002363   Chadha R K;Latha G;Yeh H;Peterson C;Katada T (NO, Natn Geophys Res Inst, Hyderabad-500 007) : The Tsunami of the great sumatra earthquake of M 9.0 on 26 December 2004 - impact on the east coast of India. Curr Sci 2005, 88(8), 1297-1301.

An earthquake of magnitude 9.0 occurred off the coast of Sumatra on 26 December 2004 at 00:58:50 (UTC)/06:28:50 AM (IST). The epicentre of the earthquake was located at 3.29°N and 95.94°E. The focal depth of the earthquake was 30 km. This earthquake generated huge tsunami waves which devastaated the Andaman and Nicobar Islands, east coast of India, south Kerala in india and several other countries like Sri Lanka, Indonesia, Thailand and Somalia in the Indian Ocean. The tsunami claimed more than 250,000 human lives in these countries. The aftershocks of this earthquakel numbering more than 250 in the magnitude range 5 ≤ M <60> 7.3, were located for a length of 1300 km from Sumatra in the south to the Andaman and Nicobar islands in the north, till 30 January 2005. A tsunami run-up survey was conducted immediately after the event to study tsunami damages, inundation areas and to obtain estimates of tsunami heights from perishable evidences like watermarks on houses and ocean debris transported inland. This communication presents results on tsunami heights at different locations along the coastal areas of Tamil Nadu.

2 illus, 1 table, 2 ref

002362   Bhattacharya A K;Dhar N;Lahiri S (Opn:WB-SK-A&N, Geol Surv of India, North Block, 4th Floor, DK-6, Sector II, Salt Lake, Kolkata-700 091, Email: gsiopwsa@cal3.vsnl.net.in) : Occurrence of scorodite, a secondary arsenate in alluvial deposits around Durgapur, Bardhaman district, West Bengal. J Geol Soc India 2005, 65(1), 88-91.

Scorodite (FeAsO₄.2H₂O) has been identified for the first time in the alluvial samples around Durgapur in the Bardhaman district of West Bengal necessitating further detailed studies. Arsenic pollution in groundwater is one of the most focussed problem in the present day world in many countries. Presence of As <62>0.01 mgl^-1 in drinking water has toxicological effects. The primary sources of As in groundwater include elemental arsenic, arsenides, sulphides, oxides, arsenates and arsenites. In West Bengal, elevated groundwater has been reported from a numb localities, the source of which has been attributed to pyrite, arsenopyrite, and siderite concretions conta bacteria.

^ssc1 illus, 1 table, 21 ref

002361   Baskar S;Baskar R;Mauclaire L;McKenzie J A (NO, Geol Inst, ETH-Zentrum, 8092 Zurich, Switzerland, Email: rbaskargjuhisar@yahoo.com) : Role of microbial community in stalactite formation, Sahastradhara caves, Dehradun, India. Curr Sci 2005, 88(8), 1305-8.

Speleothems found in three caves in Sahastradhara, Dehradun, India were studied to understand if geomicrobiological processes were involved in mineral formation. Mineralogical studies (XRD and SEM-EDAX) of the stalactite samples revealed that calcite is the dominant mineral. An abundant microbial community (9 x 10⁵ cells, g sed^-1) was detected by direct microscopic observation after DAPI staining. Application of fluorescence in situ hybridization techniques (FISH), based on the presence of rRNA, demonstrates the presence of a large number of active microbial cells (around 55% of the total cell number). The microbial community is dominated by Eubacteria, mainly sulphate-reducing bacteria (representing 10% of the total microbial comniunity), but Archaea are also present. A significant fraction of these cells are active, indicating the high probability of their participation in biomineralization processes involved in the stalactite formation. This conclusion is at variance with the established classical model for stalactite formation based entirely on inorganic processes associated with carbonate solubility.

5 illus, 16 ref

002360   Bandyopadhyay A;Mahapatra S (NO, , , Email: bandop@tropmet.res.in) : Impact of recursive digital filtering initialization on the forecast performance of a limited area model over Indian region. J Indian Geophys Union 2005, 9(1), 29-40.

Two versions of recursive digital filtering initialization (DFI) schemes have been applied to a limited area model to examine their impact on the model performance on short-range forecast over Indian region. For comparison, the input is also initialized by non-recursive diabatic digital filtering initialization (DDFI) technique. It is found that both the versions of recursive filter could effectively suppress the high-frequency oscillations from the forecasts. The filters are found to be more effective in controlling the noise in the first few hours of integration. The changes induced to the analysis by both the versions of recursive filters are reasonably small and are comparable with changes made by non-recursive filter (DDFI). The 24 hr forecasts from the either of the two-recursive DFI schemes are comparable with those produced from DDFI scheme and also with the forecasts obtained from un-initialized input. The main advantage of DPI is found to be its great simplicity in conception and application. Its implementation is very easy, requiring only the calculation of the filter coefficients and minor adjustments of the model code.

5 illus, 6 ref

002359   Bajaj a K;Tikku V K;Paul R (NO, Geol Surv of India, NH-5P, NIT, Faridabad-121 001) : Ferrosilicon/ceramic-grade quartzite from Delhi supergroup - a case histroy from Haryana. Indian Miner 2004, 58(1-2), 99-106.

Rocks of Delhi Supergroup occur as isolated ridges and hillocks separated by alluvial-filled stretches from Rajasthan to southern Haryana. Some of the isolated outcrops are of high-grade silica quartzite, which belong to Alwar Group. This quartzite can provide raw material for ferrosilicon, ceramic, super duty silica brick, - a high-temperature refractory used in lining coke oven, metallurgical furnace. Study for locating high-grade silica quartzite was carried out at Bayal and Doiwala-ki-Dhani hills of Mahendragarh district, Haryana, with a view to assess quality, quantity and nature of quartzite for its use as raw material in ferrosilicon and ceramic industries. The rocks exposed in the study area belong to the Bayal-Panchnota Formation (Pratabgarh Formation of Rajasthan) of Alwar Group of Delhi Supergroup. These are represented by quartzites, muscovite schist, amphibole schist, anthophyllite schist and chlorite schist. The main country rock in Bayal and Doiwala-ki-Dhani hills is quartzite, which forms the crest of the ridge, while muscovite schist, amphibole schist, anthophyllite schist and chlorite schist are exposed on the eastern slope. Analytical results of chip samples indicate that the white quartzite of Doiwala-ki-Dhani can be used, as raw material for manufacturing ferrosilicon with average grade: SiO₂-97.89%, Al₂O₃-0.94%, Fe₂O₃-0.98%, CaO-0.08%, MgO-0.02%, P₂O₅-0.02% and LOI-0.31%. In comparison, the average grade of white quartzite from Bayal hill is SiO₂-96.40%, Al₂O₃-1.42%, Fe₂O₃-1.46%, CaO-0.12%, MgO-0.01%, P₂O₅-0.03% and LOI-0.33%, which conforms to the requirement of grade-2 of ceramic industries. A tentative resource of 0.153 million tonnes of ferrosilicon-grade quartzite and 1.029 million tonnes of ceramic-grade quartzite from Doiwala-ki-Dhani and Bayal hill respectively has been estimated.

2 illus, 5 tables, 4 ref

001225   Yang X Y (Key Lab of Gas Geochemistry, Lanzhou Inst of Geol Chin Acad of Sci, Lanzhou-730000, Email: xyyang@ustc.edu.cn) : Geochemistry of rare-gases in eclogites from Dabie Shan orogenic belt, eastern China. J Geol Soc India 2005, 65(4), 478-81.

Studies the fluid inclusions in coesite-bearing eclogites in the Dabie Shan terranes (Yang et al. 1999, 2000, 2001), and reported one extremely high H₂-bearing fluid inclusion (Yang et al. 2003), where the Triassic ultra-high pressure (UHP) metamorphism occurred at mantle depths (Okay et al. 1989; Wang et al. 1989, Xu et al. 1992; Li et al. 1993). This paper reports the result of rare gas geochemistry of the UHP eclogites.

