002299   Alom M N;Zaman M (NO, Phycology and Limnology Laboratory, University of Rajshahi, Rajshahi 6205, Bangladesh) : Interrelationship between bottom soil nutrients and physico-chemical variables in a fresh water impoundment in Northern Bangladesh. Ecol Envir Conserv 2009, 15(1), 23-8.

The interrelationships between the bottom soil nutrients (i.e. pH, potassium, calcium, magnesium, iron, manganese, organic matter, nitrogen, phosphorus, sulphur, boron etc.) and the physico-chemical conditions of water (i.e. depth, temperature, transparency, total solid, electrolytic conductivity, pH, carbon-di oxide, bi-carbonate, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, calcium, magnesium content, total hardness, nitrate nitrogen, total phosphate, oxidation reduction potential, oxidation reduction index and soluble salt) in a large fresh water reservoir in the northern part of Bangladesh has been studied. The bottom soil nutrients and the physico- chemical variables of the water body were found to have positive or negative correlation with each other as revealed by correlation analysis. Contents of the physico-chemical variables of the water did not exceed the ISI and USA limit of drinking water quality standard (DWQS) and irrigation water quality standard (IWQS).

3 tables, 13 ref

002298   Alappattu D P;Kunhikrishnan P P;Aloysius M; Mohan M (Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum-695 022, Email: dennyalp@gmail.com) : Atmospheric boundary layer features during winter over a tropical inland station-Kharagpur (22.32°N, 87.32°E). J Earth Syst Sci 2009, 118(4), 281-93.

The local weather and air quality over a region are greatly influenced by the atmospheric boundary layer (ABL) structure and dynamics. ABL characteristics were measured using a tethered balloon-sonde system over Kharagpur (22.32°N, 87.32°E, 40 m above MSL), India, for the period 7 December 2004 to 30 December 2004, as a part of the Indian Space Research Organization-Geosphere Biosphere Program (ISRO-GBP) Aerosol Land Campaign II. High-resolution data of pressure, temperature, humidity, wind speed and wind direction were archived along with surface layer measurements using an automatic weather station. This paper presents the features of ABL, like ABL depth and nocturnal boundary layer (NBL) depth. The sea surface winds from Quikscat over the oceanic regions near the experiment site were analyzed along with the NCEP/NCAR reanalysis winds over Kharagpur to estimate the convergence of wind, moisture and vorticity to understand the observed variations in wind speed and relative humidity, and also the increased aerosol concentrations. The variation of ventilation coefficient (VC). a factor determining the air pollution potential over a region, is also discussed in detail.

12 illus, 27 ref

002297   Akbari M;Behbahany A M;Arzjani Z (Faculty of Geography, Tehran Univ, Iran) : Morphological characteristics of qanats in Iran: suburb of the Boushehr city-a case study. Int J Agric Envir Biotechnol 2009, 2(3), 214-18.

Qanats (infiltrating tunnels) have been used in Iran for about 3000 years. Their role in farms irrigation and beverage water supply for ancient cities has been so efficient that the technique of qanat-making has been developed in one-fifth of the world countries too. Unfortunately, the construction of deep and semi-deep wells, and uncontrolled water extraction from them have caused an intense drawdown of underground water level and loss of underground water tables. Considering uncontrolled water extraction, severe floods, and the type of precipitation regime in Jam and Riz catchments in the suburb of the Boushehr city, watershed studies in this region appear to be necessary. In this research, morphological characteristics of qanats in the Boushehr suburb are reviewed first. Then the study is concentrated on the reformation and reclamation systems of this region. Collection of data has been carried out by providing the users with particular questionnaire. 24 qanats have been identified in the region after field studies and reconnaissance. Their average age and average discharge are estimated 934 years and 12.22 l/s, respectively. The results of this research show that out of eight factors of mending and maintaining operations, not dredging and not coating of the streams have led to the failure of qanats and reduction in theirdischarge.

3 tables, 17 ref

002296   Aguilar D O M;Pando Moreno M;Gunzalez Rodriguez H G;Jurado E (Facultad de Ciencias Forestales, Universidad Autonoma de Nuevo Leon, Carretera Nacional Km 145, AP 41, CP 67700, Linares, N.L.; Mexico, Email: dinorah2741@hotmail.com) : Effect of ground water on irrigated lands of northeastern Mexico. Int J Agric Envir Biotechnol 2009, 2(3), 255-59.

Salinization is a serious threat for ecosystems of arid and semi-arid environments, due to the extension affected, and for its socio-economic and environmental repercussions. The hypothesis for this study was that water used for irrigation in the area presents high concentration of salts and its use is leading to degradation of the irrigated lands. The study area is characterized by the intensive use of ground water for agriculture, but also for the increasing clearing of native grasslands that are habitat for a large number of species catalogued in some status of conservation. Samples of water from 4 active wells used for irrigation and soil of three land uses (agriculture, native-grassland and abandoned-agriculture) were analyzed for salts concentration (sodium). Water from all evaluated wells was classified as high and very high salinity. Water from well 3 showed the highest salinity values (2.54 mS cm^-1) and highest sodium concentration (133.34 mg L^-1). Concentration of sodium in the other wells did not exceed 18 mg L^-1 Analysis of sodium concentration in the top 30 cm of soils showed that fields watered with water from well 3 had the highest values (511.69 mg L^-1) of this element than the otherfields, indicating its accumulation into the soil due to irrigation practices.

3 illus, 3 tables, 16 ref

003210   Valsangkar A B (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: vals@nio.org) : Device for finer-scale sub-sectioning of aqueous sediments. Curr Sci 2007, 92(4), 428-31.

Modified hand-operated mechanical device has been developed to facilitate precise sectioning of the aqueous sediment in a core liner. The device allows the core liner to remain vertical on the disk protecting physical, chemical and mechanical properties of the sediment. The disk rotations are initially calibrated for moving unit distance on the threaded rod and later used proportionately for desired increment of the sediment. The sediment is exposed on the top of the liner when the disk and liner are lowered. A collapsible scale provided with the coupler on the top of the liner helps verify the required thickness of the sediment to be sectioned. Disk rotation does not cause compaction of sub-core sediment, and sub-samples are not mixed or contaminated. The apparatus is low-cost (<60> Rs 2000), portable, user-friendly, lightweight (about 9 kg) and occupies small floor area (0.25 sq. m). The apparatus is made up of non-magnetic and anti-rusting material for widescale application. It can be taken to the field or on a small boat or a research vessel, and quickly assembled and or dissembled. It is especially useful in a team with limited manpower. The core liners can be cleaned, washed and reused

^ssc5 illus, 1 table, 6 ref

003209   Thakur N K;Pradeep Kumar A (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: nkthakur46@yahoo.com) : Role of bathymetry in tsunami devastation along the east coast of India. Curr Sci 2007, 92(4), 432-4.

