A stepped heating gas extraction technique has been developed which is capable of isolating C02 released by fluid inclusions from that released by contamination and other sources. In some cases specific generations of inclusions may be extracted. This technique represents a significant advance in the measurement of carbon isotopes from fluid inclusions. Isotopic results are reproducible to ± 0.296 for gas-rich samples, but sample heterogeneity results in variable yield measurements (occasionally up to 200%). The technique has been applied to charnockites and related rocks from South India to constrain the role of C02 in their petrogenesis. Results from a data base of 65 samples show that charnocidtes released more inclusion-C02 than did associated amphibolite facies gneisses, implying that C02 plays a significant role in charnockite formation. Field observations and theoretical phase equilibria, suggest incipient charnockites (partially transformed gneiss) form by sub-solidus transformation (induced by influx of C02) and by melting (triggered by influx of mixed C02-H20). This melting reaction occurs at least 50°C below vapour-absent melting, so it may be an important mechanism for granulite and granite formation in the middle and lower crust. Massive charnockites (monotonous granulite) are believed to form mainly by direct crystallisation from a H20-poor, C02-rich melt. 513C values support radiogenic and field evidence for at least two charnockite formation events in South India. The 2500 Ga event at the southern margin of the Archxan Craton yields a range of 613C values (-4%o to -13%o), tentatively interpreted as C02 derived from subducting sediments. The younger event (500 Ma) affects the southern blocks (of probable early Proterozoic age), and is characterised by a bimodal distribution of 813C values (-6%o to -7%o and -9%o to -13%o). A sub-continental lithospheric source of C02 (transported by magmas associated with crustal extension) is suggested by the heavier values. The lighter isotopes result mainly from mixing between this mantle source and organic graphite, but inclusion capture during an earlier event cannot be ruled out in a few cases. C02-rich fluids are found to propagate by advective fluid flow through a microhydraulic fracture mechanism. A detailed case study of local charnockite formation indicates that isotope and reaction fronts are diffuse, almost over the entire distance of fluid flow (60 m), and fluid/rock disequilibrium suggests that fluid-rock ratios must be treated with care.

The oldest dated rocks from the Acasta gneisses of the western Slave Province, Canada present an igneous age of ~4030 Ma. Following this the detrital zircons from the Jack Hills, Narryer Gneiss Terrane, Yilgarn Craton, Western Australia are identified as 4404 ±8 Ma. These discoveries suggest that crustal formation started as early as the Priscian Eon. Hitherto the Earth has gone through a series of interactions involving the atmosphere, hydrosphere, crust, mantle and core. However, only limited remnants of these early processes remain on the accessible crust due to extensive crustal reworking. The Southern Granulite Terrane (SGT) in the southern part of India represents the most extensive exposure of lower crustal granulite terranes in the world. This study mainly focuses on the characteristics of Archean (~2500 Ma) tectonics and nature of subsequent crustal growth, which led to the formation of Archean Nilgiri Block. Detailed fieldwork in this terrane and subsequent petrographic analysis revealed charnockites, hornblende-biotite gneiss, metagabbro/mafic granulite, websterite, amphibolite, Grt-Ky metasediment, metatuff and banded iron formation as the main rock types in this terrane. Field and petrographic results show a regional trend with garnet-orthopyroxene-biotite-quartz-plagioclase-K- feldspar bearing charnockites in the southern part which gets subsequently enriched in clinopyroxene that forms garnet-absent two pyroxene granulites consisting of orthopyroxene-clinopyroxene-quartz-plagioclase-K-feldspar towards the central part. Further north, metagabbro/mafic granulite is enriched in garnet-clinopyroxene-plagioclase assemblage. Websterite, amphibolite, metasediment, metatuff and banded iron formation are stacked and closely associated within this mafic belt in the north. The metagabbro represents peak P-T conditions of ~850°C and ~14kbar compared to the charnockites, which recorded a peak P-T of ~850°C and 9-10kbar. Petrographic results of oxide minerals show that the southern charnockitic part is abundant in rutile-ilmenite association represent reduced conditions compared to the oxidized magnetite-hematite-ilmenite associations in the mafic rocks. This oxidation trend is followed by pyrrhotite-chalcopyrite enriched southern charnockitic region that transforms to pyrite rich northern mafic belt. Ilmenite¬titanite association with no sulphides characterizes the hornblende-biotite gneiss in the entire Nilgiri Block. The geochemical variations of major, trace and rare earth elements show that the granulite-amphibolite grade felsic rocks evolved in an arc magmatic process leaving behind mafic magma, which later intruded into these rocks, in a subduction related arc magmatic process. The U-Pb LA-ICPMS and SHRIMP dating of charnockite, hornblende-biotite gneiss and met gabbros shows ca. 2550 Ma formation age and ca. 2450 Ma metamorphism in this terrane.