^ssc1 illus, 1 table, 19 ref

001224   Tomar S S;Gautam H C (Ministry of Agric, , Krishi Bhavan, New Delhi-110 001) : Need to exploit water resources in Eastern India. Indian Fmg 2004, 52(2), 21-3.

The eastern India has great potentiality with abundant water resources available for irrigations. At present, the utilization is, however, meagre. Due to high precipitation, there is tremendous recharge of ground as well as surface water resources. There is a great scope for extensive use of the shallow tube well, lift irrigation scheme and dug wells in the region. The development has a potential to convert mono crop rice to assured double cropped area. This could be a boon to the small and marginal farmers and may help in recharging the ground water-table, the authors suggest.

001223   Tewari R C (Dep of Geol, D S Coll, Aligarh-202 001, Email: ram tewari@rediffmail.com) : Sedimentolog synthesis of Gondwana formations of peninsular India and its bearing on stratigraphy. Indian J Petrol Geol 2004, 13(2), 75-85.

Late-Carboniferous to early Cretaceous Gondwana rocks of peninsular India represent dominantly elastics accumulated for about 160 m.y. The Gondwana sequence correspond to three tectono-sedimentary provinces. The first late-carboniferous province comprises glacial, glacigene and fluvio-glacial Talchir sediments. The second tectono-sedimentary province is characterized by overlying early Permian to late Triassic / early Jurassic (?) sediments which were deposited by northwesterly flowing braided and meandering streams. The succeeding late Jurassic-early cretaceous sediments with their localized development as pull-apart pericratonic basins filled up largely by alluvial fan facies on an inverse southerly paleoslope marks the third tectono-sedimentary province. These three Gondwana provinces are marked by different tectonic setting, lithofacies assemblage, paleoslope, and texture and composition of sandstone. By and large, they correspond to three paleoclimatic zones of cold, humid-warm and warm-semi arid. The Gondwana sequence of peninsular India therefore represents three distinct but successive tectono-stratigraphic sedimentary provinces.

1 illus, 2 tables, 31 ref

001222   Suryabhagavan K V;Seetharamaiah J;Dhananjaya Rao E N;Nagarjuna V (Dep of Geol, Andhra Univ, Visakhapatnam-530 003) : Temporal variations of the penner river mouth during the recent past and their quanitification through remote sensing and GIS. Indian J Petrol Geol 2004, 13(2), 25-30.

River Penner had reportedly undergone a number of temporal changes, especially at its mouth during the recent past. The temporal changes that had occurred in the Penner river mouth during the past 83 years were traced out and quantified based on Survey of India Toposheets and IRS ID satellite imagery applying Remote Sensing and Geographical Information System technique. The study reveals that shifting of the channel flow, elongation and protrusion of barrier spits opposite the river mouth, 5.52 sq.km of land was added on the whole to the Penner delta in the past 83 years.

2 illus, 1 table, 6 ref

001221   Suresha K J;Srikantappa C (Dep of Geol, Univ of Mysore, Manasagangotri, Mysore-570 006, Email: kjsuri@rediffmail.com) : Igneous charno-enderbites and charnockites (C-type magmas) around Dindigul, Tamil Nadu. J Geol Soc India 2005, 65(4), 403-10.

Charnockites from the Southern Granulite Terrane were considered to be product of regional high-grade metamorphism, aided by CO₂-rich and alkaline fluids. Reports the occurrence of intrusive charno-enderbites and charnockites around Dindigul, which consist of pyroxenes, plagioclase, alkali feldspar, quartz, biotite, titanomagnetite, ilmenite and apatite. These rocks are characterized by higher abundance of K₂O, TiO₂ and P₂O₅ and lower contents of CaO with lower m* for a given SiO₂ content, relative to metamorphic charnockites from the Biligiri Rangan and Nilgiri granulites, and have the geochemical similarities with the Ardery charnockitic intrusions from Antarctica.

7 illus, 1 table, 20 ref

001220   Sunil Kumar;Pandita S K (P G Dep of Geol, Univ of Jammu, Jammu-180 006) : Soil degradation and hydraulic aspects of Kangar watershed northwest of Jammu. Bull Indian Geol Ass 2004, 37(1-2), 47-57.

The watershed of Kangar village in Jammu district of Jammu and Kashmir State is about 2 km² in the kandi belt of Northwest Himalaya. Denuded hills, undulating topography, erratic rainfall in space and time, high soil erosion, coarse texture, infertile soil, and acute shortage of water are typical features in this region. Repeated cycles of erosion and dissection of the lithounits give the present geomorphology of the area. Boulders and gravels with ferruginous clay matrix and texture are part of the loose sandy loam soils. Low water holding capacity of soil together with loss of nutrients by leaching and high permeability has made this area devoid of proper vegetation. The measures suggested to improve the watershed development in terms of groundwater recharge, soil fertility and reduction of soil erosion include hydrometeorological monitoring of the area, scientific landuse and water management practices, land grading to bring down slope, terracing within field boundaries, field bunding and afforestation.

5 illus, 3 tables, 11 ref

001219   Sundararajan N;Rao B M (Cent of Explor Geophysics, Osmania Univ, Hyderabad-500 007, Email: sundarajan_n@yahoo.com) : A note on the petrophysical properties and geological interpretation in Schirmacher oasis, East Antarctica. J Geol Soc India 2005, 65(4), 497-503.

Vertical magnetic measurements were carried out along three chosen profiles to have an insight and inference about the subsurface geology and structures of Schirmacher region of east Antarctica. The interpretation of magnetic profiles based on amplitude analysis using the Hilbert transform and traditional Fourier spectral analysis in frequency domain reveal certain structural features such as faults/contacts at shallow depth. Depths from modeling of the magnetic anomalies agree well with the interpreted depths particularly in the case of profiles II and III. Measured densities and magnetic susceptibilities of the rock samples are found to be marginally high in some cases in comparison with those of the Indian Peninsula.

5 illus, 2 tables, 8 ref

001218   Sinha R;Gibling M R;Tandon S K;Jain V; Dasgupta A S (Engng Geosciences Grp, IIT, Kanpur-208 016, Email: rsinha@iitk.ac.in) : Quaternary stratigraphy and sedimentology of the Kotra section on the Betwa river, Southern Gangetic plains, Uttar Pradesh. J Geol Soc India 2005, 65(4), 441-50.

Floodplain deposits are exposed in an about 29 m high cliff section at Kotra along the Betwa river, a tributary of the Yamuna river at the southern margin of the Gangetic Plains. The Betwa is a peninsular river originating in the Bundelkhand Craton parts of which are exposed as bedrock close to the section. The Betwa river is incised and bordered by an extensive zone of badland (dissected into gullies). The stratigraphic units comprise pedogenized floodplain muds and reworked carbonate gravels that fill small plains-fed channels. Gully fills of mud and gravel mark extensive degradational surfaces that divide the section into discontinuity-bounded units, currently of unknown duration and age. Closely spaced discontinuities low in the section may mark a former interfluve level, after which a thick floodplain succession accumulated up to the level of the modern clifftop. Presence of prominent discontinuities and thick floodplain deposits in the cliff sections suggest that the late Quaternary history of the southern plains is marked by cycles of channel incision and floodplain degradation and alluviation.

7 illus, 22 ref

001217   Singh B N;Joshi M (Geol Lab Dep of Civ Engng, Inst of Technol Banaras Hindu Univ, Varanasi-221 005) : Occurrence of rhyolitic dykes within the Mt Abu batholith, Southwestern Rajasthan. J Geol Soc India 2005, 65(3), 309-16.

