Japan), are analysed following the proposed method and the results are quite in good agreement with those of recommended values. The above method is now being routinely used in the chemical Laboratory, ERO, GSI for analysis of iron are samples.

1 illus, 4 tables, 7 ref

002273   Badu Lal (Geophysics Div, Western Region Geol Surv of India, Jaipur-302 004) : Diagnostic characters of geoelectrical sounding curve over lignite-bearing vis-a-vis barren formations, Palana area, Bikaner district, Rajasthan. Indian Miner 2004, 58(3-4), 205-8.

Palana area in Bikaner district of Rajasthan is known for the Tertiary lignite deposit under the desert tract of Thar. In view of low-resistivity property of lignite, electrical soundings were carried out. The sounding curves over the lignite-bearing area are characterised by asymptotic rise of 45° and exhibit the infinite resistivity to the bedrock (Nagaur sandstone). Further, the lignite-bearing horizon overlying the bedrock possesses lower order of resistivity value (3 to 5 ohm-m) in comparison to the barren area having about 10 to 20 ohm-m. In barren area, the asymptotic segment indicating the bedrock (Nagaurs) possesses finite resistivity value and rise of segment is less than 45°. The depth to the bedrock is observed to be larger in the lignite-bearing area than that of the barren area, which suggests favourable basinal/sub-basinal environment for lignite deposition over the bedrock.

3 illus, 8 ref

001177   Whatley R;Bajpai S (NO, , , Email: sunilfes@iitr.ernet.in) : Some aspects of the palaeoecology and distribution of non-marine ostracoda from upper cretaceous intertrappean deposits and the lameta formation of pennsular India. J Palaeont Soc India 2005, 50(2), 61-76.

Ninety-two valid or possibly valid ostracod species from the Maastrichtian intertrappeans and the Lameta Formation are listed in the text and are evaluated in terms of their probable ecology. Some of the 24 communities are analysed in detail. Twenty-two of the 24 localities are grouped into 8 areas (Gujarat, SE Rajasthan, Madhya Pradesh, Maharashtra I- Nagpur District, Maharashtra II- Chandrapur District, Andhra Pradesh, Karnataka, Maharashtra III- Bombay). The degree of communality in terms of numbers of species is expressed diagrammatically and is shown to be little influenced by geographical distance. The relationship between palaeoenvironment and distribution is discussed and explanations involving communality of palaeoenvironment are advanced. Relatively few species are very widespread. These seem to be taxa that are rather environmentally tolerant and, with a notable exception, with good dispersal potential. A surprisingly large number of the 92 species (41 or 44%) are confined to a single locality. Two major groups of communities from different areas are evaluated in more detail. In one case it is thought that water chemistry may have been the controlling factor in the observed difference in the populations of three localities, while in the other, a difference in environmental energy levels is invoked. It is hoped that, with the exposition of some of the virtues that Ostracoda enjoy in environmental reconstruction, future workers make greater use of them for this purpose.

2 illus, 69 ref

001176   Tripathi A;Vijaya;Raychowdhuri A K (NO, Birbal Sahni Inst of Palaeobotany, Lucknow) : Triassic palynoflora from the Mahuli-Mahersop area Singrauli coalfield (Southern extension), Sarguja district, Chhattisgarh, India. J Palaeont Soc India 2005, 50(2), 77-99.

This is the first spore-pollen study of the subsurface strata (Raniganj and Parsora formations) in two boreholes, SSM-1 and SSM-2, from the Maffllli-Mahersop area, Singrauli Coalfield, Chhattisgarh. In all, the five palynoassemblages identified suggest the deposits of latest Permian (Assemblage 1 in SSM-2), earliest Triassic (Assemblage 11 in SSM-2), and Late Triassic (Assemblage A in SSM-1; Assemblage III in SSM-2 and Assemblage B in SSM-1) ages. The palynological data indicates the Permo-Triassic boundary between 542.00 and 537.00m in Borehole SSM-2, whereas the occurrence of the marker paleosol horizon at 509.50m in the same borehole determines the lithological break between the top of the Raniganj Formation and the basal Parsora Formation. Absence of the major part of Early and Middle Triassic deposits is also proved by the present study.

