022947   Sarma K V L N S;Subrahmanyam V;Subrahmanyam A S;Murty G P S;Murthy K S R (NO, National Institute of Oceanography, Regional Centre; 176-Lawson's By Colony, Visakhapatnam-530 017, Email: kvlns@nio.org) : Extension of gundlakamma river fault over eastern continental margin of India. Curr Sci 2010, 98(11), 1438-9.

2 illus, 5 ref

022946   Sarkar S;Kanungo D P (NO, Central Building Research Institute, CSIR, Roorkee-247 667, Email: shantanu_cbri@yahoo.co.in) : Landslide disaster on Berinag-Munsiyari road, Pithoragarh district, Uttarakhand. Curr Sci 2010, 98(7), 900-2.

The landslide disaster on 8 August 2009 near Kuity village in Pithoragarh district of Uttarakhand State buried two villages and took 43 lives. The landslide, triggered by cloud burst resulted in massive debris flow along a stream channel. The site is still in danger as shown by the presence of huge quantity of debris and ground cracks on the slope. Presents inferences drawn from the field observations.

8 illus, 3 ref

022945   Rathore B P;Kulkarni A V;Sherasia N K (Earth Sciences and Hydrology Div, Marine and Earth Sciences Group, Space Applications Centre (ISRO), Ahmedabad-380 015, Email: anil_vishnu@yahoo.com) : Understanding future changes in snow and glacier melt runoff due to global warming in Wanger gad basin, India. Curr Sci 2009, 97(7), 1077-81.

Himalayas has one of the largest concentrations of glaciers and permanent snow fields. These are sensitive to climate change. Snow and glacier runoffs are important sources of water for the Himalayan rivers. Due to steep slopes, all these streams are potential sites for hydropower generation. To understand the power potential of small sub-basins, a snowmelt run-off model has been developed for Malana nala located in the Parbati river basin near Kullu in Himachal Pradesh and validated at the adjacent Tosh nala in the same basin. In the model, information generated through remote sensing techniques were used in conjunction with the daily maximum and minimum temperatures, rainfall and snow fall. This model is now extended to understand the effect of global warming in stream runoff and power generation. To understand changes in runoff and power potential, possible changes in the input parameters were estimated by considering 1°C rise in temperature from 2004 to 2040. Snow line is calculated for 2040 using present altitude and lapse rate. Future change in areal extent of glacier and permanent snow were estimated using mass balance, response time and rate of melting at terminus for all glaciers in the basin. The model was validated for all seasons in 2004 and for selected seasons from 1997 to 2002. The error in runoff estimate was observed between 2 and 5%, except for the summer of 2002. The model suggests overall reduction in stream runoff by 8-28%, depending on the season.

4 illus, 2 tables, 18 ref

022944   Rani Nishi;Shrivastava J P;Bajpai R K (Geology Dep, Delhi Univ, Delhi-110 007, Email: jpshrivastava.du@gmail.com ) : Obsidian: a potential natural analogue for nuclear waste glass. Curr Sci 2010, 98(7), 950-4.

For long-term performance assessment of obsidian, we present computation chemistry and experimental data sets on glass dissolution and associated ionic release obtained after treating specimens under near hydro-thermal conditions (for 1-64 h time intervals). The EQ3/6 simulated results indicate appearance of quartz (chalcedony) and other mineral species. Besides quartz, SEM-EDX of the precipitate shows presence of smectite having two distinct microstructures which consist of small and large lamellae and their formation is linked with the release of Na, K and other ions accountable for increase in the pH and conductivity of the leachates. The former structure represents paragenesis of an earlier formed alteration product. These observations largely correspond to the simulated results, suggesting its suitability in geological repository.

5 illus, 25 ref

022943   Rajender T;Kumar S R;Dingh D S (Remote Sensing Centre, Science Technology and Environment, Shimla-171 009, Email: rajenderthapa@yahoo.co.in) : Database creation using high resolution IRS PAN_LISS III satellite data for ecological modelling of Himalayas under GIS environment - a study in Shiwalik range, Himachal Pradesh, India. Curr Sci 2010, 98(7), 944-9.

This work reports an attempt to make use of the indigenously developed high resolution IRS-1C satellite imagery to generate a database, including expertize from different organizations involved in floral, soil, microbial, hydro, socio-economic and geological fields. In the absence of large scale topographic maps, high resolution precision geocoded PAN + LISS-III imageries at 1:12,500 were used. This final database was subsequently integrated in the geographic information system environment¹ and was used to address queries of the user organization pertaining to area statistics, location, water potential, soil suitability, agricultural suitability according the prevailing ecological conditions, etc.

8 illus, 16 ref

022942   Pandit C (National Water Academy, Central Water Commission, Sinhagad Road, Khadakwasla R.S. Pune-411 024, Email: cmpandit@yahoo.com) : Some common fallacies about floods and flood management. Curr Sci 2009, 97(7), 991-3.

2 illus, 8 ref

022941   Pal T;Ghosh B;Bhattacharya A (Petrology Div, Eastern Region, Geological Survey of India, Kolkata-700 091, Email: bghosh_geol@hotmail.com) : High-si, high-ca spinel-like phase from mantle peridotte: a report from cretaceous ophiolote of Rutland Island, Andaman-java subduction complex. Curr Sci 2009, 97(7), 1081-8.

Reported here exsolved phase with unusual composition (SiO₂: 14-22 wt%, CaO: 4-10 wt% and Cr₂O₃: 17-21 wt%) from mantle peridotite of the Cretaceous ophiolite of Rutland Island in the Andamans. This high-Si, high-Ca bearing spinel-like phase occurs in two modes as fine blebs (<60>1-3 μ) within exsolved blebs of diopside and fine lamellae (<60>l-7 μ) within the or-thopyroxene host along with lamellae of diopside and Cr-spinel. The BSE image exhibiting a tonal character as well as the chemistry intermediate of Cr-spinel and diopside suggests that this phase exsolved from pigeonite at an intermediate stage before the exsolu-tion of fine lamellae of Cr-spinel and diopside in the orthopyroxene host.

2 illus, 4 tables, 21 ref

022940   Nimachow G;Rawat J S;Dai O (NO, Rajiv Gandhi Univ, Rono Hills, Itanagar-791 111, Email: jsr_06@rediffmail.com) : Status of Himalayan yews in West Kameng district of Arunachal Pradesh. Curr Sci 2010, 98(11), 1434-7.

