004313   Seralathan P;Rajkumar M S;Sunilkumar V; Anandaraj N (Dep of Mar Geol and Geophysics, Cochin Univ of Sci and Technol, Kochi-682 016, Email: pseran@yahoo.com) : Interstitial water chemistry of mangrove sediments, Kerala. J Geol Soc India 2006, 68(2), 251-8.

Vertical concentrations of salinity, Eh, pH, total alkalinity, NO₂^-, NO₃^-, NH₄⁺, PO₄^3-, SiO₂, Fe, Mn, Na and K in interstitial water as well as sediment organic carbon and CaCO₃ from three different mangrove areas, bordering the Vembanad estuary, the largest backwater system along the southwest coast of India have been studied. The selected three mangrove locations are not only kilometers apart but also differ vastly in physico-chemical environment themselves - namely a fresh water one (cores 1 and 2) a brackish (core 3) and a saline mangrove area (core 4). Relatively, lower Eh values are measured in fresh water mangrove sediments than the brackish/saline cores. pH and K show a decreasing trend with depth whereas alkalinity, NH₄⁺, PO₄^3-, SiO₂, Fe, Mn and Na increase systematically downward. The lower limit of oxic zone in fresh water environment is very much compressed than in the brackish and saline regions, where a larger oxic zones prevail. NO₂^- and NO₃^- concentrations after an initial increase (up to approximately 10 cm in cores 1 and 2) and (18 cm in core 3 and 4) decrease sharply indicating nitrification followed by denitrification. PO₄^3-, Fe, Mn, NH₄⁺, K and alkalinity production are more in fresh water mangroves than brackish/saline mangroves indicating higher degradation of organic matter under higher anoxic condition.

4 illus, 42 ref

004312   Sengupta B;Roy M;Purohit R K;Paul A K (Dep of Atom Energy Atom Miner Directorate for Explor and Res, , Hyderabad-500 016, Email: biksen@rediffmail.com) : Petrography and mineral chemistry of the radioactive migmatitic rocks around Kudri, Sonbhadra district, U.P. and its implication of uranium and rare earth mobility and genesis. J Geol Soc India 2006, 68(1), 87-94.

The Precambrian migmatites around Kudri host uranium, rare earth and zirconium mineralization, manifested, respectively in the form of discrete uraninite, allanite and zircon. Mineralization is mostly in thebiotite-rich melanosome (restite), albite-rich leucosome and mesosome (mobilizate). Uraninite with UO₂ content of 79.93-82.45% (av.81.36%), and content of high Th (ThO₂:2.98-5.71%, av.4.37%) and high REE (RE₂O₃: 0.82-2.11, av.1.41%) and chemical age (736- 929 Ma, av.824 Ma) of uraninite (n=14) point towards its origin during Neoproterozoic (av. 824 Ma) probably by epigenetic, high-temperature, synmagmatic origin which later subjected to dissolution and alteration by hydrothermal process. However, textural evidence of corrosion of erstwhile euhedral uraninite sugests its subsequent dissolution and alteration, together with expulsion of REE, possibly by a saline, moderately acidic hydrothemal (100-300°C), reducing solution at a lower pressure, related to regional tectonic episode.

1 il, 4 ts, 13 ref, 1 p

004311   Sanjeev Kumar;Dewashish Kumar;Ahmed S (Indo French Cent for Groundwater Res, Natn Geophys Res Inst, Hyderabad-500 007, Email: sanjeevngri@yahoo.co.in) : Delineation of groundwater prospect zones in hard rocks using remote sensing and GIS-A case study from Rajasthan. J Geol Soc India 2006, 68(2), 259-68.

Groundwater resources are extremely important in Rajasthan as almost the entire region lies in arid/semi-arid tropics especially in the hard rock areas. The recharge being less due to scanty rainfall. Revealed the advantages of remotely sensed data in identifying the prospects of groundwater in geologically and structurally complex terrain. Remote Sensing (RS) and Geographic Information System (GIS) is a dynamic tool for facilitating the generation and use of thematic information; has been applied to know the groundwater potentiality of the Upper Kali Sindh Chauli watershed in the Jhalawar district of Rajasthan, India. The role of different parameters namely geology, geomorphology, structures, lineaments, slope, land use and land cover, digital elevation model, etc. have been emphasized for delineation of the groundwater potential zones. The groundwater potential zone map was prepared based on the visual interpretation of satellite Geocoded data of IRS-1D, LISS III, FCC and the topographic maps on 1:50,000 scale. Area major lineaments are identified from the satellite data interpretation, which are surface manifestation of some structural features in the bedrocks as fractures and joints. The study area is divided into mini-watershed and micro-watershed on the basis of area and stream channels. Groundwater prospects are controlled by the lineaments/joints, as the lithology is not much suitable for groundwater development. Ultimate groundwater prospecting map indicate a variable groundwater potentiality in the area i.e. good, moderate, limited, and poor and based on these categorization the depth of wells are recommended for drilling.

5 illus, 4 tables, 8 ref

004310   Saini K R;Chakrapani G J;Sen A K (Dep of Earth Sci, Indian Inst of Technol, Roorkee-247 667) : Geochemical studies of groundwater in Saharanpur, Uttar Pradesh. J Geol Soc India 2006, 68(1), 50-8.

The geochemical characteristics of groundwater in Saharanpur city of Uttar Pradesh have been studied with a set of fifty water samples representing shallow groundwater of the area. The samples were collected during January and April 2003 which represent a season not characterized by excessive precipitation or evaporation. The samples were analyzed for various water quality parameters such as pH, electric conductivity, total dissolved solids, calcium, magnesium, sodium, potassium, bicarbonate, sulphate and chloride. Five groundwater samples were analyzed for Sr isotopic composition. The water is mostly Ca-Mg-HCO₃ type and is derived from the carbonate lithology. A few rainwater samples were also analyzed. Chemical weathering process is the dominant factor in the overall water chemistry, however for some parameters like SO₄, industrial effluents and/or atmospheric precipitation could be a major source. Dominance of carbonate lithology on water chemistry is also observed by the low Sr isotopic ratios (⁸⁷Sr/⁸⁶Sr) in waters. The high carbonate contents could lead to scale formation, which is a major problem in the region for domestic and industrial uses of water.

8 illus, 4 tables, 22 ref

004309   Ravindran J;Raghukumar C (NO, Natn Inst of Oceanography Regional Cent, Cochin-682 018, Email: jravi@nio.org) : Histological observation on the scleractinian coral Porites lutea affected by pink line syndrome. Curr Sci 2006, 90(5), 720-4.

Pink-line syndrome (PLS) was reported in the reef bunding coral Porites lutea in Kavaratti island of the Lakshadweep archipelago. The affected corals had dead patches colonized by a cyanobacterium Phormidium valderianum and the bordering coral tissue was pink. Examined the histological changes associated with the PLS-affected tissue. Results showed that the zooxanthellae were released from the gastrodermal cells into the coelenteron. Gastrodermal cells undergo necrosis and detachment from the basal membrane. The basic staining of the cytoplasm in the gastrodermal cells bordering the calicoblastic layer suggests accumulation of calcium ions. The ectodermal epithelium and calicoblastic cells showed destruction through 'apoptosis-like' processes. Cell swelling and vacuolation were observed in the gastrodermal and ectodermal cells. Discussed how the presence of the cyanobacterium adjacent to the PLS-affected tissue could cause the observed damage, bring about imbalance and a shift in the coral-zooxanthellae symbiosis.

12 illus, 12 ref

004308   Rao N V C;Ram M;Sutaone A T;Gundewar C S (Div of Ore Dressing Indian Bur of Mines Ministry of Mines, , L-8, MIDC-Hingna Road, Nagpur-440 016, Email: codoibm_ngp@sancharnet.in) : Gold in chromite ore of South Kaliapani mines, Sukinda ultramafic belt, Jaipur district, Orissa. J Geol Soc India 2006, 68(2), 171-5.

Gold in the form of cuprian grains is reported based on Electron Probe Micro Analvzer (EPMA) study of a sample received from the chromite tailing dumps of South Kaliapani mines, Sukinda Ultramafic Belt, Jajpur district, Orissa. The cuprian gold grains vary in size from 3 microns to 10 microns and are found as disseminations within the chromite host-phase. Chromite is one of the earliest minerals to form whereas hydrothermal process is characteristic of gold. The association of chromite and gold grains is therefore unusual and highly interesting. Textural features suggest that the gold grains are more likely to be genuine primary inclusions within the host chromite rather than being late stage hydrothermal products filling up cavities or open spaces. A preliminary account of characterization studies of gold grains involving back-scattered electron imaging, X-ray element 'dot' mapping, and qualitative elemental scanning are presented.