The occurrence of Malani rhyolites as dykes within the Mt. Abu batholith has been studied. The Mt. Abu rhyolitic dykes are peraluminous and of subalkaline nature. These are enriched in trace elements such as Rb, Mb, Zr, Y, Ga, Th and Zn, and depleted in Ba and Sr resulting in high K/Rb, Rb/Sr, Ba/Sr and Ga/Al ratios. The geochemical characters indicate Mt. Abu rhyolitic dykes to be A-type, within-plate granites (WPG) with high SiO₂, Na₂O + K₂O and Fe/Mg. These rhyolites are likely to have formed in anorogenic rift-related setting and the volcanism may be correlated to early stages of Pan-African magmatic event (850-750 Ma).

7 illus, 2 tables, 25 ref

001216   Shukla M;Babu R;Mathur V K;Srivastava D K (Birbal Sahni Inst of Palaeobotany, , Lucknow-226 007, Email: manoj_shukla_1999@yahoo.com) : Additional terminal proterozoic organic-walled microfossils from the infra-krol formation, Nainital syncline, Lesser Himalaya, Uttaranchal. J Geol Soc India 2005, 65(2), 197-210.

Black carbonaceous shale associated with black chert nodules of Infra Krol Formation, Baliana Group yielded diversified assemblage comprising 20 taxa of organic-walled microfossils (OWM) represented by acritarchs and cyanobacterial remains. Out of these, 16 taxa are reported for the first time from this area which include five genera of acritarchs (sphaeromorphida subgroup) viz. Margominusciila simplex, Granomarginata primitiva, Satka colonialica, Paracrassosphaera dedalea, Micmconcentrica incrustata, and six genera (sphaerohystrichomorphida subgroup) viz. Baltisphaeridium perraruin, Trachyhystrichosphaera vidalii, Gorgonisphaeridium maximum, Micrhystridium echinuatum, M. regulare, M. eatonensis, Archaeohystrichosphaeridium cellulare, A. semireticulatum, Germinosphaera unispinosa; four taxa of the cyanobacterial remains viz. Globophycus rugosum, Bavlinella faveolata, Eomicrocystis malgica, Tetraphycus hebeiensis, Eophormidium orculiformis belong to Synaplomorphitae subgroup and single genus of VSM viz., Melanocyrillium hexodiadema. The recovered microbiotic assemblage compares well with the assemblages known from the Terminal Proterozoic sediments. The large sized acanthomorph Trachyhystrichosphaera vidalii, recorded here for the first time, is known globally after Varanger glaciation and before diversification of Ediacaran biota. An analysis of the recovered microbiotic assemblage in the Infra Krol Formation suggests its autochthonous nature. It was deposited in stable, shallow water, restricted pond or lake which had occasional contact with the open sea.

1 illus, 1 table, 115 ref

001215   Sarkar S K;Ahmad I;Gupta M M (Radio and Atmospheric Sci Div, NPL, Dr K S Krishnan Road, New Delhi-110 012, Email: sksarkar@mail.nplindia.ernet.in) : Statistical morphology of cloud occurrences and cloud attenuation over Hyderabad, India. Indian J Radio Space Phys 2005, 34(2), 119-24.

Attenuation due to clouds in millimeter wave and microwave frequency bands lead to degradation in the performance of radio communication, especially for low noise systems. Frequent presence of cloud causes some amount of link degradation for significant percentage of time over the tropical Indian subcontinent. The cloud morphology particularly in relation to radio wave propagation over different geographical region of India is very essential and important. In view of this, systematic studies on cloud occurrence morphology over different geographical locations in India have been undertaken. Based on low level cloud coverage observations, frequency of cloud occurrences over Hyderabad (17.27°N, 78.28°E), situated in Indian tropical southern region in different months during daytime and nighttime has been deduced and presented in the paper. The low-level cloud over Hyderabad has been found to occur for many days and nights and particularly in the months of June-September. The low level cloud occurrences are minimum in winter months. The specific attenuation of radiowave due to clouds at various frequencies <126>10, 20, 30, 40, 50, 75 and 100 GHz for summer and monsoon seasons has also been deduced. The specific attenuation of radio wave due to cloud at 30 GHz for liquid water content <126>1 g/m³ is found to be 0.88 dB/km, while at 75 GHz the specific attenuation is <126>5.55 dB/km.

3 illus, 3 tables, 24 ref

001214   Sarkar S;Gupta P K (Cent Bldg Res Inst, , Roorkee-247 667, Email: shantanu_cbri@yahoo.co.in) : Techniques for landslide hazard zonation - application to srinagar-Rudraprayag area of Garhwal Himalaya. J Geol Soc India 2005, 65(2), 217-30.

The work deals with the development and evaluation of landslide hazard zonation techniques which have been applied to parts of Garhwal Himalaya. The binary relationships between the factors and landslides have been determined. These relationships revealed the degree of susceptibility to landslide occurrence. The two techniques developed for landslide hazard zonation are the Subjective Rating Technique (SRT) and Objective Rating Technique (ORT). Although the SRT employs the inferred relationships between the landslide occurrence and the terrain factors to assign ratings to the factor categories, yet the rating assignment to the individual factors is subjective. The ORT reduces the impact of subjectivity in rating assignment, by deriving these from the frequency distribution of landslides. In this technique an attempt has also been made to judiciously classify the different hazard classes. Finally, the maps prepared from two different techniques have been validated and compared. The work presents a systematic approach to a comprehensive landslide hazard assessment of a large region.

9 illus, 6 tables, 13 ref

001213   Ravindra Kumar;Gupta L N;Gill G S (Cent of Advd Study in Geol, Panjab Univ, Chandigarh-160 014) : Neotectonic structures and newly formed fissures of Nadah area, Himalayan foothills, Haryana. Bull Indian Geol Ass 2004, 37(1-2), 1-13.

Multiple phased neotectonic structures are discernible in the vicinity of Himalayan Frontal Fault (HFF) in Nadah area. Seismites that occur in the basal Pinjor Formation (Pliocenej Pleistocene) represent the earliest neotectonic event in the area. Folding and faulting of the Pinjor beds have given rise to the first group of post-Pinjor neotectonic structures. Younger events are represented by three generations of faults (F1, F2 and F3) in Pinjor Formation and Holocene terraces. F1 faults are observed to have displaced the Pinjor Formation only. F2 faulting has affected both, the Pinjor Formation and the overlying T₁ - Terraces whereas F3 faults have displaced the beds of Pinjor Formation and T₁, and T₂ - Terraces. Appearance of fissures, subsidence and uplift in the Nadah area in March 2001 is considered to represent active tectonics related to HFF. The newly formed fissures are identified as faults that have displaced the gently dipping beds of Pinjor Formation and Holocene terraces. Two types of faulting are identified. Strike-slip faulting has caused uplifts and development of mounds on terrace surfaces whereas normal faulting have given rise to subsidence features.

5 illus, 11 ref

001212   Ravindra Kumar;Gill G S;Gupta L N (Cent of Advd Study in Geol, Panjab Univ, Chandigarh-160 014, Email: ravindrak@sancharnet.in) : Earthquake-induced structures in Pinjor formation on Nadah area, Haryana. J Geol Soc India 2005, 65(3), 346-52.

Soft sediment deformational structures have been observed in three sections of the basal Pinjor Formation exposed in the frontal Himalayan foothills in northern Haryana. The Nadah Choe section (A) shows contortion, thinning-thickening and faulting within 5 m thick sequence of sandstone, sandy shale and calcareous siltstone. The section (B) in a stream in the southwest of Nadah shows autoclasts, contortions around clay ball and faulting about 2 m thick fluviolacustrine sequence. The third section (C) is exposed in the Ghaggar river shows diapiric, flame-like intrusion of mud into the overlying beds of siltstone. The three sections are about 1.5 km strike length of gently dipping beds of basal Pinjor Formation. These structures were formed by liquefaction attending shear stress and can be related to major seismic events in this region during the deposition of the basal Pinjor Formation.

