Browsing Scholarly literature by Author "Rao, V.P."
Now showing items 61-80 of 96
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Origin and significance of high-grade phosphorite in a sediment core from the continental slope off Goa, India
Rao, V.P.; Rao, Ch.M.; Thamban, M.; Natarajan, R.; Rao, B.R. (Current Science Association, Bangalore, India, 1995)A phosphorite crust was found at 380-390 cm depth interval of a sediment core collected from the topographic high occurring on the continental slope off Goa. This crust is fragile and grey to light brown in colour. Carbonate ... -
Origin of cretaceous phosphorites from the onshore of Tamil Nadu, India
Rao, V.P.; Kessarkar, P.M.; Nagendra, R.; Babu, E.V.S.S.K. (Indian Academy of Science, 2007)Cretaceous phosphorites from the onshore of Tamil Nadu have been investigated for their origin and compared with those in the offshore. Cretaceous phosphorites occur as light brown to yellowish brown or white nodules in ... -
Palaeoclimatic significance of gypsum pseudomorphs in the inner shelf sediments off Machalipatnam bay
Rao, V.P. (Geological Society of India, 1988)Pseudo-gypsum crystals have been found in the coarse fraction of the sediments from the inner continental shelf off Machilipatnam Bay. They range in size from 3 to 7 mm are elongate and lenticular in shape. Bassanite and ... -
Paleoclimatic and diagenetic history of the Late Quaternary sediments in a core from the southeastern Arabian Sea: Geochemical and magnetic signals
Rao, V.P.; Kessarkar, P.M.; Thamban, M.; Patil, S.K. (The Oceanographic Society of Japan, 2010)Geochemical and rock-magnetic investigations were carried out on a sediment core collected from the SE Arabian Sea at 1420 m depth in oxygenated waters below the present-day oxygen minimum zone. The top 250 cm of the core ... -
Phosphatic rocks and manganese crusts from seamounts in the EEZ of Kiribati and Tuvalu, Central Pacific Ocean
Rao, V.P.; Burnett, W.C. (Circum-Pacific Council for Energy and Mineral Resources, 1992) -
Phosphatised limestones and associated sediments from the western continental shelf of India
Rao, V.P.; Natarajan, R.; Parthiban, G.; Mascarenhas, A. (Elsevier, 1990) -
Phosphorites from the error seamount, Northern Arabian Sea
Rao, V.P. (Elsevier, 1986)Phosphorites were dredged from the flanks of the Error Seamount, off the Somali Coast from depths of 400-460 m. These occur as dense slabs and irregular lumps associated with limestones. Polished and thin section studies ... -
Phosphorites from the Oman Margin, ODP Leg 117
Rao, V.P.; Lamboy, M. (Ifremer/ CNRS/ IRD/ Editions scientifiques et medicales Elsevier SAS. Tous droits reserves, 1995)The phosphorite levels present in the ODP cores of the Oman margin are of two types: (a) sediment levels dominated by phosphate grains with a few white to light-brown nodules; these are sandy and predominantly occur in ... -
Possible microbial origin of phosphorites on Error Seamount, northwestern Arabian Sea
Rao, V.P.; Lamboy, M.; Natarajan, R. (Elsevier, 1992)Petrographical, mineralogical and microprobe analysis of phosphorites from Error Seamount, in the northwestern Arabian Sea, demonstrates that microbial processes played an important role in the early diagenetic formation ... -
Precipitation of iron in windopane oyster shells by marine shell-boring cyanobacteria
Raghukumar, C.; Rao, V.P.; Iyer, S.D. (Taylor & Francis, 1989)Shells of windowpane oyster (Placuna placenta (L.)) in the intertidal zone of the Zuari Estuary, Goa, India were often found to be black in color. Microscopical observation of partially decalcified shells showed the presence ... -
Proceedings volume of the national seminar 'Four Decades of Marine Geosciences in India - A Retrospect'
Rao, V.P. (Geological Society of India, 2003) -
Provenance and distribution of clay minerals in the sediments of the western continental shelf and slope of India
Rao, V.P.; Rao, B.R. (Pergamon, 1995)The distribution of clay minerals from 156 surficial sediments of the western continental margin of India, ranging from 17 to 2000 m water depth, indicate that there are three principal sources of sediments. The illite and ... -
Quartz and feldspar distribution in continental shelf sediments of east coast of India
Rao, V.P.; VijayKumar, B. (NISCAIR, CSIR, 1990) -
Quaternary phosphorites from the continental margin off Chennai, southeast India: Analogs of ancient phosphate stromatolites
Rao, V.P.; Rao, K.M.; Raju, D.S.N. (SEPM, Society for Sedimentary Geology, 2000)Pleistocene phosphorites occur on the continental margin off Chennai abundantly in the depth range of 186-293 m. They are associated with outer-shelf glauconites and carbonate skeletals including large shells of molluscs ... -
Quaternary phosphorites off the southeast coast of India
Rao, V.P.; Michard, A.; Naqvi, S.W.A.; Boettcher, M.E.; Krishnaswamy, R.; Thamban, M.; Natarajan, R.; Borole, D.V. (Elsevier, 2002)Detailed petrological, mineralogical, geochemical and radiogenic (U, Sr, Nd) and stable isotope (C, O, S) studies have been carried out on the Quaternary phosphorites of the continental margin off Chennai, southeast coast ... -
Rare earth elements in suspended and bottom sediments of the Mandovi estuary,central west coast of India: Influence of mining
Shynu, R.; Rao, V.P.; Kessarkar, P.M.; Rao, T.G. (Elsevier, 2011)Rare earth elements (REEs) in the suspended particulate matter (SPM) of the Mandovi estuary indicated that the mean total-REEs and light REE to heavy REE ratios are lower than that of the average suspended sediment in World ... -
Reconstruction of late Quaternary monsoon oscillations based on clay mineral proxies using sediment cores from the western margin of India
Thamban, M.; Rao, V.P.; Schneider, R.R. (Elsevier, 2002)In order to reconstruct the variations in the intensity of summer monsoon precipitation during the late Quaternary, two sediment cores from the southwestern continental margin of India were studied for their clay mineral ... -
REE in suspended particulate matter and sediment of the Zuari estuary and adjacent shelf, western India: Influence of mining and estuarine turbidity
Shynu, R.; Rao, V.P.; Parthiban, G.; Balakrishnan, S.; Narvekar, T.; Kessarkar, P.M. (Elsevier, 2013)Concentrations of Al, Fe, Mn and rare earth elements (REE) were measured in 122 samples of suspended particulate matter (SPM) and 70 surficial sediments from the Zuari estuary and the adjacent shelf to understand their ... -
Relict ooids off northwestern India: Inferences on their genesis and late Quaternary sea level
Rao, V.P.; Milliman, J.D. (Elsevier, 2017)Relict carbonate sands dominated by ooids and faecal pellets are common on the continental shelf, between 60 and 110m, off northwestern India. The shiny tan/white aragonitic ooids closely resemble modern Bahamian ooids, ... -
Rock magnetic and geochemical record in a sediment core from the eastern Arabian Sea: Diagenetic and environmental implications during the late quaternary
Rao, V.P.; Kessarkar, P.M.; Patil, S.K.; Ahmad, S.M. (Elsevier, 2008)Rock magnetic concentration, grain size and mineralogy parameters together with organic carbon, calcium carbonate, redox-sensitive elements, delta sup(18) O of Globigerinoides ruber and radiocarbon dating were carried out ...