^ssc4 illus, 12 ref

004307   Ramam P K;Aruna P E (NO, , Plot No.22, # 202, Naimisam, Srinagar Colony, Hyderabad-500 073, Email: pk_ramam@yahoo.com) : Balancing mining and environment at Talaricheruvu limestone mine in Anantapur district, Andhra Pradesh. J Geol Soc India 2006, 68(2), 207-12.

Talaricheruvu Limestone Mine serves as a captive raw material source to a cement plant. Located on a plateau landscape, 379 m above MSL, the Mining Lease area is underlain by Narji limestones of the Proterozoic Kurnool group (Cuddapah Supergroup). Mining is accomplished by the opencast, mechanized method of working, producing about one million tonnes of limestone per annum now. A case study of this mining project is presented to demonstrate how, through prudent environmental management implemented pari passu with mining, significant ecological and socio-economic benefits (viz. drinking water for cattle, greening of the landscape, better communications etc) are brought about to the community.

3 illus, 2 tables,6 ref

004306   Prasad L K;Ghosh S K (NO, ICAR-RCER Walmi Complex, Phulwarisharif, Patna, Bihar-801 505) : Allophanes and free oxides in soils developed of four different parent materials in southeast peninsular region of India. Int J Trop Agric 2006, 24(1-2), 121-32.

Eastern part of Godavari river basin in southeast peninsular region of India is covered by four different parent materials forming a mosaic of soils was studied to know soil development. Lower SiO2 contents and a little change with depth indicated low degree of horizonation in pedons 1 to 4. Lower allophane and silica-alumina ratios indicated little development of profile and nature of parent material composition. In contrast, Sandstones and Crystallines resulted in soils with high SiO2 and the SiO2/R2O3 ratio and allophane content revealed that these soils were intensively weathered compared to pedons 1 to 4. Nature of parent material and occurrence influenced the soil development as indicated by the component ratios and allophane content.

3 tables, 16 ref

004305   Patra A K;Pendkar N;Chakrapani G J (Dep of Earth Sci, Indian Inst of Technol, Roorkee-247 667, Email: gjcurfes@iitr.ernet.in) : Heavy metal fractionation and mineralogy in sediments of Nainital lake, Kumaun Himalayas. J Geol Soc India 2006, 68(2), 181-5.

The major objective has been to determine the mineralogy and chemical composition of sediments of Nainital lake, a major tourist destination situated in the Kumaun Himalayas. Determined the mineral content in the sediments of the lake and analysed the associations of toxic metals in various chemical fractions such as, metals which are easily released to water from sediments, and metals bound to carbonates, manganese oxides, iron oxides, organic matter and residual matter. Although detrital minerals quartz and feldspar are dominant, calcite, aragonite, illite and gypsum are also present in appreciable quantities. Quartz and illite are the dominant minerals in the coarse fractions of sediments, whereas calcite, aragonite and gypsum are mostly present in finer sediments. Among the various chemical fractions, most of the metal concentrations are associated with the residual fraction, whereas, organic matter fraction is a major sink for Mn, Zn and Cu. Hence, under conditions where organic matter gets oxidized, the metals may be released into the water column, thus resulting in high pollution levels in the lake waters.

^ssc2 illus, 4 tables, 12 ref

004304   Parthasarathy G;Collins A S;Chetty T R K (NO, Natn Geophys Res Inst, Hyderabad-500 007, Email: gpsarathy@ngri.res.in ) : Natural graphite from neoproterozoic psammitic gneiss, Inanalo mountain, Southern Madagascar. J Geol Soc India 2006, 68(2), 176-80.

Reports, for the first time, powder X-ray diffraction, and laser-Raman spectroscopic data on the graphite samples from Inanalo mountain (S24°24'31.2" E45°23'18.3"), 20 km east of the Ampanihy shear zone of the southern Madagascar. Experimental results show that the graphite is highly crystalline, and syngenetic with the degree of graphitisation varying from 148 to 180, yielding the peak metamorphic temperatures of 750 to 850°C. Laser Raman spectroscopic studies show only ordered peak at around 1580 cm^-1 in the frequency range from 1000 to 2000 cm^-1. The commonly observed disordered peak in natural graphite is found to be absent in the studied sample, indicating high-temperature metamorphism. There is no fluid deposited graphite (epigenetic graphite) in the sample. The peak metamorphic temperature obtained in the study is found to be in good agreement with that obtained from the conventional geothermometry studies on the sample from the Beraketa shear zone or the Betroka tectonic belt.

^ssc3 illus, 1 table, 31 ref

004303   Paripurno ET (Disaster Mgmt Cent, Natn Dev Univ Yogyakarta, JI Lingkar Utara, Condongcatur Yogyakarta, 55283 Indonesia, Email: paripurno@telcom.net) : Studies on cause and impact of flood disaster in Central Java, Indonesia: a community-based disaster management perspective. Sci Cult 2006, 72(1-2), 32-9.

Indonesia is prone to natural disasters. Soil erosion and floods in the northern roasts of Central Java are triggered not only by heavy ram and tidal activity but also due to economic development and social changes. In many cases, the natural phenomena or hazards often can change to "disaster". The term disaster has been defined in many ways. As a social phenomena, disaster could (1) disrupt the normal patterns of life (2) be detrimental to humans (3) damage social structures (4) and lead to a sharp increase of needs. Central Java's vulnerability to natural disasters is caused by several factors. First, the flood plains are exposed to extreme events. Second, increased development activities and social changes in the flood plains are not in harmony with nature and environment. Third, social organizations for disaster management have low capacity for disaster management. Fourth, disaster management institutions in the local levels are not active.

3 illus, 4 tables, 10 ref

004302   Narayana A C;Priju C P (Dep of Mar Geol and Geophysics, Cochin Univ of Sci & Technol Lakeside Campus, Cochin-682 016, Email: acnarayana@cusat.ac.in) : Landform and shoreline changes inferred from satellite images along the Central Kerala coast. J Geol Soc India 2006, 68(1), 35-49.

The coastal landforms and land use/land cover changes of central Kerala have been studied with the aid of topographic maps, satellite images and extensive field checks. The landforms identified are barrier islands, beach ridges and swales, strandlines, flood plains and marshy swamps. Several parallely positioned barrier islands and paleo-beach ridges reveal that the central Kerala coast has been prograding. It is observed that the evolution of coastal landforms is influenced by the fall in sea level and/or uplift of the coast. Extensive occurrence of strandline/chenier deposits supports the view that the rivers of central Kerala once have supplied enormous amount of sediments. Land use/land cover changes, which have occurred during 1966-1995 are quite alarming. The reduction of about 50% in both flood plain and river channel area is due to changes in the land use pattern. Significant changes in the shoreline and morphology of river mouths are recorded. Area of accretional shoreline is more than that of erosion-prone shoreline. Major morphological changes are observed near the Cochin inlet. The factors affecting the shoreline and landform changes are natural as well as anthropogenic. The natural processes affecting the shoreline changes are sediment supply, coastal processes, and anthropogenic activities such as dredging. Important factors affecting the land use/land cover changes are reclamation of land for agricultural and industrial purposes, and sand mining in riverbeds and paleostrandline areas.

7 ils, 1 t, 43 ref, 1 p

004301   Naik R K;Naik A (Dep of Earth Sci, Sambalpur Univ, Jyoti Vihar, Burla, Sambalpur-768 019) : Revision of the structure and stratigraphy of Sargipali area, Sundargarh district, Orissa. J Geol Soc India 2006, 68(2), 269-76.

The metasedimentary assemblage of Sargipali area in western part of Sundargarh district is considered to be the western extension of Gangpur sequence. Detailed mapping reveals the assemblage to be composed of a variety of rocks like conglomerate, quartzite, banded biotite schist, quartz-biotite schist, calc-gneiss, limestone etc. folded in the form of a large syncline. The order of superposition of beds established on the basis of the sedimentary structures and analysis of structural data is found to be just the reverse of the order suggested by earlier workers.

5 illus, 2 tables, 15 ref

004300   Mukherjee A;Prabhakar G (Natn Miner Dev Corporation Limited, , Khanij Bhavan, Masab Tank, Hyderabad-500 028, Email: abhijeetmukherjee_2000@yahoo.com) : Fluid inclusion studies and sulphur and strontium isotope geochemistry of vein barites of velugumetla, Khamman district, Andhra Pradesh. J Geol Soc India 2006, 68(2), 201-6.