Archaeological and genetic evidence have long supported the notion that the Indian subcontinent played an important role in the dispersal of modern humans out of Africa. In the present study, two Dravidian populations, namely Lingayat (N=101) and Vokkaliga (N=102) were examined using high-resolution analyses of Y-chromosome single nucleotide polymorphism (Y-SNP) and their associated seventeen short tandem repeat (STR) loci. The results revealed a prevalence of the major indigenous Indian Y-haplogroups (H, L, F* and R2), which collectively accounted for three-fourths of the Lingayat and Vokkaliga paternal gene pool. In addition, the presence of ancient lineages such as F*-M213, H*-M69 and C*-M216 suggested that modern humans reached India very early after their migration out of Africa. Finally, high haplotype diversity values at 17 Y-STR loci for Lingayat (0.9981) and Vokkaliga (0.9901) populations as well as the absence of shared haplotypes between them emphasized the importance of independent databases for forensic casework.

Yes / This paper focuses on the dispute over river Cauvery in Southern India. Among the causes of river water disputes are contested property rights, difficulty in enforcing such rights, conflict of uses and a lack of willingness to compromise. A co-operative outcome in such cases depends on several factors: asymmetry of power in a triadic relationship between a federal government and two riparian states (one upstream and one downstream). Other factors influencing co-operation are the extent to which the claims of river waters can be elevated from those of immediate riparian peoples to those of an entire state; the dominance of a masculine paradigm towards 'taming' river waters using 'hard' investments rather than 'soft' and decentralised alternatives. On the basis of district level data, the importance of river Cauvery to the hydrology, economy and polity of the two contesting states is examined. This analysis helps us to appreciate why the two riparian state governments have limited room to manouvre. Drawing from two brief case studies of Murray Darling Basin and recent litigation in the USA, and other international experiences of river water treaties, the paper identifies various implications for the resolution of Cauvery and other river water disputes.

Tree growth influences forest community dynamics and responses to environmental variations, but currently is not well understood. Tree growth in highly diverse wet tropical forests have been well studied and characterised compared to the species-poor dry tropical forests. Thus, it is not clear if growth rates and community dynamics of dry forests are similar to those of wet forests, given the longer dry season, greater rainfall variability, more open canopy and lower number of species in dry forests. This thesis focuses on identifying important factors that influence tree diameter growth rates in the dry tropical forest at Mudumalai, southern India, and also compares growth patterns at this dry forest with those at moister forests. The thesis thus contributes towards closing the gap in understanding of tree growth patterns across the tropics. An initial analysis involving matrix-based population projections of four common canopy species at Mudumalai showed that variations in diameter growth have the potential to drastically modify population trajectories of dominant species. Thus the main focus of this thesis is aimed at identifying the important intrinsic and extrinsic factors affecting growth in this dry forest, as this information could be useful for future management of the forest. The second important aim of the thesis was to find out if growth rates are influenced by different sets of factors in tropical dry versus moist forests. A large permanent 50ha plot vegetation monitoring plot was set up in 1988-89 in the Mudumalai dry deciduous forest, and was subsequently monitored annually by staff of the Centre for Ecological Sciences. Data used in this thesis represent a 12-year interval between 1988 and 2000. Girth measurements were obtained from all woody tree stems ≥1cm in diameter every four years during this 12 year interval, which provided three census intervals of diameter increment data on >13,000 trees. For the comparison between dry and moist deciduous forests, data were obtained from a similar large plot maintained and monitored at the Barro Colorado Island (BCI) in Panama. Influences of the intrinsic factors, tree size, individual identity, species identity and growth form, were examined using t-tests, Wilcoxon signed ranks tests, linear regressions, analysis of variance (ANOVA), principal components analysis (PCA) and cluster analysis. Among the intrinsic factors tested, species identity explained approximately 20% of growth rates at the community level, while tree diameter explained less of growth variation, and growth form had a minor influence on growth. Growth rates also were examined for variations across the three census intervals, and for relationships with rainfall and survival from fire. Statistical tests included t-tests, Wilcoxon and other non-parametric sign tests, logistic regression and ANOVA. Most species and individuals showed significant reductions of growth in the second census interval (1992-1996), and growth rates of most trees were positively related to rainfall. Growth rate variations generally were not related to survival from fire, and few species were capable of escaping fire mortality by fast growth. Spatial environmental influences were tested in the commonest fifteen species, using five habitat categories, local elevation, slope, aspect, and the biotic neighbourhood variables of local conspecific and heterospecific density. Statistical tests included analysis of covariance, multiple linear regression and redundancy analysis. The tests were quadrat-based or individual-based, and species' growth responses were tested at different levels of distance and spatial scale. Topographic features and habitat categories had ephemeral effects on