007968   Saha S;Ghosh A;Banerjee S;Saraswati P K; Burley S D (Earth Sciences Dep, Indian Institute of Technology Bombay, Powai, Mumbai, Email: santanu@iitb.ac.in) : Characteristics of an open coast tidal flat: example from Daman, West coast of India. J Geol Soc India 2011, 77(5), 409-18.

This study highlights lithofacies and biofacies characteristics of the open coast tidal flat near Daman on the eastern flank of Gulf of Khambhat. Sedimentological and biological observation record six facies within the tidal flat area including older beach, beach face, sand flat, mud flat/mixed flat, sand bar and beach rock. Distinct sedimentary structures, foraminiferal assemblage and bioturbation intensity characterize each facies. A wide variety of wave and current generated sedimentary features characterize the sand flat facies. Semiconsolidated sands of older beach running parallel the coastline at a level higher than the present beach face possibly records the latest sea level highstand. The beach rock reflects early cementation of sands in tropical environments. Foraminifera are widely distributed in sand flats, mixed flats and mud flats and grouped into two biofacies - Ammonia-Elphidium-Quinqueloculina biofacies (sand flat and mixed flat) and Trochammina-Miliammina biofacies (mud flats). The beach face and sand bar facies contain forminifera reworked from sand flat and mud/mixed flat. Seasonal variation in depositional style is marked by deposition of fresh mud deposited over large areas of the intertidal flat during monsoon time, most of which is washed away by waves and current actions well before the onset of the next monsoon.

9 illus, 1 table, 34 ref

007967   Roscoe K L;Wallender W W;Carlson H; Raghuwanshi N S (Land, Air and Water Resources Dep, California Davis Univ, One Shield Avenue, Davis, CA 95616, USA) : Estimation of annual spatial and volumetric precipitation in the klamath basin. J Indian Wat Resour Soc 2010, 30(2), 1-11.

Model was developed to estimate the spatial distribution and volume of annual precipitation using precipitation measurements at a single gage. The study area comprises the watershed of the Klamath River above Keno, Oregon, The model was developed by determining large-scale orographic regions in the study area using the Parameter-elevation Regression on Independent Slopes Model (PRISM). Within each orographic region. PRISM-modeled time-averaged precipitation values were used to calculate a linear average precipitation-elevation model. These average models were used to develop an annual precipitation model for all locations and for all years for which there were measurements at the Klamath precipitation gage. Modeled precipitation was compared to measured precipitation at each gage in the study area, showing that modeled precipitation in three of the four orographic regions was accurate. Average historic flow, prior to the Bureau of Reclamation Klamath Project, was estimated by correlating volumetric precipitation with flow in the Klamath River at Keno from 1930-1997 (post-project) and compared with the measured flow from 1905-1912 (pre-project). Statistical tests showed that the pre- and post-project flows were significantly different, while the pre- and post-project precipitation values were not shown to be significantly different. The average pre-project volumetric precipitation and flow at Keno were 7.63 x 10⁹ m³ and 1.73 x 10⁹ m³ respectively. This flow value is six percent lower than the value 1.85 x 10⁹ m³, obtained by Hecht and Kamman (1996). The application of Klamath Basin (KB) precipitation model in filling the gaps in data sets at all gages within the study area showed that the model estimates were good for all regions except for region 4. The methodology used here can be used to extend the precipitation records at the other stations based on the extensive data of one station.

9 illus, 7 tables, 20 ref

007966   Prabhat Kumar;Jha N;Bhattacharya D D;Pande A C (Zoology Dep, Lucknow Univ, Lucknow, Email: neerjajha@yahoo.co.uk) : Acarid mites from early permian sediments of the Chamba valley, Himachal Pradesh, India. J Palaeont Soc India 2011, 56(2), 171-9.

Acarid mites have been described for the first time from the sediments of the Manjir Formation, Chamba Valley, Himachal Pradesh, which have yielded Early Permian palynomorphs. The reported two fossil specimens are almost well preserved, weakly sclerotised astigmatid mites, having no spiracles or stigmata and trachea, hence respiration cutaneously. These minute, microscopic acarid mites are extremely important as acarid mites are currently not recorded from the Permian. These mites are 365 x 180 μm and 450x200 μm in size. Triangular gnathosoma (capitulum), 38 x 30 μm and 45x35 μm in size, is much smaller than idiosoma, narrowing towards the front side where it becomes pointed.

5 illus, 4 tables, 39 ref

007965   Pandey D K;Fursich F T;Gameil M;Ayoub-Hannaa W S (NO, Rajasthan Univ, Jaipur-302 004, Email: dhirendrap@hotmail.com) : Aspidiscus cristatus (lamarck) from the cenomanian sediments of wadi quseib, east sinai, Egypt. J Palaeont Soc India 2011, 56(1), 29-37.

Aspidiscus cristatus (Lamarck) has been described and illustrated from three coral-bearing horizons of the Cenomanian sedimentary succession of Wadi Quseib, East Sinai, Egypt. The new specimens show well-preserved internal microarchitectures, which corroborate its assignment to family. Latomeandridae Alloiteau, 1952. The stratigraphic range of Aspidiscus cristatus suggests that it can be used as index for the Middle to early Late Cenomanian. Based on the morphology of Aspidiscus cristatus and its consistent record, it is suggested here that the coral had a narrow facies range, being adapted to a free mode of life on soft, marly to argillaceous substrate, in low-energy environments subjected to high rates of sedimentation.

3 illus, 52 ref

007964   Nagendra R;Prakash T N;Jayamurugan K;Gayathri R;Reddy A N (Geology Dep, Anna Univ, Chennai-600 025, Email: geonag@annauniv.edu) : Preliminary report on benthic foraminiferal assemblage in the Ashtamudi estuary, Kerala. J Palaeont Soc India 2011, 56(2), 137-42.

Sediment samples of Ashtamudi estuary were studied for foraminiferal assemblages as no systematic records are available on the spatial distribution in the estuary. Out of 30 stations sampled, only 13 stations (A 3, A11, A14, A15, A16, A17, A19, A20, A22, A25, A26, A32 and A35) have yielded a good faunal control. Twenty-nine foraminiferal species belonging to seventeen genera have been recorded from the estuarine sediments. The spatial distribution of foraminifera analyzed by Q-mode cluster analysis has revealed four distinct biotopes. The low diversity and low frequency of foraminifera in eastern, western and southern parts of the estuary have been attributed to inhospitable microniches possibly contributed by coir husk retting activities.

2 illus, 2 tables, 6 ref

007963   Mohapatra B K;Jena S;Singh P P (NO, Institute of Minerals and Materials Technology, Bhubaneswar, Email: bkmohapatra@immt.res.in) : Microstructure-compositional variation in iron oxy-hydroxide minerals formed with manganese mineralization, eastern ghats supergroup, Orissa. J Geol Soc India 2011, 77(5), 450-8.

Large volume of iron oxy-hydroxide minerals occur in association with manganese oxide phase in manganese ores of the Eastern Ghats Supergroup, Koraput district, Orissa. On the basis of OH content, the iron mineral can be classified into hydrohematite, goethite, and hydrogoethite. These minerals exhibit eight types of microstructures such as ooloidal, caterpillar, disseminated, reniform, worm, mosaic, globular and spherulitic. Chemical composition of such micro-structures obtained through EPMA, distinguishes them into three domains, developed under different environment. Hydrohematite, having 8-10% H₂O, characteristically contains higher pc of manganese (<62>5%) and phosphorous (<62>0.6%) but have low silica and alumina. These are formed syngenetically with Mn-oxide minerals in a manganese rich paragenesis. Goethite containing 11 to 12% water, has relatively low level of manganese and phosphorous, and formed in a later period, as secondary open space filling. Hydrogoethite shows very high water content (<62> 16%), almost devoid of manganese, and impoverished in phosphorous but having higher percentage of alumina, silica and appreciable copper and nickel. This was latest to form in the zone of oxidation under supergene condition.

5 illus, 3 tables, 22 ref

007962   Mandal J;Vijaya (Birbal Sahni Institute of Palaeobotany, 53 Road Univ, Lucknow-226 007) : Palynology of the subsurface early eocene sediments of the Birbhum Coalfield, West Bengal, India. J Palaeont Soc India 2011, 56(1), 83-117.

Rich palynological assemblage from the bore-core BGG-3 in the Birbhum Coalfield cosists of 195 species belonging to 130 genera, of which 2 genera-Baksipollenites and Granutricolpites and 19-species are described as new. The new species are Cingulatisporites microreticulatus, Acanthotricolpites baculatus, Baksipollenites bengalensis, B. crassitectatus, Cryptopolyporites punctatus, Florschuetzia indica, Granutricolpites triangulatus, Grevilloideaepites karii, Hippocrateaceaedites ramanujamii, Intectocolporites baksii, Lakiapollis birbhumensis, Mauritiidites longispinosus, Proxapertites mollarpurensis, Tricolporopollis bengalensis, Verrupolyporites pachydermis, Monoporisporites banerjei, Brachysporisporites magnus, Spinosporonites angularis, S. saxenae. Beside, a new combination of Grevilloideaepites has been proposed. Floral groups within the recorded taxa are represented by pteridophytic spores (19 genera and 24 species), angiosperm pollen grains (69 genera and 104 species), fungal remains (35 genera and 61 species) and others (gymnosperm pollen, algal spore and incertae sedis) are 7 genera and 6 species. The stratigraphically significant taxa such as Incrotonipollis burdwanensis, Clavaperiporites homoclavatus, Arengapollenites spp., Spinizonocolpites thanikaimonii, Minutitricolporites minutus suggest an early Eocene (Ypresian) age for the subsurface supratrappean sediments of the Birbhum Coalfield. A comparison of the present palynoassemblage with other contemporaneous Tertiary assemblages of India reveals close similarity with floras of the Bengal, Kachchh and Cambay basins. Moreover, palaeoclimate and environment of deposition have also been discussed on the basis of palynotaxa.