7 illus, 7 tables, 25 ref

001175   Tiwari M;Ramesh R;Somayajulu B L K;Jull A J T;Burr G S (NO, Phys Res Lab, Ahmedabad-380 009, Email: tmanish@prl.res.in) : Solar control of southwest monsoon on centennial timescales. Curr Sci 2005, 89(9), 1583-8.

Solar forcing is proposed to be a major governing factor for the southwest monsoon (SWM) strength during the Holocene. The southeastern Arabian Sea is significantly affected by monsoon run-off and is an ideal testing ground. Analysed stable oxygen isotopic composition (δ¹⁸O) of three species of planktonic foraminifera (Globigerinoides ruber, Gs. sacculifer and Globarotalia menardii) with high time-resolution (<126> 50 yrs) in a sediment core raised from the region, and documented past variations in SWM precipitation. High-resolution isotopic and spectral analyses show that solar forcing indeed played a major role in governing the past variations in SWM precipitation on centennial timescales.

4 illus, 36 ref

001174   Thewissen J G M;Bajpal S;Hussain S T (Dep of Anat, Northeastern Ohio Universities Coll of Med, P.O. Box 95,4209 State Route 44, Rootstown Ohio 44272, U.S.A, Email: thewissen@neoucom.edu) : New insectivorous placentals from the eocene of Pakistan. J Palaeont Soc India 2005, 50(2), 37-41.

Reports discovery of two lower molars of small placental mammals from the late early/middle Eocene Kuldana Formation of the Kala Chitta Hills, Punjabi Pakistan. The first of these is tribosphenic, but lacks an entoconid. Authors name it Perizalambdodon punjabiensis and suggest that it may be related to the tenrecoid radiation of Africa. A second partial lower molar of a small tribosphenic placental is too incomplete to be identified to the family level. However, it does not pertain to any described taxon from Indo-Pakistan. Together with recent finds in the early Eocene of India, these teeth suggest that the diversity of the small insectivorous placentals from Indo-Pakistan was significant, and that much of this fauna remains to be discovered.

2 illus, 23 ref

001173   Taylor P D (Dep of Palaeont, Nat Hist Mus, Cromwell Road, London SW7 5BD, UK) : Bryozoans and palaeoenvironmental interpertation. J Palaeont Soc India 2005, 50(2), 1-11.

Bryozoans are locally abundant as fossils in many marine deposits from the Ordovician to the Holocene. The value of bryozoans in palaeoenvironmental interpretation has been widely acknowledged but their application has yet to be adequately developed, mainly because the environmental factors (both biological and physical) controlling the distributions of modern bryozoans are still poorly understood. Simplistic use of bryozoan colony-forms as palaeoenvironmental indicators, as often "attempted, suffers from several problems. This essay focuses instead on the potential for using intraspecific variability in palaeoenvironmental studies. Bryozoan species are often plastic in their growth and form, with ecophenotypic variations potentially providing useful information on depositional depth, temperature and other environmental factors. Branch thickness in many erect species, especially bushy cyclostomes, decreases with increasing depth. Zooid size in cheilostomes decreases with increasing temperature. This relationship means that variance in zooid size within a colony can be used as a proxy for seasonality, being greater in more seasonal environments.

80 ref

001172   Singh S K;Ram H;Meena H R;Sharma A K;Rasool T J (NO, Temperate Anim Husbandary Div Indian Veternary Res Inst, Mukteswar, Nainital-263 138) : Induction of estrus using PGF 2alfa in non-descript hilly goats. Indian J Anim Reprod 2005, 26(2), 170-1.

Efficacy of PGF_2α injection on induction of estrus in 48 healthy hill goats. The PGF_2α (Dinoprost tromethamine-7.5 mg/goats) was injected intramuscularly in half of the goats (n=24) and rest 24 goats were kept as control and they were exposed to buck only. The behavioural estrus was observed following buck parading twice only. The non-responders were injected with another similar dose of PGF_2α 10-11 days after the first one. The first and second PGF_2α injection induced estrus in 9/24(37.5%) and 9/15(60%) goats, respectively with an overall induction of estrus in 18/24 goats (75%) in comparison to only 5/24 (21%) goats in control. Most of the goats (11; 61.11%) exhibited estrus within 72 hours with an average of 108.22±27.39 and 95.77±22.26 hrs to first and second injection of PGF_2α, respectively. The goats observed in estrus were served to buck of high vigour on two occasions leading to pregnancy in 16/18 (88.88%) goats. The results indicated that PGF_2α could be used effectively to induce estrus in hilly goats with high fertility.