The Velugumetla barite deposit, Khammam district is studied for fluid inclusions, sulphur and strontium isotopes. The inclusions that are random in distribution and varying in size from 15-30 μ are classed as primary and the inclusions less than 15 μ in size and having linear trails as secondary. Heating runs of the primary and secondary inclusions show peaks at 235°C to 245°C(T_h) and 130°C to 140°C respectively. Both the primary and secondary biphase liquid rich(L+V) inclusions homogenized by the disappearance of the vapour phase. The composition of fluid has been surmised as H₂O+NaCl+KCl. The salinity was calculated as 12.7 wt% NaCl eqv. The minimum depth of precipitation of barite was estimated to be 300 m and the density calculated as 0.94g/cm³ with a fluid pressure of 31.2 bars. The fluid inclusion data of barite veins of vein barites of Velugumetla, Khammam district and other vein deposits of the Cuddapah Basin are correlatable in terms of composition, salinity, density, pressure, depth of entrapment and temperature of homogenization. The δ³⁴S values for barite varies between +23.5 to+25.6% and pyrite has values between -0.9 to+1.9% in case of the barite pyrite pairs that were studied from six different localities of the Cuddapah Basin and Khammam. The δ³⁴S values of the vein barite deposits of the Cuddapah Basin and Khammam area are similar to the contemporaneous sea water. The strontium isotope (⁸⁷Sr/⁸⁶Sr) ratios show wide variation 0.705 to 0.722 for the vein barites of Cuddapah Basin and Khammam and indicates significant contribution of radiogenic Sr from older continental crust.

4 illus, 3 tables, 16 ref

004299   Mohan R;Guptha M V S (Natn Cent for Antarctic & Ocean Res Goverment of India Headland Sada, , Goa-403 804, Email: rbanaras@yahoo.com) : Corroded planktic foraminifer (Globorotalia menardii) in the southern Bay of Bengal sediment trap sample of february 1992. J Geol Soc India 2006, 68(2), 225-9.

Planktic foraminiferal studies from the southern Bay of Bengal (SBBT) indicate the presence of corroded specimens of Globorotalia menardii in the deep trap at a depth of 3011 m during February-March 1992. Strangely, all the other spinose and less resistant spinose foraminiferal species are found devoid of any signs of dissolution in association with the highly corroded specimens of Gr.menardii. In view of the above and also to the fact that this trap depth is well above the lysocline, it is postulated that these corroded specimens of Gr.menardii tests could have been supplied by lateral advection and mixed up with the settling particles at SBBT, thus this assemblage is a resultant of two different sources, during this particular period.

2 illus, 18 ref, 1 plate

004298   Manuta J;Khrutmuang S;Huaisai D;Lebel L (Unit for Social and Envir Res, Chiang Mai Univ, Chiang Mai 50200, Thailand, Email: jesse@sea-user.org) : Institutionalized incapacities and practice in flood disaster manangement in Thailand. Sci Cult 2006, 72(1-2), 10-22.

Focuses on the institutional capacity within the Thai nation-state to manage floods and the risks of flood-related disasters. The research aims to understand how various laws, policies, programs and procedures for managing floods and the risks of flood-related disaster came about and how they have performed. It further examines the capacity to mobilize and coordinate resources as well as deliberate, negotiate, monitor and evaluate the formal institutions from the national to local level. Focusing the analysis on institutional changes and river-based flood events during the last two decades, explores ways of reducing the risks of flood disasters in ways that do not further disadvantage already socially vulnerable groups. Documents and reports were reviewed. In addition, interviews and field observations on site after flood events were carried out. There are indications of improved institutional performance of the government in the areas of relief and emergency, the formation of the flood disaster emergency committee at the outset of the monsoon season in flood prone areas, and initial efforts to involve communities in flood prevention and mitigation. Several institutionalized incapacities, however, continue to undermine the provision of assistance and services that would reduce the risk of flood disaster. Poor coordination across administrative bodies and line agencies results in fragmented flood mitigation and prevention intervention measures. Flood disaster victims are left alone to fend themselves especially in remote areas due to incomplete implementation, poor follow-up, and structural biases. Many problems are aggravated by the absence of monitoring and evaluation of state agency's performance. Social mobilization on flood management may be necessary to re-enable these institutions to perform the roles in society for which they were intended - reducing vulnerabilities and risks of flood disasters.

2 tables, 24 ref

004297   Maithy P K;Bindal C M;Bhushan S K;Sharma S; Banerji D C;Kumar G (NO, , F2212, Rajajipuram, Lucknow, Email: kumarg@sancharnet.in) : Lower gondwana plant fossils from Arunachal lesser Himalaya and their age. J Geol Soc India 2006, 68(2), 316-26.

Lower Gondwana plant fossils from the Bhareli Formation, exposed between Pinjoli Nala and Sessa along the Bhalukpong - Bomdila Road, West Kameng district, Arunachal Pradesh, are described and reviewed. The assemblage comprises Gangamopteris cyclopteroides, G. intermedia, Glossopteris angustifolia, G. communis, G. damudica, G. indica, G. intermittens, Scutum cf. stowanum, Vertebraria indica, Noeggerathiopsis sp., Cheirophyllum lacerata, stem of Buriadia, Cordaicarpus cordai, Rotundocarpus striatus and Walikalia cahenii. The assemblage is comparable to that of the Karharbari Formation of Early Permian Coalfields of Peninsular India.

2 illus, 47 ref, 2 plate

004296   Luna E M (NO, , , Email: lunakids@ibahn.net) : Power from within to overcome vulnerabilities: a Philippine case on endogenous system of response to river flooding. Sci Cult 2006, 72(1-2), 40-51.

As a tropical country facing the Pacific Ocean, the Philippines is very vulnerable to typhoons. The people have different levels of vulnerability and capacity, based on socio-economic differentiation and the level of development of the communities where they live. When the formal local institutions fail to respond to disasters, the people are left to depend on themselves. Using their resources and capacities, the families from various vulnerable groups come and complement each other into an endogenous system of responding to disaster events Looks at the endogenous system of response in a typical rural municipality in the Philippines that is often affected by typhoons. The endogenous way of the people is a source of power from within, collectively manifested as community resilience that can help overcome vulnerabilities and disasters. As a universal phenomenon that cuts across lime, space and cultures, the endogenous system has to be recognized and mobilized in initiating changes and transforming communities to reduce risks and disasters.

5 tables, 10 ref

004295   Lehmann B;Mainkar D;Belyatsky B (Inst of Mineralogy and Miner Resour, Tech Univ of Clausthal, Adolph-Roemer-Strasse 2a, 38678 Clausthal-Zellerfeld, Germany, Email: Lehmann@min.tu-clausthal.de) : The tokapal crater facies kimberlite system, Chhattisgarh, India: reconnaissance petrography and geochemistry. J Geol Soc India 2006, 68(1), 9-18.

The crater-facies kimberlite system at Tokapal occurs within the Late Proterozoic chemoclastic cover sequence of the Indravati Basin on the Meso-Proterozoic/Archaean Bastar craton in central India. The pyroclastic lapilli tuffs consist of pseudomorphs of olivine macrocrysts and juvenile lapilli set in a fine-grained talc-serpentine-carbonate matrix with locally abundant spinel and titanite. No garnets or diamonds have been found so far. The inequigranular and locally bedded texture is largely preserved, although the olivine component has been completely destroyed. The multiple kimberlite system has about circular shape (2.5 km in diameter) and is probably the oldest and largest crater-facies kimberlite system known in the world. The satellite Bhejripadar system of similar petrographic and chemical characteristics is situated about 4 km to the northwest and has a few hundred meters of diameter. Samples from both systems have mostly moderated degree of contamination (35-50 wt% SiO₂, <60>4 wt% Al₂O₃) and Mg numbers of 82-89. The trace element patterns are typical of kimberlitic rocks (REE, Cr, Ni, Nb, Zr), with mobile elements strongly leached due to intense postmagmatics alteration and weathering (Ba, Sr, Rb, alkalis). The Nd isotops composition of E_nd around 2 (T=1100 Ma) is diagnostic of arthetypal (Group (I) kimberlites an similar to the diamondiferous Majhgawan pipe with E_nd) and the kimberlites of southern India with E_nd 2 (T=1080 Ma). The Early paleozoic diamondiferous Kodomali kimberlite pipe from the nearby Mainpur kimberlite field also has E_nd 1 to 2 (T=480 Ma), suggestive of a slightlydepleted to undifferentiated asthenospheric mantle source for all Indian kimberlite rocks.