^ssc3 illus, 12 ref

003208   Syed A A;Khan S;Manoharan D A (Studies in Chem Dep, Univ of Mysore, Manasagangotri, Mysore-570 006) : Novel electrophilic coupling reactions for the spectrophotometric determination of Iron(III) in polluted lake water, sewage water and industrial effluent samples. Chem envir Res 2006, 15(1-2), 51-9.

Novel and newer spectrophotometric reactions, using desipramine hydrochloride (DPH) and trimipramine maleate (TPM) as chromogenic reagents for determination of iron(lII) are proposed. The reaction methods are based on the reduction of iron(III) by an electrophilic coupling reagent, 3-methyl-2-benzothiazoline hydrazono hydrochloride hydrate (MBTH) in aqueous neutral medium and subsequent coupling with DPH or TPM. The blue colour formed in the reaction showed maximum absorbance at 630 nm and obeyed Beer's law over the range 0.4-4.4 μg ml^-1 and 0.4-6.0 μg ml^-1. The molar absorptivity values with DPH and TPM were 3.288 x 103 and 3.374 x 103 1 mol^-1cm^-1 and Sandell's sensitivity values were 0.0 130 and 0.0331 μg cm^-2 respectively. The proposed methods were successfully applied in the determination of iron (III) in polluted lake water, sewage water and industrial effluent samples. The performances of proposed methods were evaluated in terms of Student t-test and variance ratio F-test which indicated the significance of proposed methods over the standard spectrophotometric method.

2 tables, 14 ref

003207   Sujatha D;Rajeswara Reddy B (NO, National Geophysical Research Institute, Uppal Road, Hyderabad) : Nitrates in groundwater soruces in southeastern part of Ranga Reddy district, Andhra Pradesh, India. J appl Geochem 2006, 8(2), 169-80.

Nitrate contamination of the world's groundwater supply poses a serious human health threat. High nitrate levels found in drinking water proved to be the cause for numerous health conditions across the world. Nitrate is often seen as an agricultural pollutant of groundwater and is expected to be at higher concentrations in the groundwaters surrounding a city than in those beneath it. However, the difference between nitrate concentrations in urban and rural is often small, due to the non-agricultural sources of nitrogen, which are concentrated in cities. Detailed study of the groundwater in southeastern part of Ranga Reddy district revealed that the nitrate levels are several times higher than the prescribed limit of 50 mg/l. Seasonal changes and a progressive increase of nitrate concentrations have been noticed in some bore wells. Leaching of nitrate to groundwater is mainly due to septic tanks, improper disposal of domestic wastes, excessive application of N-fertilizer and the absence of proper soil and water management practices.

3 illus, 2 tables, 28 ref

003206   Subba Rao N;John Devadas D;Bangaru Raju I (Geology Dep, Andhra University, Visakhapatnam-530 003, Email: srnandipati@rediffmail.com) : Identification of factors controlling the surface water quality using principal component analysis. J appl Geochem 2006, 8(2), 154-61.

Samples from surface water bodies in Anantapur district, Andhra Pradesh were analyzed for major ion chemistry to identify the factors that determine the water quality. Principal component analysis was made on major ion chemistry. The first two principal components were chosen; the association of TDS, Na+, HCO₃^- and F^- characterize the first one, and the combination of Cl^-1, SO₂^4-, NO₃^- and K⁺ the second one. They measure salinity (TDS and Na⁺), alkalinity (HCO₃^- and F^-) and pollution (NO₃^-, SO₄^2-, Cl and K⁺) factors, resulting from the effects of semi-arid climate; water-soil interaction and anthropogenic activities, which control the water chemistry regionally. Management measures are suggested to have a better water quality for sustainable development.

5 illus, 2 tables, 23 ref

003205   Singh B P;Lee Y I (Geology Dep, Banaras Hindu University, Varanasi-221 005, Email: bpsingh_in@yahoo.com) : Atmospheric pCO₂ and climate during late Eocene (36 ± 5 Ma) on the Indian subcontinent. Curr Sci 2007, 92(4), 518-23.

Highlights the level of atmospheric CO₂ and the climatic conditions during Eocene (36 ± 5 Ma) based on measurements of stable carbon and oxygen isotopes of late Eocene soil carbonate (calcretes) occurring in the Himalayan foreland sequences. The atmospheric pCO₂ is estimated to be about 930 ppm V at high productivity and about 465 ppm V at low productivity. The covariance of δ¹³C suggests that the higher atmospheric CO₂ may be responsible for higher temperature. Moderate weathering intensity (CIA value 70-82) of the host mudstones suggests warm climate associated with reasonable wetness that became dry-subtropical, resulting in calcrete development in the northern part of the Indian subcontinent during late Eocene. Wet subtropical climate demonstrates considerable rainfall at this time interval in the region long before the uplift of the Tibetan plateau. Alternatively, it can be suggested that uplift of the Tibetan plateau began much earlier than presently considered.

^ssc1 table, 26 ref

003204   Rattan B;Tuli N;Kapila S P;Prasad A K (Centre of Advanced Study in Geology, Punjab University, Chandigarh-160 014) : Petrochemistry of the granitoids of the Saladipura area, district Sikar, Rjasthan, India. J appl Geochem 2006, 8(2), 137-47.

Granitoids occurring in Saladipura area forming a part of the Aravali mountain range are represented by porphyritic granite gneiss. The rocks have concordant relationship with the schists and phyllites and show xenoliths of the enclosing metasediments. Geochemically, all the rocks are corundum normative, subsolvus, peraluminous and S-type in nature. The granitoids are considered to have crystallized from a melt which was generated at a temperature of 670°-685°C and pressure of around 4.5 Kb.

6 illus, 3 tables, 18 ref

003203   Rao A T;Dhananjaya Rao E N;Deva Verma D;Aruna Kumar P (Geology Dep, Andhra University, Visakhapatnam-530 003) : Uralitised and saussuritised gabbroic rocks from the Kandra Igenous Complex, Nellore schist belt. J appl Geochem 2006, 8(2), 116-26.