species growth. Only the most dominant species, Lagerstroemia microcarpa, showed consistent conspecific neighbour density effects. Redundancy analysis using a subset of common species and environmental factors did not reveal common growth responses to spatial environmental factors. Comparison of factors influencing growth at Mudumalai versus at BCI using multiple factor ANOVA and multiple linear regressions showed a similar influence of temporal variation at the two sites, but stronger and more widespread influence of tree size (diameter) at BCI. The greater influence of tree size at BCI may be related to greater light limitation in this dense moist forest. Spatial environmental factors had weak influences at both plots. Species were less differentiated from each other at the more diverse BCI plot compared to the relatively species-poor Mudumalai plot, suggesting that species' growth niches may be weakly related to diversity across tropical forests. Overall the results showed that among the factors tested species identity and census intervals were the most important influences on diameter growth at the Mudumalai dry deciduous forest. Tree diameter was less important and less consistent in affecting growth at the Mudumalai dry forest, contrary to expectations based on moist tropical forests where this relationship has been established previously. When comparing Mudumalai and BCI, the relative importance of different factors was different at the two sites, and the most important difference was a dominant influence of light limitation at the wetter forest in Panama. In terms of management applications, this study showed that fires at Mudumalai might be an inescapable source of mortality for many vulnerable species, and improved fire management is crucial for long term survival of species in this dry forest. At a larger scale, light and other environmental variables were found to influence growth differently at Mudumalai compared to BCI. This suggests that location-specific responses may be important for projections of tree biomass and carbon sequestration, especially under future climatic change scenarios.

Aerosol are solid or liquid particles suspended in the atmosphere ranging in size from 10 3 to 102 m. Aerosol influence both the regional and global climate of the earth by its direct and indirect effect. Role of atmospheric aerosols on the radiative forcing of atmosphere is a matter of serious research for past few decades and still it remains highly uncertain as acknowledged by Intergovernmental Panel on Climate Change. Heterogeneous nature of aerosol both spatially and temporally makes it more complex in estimating radiative forcing compared to that of greenhouse gases. Compounding to the existing difficulty in determining the climate effects, changing aerosol concentration and nature of the aerosol further increases the complexity in determining its effects in both regional and global climate. Increasing aerosol loading is emerging to be an issue of major concern over several regions. The first step towards achieving this goal is by determining the trends in the physical and optical properties of aerosol over the globe. Main objective of the thesis is the determination of the recent trends in aerosol loading over the globe and then to focus specifically on the properties of aerosol over an urban site in southern India. Specific objectives are (a) to determine the trend in aerosol physical and optical properties over the globe using AERONET surface observations (b) to characterize the chemical properties of water soluble inorganic aerosol over an urban site in Southern India, Bangalore (c) to have a better estimation of aerosol radiative forcing over Bangalore with measured aerosol chemical concentration, black carbon concentration and aerosol optical depth (AOD). To quantify the recent trends in aerosol loading over the globe, we have used the surface observations from AERONET and the study provided the first step in giving a global picture of the recent trends in the fundamental optical and physical property of aerosol. Trend analysis showed a significant spatial inhomogenity, and Asian continent clearly showed an increasing trend in AOD compared to other continents. Solar village (24.9oN, 46.4oE) of Saudi Arabia showed a maximum with a value of 0.04/yr and Bac -Giang (21oN, 106oE) of Vietnam showed the minimum value of -0.04/yr. North American study region included 18 sites in which eastern US (E.US) exhibited a decreasing trend while the scenario in western US (W.US) is different with more of sites with increasing AOD trend. Single scattering albedo (SSA) trend in W. US showed a decreasing trend irrespective of the AOD trend. Study sites in South America include Cordoba -CETT (31.5oNS, 64.5 oN W) Alta Floresta (9.8oS, 56.1 o W), Riobranco (9.9oNS, 67.8o W) and Soa Poulo (23.5oS, 46.7o W).Except Riobranco which has a positive trend in AOD, all other sites exhibited a statistically signi cant negative trend. Over Australia, there is an inclination towards increasing AOD in sites and all the three sites in Australia exhibit a statistically significant increasing trend in SSA. According to the recent trends in AOD over African region, there exists a significant decrease in AOD compared to that reported for few years earlier, showing the high temporal in homogeneity and need for continuous observation of aerosol over the regions. European study region included 15 stations, among them only 3 sites showed an increasing trend in AOD, remaining 12 sites showed a significant decreasing trend in aerosol loading over the period of study. SSA was also observed to be decreasing over most of the European sites, even with a decreasing AOD over most of the sites. A Comparison study carried out to determine the relation of population growth rate and aerosol loading, and it revealed that the increasing AOD trend not always coincided with the sites having high population growth rate. Having determined the trends in AOD and other aerosol parameters over the globe and