2 illus, 4 tables, 94 ref

007961   Maki M;Maesaka T;Kato A;Kim D S;Iwanami K (NO, National Research Institute for Earth Science and Disaster Prevention, 3-1 Tennodai, Tsukuba, Ibaraki-305 0006, Japan, Email: maki@bosai.go.jp) : Developing a composite rainfall map based on observations from an X-band polarimetric radar network and conventional C-band radar. Indian J Radio Space Phys 2012, 41(4), 461-70.

This paper aims to demonstrate the benefits of using X-band polarimetric radar networks for hydrological monitoring. A method of deriving composite rainfall maps is presented based on data from a combination of an X-band polarimetric radar network (X-NET) and supplementary conventional C-band radar, the latter used to extend the observation area. This approach was applied to a heavy rainfall event observed on 7 October 2009 associated with typhoon T0918 (located south of Japan). It was found that a signal extinction area developed behind the band of heavy rainfall, where the scattered signal was below the receiver's noise level. Three networked X-band radars were able to fill in the signal extinction area, but the blanking azimuthal area of one of X-band radars remained. The use of C-band operational radar provides an alternative and effective approach to filling in the signal extinction area and extending the coverage area when the number of X-band polarimetric radars available is limited. Validation of the composite radar rainfall map using surface rain gauge data showed a good correlation between the two data sources, although the radar tends to underestimate rainfall amounts by around 20% compared with the rain gauges.

10 illus, 38 ref

007960   Maitra A;Adhikari A;Bhattacharya A (S K Mitra Centre for Research in Space Environment, Institute of Radio Physics and Electronics, Calcutta Univz, Kolkata-700 009, Email: animesh.maitra@gmail.com) : Some characteristics of earth-space path propagation phenomena at a tropical location. Indian J Radio Space Phys 2012, 41(4), 481-7.

Two significant propagation characteristics of Ku-band satellite signal, namely rain attenuation and depolarization have been studied over Kolkata (22°34N, 88°29'E), a tropical location. The existing Simple Attenuation Model (SAM) for rain attenuation estimation has been improved by incorporating the effective rain rate at different rain rates. The impact of rain drop size distribution (DSD) on determining the extent of depolarization at the tropical location is investigated. The lognormal distribution has been found to be more accurate than the gamma distribution to model rain drop sizes in the present case. Rain DSD varies for different types of rain, even during different phases of rain event and is found to influence the cross-polar enhancement of Ku-band signal. The annual variation of cross-polar enhancement indicates the dominance of different types of rain during different seasons of the year.

8 illus, 24 ref

007959   Kundal P;Humane S S;Humane S K (Postgraduate Geology Dep, Rashtrssant Tukadoji Maharaj Nagpur Univ, RBD Laxminarayan Campus, Law College Square, Nagpur-440 001, Email: ppk_kundal@rediffmail.com) : Calcareous algae from the miliolite formation (middle pleistocene) of DIU, Saurashtra. J Palaeont Soc India 2011, 56(2), 181-94.

Present communication records 06 nongeniculate coralline, 05 geniculate coralline, 01 halimedacean and 01 dasycladalean algal species for the first time from the Miliolite Limestone belonging to the Dhoabalia Talav and Adatiana Members of the Miliolite Formation (middle Pleistocene) of Diu and the adjacent areas, southern Saurashtra, Gujarat. The Dhobalia Talav member of the Miliolite Formation shows presence of a dasyclad Dissocladella sp., and a geniculate coralline alga Amphiroa regularis. The presence of these algal elements indicates that this member was deposited at a depth of 5-6 m below the tide level. The Adatiana Member of the Miliolite Formation shows presence of 11 coralline and 01 halimedacean algal species. These species suggest that this member was deposited at a comparatively more depth, i. e. 25 to 30 m below low-tide level.

2 illus, 42 ref

007958   Kumar S;Saxena A (Centre of Advanced Study in Geology, Lucknow Univ, Lucknow-226 007, Email: surendra100@hotmail.com ) : Chemical weathering of the Indo-Gangetic alluvium with special reference to release of fluoride in the groundwater, Unnao district, Uttar Pradesh. J Geol Soc India 2011, 77(5), 459-77.

In the central part of Indo-Gangetic alluvium in the Unnao district, Uttar Pradesh there are many pockets where groundwater shows high fluoride content. Drinking of fluorinated ground water has effected a large population and in many villages more than 80% of the population is suffering from fluorosis. The source of this fluoride appears to be the alluvial sediments deposited in the geological past as no hard rock terrain is present in the nearby areas. The area is dominantly made up of mud with pockets of sand. The sand fraction is made up of quartz, plagioclase, microcline, muscovite and biotite along with some accessory minerals like garnet, epidote, chlorite, tourmaline, hornblende, kyanite and a few opaque minerals. Moreover, the fluoride content in the groundwater varies both spatially and with depth indicating a sporadic occurrence. The surface water is devoid of high content of fluoride but is reported in hand pumps and in the dug wells. This paper deals with the geochemical study of the sediments up to a depth of 45m as most of the hand pumps are up to this depth to understand the source of fluoride. ¹⁴C dates of calcretes have suggested that the 45 m thick succession must have been formed in about 45000 years. Two different location sites were selected; one showing higher concentration of fluoride (Marksnagar village) while at other site which is about 4 km east of Marksnagar, the fluoride content was minimal (Durgajkhera village). Major elements and 24 trace elements were determined using XRF and it was found that when major elements are normalized with respect to upper continental crust (UCC) there is an enrichment of Si in all the samples. Na shows depletion where as Ti and K show enrichment. Fe and Mn show enrichment probably due to the formation of clay minerals. Si, and K enrichment is due to weathering of feldspar while Mg, Fe and K may have been released by the weathering of biotite. The CIA for the ancient sediments ranges from 54 - 64 while for the modern sediments of the Ganga River it varies from 50 - 64 indicating that there is no change in the rate of weathering in both modern and ancient sediments. The rate of weathering at all the sample locations was compared with that of UCC. The CIA values also suggest that there is an incipient weathering and indicate that the weathering of biotite is more progressive than muscovite. There is also a positive correlation between CIA values and the fluoride content in the ground water. Higher percentage of biotite and chlorite (altered biotite) was found at Marksnagar in comparison to Durgajkhera. It appears that the fluoride content in the ground water is due to dissociation/alteration of mica minerals mainly biotite.

16 illus, 5 tables, 27 ref

007957   Kotlia B S;Joshi M (Geology Dep, The Durham, Kumaun Univ, Nainital-263 002, Email: bahadur.kotlia@gmail.com) : Freshwater molluscs from the upper pleistocene sediments of the Narmada Valley, Central India: palaeoecological implications. J Palaeont Soc India 2011, 56(1), 1-15.

Carried out the invertebrate palaeontological studies between Jabalpur and Devakachar. Two sections, namely Bhedaghat section and Devakachar section, located 12 km and 120 km respectively southwest of Jabalpur and belonging to the Hirdepur Formation were studied. One fossiliferous horizon each at both the sites was found to be rich in molluscs, e.g. gastropods and bivalvia. Eighteen species of freshwater gastropods and one species of bivalvia were recovered from the two sections. Out of these, four new species of gastropods, e.g. Lymnaea theobaldi, Tricula bhatiai, Digoniostoma annandalei and Planorbis narmadaensis are reported for the first time. The bivalves are represented by Pisidium mitchelli. This is the first attempt to reconstruct the landscape structure around the environment of Homo erectus by using invertebrate fossils. The faunal assemblage appears to belong to four distinct habitats, viz., still water, riverine, open scrub and savannah woodland. Still-water habitat seems to be the major habitat in the study area.

3 illus, 3 tables, 42 ref

007956   Kishore S;Singh A P;Jauhri A K;Singh S K; Misra P K;Tiwari R P (Botany Dep, Lucknow Univ, Lucknow) : Middle eocene calcareous algae from the prang formation of the therria area, East Khasi Hills, Meghalaya, N.E. India. J Palaeont Soc India 2011, 56(2), 219-30.

Fossiliferous Prang Limestone which forms the uppermost stratigraphic unit of the Sylhet Limestone Group is widespread in the South Shillong Plateau and is well exposed in the Um Sohryngkew River section of the East Khasi Hills. The succession is characterized by a sequence of well-preserved calcareous algae and larger foraminifera. The 40m thick unit in this section belongs to Shallow Benthic Zones SB 15 - SB 18 (based on larger foraminifera) which correlate with planktic foraminifera zones PI3 and P14. The present paper reports ten species of the calcareous algae, of which eight species represent the rhodophycean group and two species belong to the chloropycean group. Out of these, the occurrence of one species, Sporolithon lauensum is noticed for the first time from India, and two species (Halimeda nana and Ovulites arabica) are first time recorded from the study area. Melobesioideae gen et. spec, indet 1, a new combination, is erected on the basis of the female carposporophytic plant. The calcareous algae dominated by coralline red algae occurs in association with the poorly represented chlorophycean algae. Associated larger foraminiferal genera are Nummulites, Assilina, Discocyclina and Alveolina. The studied succession is suggested to have been deposited in environments ranging from shallow lagoons to inner- to upper mid-shelf with fluctuating energy conditions.