^ssc1 tables, 8 ref

001171   Shukla M K;Mishra A K;Gupta H P;Singh S P (Dep of Anim Reproduction Gynec and Obstertrics, Coll of Vet and Anim Sci G.B. Pant Univ of Agric and Technol, Pantnagar-2631456) : Studies on the microbial load of cryopreserved Murrah semen. Indian J Anim Reprod 2005, 26(2), 168-9.

Determine microbial load in frozen semen of three Murrah bulls using ten ejaculates from each bulls. The average bacterial load determined using pour plate method in the frozen semen of the three bulls was 79.00±0.76, 7.00±0.91 and 60.00±0.87, respectively with an overall mean of 48.60±0.73 colony forming units (CPU) ml^-1. The SPC differed significantly (P<60> 0.01) between the three bulls. All the semen samples were found to be negative for fungus, mucor and yeast.

^ssc13 ref

001170   Samant B;Bajpai S (Dep of Geol, Banaras Hindu Univ, Varanasi-221 005, Email: sunilfes@iitr.ernet.in) : Palynoflora from the Lakshmipur intertrappean deposits of Kutch Gujarat: age implications. J Palaeont Soc India 2005, 50(2), 169-76.

Diverse spore and pollen assemblage, is reported for the first time from the northwesternmost Deccan intertrappeans exposed near Lakshmipur, District Kutch, in the western Indian state of Gujarat. The assemblage is indicative of distinct variations within the Maastrichtian intertrappean palynofloras occurring in different sections across the Deccan province. The flora is significant as it helps to establish a palynological basis for ascertaining temporal differences between the widely separated individual parts of the Deccan volcano-sedimentary province.

1 illus, 1 table, 43 ref

001169   Sahayak S et al (NO, Natn Inst of Oceanography Regional Cent, Kochi-682 018, Email: rjyothi1@yahoo.com) : Red tide of Noctiluca miliaris off south of Thiruvananthapuram subsequent to the 'stench event' at the southern Kerala coast. Curr Sci 2005, 89(9), 1472-3.

2 illus, 12 ref

001168   Rao M V M S;Prasanna Lakshmi K J (NO, Natn Geophys Res Inst, Hyderabad-500 007) : Analysis of b-value and improved b-value of acoustic emissions accompanying rock fracture. Curr Sci 2005, 89(9), 1577-82.

Acoustic emissions (AE) produced during the compressive fracture of a brittle rock have been subjected to detailed analysis using an advanced software for the computation of b-value as well as improved b-value. Conventionally, the b-value of AE is calculated using the Gutenberg-Richter relationship, which is widely used in seismology. Determination of improved b-value is a new approach, which is computed from AE amplitude distribution data. It involves filtering of high and low amplitude AE hits (or events) in a selective manner. The results obtained by both these methods to evaluate the fracture process in the rock are compared and discussed.

5 illus, 25 ref

001167   Rahul ChandReddy P;Salvekar P S (NO, Indian Inst of Trop Meteorology, Pune-411 008) : Presence/role of twin gyres in the El Nino 3.4 domain. Curr Sci 2005, 89(9), 1588-92.

El Nino is the 'weather pulse' of the world climate, arising out of the interactions between ocean and atmosphere. In the ocean, it is caused and cushioned by the interaction of the Kelvin and Rossby waves, but the mode/method and the consequences of their interaction are still not clear. It has been shown in the Indian Ocean that such interference results in a system of westward propagating equatorial twin gyres1. By analysing the surface circulations of a global model (MIT-OGCM) as well from WOCE, TOPEX SSHs, TAO and AVHRR SSTs, Reported a similar feature of the Pacific twin gyres along the equator in the El Nino, domain, especially in the Nino 3.4 domain (170°E-120°W, 10°S-10°N). The possible role of these eddies in inducing warmer temperatures with reference to the El Nino period is investigated.