Taxus, commonly known as yews, is a primary source of taxol used in the treatment of ovarian and breast cancers. It is found in the world's temperate forests and in Asia it occurs from Afghanistan through Himalayas to the Philippines. Owing to over exploitation, this species is disappearing rapidly. The present study in West Kameng district of Arunachal Pradesh, where maximum occurrences were reported, reveals that merciless and mass exploitation has converted the area into a 'death valley' of Taxus trees. Out of the 145 total plants located, 105 were dead trees. Efforts from stakeholders are essential for conservation and regeneration.

2 illus, 19 ref

022939   Nevin C G;Pandalai H S (Earth Sciences Dep, Indian Institute of Technology, Mumbai-400 076, Email: nevincg@iitb.ac.in ) : Fluid inclusion studies on barite from Hutti gold mines, Karnataka, India: inferences on late-stage hydrothermal fluid. Curr Sci 2010, 98(7), 955-62.

Late-stage, post-gold mineralization, cavity-filling veins with barite are reported here from the Hutti gold deposit of Karnataka. Large (10-15 cm) to medium (2-5 cm) sized translucent crystals of barite studded with numerous pyrite grains commonly of 1-2 mm size occur in these veins. Monophase and biphase fluid inclusions occur in primary clusters and pseudo-secondary trails in the barite crystals. Microthermo-metric and laser-Raman studies show that the barite has formed from aqueous fluids of relatively high salinity (14-22 eq. wt% NaCl). Minor Raman-shift peaks of methane are observed in the vapour phase of a few biphase fluid inclusions. Assuming pressure of less than 1 kbar, trapping temperature would be less than 200°C. These post-ore veins at Hutti point to a source of oxidized fluid subsequent to the phase of gold mineralization.

9 illus, 1 table, 19 ref

022938   Mitra A;Gangopadhyay A;Dube A;Schmidt A C K; Banerjee K (Marine Science Dep, Calcutta Univ, 35 B.C. Road, Kolkata-700 019, Email: avijit@umassd.edu) : Observed changes in water mass properties in the Indian Sundarbans (northwestern Bay of Bengal) during 1980-2007. Curr Sci 2009, 97(10), 1445-52.

Present evidence that the Indian Sundarbans is experiencing the effects of climate change over the last three decades. Observations of selected variables, such as the surface water temperature, salinity, pH, dissolved oxygen, and transparency show significant long-term variation over a period of 27 years (1980-2007). Specifically, the temperature in these waters has risen at the rate of 0.5°C per decade, much higher than that observed globally or for the Indian Ocean. Increasing melting of Himalayan ice might have decreased the salinity at the mouth of the Ganges River, at the western end of this deltaic complex. At the same time, salinity has increased on the eastern sector, where the connections to the meltwater sources have become extinct due to heavy siltation of the Bidyad-hari Channel. The long-term changes in dissolved oxygen, pH level, transparency and water quality are also examined. The ecological impact of such changes warrants future study.

6 illus, 2 tables, 26 ref

022937   Mary A;Mary V;Lorella A;Matias J R (NO, Sacred Heart Marine Research Centre, Beach Road, Tuticorin-628 001, Email: avelinmary@yahoo.com) : Rediscovery of naturally occuring seagrape Caulerpa lentillifera from the gulf of mannar and its mariculture. Curr Sci 2009, 97(10), 1418-20.

3 illus, 12 ref

022936   Mallikharjuna Rao J;Poornachandra Rao G V S; Widdowson M;Yellappa T;Kelley S P (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: mallikharjun_ngri@yahoo.co.in) : Tectonic history and occurrence of 2.4 Ga mafic dyke swarms adjacent to Godavari basin, Karimnagar, India. Curr Sci 2010, 98(11), 1472-8.

Proterozoic dyke swarms are exposed partly in granu-litic terrain and partly in gneissic terrain and extend in a NE-SW direction near the Godavari Basin, Karimnagar area, Central India. The Karimnagar dyke swarm petrographically exhibits two groups such as fresh plagioclase and pyroxene phenocrystic dolerite dykes and altered non-phenocrystic gabbros. Dolerites show ophitic to subophitic textures and gabbros are non-porphyritic and more altered. Geochemical data suggests that these dykes are tholeiitie in nature, range from basalt to basaltic andesite in composition. The rare earth element patterns show enrichment of light rare earth elements (25-60 times) and heavy rare earth elements show flat patterns (4-10 times) supporting the presence of two varieties within the dyke swarm. A laser probe ⁴⁰Ar/³⁹ Ar study and Ar isotopic analyses suggest two magmatic emplacement ages at 2400 Ma and 2200 Ma which are present within the dyke swarm. Palaeomagnetic results reveal a characteristics remnant magnetization vector of Dm = 52.5, Im = -24.5 (K = 21.81, α₉₅ = 8.65°, N =12) and supports the presence of two phases of dyke activity in the region.

7 illus, 3 tables, 24 ref

022935   Lisa M;Qasim Jan M (Department of Earth Sciences, Quaid-i-Azam University, Islamabad, Pakistan, Email: lisa_qau@yahoo.com) : Geoseismological study of the Ziarat (Balochistan) earthquake (doublet?) of 28 october 2008. Curr Sci 2010, 98(1), 50-7.

On 28 October 2008, two main earthquakes with similar focal depth (10 km), identical magnitude (M₂ = 6.4) and focal mechanism solutions (right-lateral strike-slip) shook the town of Ziarat and surrounding areas in Sulaiman fold-and-thrust belt of NE Balochistan, Pakistan. Named here as Ziarat doublet earthquake (ZDE), it occurred in a remote and poorly accessible region in the Chilian Mountains. ZDE was accompanied by a foreshock of m_b, 5.2. It killed more than 300 people and caused widespread destruction. An intensity of VIII (MMI scale) has been assigned at the epicentre location. Epicentral distribution of 200 aftershocks indicates a clear NW-SE seismicity pattern, contrary to the general seismicity trend of the Sulaiman Belt which is sparse and scattered. It further shows that more than one tectonic subdivisions of the fold belt have experienced instability. Focal depths indicate that most activity is confined to a narrow depth range (5-10 km). The NNW oriented right-lateral strike-slip Urghargai Fault seems to be the cause of this seismic activity, as suggested by the focal mechanism of the ZDE and depth distribution of the aftershocks. Three possibilities can be postulated regarding the causative fault: (i) one single fault being the real cause of doublet, i.e. the point source model of earthquakes; (ii) more than one fault reactivated and (iii) failure of separate parts of a single fault. A number of landslides caused by active faulting and ground shaking have been observed in the villages of Kant, Shadi Khan and Warchum near Ziarat through field studies and satellite images.

8 illus, 2 tables, 23 ref

022934   Kushwaha S P S;Mukhopadhyay S;Hari Prasad V; Suresh Kumar (NO, Indian Institute of Remote Sensing, Dehradun-248 001, Email: spskushwaha@gmail.com) : Sustainable development planning in pathri rao sub-watershed using geospatial techniques. Curr Sci 2010, 98(11), 1479-86.