4 illus, 1 table, 24 ref

001211   Ravikant V (Geochronology and Istope Geol Div, Geol Surv of India, 15A&B Kyd Street, Kolkata-700 016, Email: ravi63@mantraonline.com) : Metamorphism of ultramafic and mafic enclaves within granulites, Schirmacher oasis, East Antarctica. J Geol Soc India 2005, 65(3), 279-90.

Mafic and ultramafic enclaves from Schirmacher Oasis preserve evidences for the earliest metamorphic event. In the study, the event has been constrained through reaction textures, mineral chemistry and thermobarometry by application of conventional and multireaction methods. Mafic enclaves comprise melanocratic pargasite-bearing gabbro, gabbroic anorthosite and ultramafic enclaves are spinel- and garnet-bearing websterite, ortho- and clinopyroxenite which occur as deformed enclaves within foliated norite. Deformed metanorite dykes and metagabbro pods occur within metasedimentary granulite. Most of the enclaves are massive, without chromite layering, while few preserve deformed modal layering at centimeter-scale. It is likely that the enclaves represent mantle restites during a partial melting event. Reaction textures within enclaves indicate a decompressive sense of the P-T path inferred from garnet-bearing websterite, deformed metanorite dyke and melanocratic pargasite-bearing gabbro, recorded by breakdown of blastic garnet to symplectites of orthopyroxene and highly calcic plagioclase and by the decomposition of pargasite in metagabbro to symplectites of pyroxenes and plagioclase. Thermobarometric calculations confirm that these enclaves were metamorphosed to granulite-facies conditions at <126> 8 kbar and <126> 800 °C, and underwent high-temperature decompression to a mid-crustal level.

2 illus, 5 tables, 28 ref

001210   Rath P;Panda U C;Bhatta D;Sahoo B N (Dep of Appl Chem, Kalinga Inst of Industrial Technol Deemed Univ, Bhubaneswar-751 024, Email: pr_kiit@yahoo.co.in) : Environmental quantification of heavy metals in the sediments of the Brahmani and Nandira rivers, Orissa. J Geol Soc India 2005, 65(4), 487-92.

The degree of contamination of the sediments from Brahmani and Nandira rivers, Angul-Talcher industrial belt, Orissa is evaluated using Enrichment ratio (ER), Pollution load index (PLI) and Geo-accumulation index (Igeo) for the metals like Al, Fe, Ti, Mn, Cu, Ni, Co, Pb, Zn, Cr, Cd and Hg. The metal values of the study area are also compared with other major river systems of India. The results of ER, PLI and Igeo for the Brahmani and Nandira river sediments indicate the role of anthropogenic activities (dumping of industrial/chemical wastes) in the study area. The down stream stations of Nandira and Brahmani-Nandira confluence station are contaminated with some metals, especially Hg, and Cd from the unburnt coal particles as well as fly ash from thermal plants and Cr from the solid wastes of chemical plant.

2 illus, 3 tables, 23 ref

001209   Rao P V N;Suryam R K;rao V R (Dep of Geol, Acharya Nagarjuna Univ, Nagarjunanagar-522 510, Email: pusapati_vnr@yahoomail.com) : Depositional environment inferred from grain size parameters of the beach sediments between False Devi point to Kottapatnam, Andhra Pradesh coast. J Geol Soc India 2005, 65(3), 317-24.

Eighty-eight sediment samples collected from different sub-environments along the Andhra Pradesh coast of India, between False Devi Point to Kottapatnam, were studied to understand the variations in the grain size parameters and depositional environments. The sediments are mostly fine to very fine-grained, very well sorted to moderately sorted, very coarsely skewed to fine skewed; platykurtic to leptokurtic in nature. Bivariate plots of textural parameters suggest that sediments are of beach origin. However, samples overlap in different environments are probably due to the influence of fluvial and aeolian action during or after the deposition of these sediments. The results of linear discriminant function analysis indicate the influence of littoral, shallow agitated marine and fluvial depositional environmental conditions. The C M pattern indicates that the sediments are transported mostly by graded suspension and very less by rolling processes. We therefore suggest that the sediments of study are the product of transitional environment composed of unconsolidated fluvial and fiuvio-marine material, predominantly from the Krishna delta region.

4 illus, 2 tables, 31 ref

001208   Ranawat P S;Rouer O;Ramboz C;Lakshmi N (Dep of Geol, M L Sukhadia Univ, Udaipur-313 001, Email: psranawat@geolmlsu.org) : Native antimony float-ore from the precambrian of Rajasthan. J Geol Soc India 2005, 65(3), 353-6.

Placer concentrations of rolled chunks of heavy, very-white, metallic mineral occur along a rivulet (N25 ° 40.0.13m E75 °20.851* 15 km eastof Jahazpur town of eastern Rajasthan. The float-ore occurs in the precambrian phyllite that is profusely traversed by vein quartz. Its physical, optical, XRD, EPMA data show that the mineral is native antimony (averaging 97.12% Sb) having <126>2%. As minor grains of PbTe are also recognized. Prospecting by the Department of Mines and Geology, Rajasthan has not yet resulted in the discovery of the mother land. Describes the mineralogy of the float-ore that has scientific value and is a new occurrence in India.

^ssc7 illus, 1 table, 7 ref

001207   Rai H;Rao D R (Wadia Inst of Himalayan Geol, , 33 General Mahadeo Singh Road, Dehradun-248 001, Email: drrao4@rediffmail.com) : Geochemical and isotopic studies of the granitoids exposed on the southern slope in the Sasoma-Saser Brangra section of Karakoram Batholith, Jammu and Kashmir. J Geol Soc India 2005, 65(3), 325-34.

The Karakoram Batholith is one of the geological features that traverses the entire Karakoram range. There is wide compositional variation across the batholith. The granitoids of Karakoram Batholith separate the metamorphic complex from the Karakoram Tethys sequence. The purpose of the study is to provide geological information on the Karakoram batholith and to suggest possible mechanisms that were responsible for the development of granitoids of the southern slope of the Karakoram Batholith between Sasoma-Saser Brangra regions. The studies suggest that, the granitoids are metaluminous to peraluminous (mol. A/CNK value is <126>1.0), have Sr_i ratio <126>0.709, show volcanic-arc affinity, and suggest emplacement age of <126>124 Ma. They represent the reworking of lower crustal calc-alkaline parental rocks.

7 illus, 2 tables, 40 ref

001206   Piresteh S;ali S A (Fac of Engng, Islamic Azad Univ of Dezful, Dezful, Iran) : Lithostratigraphical study from Dezful to Brojerd-Dorood areas SW Iran using digital topography remote sensing and GIS. Indian J Petrol Geol 2004, 13(2), 13-23.

Zagros Structural Belt is one the best exposed fold-thrust belts of Iran. Stratigraphically the study area consists of rocks from Precambrian to Cenozoic age. The integrated use of digital topography, remotely sensed data and GIS were undertaken to study lithology of the area between Dezful and Brojerd-Dorood, SW Iran. For the study Landsat-7 ETM+ data dated 2002 was used. Interpretation of the digital Landsat imagery for the lithology was carried out using image interpretation elements. Lithological units were digitally processed within the ENVI software to generate geological map of the area. Landsat data were calibrated by field data and then combined with existing geological map derived to prepare a digital geological map of the area in GIS environment, which provides an easy assessment of information. With the help of spatial analysis in GIS environment the percentage of each lithounits of each formation has been calculated which indicated that the area is mostly dominated by Asmari (16.71%) and Gachsaran (17.77%) Formations. This type of analysis would be much preferable than traditional one because it can be assessed in GIS environment within a few second.