4 illus, 10 ref

001166   Nigam R (NO, Natn Inst of Oceanography, Dona Paula, Goa-403 004, Email: nigam@nio.org) : Addressing environmental issues through foraminifera case studies from the Arabian sea. J Palaeont Soc India 2005, 50(2), 25-36.

Present global scenario poses multiple environmental problems such as the green house effect, ozone holes, global warming and consequential sea level rise, all being attributed to anthropogenic contributions. Obviously, there is an increased awareness about the past and the present environment, so as to be able to foresee the future variability in climate. However, climate prediction is a very delicate task and needs a thorough knowledge about the past. Past records have been maintained for not more than past 100-150 years, beyond which we would need proxies to give us information about the past climate. During the past few decades, microfossilt, especially foraminifers have become the prime source to address environmental issues. Extreme sensitivity of foraminifera to changing environmental conditions have led to development of techniques to understand the past sea-level fluctuations, monsoons, cyclones and storms, using their specific characteristics. The significant results thereby produced are also listed here. Besides being one of the most extensively used proxies for palaeoclimatic variations, foraminifers have also found applicability in marine -pollution and -archaeological studies. There exists both need and scope for further development of foraminiferal techniques useful in environment impact assessment. So as to keep these techniques in sync with the changing modem trends, the traditional hard part studies of foraminifera need to be supplemented with a detailed foraminiferal-culture programme with a molecular biological approach.

^ccr16 illus, 51 ref

001165   Mishra Y;Kumar S (Dep of Geol, Univ of Lucknow, Lucknow, U.P., Email: surendral@hotmail.com) : Coniform stromatolites and the Vindhyan supergroup, central India: implication for basinal correlation and age. J Palaeont Soc India 2005, 50(2), 153-67.

Five coniform stromatolites are described from the Semri Group. Two are from the Kajrahat Limestone viz., Calypso sp. and Thyssagetes sp., and three are from the Fawn Limestone viz., Ephyaltes myriocranus. Siren sp. and Cyathotes phorbadicia. The Upper Vindhyans are completely devoid of coniform stromatolites though other columnar forms are abundant. The coniform stromatolite assemblage supports an age assignment of 1800 to 1600 Ma for the Semri Group and confirms the utility of stromatolites in both intrabasinal and interbasinal correlations.

2 illus, 2 tables, 35 ref

001164   Matsumaru K;Yoshida A;Hayashi A (Dep of Geol, Fac of Educ, Saitama University, Saitama-338 8570, Japan, Email: matsumar@post.saitama_u.ac.jp) : Orbirolinid foraminifera from the lower aptian ishido formation of the Sanchu cretaceous system kanto Central Japan. J Palaeont Soc India 2005, 50(2), 55-60.

Polorbitolina lenticularis (Blumenbach) is described for the first time from the Lower Aptian Orbitolina-bearing sandstone and limestone, Ishido Formation, Sanchu Cretaceous System, Honshu, Japan. Palorbitolina lenticularis is associated with (Lraqia simplex Henson).

2 illus, 2 P, 30 ref

001163   Kundal P;Mude S;Humane S K (Post-Graduate Dep of Geol, R.T.M. Nagpur Univ Law Coll Square, Nagpur-440 001, Email: ppk_kundal@rediffmail.com) : Ichnofossils from the late eocene to early miocene of the Narmada block of the Cambay basin Gujarat, India. J Palaeont Soc India 2005, 50(2), 177-82.

Yellow limestone of the Dinod Formation (late Eocene) exposed at Dinod village, Ankleshwar taluka, Broach District, Gujarat has yielded one ichnospecies, namely Skolithosi ichnosp., whereas the alternation of sandstone and clays of the Babaguru Formation (early Miocene) oyoutcropping at Bhilod village of Valia taluka of Broach District shows presence of six ichnospecies, viz. (Keckia annulata) Ophiomorpha nodosa (Paleophycus tubularis)(Planolites beverleyensis) Planolites montenus and Thalassinoides paradoxicus. Skolithos ichnospecies belonging to Skolilhos facies indicates .that the Dinod Formation was deposited TBeJ3osilea"un3er littoral to very shallow sublittoral zone under high energy conditions. The ichnoassemblage from the Babaguru Formation is referable both to Skolithos facies and Cruziana facies which indicate that the Babaguru Formation was deposited under littoral to shallow sublittoral environment.