7 illus, 2 tables, 26 ref

004294   Lebel Y L;Nikitina L;Manuta J (Unit for Social and Envir Res, Chiang Mai Univ, Chiang Mai, Thailand, Email: louis@sea-user.org) : Flood disaster risk managment in Asia : an institutional and political perspective. Sci Cult 2006, 72(1-2), 2-9.

Reviews experiences in reforming flood disaster management and from this derives an initial framework for assessing institutional capacities for flood disaster risk reductioin. Raises several questions that lead up to this framework: When is a flood a disaster? Who and what should be at risk? Who is or should be responsible? How were risks of disaster changed? How was performance evaluated?

1 table, 36 ref

004293   Lasitha S;Radhakrishna M;Sanu T D (Dep of Mar Geol and Geophysics, Sch of Mar Sci Fine Arts Avenue, Cochin-682 016, Email: mr_radhakrishna@hotmail.com) : Seismically active deformation in the sumatra java trench-arc region: geodynamic implications. Curr Sci 2006, 90(5), 690-6.

Crustal deformation rates (1900-2000) estimated for the Sumatra-Java are region highlight (i) large variations in dextral shear motion (seismic slip) from 1 mm/yr to 29 mm/yr along the Sumatran Fault Zone (SFZ), (ii) dominantly compression with deformation velocities as high as 19 mm/yr near the equator along offshore Sumatra fore-arc and, (iii) dominance of compression (average 19 mm/yr) in the western part of offshore Java fore-arc that gradually changes to extension (average 3 mm/yr) towards east. While seismic slip rates match well with the geological or GPS derived slip rates between 0° and 2°S along SFZ, the values are much lower for the fault segments north of equator. The deformation pattern in the offshore Sumatra indicates that the Mentawai fault partly accommodates motion due to oblique subduction and suggests local interaction of the Investigator Fracture Zone near the equator. However, north of 2°N, the low deformation velocities in the offshore Sumatra can be attributed to the absence of significant earthquakes during the period of investigation. This long-term seismic quiescence might have caused lock up of stresses that resulted in highly devastating 26 December 2004 earthquake.

4 illus, 47 ref

004292   Kurum S;Akgul B;Erdem E (Dep of Geol Engng, Firat Univ, 23119 Elazig, Turkey, Email: skurum@firat.edu.tr) : Examples of neogene volcanism in eastern Turkey: comparative petrographic geochemical and petrologic features of Malatya-Elazig-Tunceli volcanics. J Geol Soc India 2006, 68(1), 129-36.

Neogene-age volcanics having within plate character widely outcrop in the east Anatolia region. Complex zonation indicating magma mixing is commonly observed in petrographic sections. Geochemical data shows that these volcanics are alkalic, calc-alkalic and tholeiitic in character. Three possible sources responsible for the composition of these volcanics are fractional crystallization of a mafic magma, magma mixing and crustal contamination resulting from continent - continent collision.

7 illus, 4 tables, 29 ref

004291   Kundal P;Dharashivkar A P (Dep of Geol, Postgrad Univ Law Coll Square, RTM Nagpur, Nagpur-440 001, Email: ppk_kundal@rediffmail.com) : Ichnofossils from the neogene and quaternary deposits of Dwarka-Okha area, Jamnagar district, Gujarat. J Geol Soc India 2006, 68(2), 299-315.

A rich and diversified ichnofossil assemblage comprising seventeen ichnospecies distributed among ten ichnogenera have been discovered for the first time from Neogene-Quaternary deposits of Dwarka-Okha area, Jamnagar district, Gujarat, India. The ichnospecies are Cylindrichnus concentrichus (Howard), Keckia annulata Glocker, laevicyclus mongraensis Verma, Ophiomorpha borneensis Keij, O. irregulaire Frey, Howard and Pryor, O. nodosa Lundgren, Palaeophycus heberti (Saporta), P. tubularis Hall, Planolites annularis Walcott?, P. beverleyensis (Billings), P. montanus Richter, Psilonichnus upsilon Frey, Curran and Pemberton, Rhizocorallium karaiensis Chiplonkar and Ghare, R. yelamensis Sanganwar and Kundal, Skolithos ichnospecies, Thalassinoides paradoxicus Woodward and T. suevicus Rieth. Of these three species, namely Cylindrichnus concentrichus, Ophiomorpha borneensis and O. irregulaire Frey, Howard and Pryor are being reported for the first time from India. Barring Ranjitpur Limestone Member of Gaj Formation and Aramda Reef Member of Chaya Formation, the rocks of all other members have yielded ichnofossils. Provides systematic description of aforementioned seventeen ichnospecies and analyses them for depositional environments. The present ichnocoenose defines Skolithos-Cruziana mixed ichnofacies that indicates littoral to shallow sublittoral sandy shore with very high energy conditions of deposition.

5 il, 1 t, 39 ref, 4 pl

004290   Joshi A;Pant N C;Neogi S;Nanda J K (Geol Surv of India, , A-2, Pushpa Bhavan, New Delhi-110 049, Email: joanil@rediffmail.com) : High-Al gabbro in proterozoic anorthosite massifs of Orissa: implication for anorthosite genesis. J Geol Soc India 2006, 68(1), 59-71.

High-Al gabbro is reported for the first time from three anorthosite complexes of Orissa sector of Eastern Ghats Granulite Belt (EGGB). It has distinctly different textural, mineralogical and chemical characters from the anorthosite within which it occurs, and also from the spatially associated Fe, Ti and REE enriched ferrodiorite suite. The high-Al gabbro of EGGB is comparable to similar rocks from other anorthosite complexes in major, trace element compositions and Mg<35> range (50-58). However, in contrast to the high-Al gabbro of the Laramie Anorthosite Complex (LAC), it does not form the most primitive rock of this association and exhibits negative Eu anomaly (Eu/EU*: 0.2-0.6). The Mg enriched composition of the silicates of the high-Al gabbro and higher MgO contents of the associated anorthosite and ferrodiorite of the LAC are other critical differences.

9 illus, 10 tables, 45 ref

004289   Jeyagopal A V;Singh R V;Rao P Nageswara; Saxena V P;Sinha R M (Dep of Atom Energy Atom Miner Directorate for Explor and Res, , Begumpet, Hyderabad-500 016, Email: jeyagopalav@yahoo.com) : Geology of the Julakallu area, Palnad sub-basin, Cuddapah basin, Guntur district, Andhra Pradesh. J Geol Soc India 2006, 68(1), 103-14.

Recent geological studies have brought out the presence of hitherto unknown Cumbum shale/phyllite in the Julakallu-Pinneli area, Guntur district, Andhra Pradesh within the Palnad Sub-basin of the Cuddapah basin. Cumbum shale/phyllite and quartzite was found to rest above the Narji Limestone at southeast of Petasannigandla. This has necessitated northward shift of thrust boundary separating the Cumbum Formation and Narji Limestone from earlier known location. Subsurface data have confirmed larger thickness of the Narji Limestone than that reported in the literature. Geochemical characteristics of the Cumbum shale/phyllite have indicated its deposition as first cycle of sediments in a tectonically active setting. This is supported by the depletion of immobile oxide Al₂O₃ and enrichment of mobile oxide CaO in the Cumbum shale. The A-CN-K plot indicates that provenance for shale/phyllite could be granodiorite to granite in composition, which is also supported by petrological observations. The field, petrological and geochemical interpretations have brought out much new information on this part of the basin, which necessitates, revision of the geology of area.

6 illus, 2 tables, 14 ref

004288   Islam R;Rao D R;Gururajan N S;Rai H;Khanna P P (NO, Wadia Inst of Himalayan Geol, 33 General Mahadeo Singh Road, Dehra Dun-248 001, Email: rislam@rediffmail.com) : Geochemical, geochronological and petrogenetic studies of the granitoids from the Tso-Morari crystalline complex, Ladakh, Jammu and Kashmir. J Geol Soc India 2006, 68(1), 72-86.