Gabbroic intrusives in the Arimanipadu hill range in the Kandra Igneous Complex, Nellore Schist Belt display coarse-grained uralitised pyroxenes and saussuritised plagioclase along the margins of gabbroic bodies as partial or complete sheaths. Changes from less deformed center towards deformed and recrystallised margins are inferred due to retrograde metamorphic and metasomatic effects at elevated water vapour pressure. The quartz albitite veins, associated with uralite-saussurite gabbros along the selvages, support that the differential fusion of altered gabbros under high water vapor pressure conditions produce a liquid of albitic composition at low temperature of <126>600°C. The intensive shearing stress and volatile activity required for alteration of gabbros are related to the fault zone, recognized in close proximity to gabbroic intrusives in Arimanipadu in the Nellore Schist Belt.

8 illus, 3 tables, 10 ref

003202   Rajeev Kumar;Nand Lal;Sandeep Singh;Jain A K (Earth Sciences Dep, Indian Institute of Technology Roorkee, Roorkee-247 667, Email: sandpfes@iitr.ernet.in) : Cooling and exhumation of the trans-Himalayan Ladakh batholith as constrained by fission track apatite and zircon ages. Curr Sci 2007, 92(4), 490-6.

Low-temperature thermochronology of the Trans-Himalayan Ladakh batholith has been applied, using fission track (FT) dating of apatite and zircon separates, to work out the exhumation history. Thirty FT apatite samples from the Ladakh Batholith provide an excellent constraint on its exhumation at low temperature <126>110°C. The oldest apatite ages of 23.1 ± 1.1 Ma from the Khardung La (5440 m) and 25.4 ± 2.6 Ma from the Chang La (5301 m) have been obtained from the highest uplifted parts of the batholith, while the youngest ages are 11.8 ± 1.1 Ma (4038 m) and 9.2 ± 0.9 Ma (3732 m) respectively. Apatite ages from Lyoma-Hanle section are tightly clustered between 17.8 and 12.0 Ma. Elevation profiles of these two sections yield exhumation rates of 0.1 mm/a for the Khardung La and Chang La sections between 25 and 9 Ma. In addition, three cogenetic zircons yielded FT ages of 41.4 ± 2.3, 43.8 ± 3.4 and 31.7 ± 2.7 Ma, indicating a younging of the FT age from west to east. These FT data from the batholith indicate a slow cooling and exhumation history, as inferred from elevation vs age FT apatite plots.

2 illus, 2 tables, 37 ref

003201   Philip G;Virdi N S (NO, Wadia Institute of Himalayan Geology, 33, Gen. Mahadeo Singh Road, Dehra Dun-248 001, Email: gphilip@wihg.res.in) : Active faults and neotectonic activity in the Pinjaur Dun, northwestern Frontal Himalaya. Curr Sci 2007, 92(4), 532-42.

Manifestation of ongoing active tectonics in the Himalayan foothill region is evident from a number of major M<62> 7.5 and great earthquakes (M ≅ 8) which occurred within the last century or so, besides the recurrent seismic events of moderate magnitude. Active faults of the Himalaya are significant in the study of active tectonics because displacements along them reflect the continued tectonic movements. The study deals with morpho-structural analysis using remotely sensed data along with selected field investigations in delineating new traces of active faults in the Pinjaur Dun of the northwestern Frontal Himalaya. Fault scarps with heights varying from 5 to 25 m observed along the faults are indicative of long term uplift/deformation in the current tectonic regime and cumulative slip along them. These active faults are signatures of Quaternary tectonics in the zone between the Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust.

^ssc12 illus, 1 table, 31 ref

003200   Parashar V K;Punwatkar V L;Usmani H U (Geology Dep, Government Motilal Vigyan Mahavidyalaya, Bhopal-462 002) : Assessment of agricultural quality of deep ground water in the lower alluvial plants of Narmada valley between Khalghat and Harinphal, M.P.. Oriental J Chem 2006, 22(3), 687-94.

The present study mainly concerns the agricultural quality of deep groundwater in the lower alluvial plains of Narmada Valley between Khalghat and Harinphal M.P. In the study area deep groundwater is being used for irrigational purposes. It is necessary to know the quality of deep groundwater so that it can be judiciously applied for irrigational purposes. In order to evaluate the agricultural quality, 15 representative deep groundwater samples were collected during premonsoon and postmonsoon period and analysed by using the procedure laid down by APHA (1985). The agricultural suitability of deep groundwater was determined in terms of various parameters like Sodium Adsorption Ratio (SAR), Kelly's Ratio, Residual Sodium Carbonate (RSC), Salt Index, Mg. Hazards and Adj RNa. On the basis of irrigational specifications given by Asgar et al. (1936), Kelley et al. (1940), Eaton (1950). US Salinity Laboratory Staff (1954), Wilcox (1955), Paliwal (1972), Suaraj (1981) and Ayers and Westcot (1985), it is suggested that the groundwater of the study area seems quite suitable for irrigational purposes.

2 illus, 4 tables, 10 ref

003199   Krishnakanth Singh A;Vallinayagam G (NO, Wadia Institute of Himalayan Geology, Northeast Unit, Itanagar-791 113) : Radioactive heat generation of acid volcanic rocks from the Malani Igneous Suite, western Rajasthan, India. J appl Geochem 2006, 8(2), 162-8.

Anorogenic A-type acid volcanics (rhyolite, trachyte) form the Siwana Ring Complex and Kundal area of Malani Igneous Suite (MIS) are characterized by high content of radioactive element (U, Th, K) and are classified as high heat production acid volcanic rocks. Rhyolite shows comparable heat production (3.13-8.40 HP) and total heat generation values (7.46-19.97 HGU) as compared to the values of heat production (3.71-5.94 HP) and total heat generation values (8.83-14.14 HGU) of trachyte. The U and Th contents in these rocks are higher than the normal acid volcanics; and the average value of total heat generation for acid volcanic rocks (11.02 HGU) is much higher than the average value 00.8 HGU for the continental crust and 8.3 HGU reported from the Peninsular India. The high heat generation values (7.46-14.87 HOU) of the acid volcanics indicate that the MIS belongs to the `hot crust' and suggests a possible linear relationship between the surface heat flow and the crustal heat generation in the MIS of Western Peninsular India.

3 illus, 1 table, 26 ref

003198   Hareesh Kumar P V;Sanilkumar K V;Prasada Rao C V K (NO, Naval Physical and Oceanographic Lab, Kochi-680 021) : Arabian sea mini warm pool and its influence on acoustic propagation. Def Sci J 2007, 57(1), 115-21.