2 illus, 1 table, 25 ref

001162   Janakiraman S;Nanjundiah R S;Vinayachandran P N (NO, Cent for Dev of Advd Computing, CDAC Knowledge Park, Bangalore-560 038, Email: ravi@caos.iisc.ernet.in) : Simulations of the Indian summer monsoon with a coupled ocean-atmosphere model on PARAM Padma. Curr Sci 2005, 89(9), 1555-62.

Simulations with climate models is a computationally challenging problem. It is even more challenging when a coupled model of ocean and atmosphere is used. Reported the implementation of a coupled ocean-atmospheric model on the PARAM Padma, a high-performance computer developed by Centre for Development of Advanced Computing, Bangalore and results from a 100-year simulation with this model. This is perhaps one of the largest computational experiments in the field of climate modelling conducted in the country. The computation took about 27 days of computer time on 104 processors spread over a period of three months. Found that the simulations of the Indian summer monsoon with the coupled model are more realistic than with the atmospheric component alone. Also found that the simulation of ocean state is reasonable, although the simulated sea surface temperature is colder than the observed climatology.

5 illus, 20 ref

001161   Hofmann H J (Dep of Earth and Planetary Sci, and Redpath Museum, Canada H3A 2A7, Email: hofmann@eps.mcgill.ca) : Palaeoproterzoic dubiofossils from India revisited Vindhyan triploblastic animal burrows or pseudofossils. J Palaeont Soc India 2005, 50(2), 113-20.

Purported Palaeoproterozoic triploblastic burrows from the Chorhat Formation (Semri Group, lower part of the Vindhyan Supergroup) in central India have remained controversial, Alternative explanations as inorganic structures also remain unconvincing to proponents of a burrow origin, leaving the arguments for and against biogenicity still inconclusive. The purpose of this paper is to review the evidence for a burrow origin, and to explore an alternative, abiologic explanation for the structures. They are compared to distinctive reticulate subsurface patterns on bedding and joint surfaces found in the Kaimur Group sandstones and generated during geologically more recent ferricrete formation.

1 illus, 2 p, 22 ref

001160   Guha A K;Gopikrishna K (Dep of Geol and Geophysics, Indian Inst of Technol, Kharagpur-721 302, Email: gak3366@yahoo.co.in) : Some fossil anascan bryozoan taxa from the tertiary sequences of Western Kachchh, Gujarat. J Palaeont Soc India 2005, 50(2), 135-51.

Fifteen fossil anascan bryozoan species viz. Biflustra mitiensis n. sp., Conopeum gohelaensis, n. sp., Herpelopora haimei n. sp., Akatopora aidaensis, n. sp., Antroporn gadhavii, n. sp., Nellia quadrangularis Tewari and Srivastava, 1967, N. kutchensis Tewari and Srivastava, 1967, N. narayani n. sp., N. walasaraensis n. sp., Vincularia ramwarnensis, n. sp., Crepis gurjnrensis, n. sp., Micropora vredenburgi n. sp., Microporina biswasi n. sp., Onychocella torquala, n. sp. and Floridina penlngonus n. sp. belonging to 12 genera in eight families are described and illustrated. Stratigraphic ranges of Nellin quadrangularis Tewari and Srivastava, 1967 and N. kutchensis Tewari and Srivastava, 1967 are revised, and neotypes for these two species have been designated.

s, 2 p, 1 tables, 60 ref

001159   Guha A K;Gopikrishna K (Dep of Geol and Geophysics, Indian Inst of Technol, Khragpur-721 302, Email: gak3366@yahoo.co.in) : Lunulitiform cheilostome bryozoans from the miocene sequences of western Kachchh, Gujarat. J Palaeont Soc India 2005, 50(2), 13-24.

Four species of lunulitiform cheilostome importan as and fauna", are described from the Miocene rocks of western Kachchh ' Gujarat. Among them two specks, Qiscoporella misrai and Anoteropora rajnathi described by Tewaria(et al. (1960) from the ("Gaj") Burdigalian (Chhasra Formation) of Kachchh, are redescribed with designation of their Neotype. Two other species Aneteropora aff. latiriostris silen 1947 and A. cookae n. sp. are described. Variability of linear zooecial dimensions, both within and among colonies, has been studied.