This study demonstrates the application of remote sensing, GIS and GPS for preparation of sustainable land and water resources development action plans for Pathri Rao sub-watershed in Haridwar district of Uttarakhand. High resolution IKONOS satellite imagery was used for detailed land use/cover mapping on 1:12,500 scale. Various primary and secondary database layers on land use/cover, forest density, biodiversity, slope, aspect, elevation, hydrogeomorpho-logy, soil types, soil erosivity and crop suitability were generated. The study also considers the social, ecological and economic factors. A set of decision rules was then applied and data layers were integrated in GIS environment for preparation of the scientific and sustainable land and water resources development action plans for the study area. The exercise indicated a good scope for geospatial techniques in integrated watershed development planning.

10 illus, 4 tables, 18 ref

022933   Kashyap M;Shrivastava J P;Raju Kumar (Geology Dep, Delhi Univ, Delhi-110 007, Email: jpshrivastava.du@gmail.com ) : Occurrence of small scale inflated pahoehoe lava flows in the mandla lobe of the eastern deccan volcanic province. Curr Sci 2010, 98(1), 72-6.

Reports here emplacement of small scale inflated pahoehoe lava flows in the Mandla lobe of the Eastern Deccan Volcanic province (EDVP). These lava flows are thick and display entire range of characters similar to that occurring in the Western Deccan Volcanic Province (WDVP). Size of the lobe in these lava flows is very small and they are less in number compared to those occurring in the WDVP. Moreover, simple lava flows that occur in the younger sequences of the basalts around Mandla area, form extensive sheets and look like a lava field. Physical characteristics of Mandla lavas are suggestive of lower effusive rates, linked with the low magnitude of eruption, possibly related to its long distance migration from a common source, located in the western Deccan province.

2 illus, 25 ref

022932   Joshi J C;Ganju A;Sharma V (Snow and Avalanche Study Establishment, Research and Development Centre, Chandigarh-160 017, Email: joshi_jc@rediffmail.com) : New approach to avalanche prediction over Indian Western Himalaya. Curr Sci 2010, 98(1), 69-72.

Avalanche prediction is mainly done by conventional and statistical techniques and over Indian Himalayas it is predicted in terms of none, low, medium and high avalanche danger as well as occurrence or non-occurrence of avalanche. In the present study, a quantitative range is calculated for each of the danger levels. Initially, normalized snow and meteorological parameters have been divided into 10 equal ranges (between 0 and 1) and an index of avalanche (IA) has been calculated for each range of every parameter. The model output has been compared with avalanches occurring over the concerned regions for the winter of 2004-05. The avalanche prediction accuracy for different regions in Lower Himalayan zone varies from 80% to 88% except at Dhundee where it is 64%. In Middle Himalayan zone, prediction accuracy on Drass is 88% and that on Patseo is 66%. It has also been concluded that the contribution of individual forecasting variables towards avalanches in different regions vary.

1 illus, 5 tables, 7 ref

022931   Gururaja K V (Centre for Infrastructure, Sustainable Transportation and Urban Planning, and Centre for Ecologi, Bangalore-560 012, Email: gururajakv@gmail.com) : Toads as astrologers of earthquakes. Curr Sci 2010, 98(11), 1429.

1 ref

022930   Gahalaut V K (NO, National Geophysical Research Institute (CSIR), Uppal Road, Hyderabad-500 060, Email: vkgahalaut@yahoo.com) : Probable role of sediments in blinding the rupture - lessons from the 2004 Sumatra - Andaman earthquake and implication for the himalayan earthquakes. Curr Sci 2010, 98(11), 1518-20.

Several evidences show that during the 2004 Sumatra-Andaman earthquake, the rupture in the Andaman region did not extend up to the trench. Consistent with the earthquake processes at several subduction zones of the world, we propose that subducted uncon-solidated sediments of Ganga and Brahmaputra rivers on the Indian plate make the shallow portion of the plate boundary interface behave aseismically and hence the rupture remained blind in the Andaman region. We propose that a similar situation exists in the Himalayan region where the subducted sediments of the Indo-Ganga plains under the Outer Himalaya limit the up-dip rupture propagation during great and major earthquakes. In such a case, rupture during great and major earthquakes may not extend up to the surface. Lack of evidence of surface faulting during the past major and great Himalayan earthquakes is consistent with this idea.

2 illus, 22 ref

022929   Borgohain P;Borah C;Gilfellon G B (Applied Geology Dep, Dibrugarh Univ, Dibrugarh-786 004, Email: pradipborgohain@yahoo.com) : Sandstone diagenesis and its impact on reservoir quality of the arenaceous unit of barail group of an oilfield of upper Assam shelf, India. Curr Sci 2010, 98(1), 82-8.

The potential of a sandstone reservoir to produce hydrocarbons is intimately related to its diagenetic history. The Barail Group of rocks within the Upper Assam Basin is considered as one of the world's major deltaic deposits with known hydrocarbon potential. The Arenaceous Unit of the Barail Group constitutes a significant percentage of the known hydrocarbon reserves, but the heterogeneity of the distribution of the diagenetic properties in these reservoir sandstones makes the wide variation in crude oil production from well to well within the reservoirs. Precipitation of authigenic mica, chert, quartz overgrowth and crystallization of cementing material are some of the diagenetic changes responsible for porosity reduction. Moreover, the presence of clay minerals in the pore spaces and their bridging nature especially of illite makes certain reservoir horizons less productive. On the other hand, dissolution and replacement of framework grains, intragranular fracturing and floating type of texture enhance the porosity as well as permeability and make the reservoir sandstone highly productive.

7 illus, 2 tables, 18 ref

022928   Baruah M;Patgiri A D;Bhattacharyya K G (Chemistry Dep, Guwahati College, Guwahati-781 021) : Seasonal variation of shallow groundwater quality in Guwahati, Assam. Envir Ecol 2010, 28(3B), 2078-85.

Guwahati, the capital city of Assam is situated in the Brahmaputra valley. Groundwater samples from a total of 51 dug wells within 20 m depth were collected through a two year sampling period in the wet season (July, August) and the dry season (February, March) for the determination of pH, electrical conductivity, total dissolved solids and major cations (Na*, K*, Ca²*, Mg₂*) and anions (HCO₃, Cl, NO₃, SO₄ and F'). The distribution of major ions and their variation in the wet and dry periods are discussed. Groundwater from the wells showed seasonal variation in the values of the physico-chemical parameters and in the concentration of groundwater constituents. The chemistry of groundwater is discussed in the light of Gibbs diagram. It is found that the groundwater quality is controlled mainly by rock weathering processes.