Systematic experiment was conducted in the eastern Arabian Sea for the first time exclusively to study the characteristics of the Arabian Sea mini warm pool¹. The analysis revealed complex nature of the thermohaline and sonic layer distributions across the Arabian Sea mini warm pool. This mini warm pool was identified between 67.5°E and 75°E, where the sea surface temperature was in excess of 30.25°C. At the core of this mini warm pool, warmer (<62>31.2°C) and low saline (<60>34.6 PSU) waters were noticed. Further, very thin sonic layer (<62> 5 m) was noticed at the mini warm pool core, which increased eastward and westward. The acoustic propagation characteristics across and outside of the core, i.e., (i) within the mini warm pool core, (ii) eastern side of the mini warm pool core, and (iii) western side of the mini warm pool core, were assessed based on the output of a range-dependant acoustic model. In general, the occurrence of this mini warm pool was found to alter the propagation characteristics. Better propagation was obtained when the simulation was carried out on die eastern side of this mini warm pool, with source near the coast (i.e., downslope condition).

^ssc4 illus, 9 ref

003197   Baskar R;Kochhar N (Environmental Science and Engineering Dep, Guru Jambheshwar University, Hisar-125 001, Email: rbaskargjuhisar@yahoo.com) : Titan-aegirine from the peralkaline Siwana granite, western Rajasthan, India. J appl Geochem 2006, 8(2), 133-6.

The occurrence of Titan-aegirine in the peralkaline granites of the Siwana ring complex, Rajasthan, India is discussed. Textural relations suggest a post-magmatic paragenesis, formed due to replacement of aenigmatite which took place at low fO₂ and increased activity of a_SiO2, along with removal of some Ti, Fe, Mn and Mg, and addition of some Ca and Na. The Ti-content of the late-stage titanian-aegirine is interpreted as largely reflecting the Ti-content of the residual silicate melt.

1 table, 20 ref

003196   Bajpai R K;Narayan P K (Back End Technology Development Div, Nuclear Recycle Group, Baba Atomic Research Center, Department of Atomic Energy, Mumbai-400 085, Email: rkumar@apsara.barc.ernet.in) : Validation of some experimental resutls of basalt-groundwater interaction around disposed nuclear waste through natural evidences from basalt-hosted unhavre thermal spring, Ratnagiri district, India. J appl Geochem 2006, 8(2), 127-32.

Long-term performance of host rock under the unique combination of groundwater chemistry and thermal input, induced by disposal of heat-emitting nuclear wastes, is a key issue in safety assessment of such disposal options. Strong evidences in support of the conclusions derived on various processes and parameters involved during the basalt-groundwater interaction at elevated temperature through experimental studies conducted on the Grande Basalts of USA have been noticed in Unhavre hot groundwater-basalt system (71 °C), Ratnagiri district of West Coast of India. The host rock and groundwater in these sites have remarkable geochemical similarity with those prevailing in the Grande Ronde Basalts, a possible host rock for disposal of nuclear wastes. The Unhavre hot springs with reservoir temperature of about 100°C have produced remarkably similar alteration products that comprise quartz, smectite, and zeolites along the fractures. The main zeolite minerals obtained in these experiments, including mordenite, heulandite, clinotilolite, stilbite, scolectite, etc., are reported to have formed in this site as well, under analogous hydrothermal conditions. Reducing conditions, as obtained during the experiment, have also been validated by the presence of minerals like glauconite and pyrite in this site. The study demonstrates that this site can serve as an ideal natural analogue for understanding the near field geochemistry around disposed nuclear wastes in basaltic rocks and validation of numerically as well as experimentally simulated waste-water-rock interactions models.

3 tables, 17 ref

003195   Ahmad S;Hasnain S I (Geology Dep, Aligarh Muslim University, Aligarh-202 002) : Chemical characteristics of atmospheric precipitation at high Himalaya, Ganga headwater, India. J appl Geochem 2006, 8(2), 148-53.

Major ions chemistry is determined for the snow, snowpack and rainwater samples in high altitude Himalaya. It revealed that the sources of solute in snow, snowpack and rainwater are marine spray, crustal particulates and atmospheric gases. The results also suggested that the seasonal snowcover influences the total solute content in precipitation. Snow and rainwater are loaded with high concentration of sulphate and nitrate as a result of high concentration SO₂ and NO₂ gases in the atmosphere. Acidity in snow, snowpack and rainwater is mainly neutralized by the basic cations in the atmosphere. Chemical characteristics of the snow changes as it transferred into snowpack. The particulate deposition on surface of the snowcover and the preferential leaching of ions due to pack weathering are the major source of these Changes.

1 illus, 1 table, 26 ref

002192   Yogesh Singh;Kaushal A (GSDG, , C-DAC, 12, Thube Park, Shivaji Nagar,, Email: yogesh_s1234@rediffmail.com) : Extraction of geomorphological features using radarsat data. J Indian Soc Remote Sens 2006, 34(2), 299-307.

A study was undertaken to evaluate the potential of RADARSAT SAR data (Standard-7 and Wide-2 beam positions) for delineating the geomophological units in Itanagar Capital Complex of Arunactial Pradesh, India. Principal Component Analysis (PCA) has been applied to Standard-7 and Wide-2 data with incidence angle 45° - 49° and 3 1° - 39° respectively. The resulting components yield imagery that highlights the Geomorphological units. The area of investigation has been classified into five geomophological units' viz., High relief structural hills, low relief structural hills, low relief rugged hills, piedmont and intermontane valley. The surface roughness can be observed by studying the difference of the responses from different incidence angles. Wide-2 beam position was found to be more useful for identifying features in flat terrain. and Standatd-7 beam position data for features of high relief.

8 illus, 2 tables, 9 rf

002191   Trivedi R K;Chourasia L P;Singh D K (Applied Geol Dep, Dr. H. S. Gour Univ, Sagar-470 003, Email: lpc55@rediffmail.com ) : Application of remote sensing in the study of geoenvironmental aspects of Rajghat dam project. J Indian Soc Remote Sens 2006, 34(2), 309-17.

This study was conducted on the Rajghat dam project situated in Lalitpur district of Uttar Pradesh, India, the remote sensing techniques have been proved to be very efficient in identification of geoenvironmental aspects of the study area. In the present paper IRS IA LISS II data has been used. The various thematic maps have been generated and integrated on 1,50,000 scale. Geology, geomorphology, Hydro-geomorphology, structure, soils and erosion, landuse / landcover helped in identification of the potential zones for developmental planning and forecasting limitations to their implementation with seasonal accuracy. Lineaments and their intersections appear to be potential sites for groundwater. Betwa drainage basin is suitable for surface reserviour and check dams. The study shows that the integration of all attributes provides more accurate results in identification of geoenvironmental characteristics.