2 illus, 1 table, 16 ref

001158   Dennell R W;Turner A;Coard R;Beech M;Anwar M (Dep Archaeology, University of Sheffied, S1 4ET, U.K) : Two upper Siwalik (Pinjor stage) fossil accumulations from localities 73 and 362 in the Pabbi Hills, Pakistan. J Palaeont Soc India 2005, 50(2), 101-11.

Small fossil accumulations from localities 73 and 362 in the Pabbi Hills, Pakistan, are ca. 1.2 - 1.4 and 1.7 - 1.9 Ma-old respectively, and are primarily interesting because of their carnivore remains. Those from locality 73 included P. brevirostris, Crocuta crocula, Panthera of P. undo, a small canid, an ursid and a herpestid. Locality 362 produced the first securely dated example from the Upper Siwaliks of the large canid C. cautleyi, of which a partial skeleton was preserved. Both localities raise general issues concerning the preservation of evidence of carnivores in the Upper Siwaliks, and the identification of the predator that killed the prey presented at these types of localities.

7 illus, 4 tables, 37 ref

001157   Bajpai S;Kapur V V;Thewissen J G M;Das D P; Tiwari B N;Sharma R;Saravanan N (Dep of Earth Sci, Indian Inst of Technol, Roorkee, Email: sunilfes@ernet.in) : Early eocene primates from Vastan lignite mine Gujarat, Western India. J Palaeont Soc India 2005, 50(2), 43-54.

New primate fauna of early Eocene (Ypresian, approximately 52 Ma) age is reported from the Vastan Lignite Mine, District Surat, Gujarat, westen India. From the Indian subcontinent, this is the oldest known Cenozoic record as well as the largest single sample of Eocene primates, consisting of 3 fragmentary jaws and 4 isolated upper cheek teeth. The assemblage comprises at least three, but possibly 4 taxa, of which only two are being named here, an adapiform Marcgodinotius indicus n. gen. & n. sp., and an omomyid Vastanomys gracilis n. gen. & n. sp., distinguished mainly on the basis of their lower dental formula and lower molar characteristics. The fauna indicates considerable diversity of Eocene primates in Indo-Pakistan and is important in understanding early primate evolution in Asia and the mammalian dispersal into, or out of, from India in response to changing paleogeographic settings associated with the initiation of India-Asia collision.

1 illus, 28 ref

001156   Arun Kumar;Patterson R T (Dep of Earth Sci Ottawa-Carleton Geoscience Cent Coll of Natutal Sci, Carleton Univ 1125 Colony by Drive Ottawa Ontario, Canada kis 5B6, Email: arunkumaro@hotmail.com) : Foraminiferal evidence of subaqueous debris flows at ODP site 1033 (LEG 169S), Saanich inlet Vancouver island, Canada. J Palaeont Soc India 2005, 50(2), 121-34.

Foraminiferal faunas of 150 Holocene-latest Pleistocene samples from ODP Site 1033 (Leg 169 S), Saanich Inlet, were quantified. Sediments of this anoxic inlet in southern Vancouver Island, British Columbia consist of varved clays interbedded with slightly coarser massive layers. The 25 species of benthic foraminifera found were predominantly shallow water, calcareous forms, although a few planktic foraminifera and rare arcellaceans, as well as deeper water dysoxic benthic forms were also recorded. Most samples contained an impoverished fauna (average of 25 to 30 individuals), but massive layers contained statistically higher numbers and diversity of foraminifera than varves. A high proportion (<62> 50 %) of the foraminiferal fauna in the massive units were also found to be either damaged or broken. Such a high proportion of broken/damaged foraminifera along with the presence of arcellaceans in the massive layers lend credence to the hypothesis that they were transported from well oxygenated shallower, and nearshore parts of the inlet and deposited on the anoxic bottom of Saanich Inlet during subaqueous debris flows. Subaqueous debris flows in the inlet are induced by both seismic and non-siesmic events. The varved sediments also contain broken specimens of foraminifera. Although intact benthic foraminifera within the varves are typical forms capable of withstanding dysoxic conditions and appear to be autochthonous, broken specimens are mostly shallow water types requiring higher levels of oxygen. They are transported to the deeper anoxic parts of the inlet during spring freshet along with mineral rich silt. It is difficult to distinguish between seismic and non-seismic debris flows as few recorded earthquakes in the region have been conclusively linked with massive layers.