3 illus, 1 table, 64 ref

007955   Kachhara R P;Jodhawat R L;Bigyapati Devi K (Geology Dep, M L Sukhadia Univ, Udaipur-313 002, Email: kachharar@yahoo.com) : Molluscan biostratigraphy of the palaeogene sediments around lakhpat, Kachchh, Gujarat, India. J Palaeont Soc India 2011, 56(1), 17-28.

The highly fossiliferous strata of Palaeogene age comprise mainly limestones and shales in the basal part, which are exposed in Lakhpat Fort (23°50'N: 68°47'E) and adjoining area. Faunally, these are very rich in foraminifers, followed by molluscs and echinoids. The present work is the first attempt to build the biostratigraphy on molluscan data. Lithostratigraphically, these strata belong to the Harudi, the Fulra Limestone Formations of middle Eocene and the Maniyara Fort Formation of the Oligocene. On the basis of molluscs, five biozones are established in addition to earlier known Coral zone. These zones are correlatable with the larger foraminiferal zones of earlier workers. The study also infers presence of upper Eocene strata in the area on the basis of molluscan evidence.

1 illus, 1 table, ref

007954   Jeet Singh K;Goswami S;Singh G (Birbal Sahni Institute of Palaeobotany, 53, Road Univ, Lucknow-226 007, Email: kamaljeet31@hotmail.com) : Palaeodiversity in the genus Glossopteris from the lower Gondwana rocks of the Korba coalfield, Chhattisgarh state, India. J Palaeont Soc India 2011, 56(1), 45-64.

The Korba Coalfield occupies the south-central part of Son-Mahanadi Master Basin and is situated in the Korba and Bilaspur districts of Chhattisgarh State. With five open cast mines (Manikpur, Kusumunda, Laxman, Dipika and Gevra) occupying over 530 sq. kms, this coalfield is the biggest coal-producing unit in India, however its megaflora has never been studied. Extensive investigations were recently conducted in this coalfield to discover fossiliferous beds in the Lower Gondwana deposits and as a result a large number of plant fossils were recovered from these collieries and their extension sites belonging to the Barakar Formation. The complete flora includes 37 taxa, representing 13 genera, which belong to three orders viz., Equisetales, Cordaitales and Glossopteridales. The order Glossopteridales is highly diversified with 33 taxa and the genus Glossopteris with 22 species dominates the flora followed by the genera Vertebraria, Sakoarota (equisetalean stems), Cordaites, Dictyopteridium, scale leaves of fertile organs, Gangamopteris, Noeggerathiopsis, Euryphyllum and Rubidgea. This is the first record for the collection of any fossil mega plants from this coalfield. Only the genus Glossopteris comprising twenty two species viz., G. intermittens, G. stenoneura, G. arberi, G. raniganjensis, G. spatulata, G. gigas, G. sastrii, G. nimishea, G. maculata, G. barakarensis, G. taenioides, G. syaldiensis, G. emarginata, G. stricta, G. communis, G. indica, G. browniana, G. pantii, G. karanpurensis, G. major, G. feistmantelii and G. euryneura and constituting 38.24% of the total plant assemblage has been systematically described and discussed in this paper, the remaining plant groups are being published elsewhere. The occurrence of Rubidgea, Euryphyllum, Noeggerathiopsis, Cordaites and Gangamopteris along with Glossopteris is indicative of the presence of Karharbari sediments (Early Permian=Lower Artinskian) in the lower part of the Barakar Formation exposed in the Gevra and Dipika collieries. The groups Lycopodiales, Sphenophyllales, Filicales, Cycadales, Ginkgoales and Coniferales are completely missing from the Korba Coalfield area. The recovered plant assemblage indicates an Early Permian age, Lower Artinskian (Early Barakar) in the case of the Gevra and Dipika collieries and Upper Artinskian (Late Barakar) for the Manikpur, Kusumunda and Laxman collieries.

6 illus, 5 tables, 78 ref

007953   Hameed A;Achyuthan H (Geology Dep, Anna Univ, Chennai-600 025, Email: hachyuthan@yahoo.com) : Benthic foraminiferal assemblages from the estuary and tidal zones along the east coast of Tamil Nadu, India: deciphering holocene sea-level change. J Palaeont Soc India 2011, 56(2), 195-200.

Author present down-core variations of foraminiferal assemblages from five shallow sediment cores retrieved from the present-day estuaries and tidal zones between Odinur and Cuddalore along the east coast of Tamilnadu, India. Down sediment core variations in foraminiferal assemblage supplemented by radiocarbon dates is used for interpreting the Holocene sea-level change. 432 subsamples were sorted under the binocular microscope. Sixty one species of the foraminiferal taxa belonging to 23 genera, 17 subfamilies, 14 families, 12 superfamiles and 4 suborders have been identified, among which ROTALIINA and MILIOLINA are predominant. Down-core variation of foraminifera with depth revealed the abundant occurrence of Ammonia beccarii, Elphidium and Quinqueloculina seminulum with varying percentage of Amphistegina radiata, and E. craticulatum in core I, II and III, indicating, high saline conditions, while in core V the occurrence of Ammobaculites agglutinans, Ammobaculites exiguus, Ammobaculites sp. and Reophax sp. indicated marsh environment with low saline and mud flat conditions. High organic matter content was observed in the sediment cores from Marakkanam and Odinur. Radiocarbon dates on shell, organic carbon at the base and intervals of the cores from Marakkanam (Core IV) and Odinur (Core V) are 8200±230, 9170±290, 5540±430 yrs BP, 2700±140 respectively. Radiocarbon dates indicate a more rapid relative sea-level rise (RSL) subsequent to 2500-3500 BP. The ¹⁴C dates indicate tidal flat sedimentation between 3475 and 3145 yrs BP. Lithounits in the tidal zone of Marakkanam and Odinur point to a local fluctuation of sea level. The terminal Pleistocene-early Holocene period was characterized by a relative low sea level, while the early Holocene period and the mid Holocene period (-9000 yrs BP and around -5000 yrs BP) were marked by high sea level. Reworking of the inner-shelf sediments as a result of the Terminal Pleistocene low sea level provided the ultimate sediment source for the progradation of the present coastline.

3 illus, 1 table, 24 ref

007952   Garg R;Prasad V;Thakur B;Singh I; Khowaja-Ateequzzaman (Geology Dep, Lucknow Univ, Lucknow-226 007, Email: rahulbsip@gmail.com) : Dinoflagellate cysts from the naredi formation, southwestern Kutch, India: implication on age and palaeoenvironment. J Palaeont Soc India 2011, 56(2), 201-18.

Lower part of the early Palaeogene deposits in the Kutch Basin, immediately overlying the Deccan Traps is generally developed as a muddy succession with lignite and rare fossils. Its age has been mostly speculative, based essentially on the age-diagnostic larger foraminiferal fauna in the carbonate horizons present several metres to tens of metres above the base. This muddy succession, named as the Naredi Formation ("Sub-Nummulitic and Gypseous Shale") has been broadly assigned an age of early Eocene or Palaeocene- early Eocene, which has been debated mainly due to the poor record of datable planktic microfossils or lack of age-diagnostic fossils with chronological significance. In the present study, dinoflagellate cyst assemblages including age-diagnostic taxa at several levels from the basal part of the Naredi Formation are recovered. Occurrence of Muratodinium fimbriatum, Heterolaucacysta granulata, Operculodinium severinii and Ginginodinium palaeocenicum in the basal part indicates an age not older than late Thanetian/Sparnacian (-55 Ma, now early Ypresian). Presence of rich Kenleyia complex including LAD of Kenleyia lophophora and K. nuda just below the Venericardia bed indicates Sparnacian/basal Ypresian age (55-54 Ma). Occurrence of Glaphyrocysta exuberans above this shell coquina also demonstrates early Ypresian age younger than -54Ma. Muratodinium fimbriatum extends up to the base of Assilina Limestone bed in the upper part of the succession. Thus, in terms of traditional European stages, the lower part of the Naredi Formation is assigned the early Ypresian age, broadly corresponding to Ilerdian, representing a time span of -55-54 Ma.

5 illus, 2 tables, 89 ref

007951   Chandrasekar V;Cifelli R (Colorado State Univ, Fort Collins-80523, USA, Email: chandra@engr.colostate.edu) : Concepts and principles of rainfall estimation from radar: multi sensor environment and data fusion. Indian J Radio Space Phys 2012, 41(4), 389-402.

Rainfall estimation has been pursued nearly since the dawn of civilization. It is also one of the most commonly used applications of modern, meteorological radars in most operational systems. Multi sensor approaches have made great strides in addressing the rainfall estimation problem through better sensor calibration and improved integration of observations at scales spanning many orders of magnitude such as radar, satellite and rain gauges. Data fusion techniques have demonstrated advantages in precipitation retrievals, especially for radar observations at attenuated frequencies. Data fusion has also shown benefits in merging data from multiple radars, as well as radars and satellites. This paper describes essential concepts of multi sensor rainfall estimation with a radar focus. Validation concepts for remote estimation of rainfall are also presented. Examples of data fusion and validation are illustrated through rainfall estimate comparisons between gauge and radar networks.