In the NW Himalaya, granite bodies of Puga, Polokongka La, Rupshu and Nyimaling intrude the Puga Formation and Taglang La Formation of the Tso-Morari Crystalline Complex of Ladakh. Integrated field, petrographic, geochemical and geochronological data from these granite bodies are compared with other granites of Cambro-Ordovician age of the northwestern Himalaya. The granites of Tso-Morari region show high mol. A/CNK values, show presence of normative corundum, and have high Sr_i ratios, suggesting that they are S-type granites. The changes in major, trace and rare-earth elemental chemistry towards more leucocratic samples suggest the involvement of fractional crystallization processes. Further, the Rb-Sr dating of peraluminous granites of Tso-Morari, Ladakh gave an isochron age of 499±8 Ma, 487±23 Ma, 475±23 Ma, and 456±16 Ma for Puga gneiss (PGn), Polokongka La granite (PG), Rupshu granite (RG) and Nyimaling granite (NG) respectively. Also reveals that the Polokongka La granite is an undeformed facies of the Puga gneiss has been carries out. The geochemical characteristics and Sr_i ratio of the Rupshu granite suggest that they are essentially S-type granite bodies, contrary to their I-type nature described by earlier workers. It is proposed that the granites of Tso-Morari Crystallines, along with the large number of other early Palaeozoic granite plutons in NW Himalaya, are the result of widespread crustal melting of quartzo-feldspathic materials saturated in Al₂O₃ during Cambro-Ordovician orogenic event.

10 illus, 4 tables, 59 ref

004287   Humane S K (Dep of Geol, Postgrad RTM Nagpur Univ, Nagpur-440 001, Email: sumedhahin@yahoo.com) : Micro scale cross laminations in the sandstone of Khari nadi formation (Aquitanian) form Laiyari area, Southwestern Kachchh. J Geol Soc India 2006, 68(1), 5-8.

The asymmetric micro scale cross ripple laminations formed under unidirectional traction current are noted from the Aquitanian sandstone of Laiyari area of south western Kachchh, Gujarat. The micro facies of micro scale cross laminations represent lower velocity migration at shallow depth waves in littoral and marine environments. Asymmetric ripples signify net landward unidirectional transport of shallow marine water.

3 illus, 14 ref

004286   Ghosh A;Roy J (Dep of Economics, Jadavpur Univ, Kolkata) : Coping with extreme climatic events: analysis of household and community responses from selected hotspots in India. Sci Cult 2006, 72(1-2), 23-31.

Brings into focus how and why a developing country like India whose primary objective is livelihood protection needs to bind climate change issues with wider developmental issues. Reinterpret sustainable development as a practical approach that addresses issues pertinent to LIFE. Though global climate change is important in the long run, in opinion climate derivative weather is also an essential resource for India's economic well being in the short term. Analyzing existing levels of climate variability and extreme events that pose significant risks to economic activities pursued by individuals as livelihood options in the river basins in India. Vulnerability assessment of the households and communities has been presented. The study areas has been presented cover flood prone villages in the Mahanadi River basin and drought prone villages in the Sabarmati River basin. Main sources of information are socio-economic field surveys carried out during 2003-2004 in the selected hotspots. Based on qualitative and quantitative assessments of the responses and of the reactive coping strategies, show that adaptive capacity goes beyond just income and access to regular infrastructure. Adaptive capacity is a complex combination of institutional governance, management and technology. Based on survey results shown the potential for an integrated strategy that can respond to climate change and to traditional development strategies, but which can also increase the likelihood of people's participation in making the developmental efforts sustainable. The research findings that present here have been validated by the feedback of the stakeholders' engaged in direct dialogue.

6 illus, 2 tables, 24 ref

004285   Few R;Tran P G (Sch of Dev Stud, Univ of East Anglia, UK, Email: r.few@uea.ac.uk) : Prevention and cure: health sector response to flooding. Sci Cult 2006, 72(1-2), 52-61.

Flooding poses multiple risks to human health. In the context of the additional threats from climate change, it is vital to improve our understanding of the health-related responses to floods and, in particular, to analyse the challenges, constraints and opportunities for flood preparedness within the health sector. Drawing on existing work about health and floads in Asia, and on new empirical research about health-related responses to flooding in the Mekong Delta, Vietnam. Describes some health sector coping mechanisms and associated challenges for adaptation. It takes a broad approach to health sector responses, covers aspects of preventive and curative health both within and beyond the formal health system, and recognises that efforts in health promotion, water/sanitation provision and protection of health infrastructure are all closely related. It finds that, as for other sectors, greater preparedness can play a crucial role in health risk reduction in two ways: by reducing the vulnerability of the public to the short- and long-term health impacts of floods; and by reducing the vulnerability of the health services to the damage and disruption caused by floods. It also emphasizes that long-term risk reduction rests on effective integration of the health sector with other sectors and the involvement of communities in the design and implementation of health protection activities.

1 illus, 2 tables, 65 ref

004284   Farooqui A;Achyuthan H (NO, Birbal Sahni Inst of Palaeobotany, 53, University Road, Lucknow-226 020, Email: afarooqui_2000@yahoo.com) : Middle to late holocene palaeoenvironmental changes: evidence from the sediments, pollen and radiocarbon dates, Adyar, Chennai. J Geol Soc India 2006, 68(2), 230-8.

Middle to Late Holocene chronostratigraphy and palynology data analyzed from three insitu cores - sedimentary profiles retrieved along the Adyar river and the Adyar estuary zone, Chennai. These cores offered excellent cross-sections along the east-west direction. Data reveals that the mangrove vegetation that existed until Middle Holocene (4180±130 Yrs. BP) became extinct since the Late Holocene. The tidal influx influenced the estuary 10 km west inland (at Saidapet) from the present shoreline until Middle Holocene providing congenial environment for mangroves. The reasons for decline in mangroves since the Late Holocene (last 2000 Yrs. BP) is attributed to the relative sea level and coastal configuration change enhanced by the anthropogenic pressure. The palynological evidences from Saidapet (Chennai) and Sulurpet (playa of the Pulicat lagoon) indicate the transgressive phase of middle Holocene in Palar Delta. Although mangroves were abundant during Middle Holocene in both the areas, it faced complete extinction or acute degradation since the Late Holocene.

5 illus, 1 table, 32 ref

004283   Fareeduddin;Pant N C;Neogi S (Div of Geol Surv of India PPOD, A.M.S.E. Wing, Bangalore-560 078, Email: fareedromani@hotmail.com) : Petrology of the kodomali diatreme, Mainpur area, Chhattisgarh, Central India: implications for a palaeozoic orangeite field. J Geol Soc India 2006, 68(1), 19-34.

The Kodomali body is one among the six pipes, reportedly of kimberlitic composition, in Mainpur area, district Raipur, Chhattisgarh. It occurs within the Bundeli granitoid that is emplaced in the lower part of the Khariar/Pairi group of rocks. Recent age determinations have indicated that the Kodomali has intruded into Bundeli granitoids at about 500 Ma. The Kodomali diatreme exhibits a distinct macrocrystal texture with coarse olivine occurring in a very fine grained groundmass made of diopside, phlogopite, spinel and secondary serpentine. Two generations of olivine occur in the rock. Macrocrystal olivine is distinctly xenocrystic whereas microphenocrystic olivine, which is zoned with more forsteritic cores than their margins, show chemical parameters suggestive of crystallization from a melt. Fe-poor diopside and Ti-rich, Al and Cr-poor phlogopite constitute the bulk of the groundmass. Phlogopite cores are richer in Ti and Al compared to rims and show crystallisation trends typical of orangeites. Spinel group minerals (magnesio-chromite) occur as (i) coarse xenocrystic zoned grains with Ti poor, Al and Mg rich cores relative to the rims and (ii) as fine size grains in groundmass. Some coarse spinel group mineral grains are enveloped by corona of sphene against macrocrystic perovskite, inferred to result from low temperature hydrothermal alteration through interaction with Si-bearing fluids. Groundmass spinel, also represented by magnesian chromite, is sparse, has no perceptible zoning and exhibits Ti-magnetite crystallization trend that is characteristic of orangeites. The petro-mineralogical attributes of the Kodomali diatreme show close affinities with the South African orangeites. Recent studies on another diatreme in the area is also suggestive of an orangeitic affinity for the rock. These studies imply that the Mainpur area represents an orangeite field of Palaeozoic age.

13 illus, 7 tables, 27 ref

004282   Elena N (Inst for Wld Economy and Int Relations, Russian Acad of Sci, Prof souznaya st 23, Moscow, Russia GSP-7 117997) : Success and failures in flood risk reduction programes across Asia: some lessons learned. Sci Cult 2006, 72(1-2), 72-83.

Takes an institutional perspective on floods risk reduction in the countries of Asia. It focuses on some problems related to design and action of institutions and implementation of anti-flood disaster policies and measures. It starts with presenting approaches to assessing institutional frameworks for floods risk reduction and describing some trends in development of domestic institutions in four countries of Asia, i.e. Japan, Russia, Thailand and Vietnam. Then it discusses some examples of success and failures during particular flood events recently taken place in these countries, and explains good and bad practices in institutional actions (or inactions). For this purpose it focuses on a number of factors defining performance of institutions and implementation problems. Concludes with outlining some lessons learned about performance of existing institutions during floods. It is based on insights drawn from ongoing joint research undertaken by a group of scholars and practitioners from Japan, Russia, Thailand and Vietnam.