5 illus, 2 tables, 18 ref

022927   Banerjee K S;Sengupta D (Geology and Geophysics Dep, Indian Institute of Technology, Kharagpur-721 302, Email: kailassekharbanerjee@gmail.com) : Distribution pattern of the In situ terrestrial gamma radiation in uranium mineralized singhbhum shear zone, Jharkhand and its correlation with local geology. Curr Sci 2010, 98(1), 76-81.

Terrestrial gamma radiation is one of the important radiation exposures on the Earth's surface that results primarily from the three primordial radionuclides, viz. U, Th and K. The elemental concentrations of these elements in the Earth's crust could result in the anomalous variation of the terrestrial gamma radiation in the environment. The geology of a region plays an important role in distribution of these radioactive elements. In situ gamma radiation measurements in the soils and adjacent rock exposures along the Singhbhum Shear Zone, Eastern India were undertaken using a portable radiation survey meter. The results showed that the area has a reasonably close concordance with the geological formations, and the observed gamma radiation levels, since both geological features and mineralogical composition have good control on the terrestrial gamma radiation in the area. Correlation between the gamma level of soils and the underlying rocks was very poor. This suggests that the soils might not have originated from underlying rocks or might have different weathering mechanisms.

4 illus, 2 tables, 35 ref

022926   Ajai;Arya A S;Dhinwa P S;Pathan S K;Ganesh Raj K (Space Applications Centre, Indian Space Research Organization, Ahmedabad-380 015, Email: ajai@sac.isro.gov.in) : Desertification/land degradation status mapping of India. Curr Sci 2009, 97(10), 1478-52.

Desertification is the process of land degradation in arid, semi-arid and dry-subhumid areas. This communication describes the classification system, methodology and the results of desertification and land degradation status mapping carried out for the entire country on 1:500,000 scale using multi-temporal Resourcesat AWiFS data. The dominant processes of land degradation, viz. water erosion, vegetal degradation, wind erosion, salinization/alkalization, water logging, frost heaving, frost shattering, mass movement, etc. have been deciphered and mapped using satellite data. The study reveals that 105.48 mha area of the country is undergoing processes of land degradation (32.07% of the total geographic area of the country). Area undergoing desertification is 81.4 mha.

6 illus, 3 tables, 4 ref

022925   Adhikari B K;Madramootoo C A;Sarangi A (Department of Bioresources Engineering, Macdonald Campus of McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, Quebec, Canada H9X 3 V9, Email: arjamadutta.sarangi@elf.mcgill.ca) : Temporal variability of phosphorus flux from Pike river watershed to the Missisquoi bay of Quebec. Curr Sci 2010, 98(1), 58-64.

Phosphorus (P) has been identified as the main cause of eutrophication in the Missisquoi Bay of Lake Champlain, of waterbody shared by the Province of Quebec (Canada) and State of Vermont (United States). The Pike River is one of the main watercourses contributing P to the bay, frequently at levels exceeding a bilaterally-imposed water quality standard (25 μg P/l), designed to address multiple-use issues such as fishing, recreation, aquatic biodiversifi-cation and aesthetic value of the bay. The overall annual P flux contributed to the bay by the Pike River watershed (28 Mg per year) exceeds target levels by 3.5-fold. Consequently, daily and seasonal variability in P flux from the Pike River watershed were monitored and analysed to provide a sound basis for the holistic development of a P reduction and management plan. Mean daily P flux at the watershed outlet ranged from 130 kg/day in spring to 22 kg/day in summer. Spring snowmelt and rainfall-generated runoff, along with that arising from rainfall on bare land after fall harvest, contributed 82% of the watershed's annual P discharge. Thus, roughly three-fifths of the P contributed to the bay was discharged over only one-fifth of the hydrological year. This clearly indicates that a more stringent and targeted P pollution reduction plan must be devised and implemented to achieve the water quality goals set for the bay.

7 illus, 4 tables, 23 ref

022000   Vaidyanandhan R (NO, , C/o V. Sridhar. 4 .. 1, Lenyadri Towers, Sector 19, Nerul (E) Navi Mumbai, Maharastra, Email: rvaidya31@gmail.com) : Some aspects of applied geomorphology. Trans Inst Indian Geogr 2010, 32(2), 105-17.

12 illus, 13 res

021999   Upadhyay R (Geology Dep, Kumaun Univ, Nainital-263 002, Email: rajeev_up@yahoo.com) : U-Pb zircon age for a granite intrusion within the Shyok suture zone, Saltoro hills, northern Ladakh. Curr Sci 2009, 97(8), 1234-9.

In the Saltoro Hills In the Saltoro Hills of northern Ladakh, Shyok volca-nics of the Shyok suture zone are dissected by a <126>5 m wide granite intrusion. Such granitic intrusions, in the Shyok volcanics are more pronounced to the west of Udmaru village and could be observed for several hundred metres. The Cretaceous Shyok volcanics consist of basalts and andesites. U-Pb age data from separated zircon suggests that the crystallization age of this calc-alkaline granitic body is 24.52 ± 0.40 Ma. Younger granitic intrusion or body has not been reported earlier from the Shyok suture zone of northern Ladakh, however, the younger intrusive bodies ranging between 25 and 17 Ma have been recorded from the Baltoro and Tangtse-Mugalib plutonic unit of the Karakoram block. Therefore, it is most likely that the young post-collisional intrusive phase of the Shyok suture zone and the Karakoram block are similar and may be part of a common major late-to-post-tectonic plutonic phase of the Karakoram batholith or they are related to the incipient synkinematic activity along the Karakoram fault.

4 illus, 1 table, 44 ref

021998   Tripathi D K (Geography Dep, Kamla Nehru Institute of Physical & Social Sciences, Sultanpur, Uttar Pradesh, Email: tripathidk.geoinformatics@gmail.com) : Identification of planning priority zones for land resource development using remote sensing technique: a case study. Trans Inst Indian Geogr 2010, 32(2), 155-66.

The study is an attempt to identify the planning priority zones (PPZ) for land resource development in Gauriganj Block, Sultanpur District (U.P). The satellite image (IRS P6, LISS III) was processed in digital image processing software ERDAS IMAGINE 9.1 using ISODATA pixel clustering algorithm (unsupervised classification approach) and spectral enhancement (NDVI) techniques for data base generation on land use/land cover and vegetation density. The data generated through remote sensing techniques have been integrated with other non-spatial socio-economic data for identification of PPZ for land resource development. Criterion based technique was used for data integration and PPZ identification. As per analysis out of 100 villages in the study area, 18 villages fall in first priority zone, 55 in second, 24 in third and 03 in fourth PPZ of land resource development. These PPZ may be taken up for developing plan in a phased manner.