8 illus, 56 ref

007950   Chakrabarti K;Ecka N R R;Mishra B;Ramesh Babu P V;Parihar P S (NO, Atomic Minerals Directorate for Exploration and Research, Jamshedpur-831 002, Email: kchakrabartiamd@gmail.in) : Paleoproterozoic quartz-pebble conglomerate type uranium mineralisation in mankarhachua area, Angul district, Orissa. J Geol Soc India 2011, 77(5), 443-9.

Ground Radiometric survey of Paleoproterozoic pyritiferous quartz-pebble conglomerate (QPC) occurring to the north of Pallahara area led to the discovery of a QPC type uranium mineralisation near Mankarhachua village. Significant radioactivity is recorded in three sub-parallel uraniferous QPC horizons with metamorphosed pebbly to medium grained recrystallised massive sandstones. Detrital grains of uranothorite, thorite, radioactive allanite, monazite, zircon, minute uraninite grains in carbonaceous matter and thucolite contributes to the radioactive phases present in QPC matrix. Adsorbed U on limonite and goethite, secondary uranyl minerals in matrix, along bedding planes and fractures are commonly observed. This discovery has opened up a new horizon for future exploration for QPC type uranium mineralization in the area. The paper presents observations on geology, radioactivity, petrological and geochemical nature of the uraniferous QPC horizons.

6 illus, 3 tables, 9 ref

007949   Bhate J;Unnikrishnan C K;Rajeevan M (NO, National Atmospheric Research Laboratory, Gadanki, P O, Chittoor District, Andhra Pradesh-517 502, Email: jyoti@narl.gov.in) : Regional climate model simulations of the 2009 Indian summer monsoon. Indian J Radio Space Phys 2012, 41(4), 488-500.

Using a regional climate model, the 2009 Indian summer monsoon circulation and rainfall are simulated using observed sea surface temperatures as boundary conditions. For this purpose, the Weather Research and Forecasting (WRF) model (V 3.2) was used as a regional climate model. The model simulations were made for the period 1 May to 30 September with 1 May initial conditions with two domains of 45 km and 15 km and 51 vertical levels. The large scale monsoon circulation and rainfall patterns simulated by the model were examined along with the diurnal and intra-seasonal variations during the 2009 monsoon season using the TRMM 3G68 rainfall data. The results showed a wet bias in the model rainfall simulations over the Indian region with more rainfall in the model compared to the TRMM rainfall observations. This wet bias was attributed to stronger low level monsoon flow in the model simulations over the Indian region. Even though, the model simulations of atmospheric humidity are reasonably accurate, the positive bias in the low level vorticity contributed to the wet bias of rainfall over the Indian region. Model simulations showed errors in characterizing the diurnal variation of monsoon rainfall over the Indian region, especially in the observed phase angle (time of rainfall peak). The model simulations could not capture the observed early morning rainfall peak along the foothills of Himalayas caused by katabatic wind flow over the hills. Model simulations of amplitude of diurnal variation are, however, comparable with the observed amplitude derived from TRMM satellite data. Model simulations also showed encouraging results in simulating the intra-seasonal rainfall variations over the central Indian region and the monsoon onset phase over the Kerala coast.

9 illus, 35 ref

007948   Bera S K;Basumatary S K;Nautiyal C M;Dixit S; Mao A A;Gogoi R (NO, Birbal Sahni Institute of Palaeobotany, Lucknow-226 007, Email: skbera_2000@yahoo.com) : Late holocene climate and vegetation change in the dzuko valley, North East India. J Palaeont Soc India 2011, 56(2), 143-8.

Pollen analysis of the ten moss cushion samples as well as one 1.3 meter deep sedimentary profile from the Dzuko valley has revealed the short term vegetation and climatic alterations in the region for the last 1600 years. The pollen study of the sedimentary profile has revealed three palynozones since 1600 yrs BP. An open land vegetation consisting largely of pollen from dwarf bamboo (Sinarundinaria rolloana) along with Primula, Anemone and Rubus interspersed with scattered cool-loving arboreals like Magnolia, Symplocos, Ilex, Carya, Lauraceae and Rhododendron, used to grow in the vicinity of the study area during 1600 yrs BP under cool and humid climate, similar to the prevailing present-day temperate conditions. The vegetation turned out to be comparatively warmer during 980 yrs BP as evidenced by the appearance of mixed tropical-subtropical plant assemblage, namely Emblica, Sapotaceae, Elaeocarpus, Meliaceae, Lagerstroemia, Ericaceae and Oleaceae. However, from 450 yrs BP onwards, a combination of Poaceae-Bambusoideae pollen as well as broad-leaved arboreals, especially Quercus, Elaeocarpus and Combretaceae along with highland conifers have appeared, indicating increased warm and humid conditions followed by a slightly drier conditions at the upper column due to increased values of Ephedra and Artemisia.

4 illus, 1 table, 8 ref

007947   Anil Kumar;Singh H;Verma S (Soil and Water Conservation Engineering Dep, College of Technology, G.B. Pant Agriculture and Technology Univ, Pantnagar-263 145) : Predicting outflow from a mountainous watershed using linear reservoir routing concept. J Indian Wat Resour Soc 2010, 30(2), 27-32.

Rainfall-runoff transformation on watershed scale is a complex process showing nonlinear relationships between various hydrologic components. A simplified approach with reasonably accurate simulations has assumed it to be a time invariant and black-box system exposed to a single lumped input and producing a single lumped output. Consequently, the linear models have received considerable attention for modeling the rainfall-runoff process due to reasonably accurate simulations. This study was undertaken to predict the direct runoff based on the conceptual linear reservoir routing approach having a single parameter (storage coefficient) for the Gagas sub-watershed of Ramganga river catchement in Uttarakhand, India. The proposed model simulates with reasonably good accuracy the outflow from the hilly watershed to facilitate planning and design of various soil and water conservation and irrigation and drainage structures in mountainous areas with limited hydrological data. A simple routing equation has been proposed to derive the instantaneous unit hydrograph, which can be used to produce the unit hydrograph and the direct runoff hydrograph by using the convolution integral.

4 illus, 2 tables, 12 ref

007946   Amar Jyothi K;Rao T N (NO, National Atmospheric Research Laboratory, Gadanki, P O Chittoor District, Andhra Pradesh-517 502, Email: amar56kaj@gmail.com) : Variability of raindrop size distribution and its impact on polarimetric rain rate estimators. Indian J Radio Space Phys 2012, 41(4), 471-80.

Four years of raindrop size distribution (DSD) by Joss-Waldvogel (JW) Disdrometer measurements made at Gadanki (13.5°N, 79.2°E) have been used to derive relations for rainfall estimation from polarimetric radar variables. The polarimetric variables are estimated in X-band (at 9.368 GHz, the chosen frequency for the radar being developed at Gadanki) from the observed DSD measurements and scattering amplitudes derived using T-matrix scattering simulations. Three rainfall estimators, namely R-Z, R-K_DP and R-(Z_H, Z_DR), are derived for both stratiform and convective types of rain. Also, following the earlier reports, which highlighted the large variability of DSD between the seasons, the above relations are derived for three seasons (pre-monsoon, southwest monsoon and northeast monsoon). The scatter plots of R and Z show large scatter around the regression fits, even after separating the data into different seasons and types of rain, indicating the large and complex variability of DSD. Among all the relations, R-Z relation depends heavily on the DSD with its coefficients vary significantly between the seasons and types of rain. The other two relations show weak dependency on DSD, however, the coefficients are found to be distinctly different from those reported elsewhere. Both qualitative and quantitative evaluation analyses on a case study reveal that R-(Z_H Z_DR) relation provides better R among the three relations.

6 illus, 6 tables, 36 ref

007945   Agrawal N;Verma M K;Tripathi M P (NO, , PFDC IGKV, Raipur, Chhattisgarh) : Development of effective management plan for critical areas of chhokranala watershed using swat model and GIS. J Indian Wat Resour Soc 2010, 30(2), 12-26.

Distributed parameter model, the Soil and Water Assessment Tool (SWAT) was tested on monthly and seasonal basis and used for developing management scenarios for the critical sub-watersheds of a small agricultural watershed of Chhattisgarh (Chhokranala). The watershed and sub-watershed boundaries, drainage networks, slope and soil texture maps were generated using GIS. Supervised classification method was adopted for land use/cover classification from satellite imagery using ERDAS Imagine. Manning's 'n 'for overland and channel flow and Fraction of Field Capacity (FFC) were calibrated for monsoon season of the years 2002 to 2003. The model was validated for the years 2004 to 2005. Results revealed that the model was predicting the monthly arid seasonal surface runoff and sediment yield satisfactorily. Simulation results of nutrients including organic N' and P in sediment and NO₃-N and soluble P in runoff were also compared with observed data for several events and found satisfactory. The critical sub-watersheds were identified on the basis of average annual sediment yield and nutrient losses during the study period. Out of seven sub-watersheds, SWS-5, SWS-6 and SWS-7 were found to be critical. Several combinations of treatment options were considered which included four crops, five tillage and three levels of fertilizer. The existing management practice was considered as the base for evaluating other management practices for rice. The results showed other crops couldn 't replace rice since these crops resulted in higher sediment yield as compared to rice. Considering both sediment and nutrient losses together the zero tillage, conservation tillage and field cultivator with half dose of fertilizer (40:30 of N:P kg/ha) were found to be better than the other treatments considered for evaluating their impact on sediment yield and nutrient losses for sub-watershed (SWS-S).