5 illus, 12 ref

001205   Parcha S K (Wadia Inst of Himalayan Geol, , Gen Mahadeo Singh Road, Dehra Dun-248 001, Email: parchask@wihg.res.in) : Biostratigraphic studies and correlation of the middle cambrian successions of northwestern Kashmir Himalaya. J Geol Soc India 2005, 65(2), 183-96.

The Middle Cambrian successions of Himalaya are well exposed in the Pohru Valley of northwestern Kashmir Himalaya. The fossiliferous successions are exposed in the Kandi, Nutunus, Taki wadopura, Zachaldor, Khanpura, Neilipora and in the Magam areas of the Kupwara district of northwestern Kashmir. The is one of the highly fossiliferous parts of the Cambrian successions of northwestern Kashmir. The fauna is characteristic of the early Middle Cambrian Maochuangian stage to the late Middle Cambrian representing Maochuangian, Hsuchuangian stages of the Middle Cambrian. The lower part of the Middle Cambrian Maochuangian is poorly fossiliferous, but the Middle Hsuchuangian and upper parts of Changhian of the successions are profusely fossiliferous. Several faunal assemblages have been recorded which includes some revised as well as new faunal elements. The fauna mainly includes polymerid and agnostid trilobites and few inarticulate brachiopods. In the light of the present biostratigraphic studies attempts have been made to correlate these Middle Cambrian faunal assemblages of Kashmir with the known analogous Middle Cambrian successions of the Tethys Himalaya and preliminarily with other corresponding successions of the Middle Cambrian, on the basis of polymerid and agnostid trilobite fauna.

2 illus, 4 tables, 93 ref

001204   Pant P D;Luirei K (Dep of Geol, Kumaun Univ, Nainital-263 002, Email: pant_pd@hotmail.com) : Amiya landslide in the catchment of Gaula river southern Kumaun, Uttaranchal. J Geol Soc India 2005, 65(3), 291-5.

The southern hills of Kumaun in the proximity of the Main Boundary Thrust (MBT) are prone to recurrent landslides. The slope failures are related to steeper angle of hillslope, extent and type of vegetation, structural condition of bedrock, and neotectonism of the MBT. Presents the case history of the Amiya landslide of 11 July 1999, which has claimed 22 lives, including 2 persons in a place 20 km northeast of Kathgodam in Kumaun. The slope failure was related to structural conditions of bedrock, particularly five sets of joint spacing and the proximity to the MBT, which has been affected by neotectonic movements in the recent past. The large number of structural discontinuities have diminished the stability of the Siwalik hill slopes, reducing the safety factor to 0.412. The landslip vector has a close parallelism with the geometrically determined wedge failures responsible for the landslide.

5 illus, 9 ref

001203   Paikaray S;Banerjee S;Mukherji S (Dep of Earth Sci, IIT, Bombay) : Facies analysis of the koldaha shale, vindhyan supergroup and its paleogeographic implications. Indian J Petrol Geol 2004, 13(2), 1-11.

Study involves detailed facies analysis for the Koldaha Shale of the Vindhyan Supergroup in the Son valley area south of Maihar, Madhya Pradesh. Four broad lithofacies types are identified. Basal part of the Shale is predominated by shales with lenticular siltstone interiayers (facies A). Facies A gradationally passes over to shale-siltstone beds of comparable thickness (facies B). Facies C is characterized by shales alternating with sheet bedded sandstones often containing erosional sole marks and wave ripples. Thicker siltstones alternate with tabular sandstone beds in facies D often associated with gutter casts and hummocky cross stratifications. The facies A indicates deposition possibly in the distal offshore setting, while facies B is possibly deposited in the proximal offshore setting. The facies C deposited in shallower bathymetry, possibly in the offshore setting between fair weather and storm wave base. Facies D represents deposition possibly in the distal part of the lower shoreface. All the four facies are repetitive in nature; nevertheless, facies D is more common towards the upper part and facies A towards the basal part of the deposition. Koldaha Shale represents overall shallowing upward progradational succession. Total organic carbon content decreases from facies A to facies D.

9 illus, 17 ref

001202   Narayana A C;Tatavarti R;Shakdwipe M (Dep of Mar Geol and Geophysics, Sch of Mar Sci Cochin Univ of Sci and Technol, Lakeside Campus, Fine Arts Avenue, Cochin-682 016, Email: a_c_narayana@yahoo.com) : Tsunami of 26 December 2004: Observations of Kerala coast. J Geol Soc India 2005, 65(2), 239-46.

2 ref

001201   Mulchandani N;Bhandari S;Raj R;Vaid S I (Dep of Geol Fac of Sci, M S Univ of Baroda, Vadodara-390 002, Email: nareshmulchandani@yahoo.com) : Alluvial fan sedimentation in Heran and Kara river valleys of lower Narmada basin, Western India. J Geol Soc India 2005, 65(4), 451-8.

Sedimentation in an alluvial fan environment in Heran and Kara river valley of lower Narmada basin has been recognized. The fans are incised by Heran and Kara rivers due to vertical movements along faults. The architecture of the fans is built by various lithofacies (Gc, Gms, Gh, Gp, Gm, Sh, Sp and Gsh) with maximum clast size ranging from cobbles to large isolated boulders, mainly of basalts. The variations in the lithofacies are considered to be largely controlled by the then prevailing climates. Tectonics created the accommodation space within which fan aggradation took place and shaped their present morphology. The fan aggradation in Heran and Kara rivers appear to have taken place during Late Pleistocene and Early Holocene, respectively. An overall humid climate together with tectonic activity is inferred for the formation of alluvial fans in Heran and Kara rivers.

6 illus, 23 ref

001200   Mishra A S;Bhathawala P H;Shah D C (Dep of Math, Veer South Guj Univ, Surat-395 007) : Pressure transient data analysis for wormholes in carbonate reservoir. Indian J Petrol Geol 2004, 13(2), 65-73.

A perssure transient data analysis model of fluid flow in a reservoir treated with closed fracture acidizing in carbonate reservoir is presented in the study. This model is characterized by a low conductive fracture and highly conductive wormholes in class of geological setting that are not amenable to conventional techniques. The use of a new concept of the model is to analyze pressure transient data for wormholes in heterogeneous formation is considered. During a closed fracture acid treatment, acid is injected at a pressure high enough to allow preferential flow into existing grooves of the already hydraulically fractured formation. Injection pressure, however, should not be high enough to propagate fracture. In this case, acid flows into existing opening between the fracture faces and creates wormholes, which generate flow channels through which formation fluid may flow into the wellbore. The several experimental studies have shown that reopening pressure of an existing fracture is dependent on rock type and the degree of fracturing. Several properties of the reservoir system can be readily estimated with judicious use of thus generated type curves from the well test data.

8 illus, 17 ref

001199   Kumar G (Deptt of Geol, B I T Sindri, P O Sindri Instt, Dhanbad-828 123) : Composition and genesis of polymetallic nodules from the central Indian Ocean basin. Indian Min Engng J 2005, 44(2-3), 31-9.

The ferromanganese nodules or simply manganese nodules or more complex polymetallic nodules are widely distributed over extensive areas of seafloor, as well as in many shallow water environments in lakes. They have been extensively studied since their discovery during the HMS Challenger expedition, 1873-1876, Muray & Renard (1891). The fact that deep sea ferromanganese nodules end encrustations can be regarded as an important source of industrial metals like nickel, copper, cobalt and managanese was recognized only within the last four decades, Mero (1965). Within this time many investigations have been carried out in order to determine the quality of composition and the coverage density in the nodule fields so as to find out areas favorable for deep sea mining. Abyssal nodules represent the largest group of ferromanganese deposits and have been described mainly from the Pacific Ocean. The Indian Ocean is next in order while the Atlantic Ocean has the lowest reserves, except the Black Plateau areas. A complex interplay of factors like the degree of oxidation of the depositional environment, abundance of nucleating agents, proximity of source elements, sedimentation rates in the seas, bottom current activity, existence of benthic organisms, biological productivity in surface waters and many other as yet unidentified phenomena determine nodule density. With an estimated total reserves of 3 x 10¹² tonnes, the nodules represent one of the world's largest untapped deposits of nonferrous metals. Molybdenum, copper, nickel and cobalt are in enormous quantities, enough to supply hundreds of years of demand at current global consumption levels. Though the nodules carry many metals, nickel is expected to be the most important single metal from the economic viewpoint. Copper and cobalt can also be concurrently produced with nickel in any processing scheme.