seeing an alarmingly increasing trend over most of the Asian sites, especially over Indian region, we have then focused over work on the aerosol properties of one of the rapidly growing urban location in southern India, Bangalore. While physical properties of aerosol have been extensively studied over Bangalore, chemical characteristics are still an unexplored area. Extensive information on aerosol chemical composition is not available over Indian region except for a few locations based on campaign mode. Even available data is of very coarse temporal resolution, since hours or full day sampling is needed to gather enough samples for chemical analysis. High temporal resolution data of aerosol chemical characteristics, especially for all season is completely lacking over Indian subcontinent. Among aerosol, water soluble aerosol form an important component in particulate matter, since it can change its size, composition, can easily mix with other aerosols and can act as cloud condensation nuclei, based on its hygroscopic nature. Present study provided the rst time results from a high temporal resolution water soluble inorganic aerosol chemical data over Indian region, which is first step towards estimating aerosol climate impacts more accurately. Water soluble inorganic aerosol ions over Bangalore namely, sulphate, nitrate, chloride, potassium, calcium, magnesium, sodium and ammonium are measured using Particle Into Liquid Sampler Ion Chromatograph (PILS-IC). PILS is an online sampling technique for quantitatively measuring the chemical concentration of ion in water soluble aerosol particles. PILS IC used in the present study is developed in Georgia Institute of Technology. Instrument samples ambient air at a flow rate of 16.7Lmin 1. Particles below PM 2.5 micron are collected for the analysis using cyclone impactor. Two annular glass denuders are used to remove inorganic gases which else will interfere with the aerosol ion concentration. Ambient air which is deprived of the inorganic gases is then mixed with steam vapours at 150oC, eventually high supersaturated atmosphere is produced with rapid adiabatic mixing of steam and ambient air. High supersaturated air allows droplets to grow enough to be collected by inertial impaction onto a quartz impactor plate. Entire PILS condensation unit is kept at a slight tilt of 15o, to remove all condensate through drain tube connected to the end of the PILS condensate body. Condensed liquid sample is collected from the impaction chamber and known concentration LiF is allowed to mix with the collected sample at a constant rate. LiF known as carrier liquid is added to know the dilution occurring to the collected sample. Sample with carrier liquid is then collected to a debubbler and is supplied to the IC through peristaltic tubings for determining the ion chemical concentration. Seasonal variation of mass concentration of water soluble aerosol species and the influence of long range transport is carried out using HYSPILT back trajectory analysis. Marine air mass from Arabian Sea dominated the air parcel reaching the site for both SW monsoon and summer. Continental air mass dominated the site during both NE monsoon and winter with slight contribution from marine atmosphere. Source characteristics of sulphate, potassium, calcium and magnesium ions are carried out based on sea salt (ss) and non sea salt (nss) origin and it is observed that the nss contribution is dominant over the site for all these ions except magnesium where ss component comparatively dominates the source. SO24 and NO3 form the dominant anions while NH+4 makes the dominant cation species. Monthly variation of the ratio of ammonium to nss -sulphate is carried out to determine the possible cation -anion relation existing between these two major ions. During later winter and summer months ammonium bi sulphate is found to be the existing chemical form and ammonium sulphate during other seasons. High temporal resolution data enabled us to study the diurnal variation of aerosol ions and it is influenced by various mechanisms from boundary layer to local emissions. Optical properties of aerosols depend upon the size and the relative abun-dance of each components. It is usual practice to assume default aerosol chemical composition in radiative transfer models due to unavailability of data, which can lead to errors in forcing estimates. Incorporating realistic aerosol chemical composition in models is essential to reduce the uncertainty in aerosol radiative forcing. Hence we have included measured aerosol chemical compositions, black carbon and AOD to improve the determination of radiative forcing of aerosol. OPAC and SBDART models were used for estimating the aerosol radiative forcing over Bangalore. We have used mainly four components namely, soot, water soluble, sea salt and dust. Except dust all are other components are measured over the site and formed a constrain for the calculation. Dust concentration was altered so that the OPAC AOD matched the measured AOD within 5%. Mineral dust shows the highest contribution in AOD among the four components, however water soluble and soot even being less is mass concentration compared to mineral dust, has significant impact on the AOD. This clearly indicate the influence of both water soluble and soot aerosol over the regional climate of the site. Sea Salt exhibited low AOD compared to other three constituents. The results presented in the thesis highlights the importance of varying trends in the aerosol properties and its effects on a global picture and speci - cally over an urban site in Indian region , we explored the temporal variations of water soluble inorganic aerosol ions and its effects on regional climate. Hence the thesis addressed some of the unexplored areas in aerosol science. This study also suggests the need of continuous observation of aerosol over both spatial and temporal scale, which is essential to estimate their effects on earth's climate.

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