12 illus, 12 tables, 29 ref

006859   Xing L;Yunxuan Z;Lianpeng Z;Runyuan K (School of Geodesy and Geomatics, Xuzhou Normal Univ, Xuzhou 221116, China, Email: li_xing99@yahoo.com.cn) : Evaluating longshore sediment transport rates by integration of beach evolution model and GIS approach. Indian J Geomar Sci 2012, 41(1), 12-8.

New integration approach of beach evolution model and Geographical Information System (GIS) is developed to evaluate the longshore sediment transport rates. Nanhui Beach of Shanghai is selected as study area to demonstrate an integration scheme. Study area is partitioned into some calculation units. It is further and modified one-line model to meet complex physical settings of the study area. Firstly, we got the 0-m isobaths, as the beach evolution indicator. It is developed by digitizing the nautical charts of 1990 and 2004. Shoreline change rates were derived from End Point Rate (EPR) method based on GIS. Bathymetry was digitized from the nautical charts to calculate the beach evolution complexity factor in the modified one-line model. The closure depth can be obtained from the published literatures about the study area. Longshore sediment transport rate of every calculation unit was calculated by inversion of the modified one-line model. Results show that integration scheme is effective and the precision is high. Total relative error is 8.77%.

5 illus, 28 ref

006858   Sensarma S (Centre of Advanced Study in Geology, Lucknow Univ, Lucknow-226 007, Email: sensarma2009@gmail.com) : Geodynamic processes at the Neoarchaean-Palaeoproterozoic transition in the Bastar Craton: insight from the Dongargarh volcanic-sedimentary sequence. Indian J Geosci 2011, 65(2), 89-96.

Records of Neoarchaean-Palaeoproterozoic (A-P) geodynamic processes in the Bastar Craton in central India as preserved in the Dongargarh volcano-sedimentary sequence are discussed. This work is a synthesis of available results to bring out a regional picture. Integration of stratigraphic and structural investigations, geochemistry and petrological studies of near-coeval silicic and mafic volcanic rocks and sedimentary research imply that large-scale crust-mantle interactions in a magma-rich extensional regime within the continent were responsible for the evolution of the Dongargarh volcanism and sedimentation. Anorogenic processes in the Bastar Craton at or near the A-P transition were related to a global tectonic regime, of which Dongargarh succession is one but typical expression.

3 illus, 1 table, 55 ref

006857   Sarangi R K (Marine and Earth Sciences Group, Remote Sensing Applications Area, Space Applications Center (ISRO), Ahmedabad, Email: sarangi@sac.isro.gov.in) : Impact of cyclones on the Bay of Bengal chlorophyll variability using remote sensing satellites. Indian J Geomar Sci 2011, 40(6), 794-801.

Impact of three different cyclones on the Bay of Bengal water and its surface chlorophyll concentration has been studied in three different zones during October-December 2000 using 24 scenes of IRS-P4 Ocean Color Monitor (OCM). The chlorophyll concentration found to be increasing up to 5.0 mg/m³ with effect of cyclones and hurricanes. The data has been correlated with Sea Surface Temperature (SST) and wind speed from NOAA-Pathfinder-5 and Quickscat scatterometer, respectively. There has been observation of 2-3°C decrease in SST with movement of cyclone. The wind speed has peaked up to 10-15 m/sec in the cyclonic zones.

5 illus, 3 tables, 20 ref

006856   Pande P (Policy Support System, Central Headquarters, Geological Survey of India, 27, J.L. Nehru Road, Kolkata-700 016, Email: prabhaspande@hotmail.com) : 16 june 1819 Kachchh earthquake, Gujarat, India and its isoseismals. Indian J Geosci 2011, 65(2), 97-106.

The intraplate region of Kachchh Rift Basin (KRB) is considered one of the most active seismotectonic domains, where earthquakes in excess of magnitude 7 have repeatedly occurred during the Holocene time. The IMD Earthquake Record lists 28 seismic events of M <62> 5 in the KRB since 1668, with release of seismic energy at the rate of 7.31 x 1020 ergs/year, which is quite comparable with some of the hyperactive seismotectonic units of the Himalaya. The KRB is capable of withholding large strains, particularly at deeper crustal levels, thereby making it a domain of low seismicity recurrence rate at high energy level, unlike the plate margins. This characteristic makes it distinct from the other peninsular rift zones, like that of the Cambay, SONATA, Godawari and Mahanadi, which have, so far, not produced earthquakes of M <62> 7. Thus, the E-W-trending KRB, occupying an area of 45,000 sq km and having length and breadth extensions 300km and 120km, respectively, constitutes a zone of maximum seismic hazard in the peninsula, where the recorded human fatalities exceed 16,000 and injuries over 200,000 in the last two centuries in a region of very low population density. The 1819 Kachchh earthquake occurred much before the practice of assessment of seismic intensities evolved. However, the records of the event provide vivid descriptions of the calamity, which have been used to assign MSK-64 intensities at 56 localities and draw the isoseismals.

6 illus, 1 table, 15 ref

006855   Nandy S;Bandyopadhyay S (Geography Dep, Calcutta Univ, Kolkata-700 019, Email: sunando@live.com) : Trend of sea level change in the Hugli estuary, India. Indian J Geomar Sci 2011, 40(6), 802-12.

Trends of annual sea level records of four tidal observatories of the Hugli estuary-Sagar, Gangra, Haldia, and Diamond Harbour-are analysed from thejecords of Permanent Service for Mean Sea Level (PSMSL). The rates of sea level changes for the stations are found to be -3.82, +0.89, +2.43 and +4.85 mm yr^-1 respectively, connoting a significant positive relation between landward distances of the stations and the rates of sea level rise. This seems to be mainly controlled by disequilibrium in the morphological state of the landward-narrowing estuary with some contribution from sediment autocompaction. Sea level trends of the Hugli have no apparent relation with erosion and accretion of its tidal islands.

5 illus, 4 tables, 53 ref

006854   Mukherjee K;Chowdhury S N;Prasad K; Chakrabarty G K (Central Geophysics Div, Geological Survey of India, 27, J.L. Nehru Road, Kolkata-700 016, Email: sumitchowdhuri@rocketmail.com) : Delineation of magnetic ore bodies around village Manjos, Jamui, Bihar. Indian J Geosci 2011, 65(2), 151-8.

Magnetic (VF) survey was carried out around Manjos (24°57'35"N: 86°06'20"E) village, district Jamui, Bihar to delineate the disposition of banded magnetite quartzite (BMQ) in mica schist and quartzite rocks. The area of investigation is bounded by the geographic co-ordinates 24°55'58" N - 24°58'02" N and 86°05'21" E - 86°09'36" E. Magnetic survey brought out two major magnetic lineaments showing bipolar nature, one trending NW- SE (Zone 1) and the other NE-SW (Zone 2). The latter occurs towards northwest of the former. The vertical derivative map prepared from this data depicts the extent of the BMQ zone. Further the magnetic source has delineated bipolar scanty anomaly southwest of the mineralised area (Zone 3), showing the presence of isolated magnetite bodies in the subsurface. The magnetic data is processed using Geosoft software to estimate the source location and depth of geological source of the anomaly. It is inferred from 2-D and 3-D modelling, that the strike length of the magnetic body is 1432m and it lies at a depth of 9.5m to 152m below the surface. The thickness estimated along the strike of the magnetic body (NW-SE) is a few metres in the northwestern extremity, attains a maximum of 300m due southeast and thereafter, it is thinned out further southeast. Similarly, across the strike (NE-SW), the causative body appears to pinch out laterally attaining a maximum thickness of 300m in the central part of the traverse.

7 illus, 6 ref

006853   Maurya U K;Vittal K P R (NO, National Institute of Abiotic Stress Management, Malegaon, Baramati-413 115, Email: uk_maurya63@yahoo.co.in) : Geological and mineralogical formations on various abiotic edaphic stresses at Malegaon, Baramati, Maharashtra. Clay Res 2011, 30(1), 61-71.

Field studies were conducted using Bore Logs and sample pits at different morphological features and elevations at NIAM Site, Malegaon, Baramati to understand the nature and alteration effects in different flows/rocks, nature of hydrothermal/secondary mineral crystallization, type of soils/paleosols formed and nature and extent of degradation for evaluating the possible role of edaphic stresses on agriculture in view of climate change effecting various soil process. Study indicated that due to average rainfall of 560 mm, the atmospheric drought will be a common experience. It was also observed that with impending increase in atmospheric temperatures due to climatic change, the rich calcium zeolites and calcite will weather faster and may accumulate on surface after sodium leaching which may lead to increased runoff due to soil sealing/capping, thereby inhibits the plant phonological expression leading to desertification process. In the extreme eventuality of above process of separation of Ca and Na ions due to alteration of intensive leaching by reduced number of rainy days under retained average rainfall and high temperature due to climate change there may be a possibility of calcic and nitric horizons underlain within a profile leading to extreme degradation.