8 illus, 3 tables, 18 ref

001198   Kumar A A;gopinathan V;Gopinath K S;Rap V P (Dep of Geol, Government Coll, Vidyanagar, Kasaragod, Kerala-671 121, Email: gopisreenair@rediffmail.com) : A review on the nomenclature of angadimogar and kumbdaje plutons, Kasaragod district, Kerala. J Geol Soc India 2005, 65(2), 141-6.

Pink and grey grarnites occur as minor, more or less circular bodies at Angadimogar and Kiambdajc areas of Kasaragod district, covering about 10 km². These granites are emplaced within the charnockites and gneisses during the Late Precambrian. These granites arc coarse grained and traversed by anastomising patches of aplite. They are in sharp contact with the country rock. The Angadimogar pluton was earlier considered a syenitic body. Normative mineralogy and petrography of the Angadimogar and Kumbdaje plutons show high content of silica and other salic minerals and confirm that they are in fact granites. The major oxide chemistry of the plutons is similar to the major granitic plutons of South India. Thus, contrary to the earlier views, authors suggest that these bodies are granites.

4 illus 3 tables, 17 ref

001197   Khadkikar A S (Geol and Palaeont Grp, Agharkar Res Inst, G G Agarkar Road, Pune-411 004, Email: askhadkikar@yahoo.com) : Hump cross-bedding and the recognition of ancient parabolic dunes with examples from the miliolite, Western India. J Geol Soc India 2005, 65(2), 169-82.

Cross-bedding is a common sedimentary structure in the global stratigraphic record with planar and trough cross-bedding occurring more frequently than hummocky cross-bedding. Whereas the latter is typical to marine environments the former is observed both in aeolian and sub-aqueous environments (fluvial and marine). A fourth variant of cross-bedding is described here that is characterized by convex-up structures in the depositional dip direction and hump-like structure across the depositional dip direction. In plan view the structure has beds that show radial fanning out dip azimuths with dip amounts varying between 25° and 30°. This structure is termed here as 'hump cross-bedding' owing to its hump like geometry across the depositional dip direction. These bedding geometries may be reconciled with sediment migration along the front of a parabolic dune. Since parabolic dunes do not form in subaqueous environments, hump cross-bedding becomes an essential aid in distinguishing aeolian from shoreface deposits in coastal environments. The recognition of this structure becomes invaluable towards reconstructing depositional environments and deducing their palaeoenvironmental significance from Quaternary deposits such as those found in the Bahamas, Bermuda and Saurashtra.

14 illus, 1 table, 21 ref

001196   Joseph S;Thrivikramaji K P (Dep of Environmental Sci, Univ of Kerala, Kariavattom-695 581, Email: sjoseph@keralauniversity.edu) : Rhizolithic calcrete in teris, southern Tamil Nadu: origin and paleoenvironmental implications. J Geol Soc India 2005, 65(2), 158-68.

The early-modern red coastal/or inland sands ("Teris") in the coastal tract of southern Tamil Nadu show the infrequent occurrence of rhizolithic calcretes in the vadose zone. These are reddish brown coloured, cemented and cylindrical in form. No other types of rhizolith and/or calcrete have been recorded from here. Textural and mineralogical studies show that these rhizoliths contain notable amounts of acid insoluble detrital sands (essentially quartz and opaques) and mud, and are presumed to be derived from the host, i.e. teris. Petrographic studies reveal that these detritals are embedded in a micritic matrix and the carbonate cement shows rim, vein and blocky structures. Further, floating, alveolar and clotting textures are also noticed. Clay minerals in the rhizoliths include kaolinite as the singular component. Rhizohths are presumed to be formed by surface weathering and pedogenic processes in the vadose zone. The pedogenesis of host teri sands might have released Ca²⁺ ions and were later deposited in the root cavities formed by the decay and complete removal of the tissues of roots. Another source of Ca²⁺ would be the calcareous sediments which underlies part of the teris. The absence of root anatomy is a characteristic feature of these rhizoliths. A sample of rhizolith collected at Sattankulam at a depth of 2.5 m gave a ¹⁴C age of 3680±110 years B.P. Hence, semi-arid conditions of the present day in the Teri tract of southern Tamil Nadu, should have set in at least as way back as 3680±110 yr. B.P.

8 illus, 3 tables, 22 ref

001195   Jodhawat R L;Kachhara R P (Dep of Geol, M L Sukhadia Univ, Udaipur-313 002) : Succession and analysis of fossil bivalves from jaisalmer formation, Rajasthan. Indian J Petrol Geol 2004, 13(2), 53-64.

Post-vindhyan time witnessed a major marine transgression during Jurassic period which covered a substantial part of Western Rajasthan. A sequence of marine sediments deposited during this period is well exposed around Jaisalmer town of the Jaisalmer basin. These sediments are grouped into Lathi, Jaisalmer, Baisakhi and Bhadasar Formations in the ascending order. Of these, the Jaisalmer Formation and bivalve fossils there from the subject matter of the paper. The bivalves attained a specific significance as these are numerous and occur through out the sequence because the ammonoids the precise time indicator are restricted to the upper most part of Formation. The Jaisaimer Formation is further divisible into six members namely Hamira, Joyan, Fort, Badabag, Kuldhar and Jajiya in the ascending order. The bivalves from this Formation comprise 171 forms (including one subspecies), arranged sequentially and are assigned to 76 genera (and 13 subgenera) distributed in 41 families. Among these, 36 species have been newly created besides 19 which are reported for the first time from the Jurassic rocks of India.

1 illus, 2 tables, 18 ref

001194   Jassal H S;Sondhi A;Sharma K R;Gill G S (Dep of Soils, Punjab Agric Univ, Ludhiana-141 004) : Implication of erosion and sedimentation in properties and formation of some siwalik foothill soils of Punjab. Bull Indian Geol Ass 2004, 37(1-2), 39-45.

The soils of Siwalik foothill of Punjab were studied to assess the impact of geomorphic processes on their properties and genesis. The Siwalik foothill belt, popularly known as kandi belt, experiences water erosion mainly in the hilly slopes and sedimentation in the piedmont plains. The hill slope soils do not have any genetic horizon whereas the piedmont plain soils, especially from stabilized terraces have shown some degree of profile development (A-Bw-C). The soils of hill slopes are relatively coarser texture (sand) whereas the soils from piedmont plains are finer texture (loam to loamy sand). The soils of the hills have relatively higher pH and lower EC compared to the soils of piedmont plains. Relatively higher salt content in piedmont soils suggest removal of salts from hills and their deposition from solution along with suspended materials in piedmont areas. The erosion and sedimentation processes kept on rejuvenating the soils on hill slopes whereas the interaction of sedimentation and pedogenic processes which have lead to differentiation of soils in the piedmont plains. The study reveals that the geomorphic processes of erosion and sedimentation have greatly influenced the Siwalik foothill soils rather than pedogenic processes.

2 tables, 14 ref

001193   Jana P K;Nandi S C (Dep of Chem, Inst of Educ (PG) for Women, Chandernagore, Hooghly-712 138) : Effect of solar parameters on Antarctic, Arctic and tropical ozone during the last solar cycle. Indian J Radio Space Phys 2005, 34(2), 114-8.