3 illus, 3 tables, 49 ref

000217   Yang X Y;Yang X M;Jiang L L;Wang K;Sun L G (Sch of Earth and Space Sci, Advd Cent for Earth Sci and Astr of the Third Wld Acad of Sci Univ Sci, Hefei 230026, China, Email: xyyang@ustc.edu.cn) : Geochemical study of Shaxi porphyry copper gold deposit in Southern part of Tan-Lu fault belt, East China. J Geol Soc India 2006, 67(4), 475-94.

Shaxi porphyry Cu-Au deposit in central Anhui Province is located in the Middle-Lower reaches of Yangtze metallogenic valley in east China. Red sandstone and conglomerate of Cretaceous age, clastic rocks of Middle and Lower Jurassic, clastic rocks of continental sea facies of Upper Devonian-Middle Silurian age, various continental volcanic rocks of Jurassic age form the rock types of the Shaxi porphyry copper-gold metallogenic belt. The ore district is cut by multiple faults, of which the most important are Tanlu fault and Fanshan-Tongling faults, the former being the largest fault system in East Asian continent and the later being the regional deep fault. The geological geochemical and mineralogical methods used to investigate the porphyry copper-gold deposit associated with large scale sulphide mineralization forms the theme of this study. Through field geological surveys, mineralogical observation, compositional analyses on minerals using EPMA, geochemical analyses on Cu-Au-bearing intrusive rocks, fluid inclusion and oxygen, hydrogen, sulphur isotopic studies, and element distributions detected by PIXE system, the characteristics of mineralization and gold occurrence in the Shaxi porphyry copper-gold deposit have been fully investigated. The results of the study form the basis for further research and exploration on the porphyry copper-gold deposit of the Middle-Lower Yangtze region.

15 illus, 9 tables, 49 ref

000216   Viljoen R P (Sch of Geosciences, Univ of the Witwatersrand, Johannesburg, Email: viljoenr@geosciences.wits.as.za) : Geological comparison between India and Southern Africa: implications for diamond exploration. J Geol Soc India 2006, 67(4), 432-41.

Kaapvaal and Zimbabwe cratons of southern Africa were compared with the Peninsular Indian Cratons with special reference to kimberlite clan of rocks and incidence of diamonds. The applicability of Clifford's Rule, host-rocks, structural controls, presence of large igneous provinces in both the regions are analysed to underscore the parallels and to draw inferences of utility in the renewed diamond exploration activity currently underway in India.

5 illus, 14 ref

000215   Venkatesh T N;Mudkavi V;Rajalakshmy S; Sarasamma V R;Sinha U N;Narasimha R (NO, Natn Aerospace Laboratories, Bangalore, Karnataka, Email: uns@flosolver.nal.res.in) : Preliminary results on the simulation of the 1999 Orissa super cyclone using a GCM with a new boundary layer code. Mausam 2006, 57(1), 119-28.

Presents preliminary results from the simulation of the Orissa super cyclone using a new AGCM code (named Varsha) written as part of a NMITLI project. The simulation is initialized at 0000 UTC, 26 October 1999, using ECMWF T-106 initial conditions. The control run is made using the Vrsha code at T-80 resolution with a standard Monin-Obukhov boundary layer code incorporating a gustiness factor. With the horizontal resolution improved to 120 spectral modes with a 78 km grid spacing, and a new boundary layer parameterization at low winds, the code shows substnatial improvements: the maximum error is reduced from 350 to 234 km at 36 hr after initialization, 310 to 34 km at 48 hr, and 410 to 55 km at 96 hr. It has been suggested that part of the explanation for this improvement lies in the improved estimation of surface forces and torque in the new boundary layer code. The role of torque is particularly interesting as the major contribution to it comes from the outer regions of the cyclone where the winds are relatively low but the area on which the surface force acts and its moment arm are both high. Intriguingly the higher surface forces arise also from the higher windss predicted by new code. An interesting finding is that, on both track and minimum pressure, the improvement due to higher resolution is greater with the new boundary layer module. Further analysis is necessary to assess the effect of other eddy fluxes (sensible heat, moisture) on cyclone track prediction.