7 illus, 2 tables, 26 ref

002190   Tiwari D R;Chakravarty S K (NO, Geology Govt M.V.M., Bhopal-462 001, Email: tiwarimvm@yahoo.com) : Hydrogeomorphological mapping a case study a part of sind basin, Datia block, distt. Datia Madhya Pradesh, India, using rs & gis technique. Ultra Scient phys Sci 2006, 18(2), 127-32.

Remote Sensing (RS) data and Geographical Information System (GIS) playa rapidly increasing role in the field of hydrology and water resources development. One of the greatest advantages of using RS data for hydrological mapping and monitoring is its ability to generate information in spatial and temporal domain, which is very crucial for successful model analysis, prediction and validation. However, the use of RS technology involves large amount of spatial data management and requires an efficient system to handle such data. The GIS technology provides suitable alternatives for efficient management of large and complex databases. Information from satellites is becoming more and more important for environmental research: an important part of this information concerns water - an clement most essential for man, its phases and peculiarities. The Principal source of ground water recharge in the study area is through rainfall, although the river and streams emerging from hills also form a significant recharge source. The advent of Remote sensing has opened up new vistas in geological, geomorphological and structural mapping from ground water exploration.

8 ref

002189   Srinivasa Vittala S;Govindaiah S;Honne gowda H (Central Ground Water Board, Ministry of Water Resources, , mid-Eastern Resgion, Patna-800 001) : Digital elevation model (DEM) for identification of groundwater prospective zones. J Indian Soc Remote Sens 2006, 34(2), 319-24.

^ssc3 illus, 15 ref 

002188   Sitharam T G;Anbazhagan P;Mahesh G U (Civil Engineering Dep, Indian Institute of Science, Bangalore-560 012, Email: sitharam@civil.iisc.ernet.in) : 3-D subsurface modelling and preliminary liquefaction hazard mapping of Bangalore using SPT data and GIS. Indian Geotech J 2007, 37(3), 210-26.

13 illus, 7 tables, 22 ref

002187   Singh Y R;Dogra N N;Thakur O P (Earth Sciences Dep, Manipur Univ, Canchipur, Imphal-795 003) : Ecostratigraphy of the Subathu formation, Solan District, Himachal Pradesh, India. Himalayan Geol 2007, 28(2), 11-9.

Subathu Formation exposed in the Solan District, Himachal Pradesh has yielded a well-preserved miofloral assemblage comprising 158 species in 79 form genera of spores, pollen grains and phytoplanktons. In addition, reworked Permo-Carboniferous palynomorphs and foraminiferal linings have also been recovered. The miofloral assemblages indicate tropical to sub-tropical climate with change in ecological successions from marine → brackish water → marine → coastal → lowland fresh water.

5 illus, 40 ref

002186   Singh S P;Singh M M;Srivastava G S;Basu A K (Geology Dep, Bundelkhand Univ, Jhansi-284 128) : Crustal evolution in Bundelkhand area, Central India. Himalayan Geol 2007, 28(2), 79-101.

Bundelkhand massif in the northern part of the Indian shield has Mid Archean gneissic nuclei in the Late Archean to Palaeo-Proterozoic granites. The massif is fringed by Bijawar and Gwalior Groups of Late Paleo-Proterozoic period in two sectors, and by the Vindhyan Supergroup of Meso to Neo-Proterozoic period almost all around. Together these form a cratonic complex. The granitic massif in the complex occupies an exposed area of about 26,000 sq km and total area of 45000 sq km. It preserves the signatures of several stages of crustal growth in the Archaean times. Tonalite-Trondhjemite-Granodiorite (TTG) gneisses, forming the oldest rocks in the massif have been reported from several localities but extensive occurrences are mainly in the central part of the massif. The study reveals and clearly categorises for the first time the lensoidal bodies of high-grade metamorphic rocks, and low-grade mafic ultramafic-metasedimentaries and metavolcanics, which occur as basement slices and pre-granite relicts. These rocks have been studied from different locations, and have provided signatures of Archaean crustal evolution. The high-grade and low-grade metamorphics are respectively proposed as Bundelkhand Gneissic Complex (BnGC), and Bundelkhand Metasedimentaries and Metavolcanics (BMM). The high-grade metamorphic rocks (BnGC) trending in WNW-ESE to NW-SE direction have discordant relationship with the low-grade metamorphic rocks (BMM), trending in ENE-WSW to E-W directions. This and other field relations indicate an older age for the high-grade BnGC in comparison to the low-grade BMM. The most extensively widespread Bundelkhand Granitoids have intrusive relationship with both BnGC and BMM. The NE-SW trending series of short and long shear zones occupied by quartz reefs are unique to the Bundelkhand craton, and are possibly the results of drags of Son Narmada sinistral megafault and rebound of the resultant collision of the Bundelkhand terrain with the Aravalli terrain to the west. The NW-SE trending swarms of mafic dykes, possibly related to the opening of the Bijawar basin mark the end of magmatism in Bundelkhand. Coeval marks of crustal evolution in the Bundelkhand and Aravalli areas point to their close connection during the Precambrian crustal evolution. The griddle like combined Bijawar-Vindhyan basin around the granitic massif points to their possible inherent linkage.

8 illus, 3 tables, 68 ref

002185   Shrivastava P;Asthana A (Ceol Dep, Govt Arts & Science College, Durg, Chhattisgarh) : Morphometric analysis of somni stream watershed, patan block, Durg district, Chhattisgarh. Ultra Scient phys Sci 2006, 18(2), 227-30.

The Somni stream watershed is drained by Somni stream and its two associate streams Pahandor and Amlidih streams. The drainage network presents dendritic pattern. The total watershed area drained by these streams is 202.18km². The general slope direction of the basin is in NE direction. The area receives average annual rainfall 101O.9mm. The quantitative morphometric analysis developed by Horton2 and Longbein are applied to evaluate characteristic linear scale dimensions of Somni 'Stream water shed. The results of morphometric analysis of the basin shows its mature surface, oval shape, coarse texture, permeable with high infiltration rate and nearly flat topography.

1 illus, 2 tables, 6 ref

002184   Shaji E;Viju B J;Thambi D S (Central Grond Water Board, , Kedaram, Thiruvananthapuram-695 004) : High fluoride in groundwater of Palghat district, Kerala. Curr Sci 2007, 92(2), 240-5.