5 illus, 4 table, 16 ref

021997   SivaSiddaiah N;Kishor Kumar (NO, Wadia Institute of Himalayan Geology, 33, General Mahadeo Singh Road, Dehradun-248 001, Email: nssiddaiah@rediffmail.com) : Discovery of minamiite from the Deccan volcanic province, India: implications for Martian surface exploration. Curr Sci 2009, 97(11), 1664-9.

Discovery of minamiite, a Ca-bearing hydrous sulphate mineral, is reported for the first time in India from the Deccan Volcanic Province at Matanumadh (Kachchh, Gujarat), Western India. Minamiite was identified by X-ray diffraction and chemical analyses. The hydrous sulphates at Matanumadh occur associated with Paleocene sediments as soft powdery deposits and consist dominantly of minamiite [(Na,K,Ca) A1₃(SO₄)₂(OH)₆1 and natroalunite [NaAl₃(SO₄)₂(OH)₆] with traces of alunite and kaolinite. The geological setting, mineralogy and geochemistry suggest that the sulphate layers at Matanumadh were produced via solfataric alteration of volcanic ash. Hydrous sulphates are abundant on the planet Mars but not common on Earth because they form under extreme conditions (low pH and high Eh). Results of the study suggest that the Deccan Volcanic Province with its gigantic flood basalts of thermal plume origin, craters of both volcanic and impact origin, and hydrous sulphates of secondary origin can serve as a potential Earth analogue for the Mars and the Martian conditions. This may help us better understand the geology of the planet Mars and compare the geologic processes on Mars and the Earth.

7 illus, 2 table, 46 ref

021996   Sinha R (Civil Engineering Dep, Engineering Geosciences Group, Indian Institute of Technology, Kanpur-208 016, Email: rsinha@iitk.ac.in) : Great avulsion of Kosi on 18 August 2008. Curr Sci 2009, 97(3), 429-33.

The 18 August 2008 avulsion of the Kosi River draining the parts of north Bihar in eastern India may well be regarded as one of the greatest avulsions in a large river in recent years. The Kosi River shifted by -120 km eastward, triggered by the breach of the eastern afflux bund at Kusaha in Nepal at a location 12 km upstream of the Kosi barrage. This event was widely perceived as a major flood in the media and scientific circles. Although a large area was indeed inundated after this event, it is important to appreciate that this inundation was different from a regular flooding event.

3 illus, 1 table, 21 ref

021995   Singh S P;Dwivedi S B (Geology Dep, Bundelkhand Univ, Jhansi-284 128, Email: spsinghbu@rediffmail.com) : Garnet-sillimanite-cordierite-quartz-bearing assemblages from early Archean supracrustal rocks of Bundelkhand Massif, central India. Curr Sci 2009, 97(1), 103-7.

The Bundelkhand gneissic complex includes the high-grade metapelites, amphibolites, calc-silicates and granite-gneisses, which are invaded by 3.2-3.3 Ga old tonalite-trondjemite-grainodiorite. Detailed petro-graphic studies and EPMA analyses of metapelites reveal the presence of garnet-sillimanite-cordierite-biotite-K-feldspar-plagioclase-quartz, biotite-silli-manite-cordierite-K-feldspar-plagioclase-quartz and garnet-sillimanite-biotite-K-feldspar-pIagioclase-quartz mineral assemblages which belong to upper amphi-bolite to granulite facies rocks and have been reported for the first time from the Bundelkhand craton. The average P-T conditions estimated by different models of geothermobarometry yield the core composition at 730°C/5.4 kbar and rim composition at 640°C/5.1 kbar.

2 illus, 2 tables, 30 ref

021994   Singh R B;Singh S;Mandal T N (NO, , Colony No. 2, Katihar, Bihar-854 105) : Water quality of village Parwa Nabtol, Madhipura, Bihar. Ecol Envir Conserv 2009, 15(2), 371-2.

Evaluation of different physico-chemical parameters of ground water of village Parwa Nabtol ( Murliganj Block, Madhipura District, Bihar) as carried out to study the water quality of the water samples. Samples were collected from different sources of different locations through out the year 2001. Parameters studied were pH, EC.TDS, fluoride, sulphate, chlorides and nitrates. The water was found to be unfit for drinking.

1 table, 5 ref

021993   Shukla S K;Rahul Mohan;Sudhakar M (NO, National Centre for Antarctic and Ocean Research, Headland Sada, Vasco-Da-Gama, Goa-403 804, Email: rahulmohangupta@gmail.com) : Diatoms: a potential tool to understand past oceanographic settings. Curr Sci 2009, 97(12), 1726-34.

Diatoms are being potentially used to decipher palaeo-ceanography and past climatic changes. They are marine primary producers which play an important role in carbon, silica and nutrient budgets of modern oceans. Their importance lies in the role they play for the export of organic carbon to the deep sea and the efficiency of the biological pump for CO₂ exchange. They are useful as biostratigraphical zone fossils in marine deposits from high latitudes or at deeper water depths, both of which lack calcareous microfossils. The role of diatoms as tracers of past oceanographic conditions with recent perspectives in diatom research is reviewed in this article.

136 ref

021992   Shukla P (General and Applied Geography Dep, Dr. H.S. Gour Central Univ, Madhya Pradesh) : Poverty in India: a geo-socio-economic analysis. Trans Inst Indian Geogr 2010, 32(2), 193-201.

Obtaining statistical data from various sources, the impoverishment of India has been analysed with respect to the present context of geo-socio-economic behaviour of different states of the country. It is found that uncontrolled growth of population and regional disparities are adversely affecting poverty removal programme. Liberalization of economy has increased insecurities and vulnerability. Economic inequalities of Dalits/Scheduled castes still prevail in every corner of the nation challenging their constitutional right. In such a situation it has been suggested that The magnitude and rate of change of inequalities is observed to be quite substantial very sharp contrasts are evident between the rural sectors of the slow growing states and the urban sectors of the fast growing states the progressive utilization theory (PROUT) propounded by Sarkar(1981) may be useful in order to eradicate poverty.

6 table, 7 ref

021991   Sheth H C;Ray J S;Bhutani R;Alok Kumar; Awasthi N (Earth Sciences Dep, Indian Institute of Technology Bombay, (IITB), Mumbai, Email: jsray@prl.res.in) : Latest (2008-09) eruption of Barren island volcano, and some thoughts on its hazards, logistics and geotourism aspects. Curr Sci 2010, 98(5), 620-26.