9 illus, 1 table, 10 ref

000214   Venkatesh T N (Flosolver Unit, Natn Aerospace Laboratories, Bangalore, Email: tnv@flosolver.nal.res.in) : Mesoscale interactions during the genesis and intensification of October 1999 Orissa super cyclone. Mausam 2006, 57(1), 31-6.

It is well known that a mature tropical cyclone is known to have a nearly axisymmetric structure but that the formation stage exhibits considerable asymmetry. Recent studies and observations in the Pacific indicate that mesoscale interactions could play an important role in the genesis of tropical cyclones. Modern theories of tropical cyclone genesis are also based on this premise. An anlysis of the IR satellite imagery and large scale vorticity fields has been presented, which shows that mesoscale vortex interactions occur in the early stages of the 1999 Orissa super cyclone also.

7 illus, 9 ref

000213   Trivedi D K;Mukhopadhyay P;Vaidya S S (NO, Indian Inst of Trop Meteorology, Pune, Email: mpartha@tropmet.res.in) : Impact of physical parameterization schemes on the numerical simulation of Orissa super cyclone (1999). Mausam 2006, 57(1), 97-110.

Non-hydrostatic version of Pennsylvania State University - National Center for Atmospheric Research mesoscale model (MM5) has been used to simulate the super cyclonic storm that crossed Orissa coast on 29 October, 1999. Experiments are carried out with four cumulus parameterization schemes namely; Kain-Fritsch, Betts-Miller, Grell and Anthes-Kuo and two planetary boundry layer parameterization (PBL) schemes namely; Hong-Pan and Burk-Thompson to study their impact on the movement and development of the cyclone. The sensitivity is examined in terms of movement, evolution of minimum pressure, rainfall pattern and vertical cross section of temperature. All the simulations were able to develop the very severe cyclonic storm from very weak circulation except with Anthes-Kuo scheme. The evolution of the minimum central pressure shows much sensitivity among the different cumulus schemes with Kain-Fritsch producing 966 hPa while Anthes-Kuo 1004 hPa during the 4 days of the integration period. Different cumulus parameterization schemes show significant impact on the simulated movement of the cyclone. The result revealed that the evolution of minimum central pressure and horizontal as well as vertical structures of winds, temperature anomalies and rainband characteristic to a cyclone are well brought out by the combination of Kain-Fritsch and Hong-Pan schemes.

9 illus, 2 tables, 17 ref

000212   Tripathi S C (Map and Cartography Div, Geol Surv of India, Sector-E, Aliganj, Lucknow - 226 024, Email: sctgsilko@rediffmail.com) : Geology and evolution of the cretaceous infratrappean basin of lower Narmada valley, Western India. J Geol Soc India 2006, 67(4), 459-68.

The Cretaceous sedimentary basins of lower Narmada valley covered a vast region in the western India and presently a large part of these basins are under the Deccan Trap cover. The geology of the exposed part shows development of continental facies with an intervening marine transgressive facies. The Nimar-Bagh-Lameta sequence was studied for their regional tectonic framework, stratigraphy and basin evolution. It has been observed that the marine transgression was limited to the half-grabens paralleling the Precambrian tectonic fabric. The Bagh area (Madhya Pradesh) is contemplated to represent a Cretaceous triple point junction formed due to the reactivation of Precambrian tectonic grain during the anticlockwise movement of India plate. A detailed stratigraphy of the area has been proposed. The continental Nimar Sandstone Formation was deposited in a large westerly sloping topographic basin. The marine transgression at the end of the Nimar period resulted into the deposition of Bagh Group. The overlying continental Lameta Group shows varied sedimentation in space and time. The calcareous sandstone and limestone with chert concretions containing dinosaur skeletal remains are the most widely deposited facies of the Lameta Group and have a striking similarity with that of the Lower Limestone (Lameta Group) of the upper Narmada valley.

4 illus, 1 table, 27 ref