High-fluoride groundwaters are present in the hardªrock aquifers of Palghat District, Kerala especially in the eastern part. The phreatic zone comprises weathered to partly weathered crystallines, and the deeper aquifer is formed by fractured crystallines. Both phreatic and deeper aquifers have high fluoride (F^-). In dug wells, F^- concentration ranges from 0.2 to 5.75 ppm with the highest being at Kopanur in Chittoor taluk. In the deeper aquifers the highest concentration of 3.12 ppm is observed at Chinnamoolathara. Other high fluoride concentration areas are Eruthenpathy, Anakatti and Vannamada in the district. The country rock, hornblende biotite gneiss, is identified as the source of this high fluoride for both phreatic as well as deep aquifers. Saturation indices with respect to CaF₂ were calªculated; all the samples are saturated with respect to fluorite. The water quality is analysed by the Piper diagram and the common ion noticed is Na⁺. Alkaline water depleted in calcium, longer residence time of water in the aquifer zone, and intensive irrigation are favourable factors for the dissolution of fluorine-bearing minerals in groundwater. Dental fluorosis is observed from the Chittoor tal uk. Since groundwater finds domestic use remedial measures including rainªwater harvesting are needed in the area.

4 illus, 2 tables, 13 ref

002183   Senthil Kumar G R;Arumugam M;Lawrence J F (Earth Sci Dep, Annamalai Univ, Chidambaram) : Hydro-chemical investigation of shallow water in Tittagudi taluk, Cuddalore dist, Tamil Nadu (India). Ultra Scient phys Sci 2006, 18(2), 109-116.

Now-a-days communities are conscious of the quality of water, before they consume. Every one realizes the gravity of water quality deterioratIon. Water quality studies becoming more significant. Hence, an attempt has been made to evaluate the shallow groundwater quality in post monsoon period of Tittagudi taluk, which lies between latitude 11°22' 03" to 11°36' 29" N and longitude 78° 52' 42' to 79° 18' 59" E and situated in Cuddalore district of Tamil Nadu state. Detailed hydrogeological survey was carried out and the shallow water samples were collected from the predetermined forty- four (44) locations. The water samples were analysed by using APHA (1996) standard methods. The analytical results have been processed using computer program with output results. The following thematic maps were prepared viz TDS, TH, CR, Scholler's water type, Stuyfzand water type, USSL Classification, Gibbs plot, etc. The IDS 'is less than 2500 mg/l. Total hardness range between 150-300 mg/l (hard water). In the post monsoon period half of the water samples fall in the type-III classification, which indicates the dominance of bicarbonate water in the domain. According to Stuyfzand classification (1989), the shallow ground water ofthe study area is classified into Oligohaline, fresh, F-Brackish and Brackish types. According to USSL classification the shallow water samples of the study area restricted to following classes C₂S₁, C₃S₁, C₃S₁, C₃S₂, C₄S₁, C₄S₂ and C₄S₃. Among these, C₃S₁ occupies the major part of the study area. Most of the groundwater of the study area is promising for irrigation purposes. Gibbs plot indicates, mostly the water quality is due to rock water interaction and in few location it is due to evaporation. Generally, the monsoon rainfall is found to be influencing factor for the change in water quality.

6 illus, 1 table, 7 ref

002182   Sangode S J;Mazari R K (Geology Dep, Pune Univ, Ganeshkhind, Pune-411 007, Email: sangode@rediffmail.com) : Mineral magnetic response to climate variability in the high altitude Kioto palaeolake, Spiti Valley, Northwestern Himalaya. Himalayan Geol 2007, 28(2), 1-9 .

Concentration dependent and qualitative mineral magnetic parameters are analyzed in 2300 cm thick varved lake sedimentation of the Kioto palaeolake in Spiti valley, northwestern Himalaya, at a sampling interval of 20 cm. , Empirical models based on mineral magnetic parameters indicate episodic influx of larger (> 40 micron) ferrimagnetic and -antiferromagnetic mineral grains and occurrence of smaller (0.03 to 0.06 micron) in-situ magnetite grains in a background variation of the hard ferrimagnetic oxide minerals (titanomagnetites <126>0.08 to 40 microns). The relative variations in the fundamental mineral magnetic parameters (X_1f, B_(0)CR, X_fd%, X_ARM: and S-Ratios) mainly in response to changes in catchment weathering style, detrital influx and in-situ productivity are used to indicate the variability between warm (oxidative) and cold (restricted) conditions in the overall high altitude Alpine climatic regime. The warm events in general show sharp drop in S-Ratios and B_(0)CR and enhanced X_1f, indicating increased catchment weathering. On the other hand the cold intervals are characterized by X_ARM: due to stable anoxic conditions of production of authigenic iron oxides. Significant warm events are noted at the tentative ages (based on varve counts) of <126>43,000 yr, <126>32,000 yr, <126>27,500 yr, <126>19,000 yr and <126>12,800 yr. With a detailed framework of mineral magnetic approach combined with sediment dating we can envisage quantitative information on the magnitude and intensity of glaciation-deglaciation and glacial advancement/ retreat in the tectonically modified topographic set up of the Himalaya.

6 illus, 33 ref

002181   Sadrekarimi J;Zekri A (Civil Engineering Faculty, Tabriz Univ, Iran, Email: jsadr@tabrizu.ac.ir) : Some geological and geotechnical features of Tabriz marl. Indian Geotech J 2007, 37(2), 143-4.

18 illus, 1 table, 17 ref

002180   Raiverman V (NO, , 708 Maitri Apartment, 255 NSC Bose Road, Kolkata-700 047, Email: raiverman_v@rediffmail.com) : Geothermic revolution, mountain elevation, tectonic pulsation and foreland sedimentation in the Himalayan system. Himalayan Geol 2007, 28(2), 33-44.

Sediments in the foreland basin of Western Himalaya have been studied for their possible unity with geothermal activity observed in the high mountain core. Pulsating tectonics operating in the orogenic system introduced cyclic pattern in various sedimentary properties in the foreland like grain size, mineral composition and colour, and in the transgression-regression depositional cycles. Chronology of the tectonic pulses has been ascertained by dating the pulse-generated stratigraphic units with available stratigraphic tools. Analysis of the radiometric ages of inner Himalayan crystallines reveals a cyclic pattern in their frequency distribution comparable with the cycles recorded by foreland sediments.

10 illus, 22 ref

002179   Padmavathi V;Reddy E S;Madhav M R (Civil Engineering Dep, J. N. T. U. College of Engineering, Hyderabad-500 072, Email: padmavathiv_2000@yahoo.com) : Analysis of laterally loaded rigid piles in sands based on kinematics and non-linear subgrade response. Indian Geotech J 2007, 37(3), 190-209.

16 illus, 7 tables, 30 ref

002178   Mundepi A K (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: akmundepi@wihg.res.in) : Comparative study of site amplification by using horizontal to vertical spectral ratio (Nakamura technique) to ground ambient noise (GAN) with earthquakes at various litho - units in NW Himalaya. Himalayan Geol 2007, 28(2), 69-74.