006852   Madhu N V;Reny P D;Paul M;Ullas N;Resmi P (CSIR-National Institute of Oceanography, Regional Centre, Kochi-682 018, Email: nmadhu@nio.org) : Occurrence of red tide caused by Karenia mikimotoi (toxic dinoflagellate) in the Southwest coast of India. Indian J Geomar Sci 2011, 40(6), 821-5.

Intense brownish discoloration was observed in the surface waters of Cochin barmouth on 21st October 2009, which found to extend a few kilometers in the coastal waters. Continuous monitoring was carried out in the region for a period of 5 days (21st to 25th October 2009) and generated data on changes in water quality and phytoplankton community associated with the bloom. Relatively high level of inorganic nutrients (ammonia 0.5-9.7 μM, nitrate 1.3-2.9 μM, phosphate 1-2.3 μM, silicate 23.5-39.9 μM) and chlorophyll a (av. 56.8 ± 23.7 mg m^-3) concentration were observed during the bloom period. Microscopic analysis revealed that the discoloration was caused by an unarmored toxic dinoflagellate, Karenia mikimotoi Miyake & Kominami ex Oda (Karenia, Gymnodiniaceae) belongs to Gymnodiniales, which cause massive fish mortality by releasing hemolytic compounds.

2 illus, 2 tables, 19 ref

006851   Khan P K;Biswas B;Samdarshi P;Prasad R (Applied Geophysics Dep, Indian School of Mines, Dhanbad-826 004, Email: pkkhan_india@yahoo.com) : Seismicity and coda-Q variation in the eastern Indian shield region. Indian J Geosci 2011, 65(2), 131-8.

The study area is located between latitudes 22.5° and 26°N and longitudes 85° and 88.3°E, and consists of composite batholithic complex of eastern Indian Shield. Several hot springs, shear zones, lineaments, faults, and numerous small hills have characterised the strange tectonic setting of the area. During 2007-08, 160-local-earthquake events recorded by broadband instrument at Indian School of Mines, Dhanbad, India were analysed for studying the seismicity of the region. The region mainly documents small magnitude (Mw) earthquakes predominantly confined between 1.0 and 2.0. Earthquakes with Mw>2.0 are not rare, and even few with Mw>4.0 also occur occasionally. Coda Q was analysed based on single back-scattering model using seismograms filtered at frequency bands 1-5, 5-10, and 10-15 Hz for 20 events with less than 250-km epicentral distance and magnitude 1.7 - 4.2 first time for the eastern Indian Shield region. Very low coda Q estimated at all frequencies probably indicates higher heterogeneity or concentrated deformation in the eastern Indian Shield. Comparatively lower coda Q at higher frequency is apparently associated with higher Ijeat-source zones. Several hot springs lying in the region presumably account for higher thermal regime and invariably support the ductile strain localisation along shear zones that allows reactivation of fractures and possibly triggers small magnitude earthquakes through brittle failure of rocks.

7 illus, 37 ref

006850   Jodhawat R L;Kachhara R P;Bigyapati Devi K (Geology Dep, M.L. Sukhadia Univ, Udaipur-313 002, Email: jainrl88@yahoo.com) : Bivalves from upper oligocene strata of Waior, Kachchh, Gujarat. Indian J Geosci 2011, 65(2), 139-50.

Detailed account of bivalves of marine strata of Upper Oligocene time i.e. Chattian Stage (= Waiorian Stage) is presented. Outcrops of the rocks are confined to smaller areas like north-northeast of Waior village and southeast of Bermoti village in Kachchh. The overall lithology consists of greyish to yellowish limestone, calcareous sandstone, claystone and ferruginous sandstone. Fossil-yielding beds are greyish to yellowish interbedded calcareous sandstones and sandy limestones, greyish to yellowish argillaceous limestone (highly fossiliferous) and hard, grey to yellowish sandy limestone with marlite in chronological order. In all, 311 specimens of bivalves are collected mainly from the beds around Waior. These represent 46 taxa of which 14 are common with Rupelian Stage (= Ramanian Stage) of Lower Oligocene, 6 are long ranging continuing from Eocene and 26 are exclusively restricted to Upper Oligocene. Among these 26 taxa, 14 are dealt here briefly including:new species Glycemeris waiorensis and Semele sp. nov. The remaining 12 have been left out due to their indeterminable status.

2 tables, 45 ref

006849   Jebamalar A S;Abraham Thambi Raja S;Jeslin Sunitha Bai S (P G Physics Dep, Women's Christian College, Nagercoil-629 001, Kanyakumari District, Email: malar_jaslin@yahoo.com) : Prediction of annual and seasonal soil temperature variation using artificial neural network. Indian J Radio Space Phys 2012, 41(1), 48-57.

Back propagation algorithm, an artificial neural network (ANN) training algorithm, is a widely applied mathematical implementation for spatial monitoring and is used in the present study for the analysis and prediction of soil temperature. The soil temperature data at 10 and 20 cm soil depths were collected from the Agricultural College and Research Institute, Killikulam, Tuticorin District of Tamil Nadu. The observed values during the year 2004 at 10 and 20 cm soil depths were plotted to understand the annual and seasonal behaviour of the temperature wave. The wave characteristics such as range of soil temperature and rate of change of temperature/week were estimated and tabulated. Data for 1993 - 1997 (5 years) and 1993 - 2002 (10 years) were separately used as inputs for the prediction of soil temperature in 2004 using ANN. The predicted values were compared with the observed values and statistically validated. The characteristics of predicted annual and seasonal wave were also compared with observed values. It was found that the predicted values of annual wave fitted well with observed ones with little variation for the seasonal waves. The range of soil temperature for predicted values coincided almost with the observed ones with regard to the annual and the seasonal waves for both 10 and 20 cm soil depths. The rate of change of temperature/week of the predicted values coincided well with the observed ones for 10 cm soil depth. For 20 cm soil depth, the predicted values deviated from the observed ones for the winter season while the annual and pre-monsoon seasonal waves coincided well with the observed values. The surface temperature was also predicted independently from 10 and 20 cm soil temperature and error validation was done. From these, it may be convincingly stated that the ANN can be used as a good mathematical model for the prediction of soil temperature.

11 illus, 9 tables, 30 ref

006848   Deshkar S;Lakhmapurkar J;Gavali D (NO, Gujarat Ecology Scociety, 3rd Floor, Synergy House, Subhanpura, Vadodara, Gujarat, Email: sdeshkar.101@gmail.com) : State of three estuaries of Gulf of Khambhat. Indian J Geomar Sci 2012, 41(1), 70-5.

Study deals with the physico-chemical parameters in three main estuaries of Gulf of Khambhat (The Narmada, Mahi and Sabarmati). Parameters like the Dissolved Oxygen, Biological oxygen demand, Salinity, all major nutrients and Petroleum Hydrocarbons have been studied in detail. Comparison between the three estuaries for the nutrient load is discussed in; detail. One-way ANOVA suggests the significant difference between the three estuaries which are discussed in detail. The correlation between Various parameters is also discussed. It is concluded from the present study that out of the three estuaries Sabarmati estuary is having high and Narmada estuary is least nutrient load.

2 illus, 5 tables, 13 ref

006847   Banerjee A;Malhotra G (State Unit: Jharkhand, Eastern Region, Geological Survey of India, 433A, Road no. 5, Ashoknagar, Ranchi-834 002, Email: apurbageol@yahoo.co.uk) : Lithofacies association, petrography and geochemistry of Kankwarhi formation, Alwar area, Delhi supergroup: implication for detailed lithostratigraphy and basin tectonics. Indian J Geosci 2011, 65(2), 159-70.

The Alwar Basin in northeast of Rajasthan comprises a thick succession of Mesoproterozoic rocks of the Kankwarhi Formation which provides an opportunity to study syndepositional tectonism, volcanism, depositional cycle and palaeoenvironment. The study of lithofacies association, petrography and geochemistry of the rocks of Kankwarhi Formation builds up a detail record of evolution of sedimentary basin through geologic time. In the present study, the Kankwarhi Formation has been subdivided into four members/lithofacies association, and each member/lithofacies is represented by distinct metre-scale volcano-sedimentary succession. The occurrence of three intersequence metavolcanic bands with metasediments indicates prolonged denudational processes leading to the deposition of quartzite as well as subsequent deepening and sagging of the basin which resulted in rupturing of the crust through which magma oozed out. Hence, the geological record bears evidence of repetitive sedimentation and magmatism within extensional basin. Geochemically Kankwarhi rocks are rich in SiO₂, A1₂O₃, K₂O, Rb, Zr, Ba and poor in MgO, and CaO (except calc-biotite quartzite). The various bilinear plots between major and trace elements suggest sporadic and localised detrital influx into the basin. The lithofacies, microfacies, metre-scale volcano-sedimentary cycle and chemical signatures of the Kankwarhi Formation advocate that the sediments were probably deposited in sagged-type intracratonic basin influenced by syndepositional tectonic activity.

4 illus, 3 tables, 27 ref

005699   Thirumalai K;Singh A;Ramesh R (NO, Jackson School of Geosciences, UT Austin, TX-78713, USA, Email: kaustubh@mail.utexas.edu) : MATLAB<. J Geol Soc India 2011, 77(4), 377-80.

MATLAB^TM is a powerful, easy to use, software package suitable for many mathematical operations, which finds plenty of scientific applications. One such application is the fitting of trend lines for a given data set so as to interpret the relationship of the variance of the parameters involved. We provide here a code in MATLAB^TM that performs the weighted linear regression with (correlated or uncorrelated) errors in bivariate data which can handle 'force-fit' regression as well.