Barren Island, Andaman Sea, is India's only active volcano and is built of lava flows and volcani-clastic deposits of prehistoric through recent ages that are mainly of basalt and basaltic andesite compositions. Historic eruptions occurred during 1787-1832, and it erupted thrice recently in 1991, 1994-95 and 2005-06. A fourth impressive one that might have begun in late 2008 was in full swing in March 2009, with a well-developed lava flow that was entering the sea from a completely different route (north) than all the recent lava flows. We describe and illustrate this new eruption and discuss aspects of hazards, logistics and geotourism potential of this active volcano.

5 illus, 40 ref

021990   Sharma R;Chauhan D S;Rameshwar Rao D (NO, Wadia Institute of Himalaya Geology, Dehradun-248 001, Email: sharmarajesh@wihg.res.in) : Polymetallic sulphide mineralization in Chiplakot crystallines, northeast Kumaun Himalaya. Curr Sci 2010, 98(5), 698-702.

Reports here occurrence of polymetallic sulphide mineralization near Gasku, about 6 km north of Tawa-ghat in Kali valley. The minerals in the ore assemblage include chalcopyrite, pyrite, sphalerite, minor galena and pyrrhotite. They are present in the sericite-muscovite-talc-chlorite (±biotite) schist, and in the quartz veins present in these schists as well as in the amphibolite of the Chiplakot Crystalline Belt, localized in the vicinity of the North Chiplakot Thrust. The initial results of ore chemical and the fluid inclusions studies are presented, and a hydrothermal origin is plausible for this mineralization.

4 illus, 2 tables, 24 ref

021989   Shamji V R;Shahul Hameed T S;Kurian N P; Thomas K V (Marine Sciences Div, Centre for Earth Science Studies, Thiruvananthapuram-695 031, Email: npkurian@gmail.com) : Application of numerical modelling for morphological changes in a high-energy beach during the south-west monsoon. Curr Sci 2010, 98(5), 691-5.

Study of beach morphological changes during monsoon and development of capabilities towards its prediction is of vital importance in coastal zone management. A study of the beach erosion/accretion processes during south-west monsoon and its numerical modelling is attempted in this communication for a micro-tidal and high-energy beach. Comprehensive hydrodynamic and beach profile data measured in the field were used for the study. The beach morphological changes as a result of the high intensity monsoon waves are found to be characterized by erosion of beach coupled with deposition in the offshore leading to formation and migration offshore longshore bar. The model LITPROF of the LITPACK software of DHI is found to simulate well the beach morphological changes by adjustment of the calibration parameters. The integrated cross-shore transport computed across the profile, using the model shows high erosion in the beach face coupled with an equivalent accretion in the offshore. The model performance computed using different statistical methods is found to be good.

10 illus, 2 tables, 19 ref

021988   Sen R;Chakrabarti S (Applied Geology and Environmental System Management, Presidency College, Kolkata-700 073, Email: rawensein@gmail.com) : Whither imperatives of environmental justice?. Curr Sci 2010, 98(4), 476-7.

The disproportionate distribution of environmental risks among the population is known as environmental justice, environmental equity or at some instance environmental racism. All these terms in fact define the status that the poor suffer greater exposure to environmental pollution than other communities. Environmental justice, however, implies that no person or group is exposed to a disproportionate share of negative environmental impact from the execution of environmental programmes. This paper focuses on developing countries - whether in the context of undesirable population increase and not so well-judged planning decisions - any initiative to achieve environmental justice is feasible. Examples are quoted from the USA to show how the initiatives could be designed.

5 ref

021987   Sangode S J;Vhatkar K;Patil S K;Meshram D C; Pawar N J;Gudadhe S S;Badekar A G;Kumaravel V (Geology Dep, Pune Univ, Pune-411 007, Email: sangode@unipune.ernet.in) : Magnetic susceptibility distribution in the soils of Pune metropolitan region: implications to soil magnetometry of anthropogenic loading. Curr Sci 2010, 98(4), 516-27.

Based on established linkages between ferrimagnetism and heavy metal concentration of anthropogenic particulates, we attempt here to delineate pollutant residing domains and study the role of surface runoff and wind circulations over its redistribution in the Pune Metropolitan Region (PMR) in Maharashtra. A total of 118 samples collected in a -3 x 3 km grid during pre- and post-monsoon seasons for surface soils, bedrock, dust and rainwaters were analysed for magnetic susceptibility (χlt) and the isothermal remanent magnetization (IRM). The x in the soil profiles decrease from bedrock to intermediate soil horizons but notably increase towards top. Spatial variations based on the fundamental rock magnetic parameters (x and their frequency dependency (χfd), saturation IRM, demagnetization ratio) and knowledge of the polluting sources show significant anthropogenic loading for the topsoils. The study further reports remarkable post-monsoon changes in all the parameters controlled by surface run-off due to slope variation which appears to be the most effective mechanism of redistribution and dumping the topsoils loaded with anthropogenic particulate matters. Distribution of ;χfd% further infers wind as another important agent for dispersal of finer ferrimagnetic particulate matters predominantly controlled by the topography amongst other meteorological factors. Additional data for succeeding years would help in modelling the redistribution sensitivity and heavy metal residence effect for the topsoils and sediments in the PMR region.

9 illus, 1 table, 45 ref

021986   Saini H S;Tandon S K;Mujtaba S A I;Pant N C; Khorana R K (NO, Geological Survey of India, N.H. 5P, NIT, Faridabad-121 001, Email: sktand@rediffmail.com) : Reconstruction of buried channel-flood plain systems of the northwestern Haryana plains and their relation to the 'Vedic' Saraswati. Curr Sci 2009, 97(11), 1634-43.

Based on the collection of subsurface lithofacies data from well logs, this study attempts to map the buried channel-floodplain systems of a part of the northwestern Haryana Plains and provides evidence of buried major sand bodies at various depths; these belong to at least two separate phases of fluvial activity. The younger phase of fluvial activity includes the previously mapped palaeochannel segment between Tohana and Sirsa that was considered as a part of the 'lost' Saraswati1. The recognition of major palaeochannel belts in the subsurface provides definite proof of the presence of a strong fluvial regime sometime in the past. Based on OSL dating, it is inferred that these relatively older palaeochannel belts pre-date the Last Glacial Maximum and are related to the later part of the wetter MIS 3; and the younger fluvial activity, recognized in a limited part of the area, is dated between ~6.0 and -2.9 Ka BP. The analysis of these subsurface data suggests the existence of integrated drainage networks in the northwestern Haryana Plains in the 20-30 Ka time interval.

9 illus, 1 table, 31 ref

021985   Ray D;Banerjee R;Iyer S D;Mukhopadhyay S (NO, National Centre for Antarctic and Occean Research, Vasco-da-Gama, Goa-403 804, Email: dwijesh@rediffmail.com) : Evidences for seawater-rock hydrothermal interaction in the serpentinites from northern central Indian ridge. Curr Sci 2009, 97(8), 1239-43.