A critical analysis has been made on the variations of Antarctic, Arctic and tropical ozone and different solar parameters during the last solar cycle. It has been observed that yearly variations of ozone concentrations at Halley Bay (76°S, 27°W), a British Antarctic survey station, at Sodankyla (67.4°N, 26.6°E), an Arctic survey station and at Ahmedabad (23°N, 72.6°E), an Indian survey station are identical to that of August, April and March concentrations, respectively. The yearly variations of solar flare numbers and solar uv-fluxes are identical to that of October values, but relative sunspot numbers and solar flare index are identical to that of April values. The correlation coefficients between ozone concentrations and different solar parameters are not so significant. It is also concluded that the intense yearly decrease of Antarctic and Arctic ozone concentrations from year to year during springtime is independent of solar parameters.

4 illus, 1 table, 32 ref

001192   Gupta B S;Paul a K;Roy M (Atom Miner Directorate for Explor and research, , Hyderabad-500 016, Email: biksen@rediffmail.com) : A rare calcium rich uraninite from Anjangira area, Sonbhadra district, Uttar Pradesh. J Geol Soc India 2005, 65(3), 296-300.

A variety of high calcic uraninite showing 3.26-10.69 % of CaO has been identified in 'Anjangira' Uranium occurrence hosted by pegmatoid leucosorne within migmatites forming part of Chhotanagpur Granite Gneiss Complex (CGGC), in Sonbhadra district, U.P. It is one of the two distinct types of uraninite, which occurs as inclusions within biotite and albite besides few grains along with microcline and quartz. The less abundant high calcic type of uraninite can be easily recognized under microscope due to its habit of occurrence encircled with the pale green rim of clayey matrix. The mode of occurrence of the two types of uraninite such as euhedral, rounded, corroded and in fracture form, rules out any specific mineralogical control and a metasomatic origin seems likely. Type I uraninite has an average chemical age 751 Ma and Type II (calcic) shows a variation from 621 -812 ma.

3 illus, 2 tables, 16 ref

001191   Gill G S;Jassal H S;Ojha R D (Cent of Advd Study in Geol, Panjab Univ, Chandigarh) : Sedimentological and geomorphological evidence of neotectonic activity along HFF in part of Bist Doab, Punjab. Bull Indian Geol Ass 2004, 37(1-2), 101-9.

Among three Himalayan thrust running more or less parallel to one another in NW-SE trend, the Himalayan Frontal Fault is responsible for evolution of major geomorphic forms due to neotectonic activity and associated deformation and uplift. An uplifted thick pile of Siwalik sediments and undulating piedmont zone to the North and South of HFF respectively exhibits a number of evidences of active tectonics in Bist Doab area of Panjab. The area presents a variety of geomorphic landforms ranging from almost flat plains to the South to steeply sloping Siwalik Hills in the North. The Siwalik sediments occupy an un-precedented thickness of sandstone and conglomerate facies wrapped along the HFF by virtue of anticlinal folds. The piedmont is made up of coalescing fans with proximal facies of gravel and coarse sand and distant facies of silty, clayey or loamy deposits.

4 illus, 15 ref

001190   Gairola R M;Verma A K;Pokhrel S;Agarwal V K (Meteorology and Oceanography Grp, Space Applic Cent (ISRO), Ahmedabad-380 015) : Integrated satellite microwave and infrared measurements of precipitation during a Bay of Bengal cyclone. Indian J Radio Space Phys 2004, 33(2), 115-24.

In the paper, an approach for integrated IR and microwave measurements using various satellite sensors have been used for the study of a severe cyclone over Bay of Bengal and adjoining Eastern India and Bangladesh during 24-29 April 1991. The rain estimates from measurements of brightness temperatures from Special Sensor Microwave /Imager (SSM/I) and Outgoing Longwave Radiation (OLR) from IR radiances of polar orbiting and geostationary satellites have been used. Since the OLR derived rainfall exhibit a larger spatial spread with lower intensities in rainfall fields, Followed the above procedure for optimally combining both the observations for more realistic rainfall on regional scale to study precipitation fields. Since the OLR rains are well represented spatially and temporally by more frequent observations from both geostationary and polar orbiting satellites, the algorithm sharpens the IR derived rains and augments it to the microwave derived rain. The combined IR and microwave rain algorithm brings out the finer details of the cyclone structure and precipitation fields, and thus seems to be highly promising for operational applications. Some aspects of the associated wind fields are also examined for their relationship with tropical rain intensity in the present case. A comparison of rainfall is performed with rare in-situ observations over the coastal regions during the severe cyclone.

6 illus, 37 ref

001189   Duraiswami R A;Dole G;Bondre N (NO, , A/6 Gurudut Housing Society, Srinagar, Kalewadi Phata, Rahatani, Pune-411 017, Email: raymond_d@rediffmail.com) : The Songir structure: inflanted lava flow or tube?. J Geol Soc India 2005, 65(3), 357-65.

A <126>9.75 km long, sinuous structure exposed near village Songir, east of Dhule has been previously interpreted to be a lava tube on the basis of remote sensing and field checks. Detailed field investigations, however, reveals an overlapping sequence of P-type lobes and sheets, constituting a small compound pahoehoe flow, whose sinuous form has been guided by pre-existing topography. The Songir structure is undoubtedly a small, sheet-flow that propagated by repeated branching of toes and lobes that have been emplaced through the mechanism of inflation. This pahoehoe flow does not bear any resemblance to a lava tube. The study of the Songir structure reiterates the fact that greater caution should be exercised while identifying similar structures in the large and ancient Continental Flood Basalt provinces.

^ssc5 illus, 2 tables, 17 ref

001188   Dhurandhar A P;Latha A;Krishna V (Atom Miner Directorate for Explor and Res, , Shillong-793 001, Email: apdhurandhar@rediffmail.com) : Geochronology and petrochemistry of the dubha granite, Sonbhadra district, Uttar Pradesh. J Geol Soc India 2005, 65(4), 459-67.

The Rb-Sr isotopic systematics and petrochemistry of Dubha Granite occurring in the migmatite complex of Chhotanagpur Granite Gneiss Complex (CGGC) in parts of Sonbhadra district, Uttar Pradesh have been investigated. The Rb-Sr data on the whole rock samples (n=13) yields an isochron age of 1754±166 Ma with initial ⁸⁷Sr/⁸⁶Sr ratio of 0.7043±0.011. The Dubha Granite is composed of quartz (34.2%), K-feldspar (37.4%), plagioclase (An2-40) (16.1%), biotite (9.6%), hornblende (1.9%), and accessory garnet, sphene, apatite, zircon, anatase, ilmenite, magnetite, goethite, and chalcopyrite (0.8%). It is an anorogenic, metaluminous, ilmenite series, rift related granite, enriched in Ni, Cr, Co, V, Zn, Cu, Rb, Ba, Zr, Nb, Ce, U, Th and depleted in Sr and Y as compared to the normal granite. The Dubha Granites may have been generated by the anatexis of lower crustal material in the vicinity Son Narmada South Fault (SNSF).

5 illus, 4 tables, 33 ref

001187   Dev P;Singh B K;Dubey R K (Sch of Stud in Geol, Vikram Univ, Ujjain-456 010) : Mitigation strategy of earthquake generated hazards - Northwest Himalayan context. Bull Indian Geol Ass 2004, 37(1-2), 31-8.