Six stations in Uttaranchal and Himachal Himalaya were deployed for regular monitoring of seismic activity of the region. The Nakamura technique (H/V ratio) was applied on the earthquake and noise data recorded at Bhatwari, Garurganga, Banikhet, Bharmour, Chhatrari and Tissa observatories, to examine differences of empirical site characteristics among coda wave of earthquakes and microtremors. Ground motion generated by moderate to small earthquakes and microtremors were used to estimate the amplification due to geological and topographical effects. It reveals that degree of compactness of the rock types and presence of sediment thickness play a significant role in site amplification. The amplification depends on the magnitude and it will be of a higher order in comparison to the microtremors.

3 illus, 2 tables, 23 ref

002177   Misra D K (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: dkmishra@wihg.res.in) : Evidence of neotectonic activity along active faults in Arunachal Himalaya, NE India. Himalayan Geol 2007, 28(2), 75-8.

Geological mapping in the Kameng and Subansiri valleys of western Arunachal Pradesh reveals the existence of five thrust bound tectonostratigraphic units. From south to north these are: 1. Siwalik Group, 2. Gondwana Group, 3. Miri Group, 4. Bomdila Group and 5. Sela Group. The Sub-Himalaya (Siwalik Group) comprises of predominantly sandstone and shale which override the Brahmaputra Alluvium along the Himalayan Frontal Thrust (HFT) and is overthrust by rocks of the Lesser Himalaya (Gondwana, Miri and Bomdila groups) along the Main Boundary Thrust (MBT). The Gondwana Group consists of mainly shale, sandstone and diamictite. It is overthrust by quartzite and carbonate association of the Miri Group along the Miri Thrust. The Miri Group is overthrust by the Bomdila Group, which consists of low to medium grade metamorphics and foliated micaceous quartzite. High grade metamorphics of the Central Crystallines (Sela Group) of Higher Himalayan Zone overlay the Bomdila Group along the Main Central Thrust (MCT). The field studies coupled with interpretation of topographic maps resulted in identification and delineation of NW-SE trending active faults. Movements along faults are responsible for abrupt rise of mountain front, occurrence of planar scarp and triangular facets, recent landslides, uplifted fluvial terraces and pounding of streams. The OSL dating of uplifted river terraces and ¹⁴C date from lacustrine deposits suggest that the faults are neotectonically active during the Late Pleistocene-Holocene time.

3 illus, 1 table, 20 ref

002176   Mazari R K (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: mazarirk@wihg.res.in ) : Outline geomorphology of the upper Bhagirathi basin, Garhwal Himalaya. Himalayan Geol 2007, 28(2), 45-57.

Uppermost part of the Bhagirathi basin in the Garhwal Higher-Trans Himalaya falls in the climatic zone that is largely of cold type. Based on form and process the constituent landforms comprise six geomorphic zones, out of which four belong to the glacial type and two to the periglacial (mountain variety) type. The Quaternary glaciated terrain is being modified by the present day cold and dry climate in conjunction with active tectonic movements of the Himalaya. A marked recession of glaciers has been observed in respect of their erstwhile confluence with the main glacier Gangotri since the Last Glacial Maximum (15, 000 yr B.P.). The post-glacial retreat is at least 12 km in the case of Chor Gad tributary glacier. In the periglacial zone, frost action, nivation and slope wash appear to be the predominant geomorphic processes responsible for modifying the present day landscape. The process of deglaciation and rapid retreat of glaciers has exposed large glacial debris to subaerial erosion. From environmental management point of view this is particularly vulnerable to downstream sedimentation especially large multipurpose reservoirs like the Tehri Dam reservoir. The situation has become even more critical with unabated human intervention in areas vacated by the glaciers in the immediate vicinity of the present area. Some preventive measures need to be undertaken if effective life span of this large reservoir is to be safeguarded for long term benefits.

4 illus, 2 tables, 28 ref

002175   Jaya V;Dodagoudar G R;Boominathan A (Civil Engineering Dep, I.I.T. Madras, Chennai-600 036, Email: jayasraj@gmail.com) : Estimation of maximum shear modulus of sand from shear wave velocity measurements by bender elements. Indian Geotech J 2007, 37(3), 159-73.

14 illus, 21 ref

002174   Hegde R A;Dodagoudar G R;Mandal J N (Civil Engineering Dep, S. P. College of Engineering, Andheri, Mumbai-400 058, Email: rahegde2002@yahoo.com) : Centrifuge modelling of contaminant transport through compacted clay liners. Indian Geotech J 2007, 37(2), 116-31.

8 illus, 6 tables, 28 ref

002173   Gupta V;Ahmed I (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: vgupta@wihg.res.in) : Geotechnical characteristics of Surabhi Resort Landslide in Mussoorie, Garhwal Himalaya, India. Himalayan Geol 2007, 28(2), 21-32.

Surabhi Resort landslide located on the Mussoorie - Kempty link road was triggered during the rains of August 1998 and is active since then. Both natural and human induced factors are responsible for the occurrence of the landslide, however, the main triggering factor was the incessant rainfall during the months of July - August 1998 along with the seepage from the upslope region. Surabhi Resort landslide is a typical debris slide and is causing serious threat to the lives and property in the region. Shear-strength characteristics of the soil in the landslide zone indicate their resistances against sliding, however, the geotechnical characteristics of the rock mass around the landslide zone is of poor class in terms of its slope stability. The movement data during 2005 suggests that area around the landslide zone is continuously subsiding at about 14 mm/yr in the crown portion and about 4 mm/yr in the left flank of the landslide and the rate of movement increases during the monsoon season i.e. during July, August and September. The study lays the foundations for further work to link landslide activity to rainfall intensity so that the stochastic relationship between the two may be established.

9 illus, 4 tables, 37 ref

002172   Gunasekaran M;Robinson R G (Civil Engineering Dep, I.I.T. Madras, Chennai-600 036, Email: gunasekaran.iitm@gmail.com) : Measurement of strains in triaxial test specimens. Indian Geotech J 2007, 37(3), 227-44.

13 illus, 2 tables, 40 ref

002171   Dewaikar D M;Varghese S P;Sawant V A;Chore H S (Civil Engineering Dep, I.I.T. Bombay, Mumbai-400 076, Email: dmde@civil.iitb.ac.in) : Non-linear 3-D FEA of laterally loaded piles incorporating no-tension behaviour of soil. Indian Geotech J 2007, 37(3), 174-89.