Serpentinites and serpentinized harzburgites were collected from a ridge-transform intersection at 6°39'S-68°19'E from the Northern Central Indian Ridge. The degree of serpentinization is extensive and varies from 90 to 100%. Olivine and orthopyroxene are largely pseudomorphed to lizardite-chrysotile 'mesh' and 'bastite' respectively. Numerous serpentine vein network associated with clusters of magnetite are also present. On the basis of mineralogical paragenesis, mineral chemistry and bulk rock analyses, we infer that the present serpentinites might have formed due to the interaction of harzburgites and seawater at a low temperature. Additionally, positive Eu anomaly, higher La/Sm and low Nb/La ratios suggest substantial hydro-thermal input during the onset of serpentinization.

4 illus, 1 table, 19 ref

021984   Ramesh Kumar K;Mishra A;Pande D;Nanda L K (Atomic Energy Dep, Atomic Minerals Directorate for Exploration and Research, Jaipur-302 030, Email: rkumark2002@yahoo.com) : Uranium in lake sediments-a report on Didwana salt lake, Nagaur district, Rajasthan. Curr Sci 2009, 97(11), 1545-6.

1 table, 12 ref

021983   Rai P;Pati J K;Patel S C;Naik A;Panda D (Nimoo-Bazgo (Alchi) Hydroelectric Project, National Hydroelectric Power Corporation Ltd., Silk Route Inn, Skara, Leh (Ladakh), Leh-194 101) : Multi-shelled orbicular olivine gabbronorite from Leh, Jammu and Kashmir, Ladakh Himalaya. Curr Sci 2009, 97(12), 1769-74.

Reports here a multi-shelled orbicular olivine gabbronorite with anorthositic rims from Leh, J&K, India. The rock occurs as a transported boulder near Nimoo (12°95'33.40"N; 38°54'45.47"E) in Leh, over the Indus Group of sediments at an elevation of 3110 m, and is most likely derived from the Ladakh Granitic Complex. We present here the morphological details, and preliminary mineralogy and petrology of the orbicular rock.

3 illus, 1 table, 31 ref

021982   Patel S C;Ravi S;Anilkumar Y;Patil J K (Earth Sciences Dep, Indian Institute of Technology, Powai, Mumbai-400 076, Email: scpatel@iitb.ac.in) : Sapphirine-bearing Mg-Al xenolith in Proterozoic kimberlite from Dharwar craton, southern India. Curr Sci 2010, 98(4), 547-50.

A rare crustal xenolith of Mg-Al rock recovered from the P3 pipe of Wajrakarur Kimberlite Field in the Dharwar craton contains the minerals sapphirine, spinel and phlogopite. AH the minerals have low iron contents with Xmg values of 0.97 in phlogopite, 0.95-0.96 in sapphirine and 0.87 in spinel. The (MgO, FeO): (Al₂O₃): SiO₂ ratio in sapphirine is close to 7:9:3. Sapphirine-spinel geothermometry indicates that the rock has undergone peak metamorphism in the amphibolite-granulite transition facies. Although sapphirine-bearing Mg-Al rocks are known from the northern and southern parts of Dharwar craton, this is the first report of such rocks from the central part of the craton.

2 illus, 1 table, 17 ref

021981   Nasipuri P;Chatterjee A (Geology Dep, Indian Institute of Technology, Kharagpur-721 302, Email: alokesh@yahoo.com) : Land use around maithon reservoir: a study from high-resolution ASTER data. Curr Sci 2009, 97(1), 25-7.

^ssc5 illus, 6 ref

021980   Naresh Kumar;Vallinayagam G (Geology Dep, Kurukshetra Univ, Kurukshetra-136 119, Email: sagwalnaresh@gmail.com) : Primary volcanic structures from Nakora area of Malani igneous suite, western Rajasthan: implications for cooling and emplacement of volcanic flows. Curr Sci 2010, 98(4), 550-7.

This communication reports Held observations and petrographical studies of 44 volcanic flows in the Na-kora ring complex. They are characterized into three different zones, viz. A, B and C, based upon the patterns of lava flows, cooling joints, vesicular nature and relative stratigraphic position observable in the field. Differences in the thicknesses of the flows have been related to total cooling time of the lava flows. Using the temperature-depth/thickness-time diagram, the total cooling time of these volcanic flows (40 flows are acidic and 4 flows are basic) with total thickness of 1776 m has been calculated and found to be 534.108-610.661 years. Flows in zone A in Nakora are more perfect, suggesting slow cooling and farther location from the volcanic vent, as compared to zone C, where flows are thicker as observed at locations closer to the vent.

4 illus, 1 table, 25 ref

021979   Murali R M;Shrivastava D;Vethamony P (NO, National Institute of Oceanography, Dona Paula, Goa-403 004) : Monitoring shoreline environment of Paradip, east coast of India using remote sensing. Curr Sci 2009, 97(1), 79-84.

In the study, authors used multi-temporal satellite images of Indian Remote Sensing Satellites (IRS1D and IRS P6 - Resourcesat) from 1998 to 2005 to monitor the coastal environment of Paradip, east coast of India. The resultant coastal vector maps were used to estimate the geomorphological changes and shifting of the shoreline position. This integrated study is found useful for exploring accretion and erosion processes in the region. The shoreline maps were compared with the 1973 Survey of India toposheets to estimate the changes which have occurred in the region. Results indicate an increase of 7.72 km in shoreline length and a net loss of 18.73 km² of beach area between the years 1973 and 1998, and 0.46 km reduction in shoreline length and 3.11 km²3 increase in beach area between 1998 and 2005. An overall net increase of 7.26 km length shoreline and a net loss of 15.6 km² was observed between 1973 and 2005. The years 2001, 2002 and 2003 exhibited loss in length of shoreline as well as area of the beach. These years coincided with certain coastal activities carried out in the study region.

6 illus, 4 tables, 20 ref

021978   Masood Ahmad S;Padmakumari V M;Anil Babu G (National Geophysical Research Institute, (Council of Scientific and Industrial Research), Hyderabad-500 606, Email: smasoodahmad@rediffmail.com) : Strontium and neodymium isotopic compositions in sediments from Godavari, Krishna and Pennar rivers. Curr Sci 2009, 97(12), 1766-9.