1 table, 13 ref

004281   Chandra Mandal B;Woobaidullah A S M (Geol Surv of Bangladesh, , 153 Pioneer Road, Shegunbagicha, Dhaka 1000, Bangladesh, Email: woobaid@udhaka.net) : Sedimentary tectonics of the eastern fold belt of the Bengal basin, Bangladesh. J Geol Soc India 2006, 68(1), 115-28.

Depositional history and tectonic evolution of the Bengal Basin commenced with the collision between Asia and Greater India in Late Paleocene (55 Ma). Sedimentation within the basin was activated during the Eocene in response to the simultaneous collision of the Indian and Burmese plates in the east and the Indian and Tibetan plate in the north. The dominant compressional force for development of the eastern fold belt resulted from subduction of the Indian plate beneath the Burmese plate in eastern part of the basin. From Miocene onward, the Indian plate has been subducting beneath the Burmese plate with a counter clockwise rotational movement, while the Burmese plate was overriding the Indian plate with a clockwise rotation. Consequently, the overall trend of folded structures varies from NNW in the southern part to NNE in the northern part of the eastern fold belt. This variation in structural style along with the presence of longitudinal thrust faults and transverse faults suggests that the Indian plate initially pushed towards east and then turned northeastward during the Cenozoic. Structural style of the eastern fold belt is characterized by the presence of a series of elongated en-echelon folds, which are tight and steep in the east, while towards the west they tend to be gentler and box shaped. Presence of longitudinal and cross faults along most of the folds suggests their hybrid origin. In seismic sections these faults appear to be heterogeneous in nature; and are believed to represent different time domain of their formation. Analysis of the stratigraphic succession in seismic profiles of selected structures suggests a close relationship between sedimentation style and tectonic framework within the eastern fold belt. Occurrence of overpressure zones in the lower Surma Group is believed to be primarily due to undercompaction caused by rapid accumulation of fine-grained elastics and not tectonic deformation. Interpretation of seismic data and comparison of subsurface structural depth contour maps of different horizons reveals heterogeneous flexuring rates. The westward shift of the culminations and closures of different horizons from bottom to top reflects the imprints of time variant evolution of the folded structures. Hence it is thought that intensity and direction of the tectonic force responsible for development of compressional deformations within eastern fold belt of the Bengal Basin was time variant and contemporaneous with sedimentation.

10 illus, 1 table, 62 ref

004280   Bandyopadhyay D N;Shah B Ali;Ghosh S C (Dep of Geol Sci, Jadavpur Univ, Kolkata-700 032, Email: bashahju@yahoo.com) : Petrography and diagenesis of the Panchet sandstones, Raniganj coalfield, West Bengal. J Geol Soc India 2006, 68(1), 137-48.

The Lower Triassic Panchet sandstones of the Gondwana Supergroup in the Raniganj coalfield are chiefly immature arkose to suh-arkose. The elastics are derived from the adjacent Precambrian granitic-gneissic terrain. Iron oxide as primary grain-coat, pore filling silica and quartz overgrowth, epimatrix formed of kaolinized feldspar and biotites, kaolinite filling up the primary pore spaces and that altered at places to montmorillonite are the episodes related to early diagenesis; compaction and oxy-acidic pore water would be playing important part during early lithificalion. Orthomatrix, neoformed primary silica, serieitized feldspars and illitized montmorillonites representing the late diagenetic products assumed to have formed under burial depth around 3 km. Chlorite also a late diagenetic product and mostly confined to the lower level of the Panchet Formation was formed through combining Fe and Mg with kaolinite under reducing environment; chlorite at places transformed as vermiculite with its probable interaction with Ca²⁺ rich groundwater. Carbonate, volumetrically important next to iron oxide mostly occurs as pore filling cement or sometimes filling up the fissures developed over micritic calcite cement, and both being related to the late part of the late diagenesis precipitated from the meteoric water penetrated through the post depositional fault and fractures planes. Mica peridotitcs too could be the sink supplying ions required for calcite precipitation. Multistage emplacement of allogenic and authigenic cements implies varying concentration of ions and fluctuating pH of the pore water during diagenesis.

6 illus, 1 table, 54 ref

004279   Ahmad A H M;Bhat G M;Khan M S;Farooq S H (Dep of Geol, Aligarh Muslim Univ, Aligarh-202 002, Email: ahmahmad2004@yahoo.com) : Provenance of glauconitic sandstones of kheinjua formation of semri group, Son valley, Central India: evidence for uplift of a rifted continental margin basin. J Geol Soc India 2006, 68(2), 288-98.

Embodies results of petrofacies, detrital mineralogy, texture and diagenetic aspects of glauconitic sandstones of Kheinjua Formation of Vindhyan Basin, Son valley. These glauconitic sandstones consisting of various types of quartz, feldspar, rock fragments, mica and a suite of heavy minerals, are medium to very fine grained, and well to moderately well sorted. These sediments including glauconite grains are generally subangular to subrounded with a few grains being well rounded. These sandstones are well compacted and dominated by interpenetrative contacts and are mainly cemented by iron cement with small amount of glauconite and silica cement. The existing optical porosity has developed due to dissolution of iron cement, feldspar and rock fragments. These observations suggest progressive compaction, which initiated at the sediment-water interface and continued till deep burial diagenesis in a rapidly subsiding basin. The plots of petrofacies in Qt-F-L, Qm-F-Lt, Qp-Lvm-Lsm and Qm-P-K ternary diagrams suggest mainly basement uplift source (craton interior) in a rifted continental margin basin setting, which has also received sediment input from recycled orogen provenance. The plot of various quartz types on diamond diagram after Basu et al. (1975) reflects derivation of the sediments from the plutonic and middle to high-rank metamorphic terrains. Besides, Lower part of the Semri Group, the most probable provenance of these sandstones is Bijawar metasedimentary and Bundelkhand Gneissic complexes, which bordered the basin in the north and northeast.

9 illus, 5 tables, 39 ref

003201   Sinha D K;Singh A K;Tiwari M (Department of Geology, Banaras Hindu University, Varanasi-221 005, Email: devasinha@yahoo.com) : Palaeoceanographic and palaeoclimatic history of ODP site 763A (exmouth plateau), southeast Indian Ocean:2.2 Ma record of planktic foraminifera. Curr Sci 2006, 90(10), 1363-9.

The western margin of Australia is unique in being the only eastern boundary region undergoing no up-welling as the poleward flowing Leeuwin Current (LC) nullifies the equatorward-driven wind-induced circulation. The principal forcing mechanism of the Leeuwin Current is the alongshore pressure gradients and associated zonal geostrophic flows along the West Australian margin. Based on planktic foraminiferal census counts and stable isotopic analysis of a surface-dwelling planktic foraminifera, Globigerinoides sacculifer, shows that during the Quaternary there have been live intervals when this eastern boundary region behaved in an opposite manner and the margin experienced extensive upwelling due to weakening of the LC and dominance of equatorward wind-driven circulation, causing offshore Ekman transport. These events occurred at 2.22, 1.83, 0.68, 0.45-and 0.04 Ma and have been named here as PL-1 to PL-5 in ascending stratigraphic order. It has been demonstrated here that the previous two events, PL-1 and PL-2, occurred due to ENSO-induced changes in the Western Pacific Warm Pool, while the last three events, PL-3, PL-4, and PL-5, occurred due to reduced Indonesian throughflow as a result of lowered sea level caused by ice volume expansion. It has been envisaged here that these periods must be those or reduced net heat input to the Indian Ocean from the Pacific via Indonesian Seaway and thus should have an effect on sea surface temperature of the Indian Ocean and Indian monsoon.

2 illus, 3 table, 33 ref

003200   Rastogi R G (Physical Research Laboratory, Navrangpura, Ahmedabad-380 009, ) : Effects of ionospheric, magnetospheric and induced current on equatorial electrojet over India. Indian J Radio Space Phys 2006, 35(3), 55.