1 illus, 3 tables, 7 ref

005698   Thakur G S;Thomas T (Applied Geology Dep, Dr.H.S. Gaur Univ, Sagar-470 003, Email: gsthakur_76@hotmail.com) : Analysis of groundwater levels for detection of trend in Sagar district, Madhya Pradesh. J Geol Soc India 2011, 77(4), 303-8.

Groundwater being an important component of the hydrological cycle as it sustains the streamflow during precipitation free periods and is a major source of water supply. The dependence on the groundwater has increased drastically over the years leading to over exploitation of the aquifers. Therefore, it is imperative to assess the extent of exploitation and analyse the groundwater level scenarios in the area of interest. The existence of a trend in a hydrological time series can be detected by statistical tests. The present study investigates the application of various methods for identification of trends in groundwater levels in few blocks of Sagar district, which faces severe water scarcity owing to the declining groundwater levels. The non-parametric Kendal rank correlation test as well as the parametric linear regression test has been used for trend detection based on the analysis of the seasonal groundwater levels. Kendal's rank correlation test, has been applied to identify the trend persisting in the data and the linear regression test is used to identify the significance of the slope. The analysis indicates that the time series of groundwater levels are cyclical with characteristics of seasonal variation in all the blocks coupled with a declining trend at Sagar, Khurai and Bina.

5 illus, 5 tables, 7 ref

005697   Srivastava K;Dimri V P;Swaroopa Rani V; Krishna Kumar R;Narain L (NO, CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad-500 007, Email: kirti@ngri.res.in) : Would makran tsunami skip Mumbai, India? No it would reach 8 minutes later than Ratnagiri. Indian J Geomar Sci 2011, 40(5), 620-3.

Tsunami from Makran subduction zone in the northern Arabian sea are seen to arrive at Ratnagiri (16°56'24.00"N, 72°40'12.00"E) along the west coast of India 8 minutes earlier than Mumbai (18°59'24.00"N,71°52'12.00"E) in spite Ratnagiri being 244 km down south of Mumbai. This can give rise to a false signal and could be interpreted as tsunami skipped Mumbai and is traveling towards south. However, this advance information at Ratnagiri could be used for quick evacuation of densely populated coastal areas of Mumbai. Reasons for later arrival of tsunami at Mumbai is mainly due to a wide shelf of greater than 250 km whilst at Ratnagiri the shelf suddenly becomes half that of Mumbai. The importance of shelf width along the west coast of India which plays a great role in the arrival of the tsunami waves and the wave heights at different locations are conferred in the present study.

3 illus, 16 ref

005696   Singh R K (Geology Dep, Govt. Science College, Rewa, C-6/142 Second Floor, Sector-5 Rohini, Delhi-110 085, Email: rajneesh.singh08@gmail.com) : EPR study of yellow and colourless fluorite from carbonatite rocks of Ambadongar, Gujarat. J Geol Soc India 2011, 77(4), 381-4.

Hyperfine structure in EPR spectra of yellow fluorite is a result of presence of paramagnetic substance which caused absorption and production of colour. Carbonatite rocks of Ambadongar are well known to have a number of trace elements and REEs in them. During crystallisation of fluorites these trace elements may replace Ca⁺² in fluorites crystal. They may also incorporate as defects sites and caused for energy absorption and consequently production of colours in fluorites. An electron microprobe analysis of certain sites of crystal is necessary to know about specific elements producing colours at that site.

4 illus, 11 ref

005695   Singh L N;Babu Lal;Singh S L;Mukherjee A K (NO, Geological Survey of India, Western Region, Jaipur-302 004, Email: lns_gsi@yahoo.com) : Role of geophysical surveys in seismic hazard management, Bhachau area, Gujarat. Indian J Geosci 2011, 65(1), 57-64.

Devastating earthquake (Mw 7.7) rocked the Kutch district of Gujarat, western India at 08:46:43 1ST on 26 January 2001. Shallow seismic refraction (hammer source), gravity and magnetic surveys were carried out by Geological Survey of India in Bhachau area, Kutch district, Gujarat after the earthquake to delineate the different subsurface lithological units. Seismic survey carried out over 6 locations in township areas of Bhachau has reflected two-layered structure. The P-wave velocity in the area varies from 690m/s to 921m/s for the upper layer while the velocity in the lower layer varies from 1567m/s to 2083 m/s. The upper layer corresponds to the top soil/overburden and the lower layer having higher P-wave velocity may correspond to relatively compact soil or weathered/fractured rock. Gravity and magnetic survey along a transect reflects deepening of the basement from north to south extending towards Gulf of Kutch through Kutch Mainland Fault (KMF). Spectral analyses of both gravity and magnetic fields have shown two interfaces at average depths of 0.80 km and 2.5 km. We have correlated these seismic, gravity and magnetic results with those of six vertical boreholes drilled at 30-40 m depth to understand the properties of the top soil / overburden. The drilling results have excellent corroboration with the results obtained by seismic refraction survey. This lends additional credence to geophysical results obtained in the area. Based on the results of seismic survey, it is suggested that the foundation of building structures in the earthquake-affected areas may be laid in the compact soil/weathered rock. The geophysical surveys in and around Bhachau town have been helpful for social development programme in the area.

4 illus, 29 ref

005694   Shekhawat M S;Prabhulingaiah G (Geology Dep, M.L. Sukhadia Univ, Udaipur-313 001, Email: shekhawatgeol@yahoo.com) : Production of gypsum from SMS-grade limestone rejects of Jaisalmer area, Rajasthan, India and its economic significance. Indian J Geosci 2011, 65(3), 235-40.

India's superior SMS-grade limestone deposit belonging to the Tertiary period is being mined and processed for sizing in Jaisalmer area of western Rajasthan. During the process of sizing through crushing plant, more than 50% of the resource is generated as under-size reject which is disposed of in worked-out pits for reclamation. To utilise this under-size valuable resource, experimental work was carried out that revealed fairly high grade gypsum can be synthesised successfully by simple chemical treatment of the rejected limestone slurry with dilute sulphuric acid at NTP. Synthetic gypsum matches with natural gypsum as evidenced by chemical composition, physical properties and XRD data. Gypsum resource assessment indicates that synthetic gypsum, if produced, will help to meet future industrial requirements of the country and earn foreign exchange. It will also help conservation of deep-seated natural gypsum.

3 illus, 2 tables, 14 ref

005693   Sengupta P;Ray J (Geology Dep, Calcutta Univ, 35 Ballygunge Circular Road, Kolkata-700 019, Email: jsray65@hotmail.com) : Petrology of the Mafic Sill of Narshingpur-Lakhnadon section, Eastern Deccan volcanic province. J Geol Soc India 2011, 77(4), 309-27.

Deccan volcanism with a tremendous burst of volcanic activity marks a unique episode in Indian geological history and covers nearly two third of Peninsular India. Occurrences of mafic sill in the continental basalts are rather rare throughout the flood basalt provinces and only few sporadic reports have been described from different Continental Flood Basalts of the world. Petrology of mafic sill from the Narshingpur-Lakhnadon section of Eastern Deccan province of India has been presented. The mafic sill in the field is found to occur in a relatively deep valley amidst Gondwana rocks, which occur as the basement of the extrusion. The sill is spatially associated with three initial flows viz. flow I, II and III of adjacent Narshingpur-Harrai-Amarwara section. The sill in its central part is a medium grained rock and petrographically corresponds to dolerite containing augite, plagioclase and rare olivine grains; the chilled facies of the sill is characterized by phenocrysts of olivine, plagioclase and augite that are set in groundmass consisting predominantly of plagioclase, olivine and glass. Mineral chemistry indicates that olivine phenocrystal phase is magnesian (Fo₆₁). Plagioclase phenocrystal composition ranges from An ₅₁ to An ₇₁ whereas the same variation of the groundmass plagioclase composition corresponds to An ₃₁ to An ₆₂ The overlap in the compositions for groundmass and phenocrystal plagioclase may be explained due to fluctuating P_H2O condition. The pyroxene compositions (both groundmass and phenocryst) in majority of the cases are clubbed well within the augite field, however, in a few cases, groundmass compositions are found to fall in the sub-calcic augite and pigeonite field. Some zoned pyroxene phenocrystf, characteristically display different types of zoning patterns. Opaque minerals in the mafic sill are found to be magnetite and ilmenite and this coexisting iron-oxide composition helps to constrain the prevalent fO₂ condition in the parent magma. The geochemistry of the mafic sill and associated basaltic lava flows indicates close genetic link amongst them. Critical consideration of trace elements indicates a distinct enriched mantle source (EM-I/EM-II/HIMU) for the parental magma. Trace element modeling indicates that equilibrium batch- melting of plume source followed by fractionation of olivine, clinopyroxene and plagioclase and subsequent heterogeneous mixing of melt and settled crystals can very well explain the genesis of the mafic sill and the associated basaltic flows.

13 illus, 10 tables, 58 ref

005692   Saha P;Saha B K;Hazra S;Sinha Roy S (School of Oceanographic Studies, Jadavpur Univ, Kolkata-700 032, Email: sahaparamita@gmail.com) : Geomorphology and sediment character of Bakkhali-Frasergunj coastal belt and adjoining inner-continental shelf, Bay of Bengal. Indian J Geosci 2011, 65(3), 195-210.