Reports here strontium (Sr) and neodymium (Nd) iso-topic compositions in bed sediments from the Goda-vari, Krishna and Pennar rivers, draining into the Bay of Bengal. The isotopic compositions of these sediments range from 0.7190 to 0.7610 for ⁸⁷Sr/⁸⁶Sr and -12.04 to -23.68 for εNd. This wide range in Sr and Nd isotopes is derived from variable proportions of sediments from different rock types in their drainage basins. All the three rivers have their characteristic isotopic signatures. The results display highest ⁸⁷Sr/⁸⁶Sr (0.7610) and most negative ε values (-23.68) for the sediments of Pennar river. This is attributed to the chemical weathering of gneisses and granites in its drainage basin. The ⁸⁷Sr/⁸⁶Sr and εN(1 values for the Godavari river sediments range from 0.7196 to 0.7210 and -15.31 to -18.22 respectively. ⁸⁷Sr/⁸⁶Sr and εm values in Krishna river sediments lie from 0.7217 to 0.7301 and -12.04 to -12.78 respectively. The results show that the sedimentary load from the Godavari and Krishna rivers is primarily derived from the older rocks in their drainage basins. It is possible that the sediments transported through peninsular Indian rivers predominantly control Sr and Nd isotope sedimentary budget in the western Bay of Bengal.

2 illus, 1 table, 28 ref

021977   Manchi S;Sankaran R (Conservation Ecology Div, Salim Ali Centre for Ornithology and Natural History, Anaikatty P.O., Coimbatore-641 108, Email: ediblenest@gmail.com) : Impact of the 2004 earthquake on the limestone caves in North and middle Andaman Islands. Curr Sci 2009, 97(8), 1230-4.

Evaluated the effects of the great earthquake of December 2004 on 43 inland caves in the Andaman and Nicobar Islands. Data was collected before and after the earthquake. The number and size of fallen rocks within the caves were taken as a measure of physical damage to the caves. Rockfall was greater in caves located above ground (Z= -3.543, P= 0.000) and in larger caves (x² = 18.545, df= 3,P = 0.000), indicating significantly higher damage to these caves. The impact of damage to the microclimate and ecosystem inside the caves is also discussed.

4 illus, 1 table, 15 ref

021976   Madhavaraju J;Lee Y L (Estacion Regional del Noroeste (ERNO), Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Sonora 83000, Mexico, Email: mj@geologia.unam.mx) : Influence of Deccan volcanism in the sedimentary rocks of late maastrichtian-Danian age of Cauvery basin southeastern India: constraints from geochemistry. Curr Sci 2010, 98(4), 528-37.

Geochemical studies have been carried out on the Late Maastrichtian-Danian sedimentary rocks of Cauvery basin to understand the terminal Cretaceous events. GeochemicalJy, the sedimentary rocks of Kallamedu and lower Niniyur formations are classified as litharenite, wacke, shale, Fe-shale and Fe-sand. Clastic rocks of the later part of Late Maastrichtian and Danian show high values of Cr and Ni and high Cr/Th ratio, which may be induced by Deccan Traps volcan-ism. Chondrite normalized REE patterns of the Late Maastrichtian and Danian rocks of Cauvery basin are more or less similar to basalt, weathered Deccan basalt and Maastrichtian Lameta beds of Central India. The presence of negative Ce anomaly in the non-marine sedimentary rocks of Kallamedu Formation (Kallamedu2, Rayambaram and lower part of Niniyur sections) strongly supports the view that these changes have been influenced by the Deccan volcan-ism. Apart from this, the high content of Mg and Fe in the Kallamedu2 section suggests that the abnormal concentration of these elements is mainly influenced by Deccan volcanism. The influence of Deccan volcan-ism is more in the Kallamedul and Rayambaram sections than the Niniyur and Ellaikadambur sections.

9 illus, 1 table, 50 ref

021975   Joshi V U (Geography Dep, Pune Univ, Pune-411 007, Email: vujoshi@unipune.ernet.in) : Temporal changes in the land-use/land-cover for the last one decade along the Pravara river basin, Maharashtra. Trans Inst Indian Geogr 2010, 32(2), 183-92.

World is witnessing a rapid increase in the population in the past few decades and the manifestations of it is clear in the form of man made structures replacing the natural landscapes all over the world. The present study attempts to investigate one such locality in the upper Pravara Basin in Maharashtra which has been undergoing rapid changes in the landuse in the last few years. The detection of the landuse changes that have occurred in this region has been conducted by analysing IRS 1 C- LISS HI and IRS I C PAN and IRS P6 - LISS III and IRS I D PAN merged images. The data resolution is 5.8 m, which is suitable for the area under investigation. The images of the year 1997 and 2007 were analyzed to detect the changes in the landuse and landcover in these past ten years. Analysis reveals that there has been an increase of 19% of the area under agricultural sector in the past ten years. Settlement also has increased from 1.36% to 5.36% of the area and dense vegetation also has marginally increased. The remarkable increase in the agricultural area is by reclaiming the natural ravines and fallow lands. The sudden major landuse changes that have occurred in these areas in the last few decades will have its impact on the landscape in the long run. Evidences have already begun to show in these areas. There has been a rapid progress in agriculture in the last few years, but the agricultural land is acquired by reclaiming badlands that are found in these areas. This is a sensitive landform feature and such massive invasion might induce positive feedback system on these landscapes and the future repercussions may be far from being desirable.

4 illus, 1 table, 20 ref

021974   Jayaprakash C;Jayakumar R;Dinesh A C;Maran N; Shareef N M (NO, Geological Survey of India, Mangalore-575 001, Email: jayaprakashc@hotmail.com) : Tephra from Quaternary sediments of western slope of Lakshadweep ridge, Arabian sea. Curr Sci 2009, 97(11), 1670-4.

Extensive occurrence of fallout tephra in the Quaternary sediments of Arabian Sea is observed in the gravity cores collected from western slope of Lak-shadweep Ridge between water depths of 2505 and 3481 m. The Western Lakshadweep Tephra (WLT) layer is associated with olive grey to dark grey, pelagic to hemi-pelagic clay and bioclasts, and occurs between depths of 95 and 156 cm below seafloor. The tephra layers are admixed with clayey sediments and are relatively hard, compact and partly dehydrated with lesser amount of biogenic material. The glass shards associated with the sediments are fresh, colourless and transparent with abundant pale-brown pyroclastic aggregates. The glass shards are mainly bubble wall type, with some having forms like cuspate, curved platy, multi-junctional and pipe vesicles. The high silica, alumina and K₂O and low FeO and MgO indicate rhyolitic composition of glass shards. In the Or-Ab-An plot the samples fall in the rhyolite field. Major element chemistry and morphology of WLT suggest Youngest Toba Ash as their source. This tephra-bearing zone may be used as a marker horizon for stratigraphic correlation and calculating the rate of sedimentation.

5 illus, 2 table, 17 ref