Describes the diurnal and latitudinal variations of the horizontal (H), eastward (Y) and vertical (Z) components of the geomagnetic field at Central African, East Brazilian and Indian sectors based on the chain of magnetic observatories operated in these areas. The observations in Brazil and African sectors conform fairly well with the expectations of Chapman's theory of equatorial electrojet. In Indian longitudes the latitudinal variation of ΔZ shows a large maximum simultaneously with the peak of ΔH over the dip equator. The daily variation of ΔZ shows a peak around 0900 hrs LT when the rate of increase of ΔH with time is largest. The peak of ΔZ is largest at Kanyakumari and decreases with increasing latitude of the station. The phenomenon is suggested due to sub-surface induction in southern Indian region and not confined to Palk Street. Solar flares cause a temporary increase of the ionospheric current along the pre-flare direction. Faster flares indicate induction effects at each of the equatorial stations. The storm time variation of Z also shows the sub-surface induction effects at electrojet stations in India Storm time variations in H are shown to be enhanced over the stations close to the dip equator during the local mid-day hours. The equatorial electrojet is shown to be closely affected by ionospheric as well as magnetospheric currents and by the currents induced by these in sub-surface conducting regions.

21 illus, 46 ref

003199   Ram Singh;Phadke V S (Department of Geography, University of Mumbai, Mumbai-400 098, Email: rrupsing@rediffmail.com) : Assessing soil loss by water erosion in Jamni river basin, Bundelkhand region, India, adopting universal soil loss equation using GIS. Curr Sci 2006, 90(10), 1431-5.

The universal soil loss equation (USLE) developed by the United States Department of Agriculture has been used, Agriculture Research Service, to predict soil erosion from a watershed. The land cover/landuse data at village level is collected from the Revenue Department, and detailed soil data from the All India Soil and Landuse Survey, New Delhi, are used in USLE for determining soil erosion rate. Maplnfo Professional Version 5.5 GIS Software has been used as a platform for spatial data analysis required in the USLE. The potential soil loss has been estimated and mapped. Maps covering each parameter were integrated to generate a composite map of erosion intensify based on advanced GIS funclionality. The map is expected to assist in the identification of priority areas of the basin and would thus help in future planning of a watershed and its sustainable development.

2 illus, 5 tables, 10 ref

003198   Prabhudesai R G;Joseph A;Agarvadekar Y; Dabholkar N;Mehra P;Gouveia A;Tengali S;Parab A (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: prabhu@nio.org ) : Development and implementation of cellular based real time reporting and internet accessible coastal sea-level gauge-A vital tool for monitoring torm surge and tsunami. Curr Sci 2006, 90(10), 1413-18.

The development and implementation of real-time reporting and Internet-accessible coastal sea-level gauge, wherein data communication between the gauge and an Internet server has been established through a cellular modem utilizing General Packet Radio Service technology have been described. Using the existing cellular phone network, a continuous real-time update of coastal sea-level changes is realized on a web-server. The system implemented, and accessible to every authorized personnel, provides a graphical illustration of the predicted fair-weather sea-level, current sea-level, and residual sea-level (i.e. measured minus predicted fair-weather sea-level), which can be monitored via Internet from any part of the world. This system provides a cost-effective and easily maintainable platform for real-time monitoring of coastal sea-level and for providing the requisite input for efficient implementation of any alert and warning mechanism in the event of oceanogenic natural disasters, particularly storm surges and tsunamis. The architecture of the system described herein, and operational since 24 September 2005 at Verem jetty in the Mandovi estuary, Goa, would complement the INSAT-based sea-level gauges that are proposed to be put in place by the Government of India by the year 2007.

4 illus, 10 ref

003197   Nagaraju D;Nagraj M;Balasubramanian A (Studies and Research in Geology Dep, University of Mysore, Manasagangotri, Mysore-570 006) : Hydrogeophysical exploration for groundwater in Mandya taluk, Karnataka, India. J Ecotoxic envir Monit 2006, 16(1), 43-53.

Mandya forms the fourth largest taluk in the Mandya district. This taluk forms a highly undulating terrain with considerable extent of barren rocky areas, comes under the semi-arid type with schist, granite and gneissic rocks. Vertical electrical soundings (VES) have been carried out at 50 locations in the area to determine the longitudinal conductance at different layer parameters for the preparation of groundwater potential map. It has been observed that all the four types of resistivity curves of the three layered geoelectrical sections (A, K, H & Q curve types) do exist in this area. The potential zones exist in and around southern parts of the taluk. Geophysical investigations are useful to ascertain the nature of aquifers and bedrock, below the soil cover, to locate potentiaal zones, to find out to delineate the structurally deformed Groundwater potential zones.

4 tables, 20 ref

003196   Mishra D C;Rajasekhar R P (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: dem_ngri@yahoo.co.in) : Crustal structure at the epicentral zone of the 2005 Kashmir Muzaffarabad earthquake and seismotectonic significance of lithospheric flexure. Curr Sci 2006, 90(10), 1406-12.

The Bouguer anomaly map of the epicentral zone of Kashmir earthquake is compiled from different sources. The observed gravity high related to Lahore-Sargodha ridge is attributed to flexural bulge due to collision of the Indian and Eurasian plates. A gravity profile is modelled across this region constrained from the available deep seismic sounding profiles, which suggest a flexural bulge of 3-4 km due to the load of the Himalayas. The hypocentre of this earthquake at a depth of 26 km lies at the junction of this flexural bulge with crustal thickening (70-72 km) towards the north under the Karakoram-Hindukush ranges, which represent the central core complex of collision tectonics. In fact, the hypocentres of all major seismic activities along the Southern Himalayan Front, which are mostly confined between 5-10 and 30-35 km coincide with this junction. These levels may represent shallow decollement plane and an intermediate weak zone caused by differential stress due to plate movement and flexural bulge, that would have caused extension and compression in the upper and lower crusts respectively. The depth to intermediate crustal zone under the Himalayas and Tibet approximately coincides with the effective elastic thickness in this region, implying weak part of the crust that my be caused by the presence of fluids.

6 illus, 34 ref

003195   Lal M (Equatorial Geophysical Research Laboratory, Indian Institute of Geomagnetism, Krishnapuram, Maharaganagar, Tirunelveli-627 011, Email: mlal@iigs.iigm.res.in) : Study of geomagnetic storm induced acoustic gravity waves over equatorial latitude. Indian J Radio Space Phys 2006, 35(3), 174-80.

An attempt has been made to study the influence of geomagnetic storm on the tropospheric acoustic gravity waves at equatorial station, Tirunelveli (8.7°N, 77.8°E), India. The daily average of the amplitude and phase of acoustic gravity waves has been studied for the period 2000-2004. Severe geomagnetic storms occurred during April and September 2000. April 2001, October and November 2003 and November 2004. It is found that geomagnetic storm influences the tropospheric acoustic gravity waves. There is a delay between the occurrence of geomagnetic storm and tropospheric acoustic gravity waves. The delay is a function of strength of the geomagnetic storm. Severe geomagnetic storm such as that of November 2004 shows a short-period delay of <126> 5 days, and strong geomagnetic storm like the one of July 2004 shows the long-period delay of about 15 days.

7 illus, 32 ref

003194   Kala R;Kala C P (NO, Environment and Mountain Development Institute, Village and PO Sumari, Pauri Garhwal-246 174, Email: cpkala@yahoo.co.uk) : Indigenous water conservation technology of Sumari village, Uttaranchal. Indian J Tradl Knowledge 2006, 5(3), 394-6.

Indigenous water conservation technology was studied in Sumari village of Pauri district, Uttaranchal. Since, the village had high population and low water Quality, therefore, they had developed an indigenous mechanism in such a way so that the available water could be managed properly for the use of humans and livestock. The indigenous technology developed by villagers is termed as Nawn and Chaunree systems of water management and conservation. Investigates in detail about the Nawn and Chaunree systems of water conservation.

4 ref

003193   Jenamani R K;Bhan S C;Kalsi S R (Office of the Director General of Meteorology, Mausam Bhavan, India Me, , Lodhi Road, New Delhi-110 003, Email: rjenamani1@yahoo.co.in) : Observational/forecasting aspects of the meteorological event that caused a record highest rainfall in Mumbai. Curr Sci 2006, 90(10), 1344-62.

The Santacruz observatory at Mumbai airport experienced unprecedented rainfall of 94.4 cm on 26 and 27 July 2005, an all-time highest record over the city. The country's commercial capital came to a complete standstill due to severe flooding/deluge. It also caused severe damage to life and property. Brought out the characteristics of this unique rainfall event, compared it with past intense rainfall events in India and other places in the world, and also analysed various data to find possible causes of occurrence of this event. Technology available for prediction of such events is also briefly touched upon.

2 tables, 29 ref

003192   Ghosh R;Ojha M;Sain K;Thakur N K (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: kalachandsain@yahoo.com) : Physical parameters of hydrated sediments estimated from nature seismic reflection data. Curr Sci 2006, 90(10), 1421-30.

