Andhra Pradesh, India

Hydrogeologic appraisal (using conventional and remote sensing methodology)

Hydrogeological study of harve watershed in Chamarajanagar District

Ostracoda from shore and off shore areas of Malabar coast

Hydrogeology around Holenarasipur

Granulite grade lithologies and associated igneous rocks

Palynostratigraphic studies of Shahabad and Halkal formations

<p>The hematite-stained grain (HSG) proxy method, commonly employed by the late G.C. Bond to detect the "1500-year cycle" in North Atlantic climate, is reproduced and verified for the first time. The exact method is compiled from various sources and presented in Chapter 1. In Chapter 2, an HSG record from classic North Atlantic DSDP Site 609 is reconsidered. While the Site 609 HSG record was initially interpreted to exhibit 1500-year variability, it did not actually contain spectral power at the 1500-year band. The chronology for Site 609 is based on radicarbon dates to 26 ka, beyond which the sea surface temperature record is matched to the record of air temperature variations over Greenland from the GISP2 ice core. However, it is now evident that the lack of spectral power at the primary period of the observed fluctuation was likely due to the GISP2 chronology, which has been subsequently shown to become progressively deficient over the course of the last glaciation. Updating the Site 609 chronology to the latest chronology for the virtually complete NGRIP Greenland ice core, which is based on layer counting to 60 ka, results in 99% significant spectral power at a 1/1415 year frequency.</p><p>In Chapter 3, the classic Site 609 lithic records are extended to the previous two glaciations, glacial Stages 6 and 8, at IODP Site U1308 (reoccupied Site 609). The "1500-year cycle" is not detected within Stage 6, perhaps indicating that D-O Events were not manifest in a similar fashion, if at all. Heinrich Event are also not detected, indicating relative stability of the North American Laurentide Ice Sheet during Stage 6. As a result, individual North Atlantic sites recorded lower-amplitude, asynchronous hydrographic changes. The SST proxy record at Site U1308 during Stage 6 primarily records intermediate temperatures. The subtle SST changes detected likely indicate local as opposed to basin-scale changes related to the migration of oceanic frontal boundaries. During Stage 6, benthic </p><p>δ13C changes are of lower amplitude than Stages 2 - 4 and correspond more strongly to variations in SST than to ice rafting, indicating that ice-rafting events did not as strongly influence NADW formation.</p><p>During Stage 8, however, well-structured cycles in HSG with a mean event spacing of ~ 1500 ± 500 years are detected, potentially indicating a greater likelihood of D-O Events during Stage 8. In addition, three Heinrich Events, defined by a large abundance of DC, occurred during MIS 8, indicating surging of the Laurentide Ice Sheet Ice Sheet. Stage 8 is therefore more analogous to that of the last glaciation than Stage 6.</p><p>Chapter 4 explores the link between HSG and cosmogenic nuclide production, which are highly coherent at a frequency of 1/950 years. A 950-year period is present in the HSG records of the last three glaciations. While a 950- year oscillation may be the product of solar forcing, due to uncertainty in paleomagnetic reconstructions and in the Site U1308 chronology, the null hypothesis that the HSG proxy does not reflect variable solar irradiance cannot be unequivocally refuted. Solar forcing does however provide an explanation for climate variability in the 950-year band during the last three glaciations.</p> / Dissertation

Lakes Koronia and Volvi, located within the Mygdonia Basin in northern Greece, comprise an internationally protected wetland. The lakes support major industrial and agricultural activities, and a population of 45,000. Consequently, both sites have been greatly impacted by the conversion of marshland to farmland, water losses to irrigation, and pollution discharges including raw sewage, agricultural run-off, and industrial wastes. Sediment chronology and accumulation rates have been determined in cores from multiple sites within the lakes using 210Pb dating techniques. Bulk sediment elemental composition (organic carbon content, C/N ratios, etc.) and trace metal concentrations have been measured to provide critical evidence for variations in land-use within watersheds. Stratigraphic variations in the carbon and nitrogen isotopic ratio of sedimented organic matter have been measured to determine changes in aquatic ecosystem productivity. The geochemical results will be compared to historical records to determine the relative importance of disturbances caused by urban, agricultural, and industrial activities.

The Morrison Formation of the Western United States is famous for the dinosaurs and other fossils that have been excavated from its beds. It was deposited during the Late Jurassic in a semi-arid, savannah-like environment. The Morrison Formation is remarkably extensive, with outcrops across eight states; however attempts to correlate between Wyoming and the Colorado Plateau have proven difficult. The goal of this research is to determine the origin of carbonate rocks from the Morrison Formation beds exposed on the Spring Creek Preserve in southeastern Wyoming, and to assess their potential for lithostratigphic correlations. A wide range of research techniques were employed, ranging from macroscopic observations in the field to geochemical and isotopic analyses. Field relationships and macro- and microtextures of nodular and calcareous units are consistent with carbonate mineral deposition of freshwater lacustrine muds and the development of palustrine limestones, nodules and calcrete as the micritic muds were exposed and desiccated. Strontium isotope data suggest that the nodules developed from alteration of nearby lacustrine carbonates with little exogenous input. The thickness and level of development of the nodular carbonate units below the mid-Morrison unconformity at 42 m and observed in nearby localities suggests an extended period of subaerial exposure and desiccation in the study area during middle Morrison time. If the presence of these palustrine carbonates found throughout Wyoming is the result of a synchronous regional lake-level lowstand, it is plausible that this nodular horizon correlates to the Mid-Morrison paleosol unconformity identified Utah and Colorado. The strontium isotope composition of a belemnite from the underlying Sundance Formation corresponds to a Late Jurassic Oxfordian age (161-157 million years ago) for this unit and places a maximum age for the Morrison Formation in the Spring Creek Reserve study area.