The major earthquake events occurred in the Himalayan region have been enumerated. It has been observed that the earthquakes having magnitude of <62> 5 have caused great damage to environmental regime including loss of the life and destruction to property. It is well established fact that the earthquake operations can not be stopped but the earthquake generated hazards can be reduced to some extent by adopting appropriate plan for disaster management. A discussion has been included on mitigation strategy for the earthquake hazards, affecting the human population and causing damage to property at sites of earthquake events, before, during and after the activity. The hazard mitigation measures include education, awareness regarding defence against earthquake, implementation of schemes of earthquake insurance, land use planning, and construction of earthquake resistant buildings. It is suggested that an integrated effort by earth scientists and planners will provide a practicable and constructive solution to the protection problem of human beings from the hazardous effects of earthquake operations.

1 table, 35 ref

001186   Datir V;Verma P K (Sch of Stud in Geol, Vikram Univ, Ujjain-456 010) : Remote sensing based study for tectonic geomorphology of Choral river basin of Narmada river system, central India. Bull Indian Geol Ass 2004, 37(1-2), 91-100.

The geodetic changes have significant imprints on geomorphology of any region. Any chnage in slope is immediately reflected in the stream profile and related parameters; sinuosity of natural curvatures etc. These geomorphic pointers may be used vice-versa to indicate the geodetic changes vis-a-vis the ground instability. The Choral River Basin cuts across the North Narmada fault (NNF) and provides an ideal basin for investigations that may provide pointers for the movements along NNF. The tectonic geomorphology of Choral basin has been studies using satellite data and selective ground checks. The morphotectonic and sinuosity parameters of the basin have been computed that provided information over ground instability. The index of topographic sinuosity, hydraulic sinuosity, standard sinuosity and sinuosity fractal dimension indicate active tectonics prevalent in the area.

6 illus, 4 tables, 17 ref

001185   Chaudhary V;Chauhan S (Snow and Avalanches Study Establ, , Him Parisar, Sector 37 A, Chandigarh, Email: vinay_sase@rediffmail.com) : Wind control structures - an effective way to curb avalanche hazard. Bull Indian Geol Ass 2004, 37(1-2), 25-9.

In northwest Himalayas, persistent winds dominate. The situation gets worsen during winters especially during snowfall periods when it results in drifting of snow. The drifted snow starts accumulating on the avalanche prone slopes and over the ridges and results in cornice formation. As the self-load of cornice Increases and owing to overhang/ cantilever effect the cornice breaks and results in major avalanches. This phenomenon is frequent during December to March every year. In the year 2003 itself approximate 54 people have lost their lives in various avalanches. The adverse effect of wind, therefore requires mitigation/ control. Placing of wind control structures in wind dominant areas is one of the cost effective measures to mitigate the said avalanche hazard. These structures are generally erected on mountain-tops for preventing drift snow accumulation. These structures are preferred because of their light weight, and ease in transportation and erection work. Jet roofs, Snow fences and Wind baffle are some of the examples of wind control structures. The above-mentioned structures have been designed, developed and tested by SASE in snow bound areas of northwest Himalaya since 1998. Paper deals with the concept and principle of wind control structures in general and field observations of Wind baffles in particular recorded at D-10 avalanche site on Jammu-Srinagar National Highway (NH-1A) during 1998 to 2003.

5 illus, 3 ref

001184   Chaki A; Bhattacharya D;Rao J S;Chaturvedi A K;Bagchi A K (Dep of Atom Energy, Atom Miner Directorate for Explor and Res, Bangalore-560 072, Email: amdhyd@ap.nic.in) : Geochronology of the granitoids of the kunjar area, Sundergarh district, Orissa : implications to the regional stratigraphy. J Geol Soc India 2005, 65(4), 428-40.

Rb-Sr isotopic data for the Tamparkola granite, northwest of Bonaigarh, and Bamra granite, southeast of Bamra Sundergarh district, Orissa have yielded similar ages of 2746±144 Ma and 2738±28 Ma, respectively. Small granite exposures intruding the Iron Ore Group in the southern part of Tamparkola granite, have also indicated similar Whole Rock Rb-Sr age of 2867±86 Ma. These may be correlated with the Bonai granite. Significant crustal component was involved in the generation of these granites, as indicated by high initial Sr ratio, and their emplacement probably marks a major terminal cratonisation event in northwestern part of the Singhbhum-North Orissa Craton. The study does not support the view that the Tamparkola Granite is equivalent to the Itma/Ekma granites that are intrusive into the Gangpur Group. These age results call for a revision of the stratigraphy of the Bonai-Gangpur tract, in that the Darjing Group unconformably overlies both the Bonai granite and Tamparkola granite, with the Mesoproterozoic Kunjar sedimentary sequence representing the youngest of the regional succession.

5 illus, 3 tables, 49 ref

001183   Catherine J K;Pandey O P (Natn Geophys Res Inst, , Uppal Road, Hyderabad-500 007, Email: om_pandey@rediffmail.com) : Differential uplift between Hyderabad and Bangalore geotectonic blocks of Eastern Dharwar craton, South India. J Geol Soc India 2005, 65(4), 493-6.

Analysis of geological, geophysical and recently obtained GPS observations over Eastern Dharwar craton of south Indian shield suggest differential uplift between Hyderabad and Bangalore geotectonic blocks. It appears that Hyderabad Granitic Region is uplifting at a high rate of <126>12 mm/yr while in contrast, Bangalore geotectonic block may possibly be subsiding(?)

4 illus, 1 table, 13 ref

001182   Buyukutku A G;Sahinturk O (Dep of Geol Engng, Ankara Univ Engng Fac, 06100 Besevler, Ankara, Turkey, Email: abuyukutu@yahoo.com) : The diagenesis of the upper oligocene and mio-pliocene sandstones and its relevance to Hydrocarbon exploration in the East Anatolia basin, Turkey. J Geol Soc India 2005, 65(4), 468-78.

Upper Oligocene (Komurlu, Penek, and Gumusali) and Mio-Pliocene (Zirnak and Aras) formations contain sandstones that are petroleum reservoirs in the East Anatolia basin. Deltaic and fluvial sandstones are the dominant facies in the basin. Petrology, depositional and diagenetic history, and reservoir quality of the Upper Oligocene and Mio-Pliocene sandstones are defined. Reservoir quality is primarily the result of burial diagenesis. Dominant textural modifications are the destruction of primary porosity by precipitation of authigenic minerals, primarily smectite-illite, feldspar overgrowths, illite, and quartz overgrowths, and porosity enhancement by dissolution of framework feldspar and calcite, to a lesser extent quartz and lithic fragments. As much as 30% of the total porosity probably was caused by the dissolution processes, largely by meteoric water introduced during Upper Oligocene and Miocene uplifts. Average porosities of the Oligocene and Mio-Pliocene sandstones range from 10 to 16% in the study area.

10 illus, 1 table, 28 ref

001181   Buyukutku A G (Ankara Univ Fac of Engng Dep of Geol Engng, , 06100 Besevelver, Ankara, Turkey, Email: butku@eng.anakara.edu.tr) : Sandstone petrology and tectonostratigraphic terranes of the northwestern thrace basin, Turkey. J Geol Soc India 2005, 65(2), 231-8.

Tectonostratigraphic study of the sandstones of the Hamitabat Group (Yenikoy and Deoirmencik Formations) of the NW Thrace Basin is described based on petrological studies of samples from six boreholes. Detrital modes determined by the Dickinson point-count method for the sandstones of Hamitabat Group are as follows: % Q_t FL_t, = 46-35-20; %Q_mFL_t = 47-35-19; %Q_pL_vL_s = 57-12-26 (for the sandstones of the Deoirmencik Formation), and Q_tFL_t = 60-18-23;%Q_mFL_t= 59-18-25; % Q_pL_vL_s= 62-13-24 (for the sandstones of the Yenikoy Formation). No significant compositional, diagenetic differences exist among the sandstones of Hamitabat Group counted. The sandstones of the Hamitabat Group were likely derived from the deeply dissected magmatic arc and recycled orogen provenance.

6 illus, 3 tables, 31 ref