Gas-hydrates in marine sediments can be identified on multi-channel seismic data by an anomalous bottom simulating reflector (BSR), often associated with the base of hydrate stability field. Physical parameters like porosity, density, thermal conductivity, temperature, geothermal gradient, hydrate saturation, electrical resistivity and heat flow provide useful inputs to understand several issues related to hydrates exploration. To determine these parameters by employing relevant techniques at depth below the sea water is not only difficult but also expensive. Case studies to derive these parameters wilh the help of BSR, identified on seismic sections from two completely different tectonic geological areas of (i) the Makran (Arabian Sea) and (ii) the Cascadia (Pacific Ocean) margins have been presented. From the available velocity-depth model in the Cascadia margin, the background velocity-depth function (without hydrates and free-gas), which is used to estimate the variation of density, porosity and hydrate saturation with depth successively have been determined. The average bulk density, seafloor porosity and maximum hydrate saturation in the Cascadia margin are calculated as 1.70 g/cc, 63.8% and 22% respectively. From the porosity-depth function and the gradient of hydrate saturation, the variation of thermal conductivity and resistivity with depth have been. The average resistivity, thermal conductivity and heat flow in the Cascadia margin are determined as 1.13 Ω-m, 1.02 W/m/K and 62.85 mW/m² respectively. Since the velocity model in the Makran accretionary prism across the BSR shows wide variation, the approach of deriving the above physical parameters has been changed. The seafloor density has been determinedfrom the seismic velocity and hence the seafloor porosity. Then the porosity-depth function is determined using Athy's law and the compaction factor available for the sediment. Porosity is then converted into density using an empirical relation between porosity and density. The remaining procedure is the same as that used for the Cascadia margin. Seafloor porosity, average density, resistivity, thermal conductivity, heat flow and maximum hydrate saturation are calculated as 54%, 1.98 g/cc, 1.96 Ω-m, 1.268 W/m/K, 43.55 mW/m³ and 13% respectively, for the Makran region. The estimated physical parameters in both the margins match well with the available results Errors in physical parameters have been estimated, assuming ± 5% error in the available velocity model.

11 illus, 20 ref

003191   Dwivedi R M;Raman M;Parab S;Matondkar S G P; Nayak S (NO, Space Applications Centre (ISRO), Ahmedabad-380 015, Email: rmdwivedi@rediffmail.com) : Influence of northeasterly trade winds on intensity of winter bloom in the Northern Arabian Sea. Curr Sci 2006, 90(10), 1397-1406.

Chlorophyll and wind pattern retrieved from remote sensing data have been used to study biological activity in the oceanic waters of Northern Arabian Sea (NAS) during February-March 2002-05. Occurrence of algal bloom in these waters during this period was noticed with the help of ship observations in the past. The same was detected from OCEANSAT I/OCM with time series chlorophyll images for January-March 2000. Occurrence of this bloom was later re-confirmed using OCM data in the subsequent years also. The time-series chlorophyll images established that the bloom develops every year during February-March. This period happens to coincide with the presence of northeasterly trade winds over the NAS. Two ship cruises were conducted with the help of research vessels FORV Sagar Sampada (SS-212 during 26 February-7 March 2003 and SS-222 during 21 February-11 March 2004) during this period at the bloom site. The aim was species identification of the bloom and to study various environmental parameters associated with the bloom. Two diverse situations in the context of biological activity were observed while collecting in situ data in 2003 and 2004. Distribution of the bloom was found uniform over a large area and concentration of phytoplankton was relatively higher in 2003. Compared to this, it was observed during the same period in 2004 that phytoplankton was distributed in scattered and small patches and its concentration was relatively less. Corresponding to this observation, it was noticed from the ship data that wind strength was significantly weaker and the oceanic waters were less turbulent in 2004 compared to the same in 2003. In the light of this elementary observation, an attempt was made to observe variations in the wind pattern during 2003 and 2004 using QuikSCAT/SeaWinds scatterometer data. It could be established that occurrence of the bloom as well as the observed inter annual variability in chlorophyll pattern were coupled with prevailing trade winds. It was found that density of surface water increased (inversion) during this period, which could result in convective action and the observed bloom. The vertical density gradient revealed an increasing pattern with increase in wind speed. Moreover, it was observed that response of chlorophyll to acting wind force is delayed by one to two weeks. This led to an important inference that wind can be treated as a precursor to predict variations in chlorophyll pattern in the context of the observed event of the bloom.

7 illus, 3 tables, 9 ref

003190   De S S;De B K;Adhikari S K;Sarkar B K;Guha A (Centre for Advanced Study in Radio Physics and Electronics, University of Calcutta, Kolkata-700 009, Email: de_syam_sundar@yahoo.co.in ) : Study of amplitude spectrum of VLF sferics and vertical electric field at Kolkata. Indian J Radio Space Phys 2006, 35(3), 187-92.

From the measurements of atmospheric electric field and VLF sferics at Kolkata (22°34' N, 88°30' E), some correlation studies have been made. It is observed that the diurnal variation of vertical electric field averaged for 20 fair weather days maintains good connectivity with diurnal variation of VLF sferics activity. The variations are in contrast with the accepted unitary diurnal changes of vertical electric field and thunderstorm occurrence frequency curve with a maximum around 1900 hrs UT and a minimum around 0400 hrs UT. Some results in this context are presented.

7 illus, 1 table, 14 ref

003189   Chakraborty B;Mukhopadhyay R (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: ranadhir@nio.org) : Imaging trench line disruptions: swath mapping of the Andaman subduction zone. Curr Sci 2006, 90(10), 1418-21.

Analogus to other subduction zones in the world where the heavier oceanic plate shoves below the lighter continental plate, crustal movement along the Sumatra-Andaman trench line over the last two centuries released enormous stress causing earthquakes of highest impunity and generating, at times, devastating tsunaims. Such significant earth movements are presumed to have wide-ranging implications, stretching from geology to climate and to astronomy. A sea expedition within three months from the 2004 Sumatra-Andaman earthquake, and during the 2005 Sumatra earthquake is able to image the exact trench line, west of the Andaman Island. The multibeam bathymetry, gravity and fractal studies of about twenty-five thousand square kilometres of the west of Andaman Island have brought out several interesting features unknown earlier, including atypical disruption of the trench line.

2 illus, 1 table, 10 ref

003188   Angchok D;Singh P (Agricultural Extension Div, Field Research Laboratory, DRDO, C/o 56 APO, Email: achuk_iari@rediffmail.com) : Traditional irrigation and water distribution system in Ladakh. Indian J Tradl Knowledge 2006, 5(3), 397-402.

Attempt has been made to discuss the importance of water to Ladakh farmers, its use pattern, traditional irrigation and water distribution methods, prevalent management institutions, and how these phenomena are codified through expression in folk tradition and local beliefs.

6 illus, 13 ref

002295   Swain P K;Hussain A (Geol Surv of India, , ) : Geology, petromineralogy, geochemistry and genesis of the manganese ore occurrences in Eastern Ghat, Bolangir district, Orissa. Indian Miner 2004, 58(3-4), 157-68.

Bedded-and replacement-type magnese ores occuring as discontinuous bands, lenses, pockets, lenticles, friable and as streaks, veins, tabular, dissemination respectively along the structurally weak planes of host rocks are found associated with khondalite, calc-silicate and quartzite rocks belonging to Eastern Ghat Supergroup of Proterozoic age in different localities of Bolangir district, Orissa. The petromineralogical studies indicate that these manganese ores at the surface contain minerals like pyrolusite, cryptomelane, minor goethite and some jacobsite whereas the common minerals found in the ore band are rhodochrosite, spessartine, garnet, rhodonite, cryptomelane, pyrolusite, feldspar are found as major good and small amount respectively on X-ray analysis. Geochemical characters of the surface manganese ore indicate the average content of Mn varying from 12.29 to 32.22%, Fe 15.30 to 32.76%, P 0.07 to 0.71%, SiO₂ 7.29 to 13.33%, Al₂O₃, 1.68 to 6.18%. Trace-element analysis of a few selected manganese ores indicate Cu 96-207 ppm, Zn 153-935 ppm, Co 58-144 ppm, Ni 130-262 ppm, Pb <60>10-21 ppm, Ba 710-2098 ppm, Sr 191-912 ppm. The manganese mineralisation is syngenetic which is later remobilised in different phases of structural deformations by meteoric water along the weak planes of the associated host rocks to form secondary minerals of epigenetic nature in the area.

4 tables, 19 ref