The Bakkhali-Frasergunj coastal belt and adjoining inner shelf, Bay of Bengal have been investigated in detail to study the coastal processes operative thereom. Analysis of shoreline position during different periods shows landward shifting of high water line by <126>325m - 400m and low water line by <126>100m - 175m since 1969 barring the western sector, where the shifting is much less. The coast has been more or less stable since 2001. The catastrophic events during seventies/eighties might have caused landward shifting of the coast. Massive erosion in the western part of Bakkhali River mouth may be due to divergence of littoral current caused by perpendicularly oriented shoreline and presence of shore-parallel sand bar off the river mouth. Rootlets, palaeo-mud, clay balls on the inter-tidal zone are the prominent erosional features. Average wave height near the coast is <126>1.2m. The gently sloping (0.5° to 1.3°) 84m- to 528-m-wide beach is veneered by fine to very fine sand with occasional silt and clay. The inner shelf up to <126>12km is shallow with maximum water depth of <126>10m (tide corrected). There is abrupt change in water depth at few sectors, due to presence of shoals and submarine erosion of the sea floor by strong tidal current. New shoals are formed and pre-existing shoals are accreted or eroded/ subsided in recent times. Increased bottom friction caused by strong tidal current in the constricted passage is responsible for steepening of eastern flank of the 'Sagar Sand Range'. Submarine erosion resulted in extension of Lacams Channel further south. The seabed is veneered mostly by fine to very fine sand, with patchy occurrences of admixed varieties of sand, silt and clay. Clay balls are found at few locations in relatively deeper parts.

10 illus, 4 tables, 16 ref

005691   Ray S K;Neogi S;Chatterjee A (Geology Dep, Presidency College, Kolkata-700 073, Email: skray45@yahoo.co.in) : Frontal thrust wedge of lingtse gneiss: evidence of basement mobilisation in the Teesta culmination zone of the Darjeeling-Sikkim Himalaya. Indian J Geosci 2011, 65(1), 1-8.

Recent mapping in the Sikkim-Darjeeling sector of the eastern Himalaya has brought out a 22-km-long (so far traced) and 2- to 4-km-wide thrust wedge of deformed granites, which can be correlated with the Lingtse Gneiss unit. In contrast to the general north-south trend of the other Lingtse Gneiss bodies mapped by the previous workers, the recently mapped thrust wedge exposed in the area south of Malli near the Rangit-Teesta confluence, is frontally disposed with east-west trend, and forms an important tectonic unit of the area. Strong ductile deformation at the contacts has transformed the basement granites into mylonitic gneisses in the course of their thrust transport from the subthrust basement to the upper tectonic levels and emplacement as thrust wedges of Lingtse Gneiss. Granitic texture however is recognisable in the central part of the wedge. The culmination zone has formed due to uparching of the Main Central Thrust (MCT) defining a northerly-plunging anticline. The general forward-breaking sequence of thrusting of the area was broken by an out-of-sequence thrust that nucleated at deeper levels within the Precambrian basement and ramped up to join the upper level Baling Thrust. A part of the basement on the hanging wall of the thrust was transported southerly and climbed the ramp to form a ramp anticline due to fault-propagation folding. Deep erosion has exposed the basement rocks along the crest of the anticline that trends parallel to the mountain front but transverse to the axial trend of the culmination.

5 illus, 20 ref

005690   Ralte V Z;Tiwari R P;Lalchawimawii;Malsawma J (Geology Dep, Mizoram Univ, Aizawal-796 004, Email: rptmzu@rediffmail.com) : Selachian fishes from Bhuban formation, Surma group, Aizawal, Mizoram. J Geol Soc India 2011, 77(4), 328-48.

An interesting selachian fish assemblage having stratigraphic and palaeoecological significance is being described from the two intraformational calcareous conglomeratic horizons within the Upper Bhuban unit of Bhuban Formation, Surma Group (Lower to Middle Miocene). The assemblage consists of eighteen species of selachian fishes including two new ones (Carcharhinus bhubanicus and Hemipristis unidenticulata) belonging to thirteen genera and another thirteen forms have been identified up to generic level. It is dominated by the families Carcharhinidae and Lamnidae, and is one of the most diversified Miocene assemblages from the Indian subcontinent. The fish fauna and the associated mega-invertebrates suggest Lower Miocene (Aquitanian - Burdigalian) age for the Upper Bhuban unit of Bhuban Formation. These further suggest that the fish yielding horizons were deposited under a warm shallow marine set-up near to the shoreline in a high-energy environment.

2 illus, 1 table, 44 ref

005689   Naskar D C;Singh O P;Das L K;Syiem S M (Geophysics Div, Western Region, Geological Survey of India, Jaipur-302 004) : Integrated geophysical survey for delineation of active fault in the foothill of Bhutan Himalaya, Northeast India. Indian J Geosci 2011, 65(3), 211-22.

Geophysical survey employing gravity, magnetic and resistivity methods was carried out in Kokrajhar area, Bhutan Himalaya with the aim of delineating the basement topography and associated structures. The gravity data indicates that crustal thickness increases towards the north i.e. the foothill of Bhutan Himalaya. Thickening of the crust causes continuous fall in gravity value which is recorded in the data. Two faults are interpreted from the changes in gradient along E - W profile (near 7 No. Ride) which is trasverse to the Sonapur - Ultapani Road, Kokrajhar, Assam. Low amplitude magnetic response is observed over the non-magnetic alluvium/sediments indicating deepening of the bedrock and/or basement because of large thickness of sediment in the area. Fluctuations in magnetic response are observed at few locations which may be due to the presence of local concentrations of magnetic minerals. Three faults are inferred near Bishmuri, north of Mahendrapur and south of Mach Bhandar Nala along the traverse originating from Sonapur in the south and ending at Ultapani in the north, Kokrajhar District, Assam. Spectral analysis of the magnetic profile indicates the first lithological interface between the boulder bed and the bedrock at a depth of 141m-291m and the second interface between the bedrock and the Archaean basement at a depth of 1486m-1919 m. Deep resistivity soundings confirm that the bedrock is represented by Tertiary sediments. Resistivity varies from 100 ohm-m to 230 Ohm-m and thickness varies from 931m to 2022m. Resistivity profiling indicates two shallow faults - one around the junction of 7 No. Ride and Sonapur - Ultapani Road and another at the junction of Mach Bhandar Nala and Sonapur - Ultapani Road. Resistivity data brings out a basement configuration for the area from Sonapur to Ultapani. Two more faults are interpreted around Bishmuri and Mahendrapur from the resistivity section. These are corroborated with magnetic data also.

12 illus, 1 table, 26 ref

005688   Naskar D C;Saha D K;Das L K (Geophysics Div, Geological Survey of India, Eastern Region, DK-6, Sector-II, Salt Lake City, Kolkata-700 091, Email: dcnaskar@yahoo.com) : Electrical imaging of shallow and deep crust using magnetotelluric (MT) survey along Islampur-Siliguri-10 mile transect, Sikkim-Darjeeling Himalayan region. Indian J Geosci 2011, 65(1), 45-56.

Tectonics in the Himalayan foothills is a result of compression since the intercontinental collision between the Indian and Eurasian plates is best understood as a continuation of thin-skin tectonics and basement-level faulting. In order to prepare the electrical image of the deep crust which is associated with seismotectonic activity and faulting in the region, wide-band magnetotelluric studies were conducted at 14 stations along the lslampur-Siliguri-10 mile transect in the Sikkim Darjeeling Himalayan region. The station interval was about 7 km. The subsurface layer is highly conductive (resistivity <60>2 Ohm-m) at a depth of about 6 km. The Siwalik formations were mapped and found to occur in the depth range of 500-3000 m. Gondwanas were observed at a depth of 2000-3500 m below the Siwaliks. The Siwalik and the Gondwana sediments overlie a rather complex, highly resistive Archaean basement at a depth of 2600 m to 5600 m. Several faults were inferred from magnetotelluric data. The conductive layer seems to be located in the deep crust of the subducting Indian plate.

11 illus, 56 ref

005687   Mondal S K (Geological Sciences Dep, Jadavpur Univ, 188 Raja S.C. Mullick Road, Kolkata-700 032, Email: sisir.mondal@gmail.com) : Platinum group element (PGE) geochemistry to understand the chemical evolution of the earth's mantle. J Geol Soc India 2011, 77(4), 295-302.

Platinum group elements (PGE: Os, Ir, Ru, Rh, Pt, Pd) are important geochemical and cosmochemical tracers. Depending on physical and chemical behaviour the PGEs are divided into two subgroups: IPGE (Ir, Os, Ru) and PPGE (Pd, Pt, Rh). Platinum group elements show strong siderophile and chalcophile affinity. Base metal sulfides control the PGE budget of the Earth's mantle. Mantle xenoliths contain two types of sulfide populations: (1) enclosed within silicate minerals, and (2) interstitial to the silicate minerals. In terms of PGE characters the included variety shows IPGE enriched patterns - similar to the melt-depleted mantle harzburgite, whereas the interstitial variety shows PPGE enriched patterns - resembling the fractionated PGE patterns of the basalt. These PGE characters of the mantle sulfides have been interpreted to be representative of multi-stages melting process of the mantle that helped to shape the chemical evolution of the Earth.

2 illus, 1 table, 65 ref