10 illus, 23 ref

002170   Dewaikar D M;Mohapatro B G;Sawant V A;Chore H S (Civil Engineering Dep, I.I.T. Bombay, Mumbai-400 076, Email: dmde@civil.iitb.ac.in) : Computation of Nγ for a smooth footing - hill mechanism. Indian Geotech J 2007, 37(2), 132-42.

4 illus, 2 tables, 11 ref

002169   Das L K;Naskar D C;Roy K K;Majumdar R K; Choudhury K;Srivastava S (NO, , Msarine Wing, Geol Survey of India, Kolkata-700 091) : Crustal structure in central India from gravity and magnetotelluric data. Curr Sci 2007, 92(2), 200-08.

Present gravity and magnetotelluric studies over a few selected transects in Central India show evidence of EW trending Palaeo-Proterozoic mantle activated rifting in the area contained between the Narmada North Fault (NNF) and Narmada South Fault (NSF). This rift was reactivated during the Neo-Proterozoic once again. After a great hiatus, left lateral movement along the NSF produced the NW-SE trending Gondwana basins in the Satpura horst region, along pre-existing weak zones in the crust with dehydration of mantle rocks, south NSF and associated upwarps. These are responsible for the many hot springs observed in te Tapti grabens and te Jabalpur earthquakes in the area. The last reactivation of NSF was seen in the Deccan volcanic episode.

6 illus, 1 table

002168   Chowdhury I;Dasgupta S P (Civil Engineering Dep, , Petrofac International Limited, Sharjah, UAE, Email: indrajit.chowdary@petrofac.ae) : Dynamic earth pressure on rigid unyielding walls under earthquake forces. Indian Geotech J 2007, 37(2), 81-93.

5 illus, 21 ref

002167   Chakravarty S K;Tiwari D R (Research Scholar R/o J- 181, Kotra Sultanabad, Bhopal, , , Email: satyagis@yahoo.com) : Evaluation of ground water through R.S. & GIS techniques a case study, a part of data block, dist, Datia M.P. (India). Ultra Scient phys Sci 2006, 18(2), 193-8.

Ground water is a precious natural resource of limited extent. Due to its longer residence time in ground, low level of contamination wide distribution and availability within the vicinity and reach of the consumer. ground water development gets first priority for meeting the over growing demand of water and occupies an important place both in hydrologic cycle as well as in the life cycle of mankind. A ground water development programme needs large volume of multidisciplinary data from various sources. In the present study an integrated remote sensing and GIS based technique has been adopted for Assessment of ground water in a part of Datia Block. Datia district Madhya Pradesh that suffers acute water crisis at times. IRS- m (LISS-II) data along with other data sets have been utilized to prepare the hydrogeomorphological map of the area. It is observed that area of Denudational Hill and Residual Hill have low ground water potential with high runoff which areas those of Pediment and Buried Pediment have comparatively higher groundwater potential with low runoff, which may be helpful in locating the productive well sites. Study of lineament map of the area further strengthens the fact that better well yields are expected in the areas traversed by NW-SE trending lineaments which may be responsible for large-scale migration of groundwater in the area.

8 ref

002166   Boominathan A;Sudhir K (Civil Engineering Dep, I.I.T. Madras, Chennai-600 036, Email: boomi@iitm.ac.in) : Cement column treatment of liquefaction mitigation. Indian Geotech J 2007, 37(3), 245-58.

11 illus, 3 tables, 19 ref

002165   Bhaumik A K;Gupta A K (Geol and Feophys Dep, Indian Inst of Technol, Kharagpur-721 302) : Evidence of methane release from Blake ridge ODP hole 997A during the Plio-Pleistocene: benthic foraminifer fauna and total organic carbon. Curr Sci 2007, 92(2), 192-9.

Methane is a powerful greenhouse gas and may have played a significant role in global climate change in the geological past. Destabilization of gas hydrates, frozen methane stored within the ocean floor sediment and in permafrost, may have provided an important source of methane to the atmosphere. Ocean Drilling Program Hole 997A (water depth 2770 m), situated on the crest of the Blake Outer Ridge, is a potentially large reservoir of gas hydrate. Methane emissions from the Blake Outer Ridge have been reported previously, which has been suggested as a driver for global climate change. Methane at this site is of biogenic origin, produced by the bacterial decomposition of organic matter. Uses benthic foraminifer faunal assemblages (<62>125 μ size fraction) and species diversity, combined with total organic carbon data from Hole 997 A, to identify intervals of methane releases during the late Neogene (last 5.4 Ma). Identifies a group of benthic foraminifera, which were taken to indicate methane fluxes based on previous work on seep-related benthic foraminifera. Then classified 'seep-related' benthic foraminifera, as well as high organic carbon taxa inªdependent of deep-sea oxygenation. Recognizes five intervals of increased abundance of the seep-related benthic foraminifera since last 3.6 Ma representing intervals of methane release, which coincide with intervals of lowered sea level. Changes in benthic foraminifera are more abrupt over the past 3.6 Ma when the northern hemisphere glaciation began to intensify and climate switched to a 41-kyr cycle world.

4illus

002164   Bhattacharyya R;Majumdar T J (Earth Sci and Hydrol Div, Marine and Water Resources Group, Remote Sen, , Ahmedabad-380 015, Email: tjmajumdar@sac.isro.gov.in) : Residual geoid and free-air gravity over the Indian offshore from ERS-1 high resolution altimeter data. J Indian Soc Remote Sens 2006, 34(2), 289-98.

In this study, ERS-I altimeter data over the Indian offshore have been processed for deriving marine geoid and gravity. Processing of altimeter data involves corrections for various atmospheric and oceanographic effects, stacking and averaging of repeat passes, cross-over correction, removal of deeper earth and bathymetric effects, spectral analyses and conversion of geoid into free-air gravity anomaly. Methods for generation of residual geoid and free-air gravity anomaly using high resolution ERS-I 168 day repeat altimeter data were developed. High resolution detailed geoid maps, gravity anomaly and their spectral components have been generated over the Indian offshore using ERS-1 altimeter data and ARCGIS system. A number of known megastructures over the study area have been successfully interpreted e.g. Bombay High, Saurastra platform, 90° east ridge etc. from these maps.

9 illus, 32 ref

002163   Balakumar V;Ilamparuthi K (Sol Mechanics and Foundation Engineering Div, Anna Univ, Chennai-600 025, Email: vb_kumar2002@yahoo.com) : Performance monitoring and numerical simulation of piled raft foundation of a twelve storeyd building. Indian Geotech J 2007, 37(2), 94-115.

13 illus, 2 tables, 46 ref