Browsing by Subject "geochemistry"
Now showing items 1-20 of 115
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A comparative study of Pleistocene phosphorites from the continental slope off western India
(Blackwell, 2000)Two types of phosphorite recovered from the continental slope off western India are described. The first type, phosphorite 1, comprises a hard, grey nodule composed of carbonate fluorapatite (CFA) and calcite as major ... -
A new report on the occurrence of zeolitites in the abyssal depths of the Central Indian Basin
(Society for Sedimentary Geology, 1993)Forty-two indurated slabs of zeolites collected from the abyssal depths of the Central Indian Basin have been studied. The slabs show characters similar to harmotome-rich scorias of the Society Ridge and phillipsite slabs ... -
A petrogenetic model of basalts from the Northern Central Indian Ridge: 3-11°S
(Geological Society of China, 2007)Mid-Ocean Ridge Basalts (MORB) from Northern Central Indian Ridge (NCIR) were recovered between latitudes 30 and 110S and are olivine tholeiite with higher abundances of K and Rb. They are of typical transitional MORB ... -
A predictive regression model for the geochemical variability of iron and manganese in a coral reef ecosystem
(Taylor and Francis, 2005)This article focuses on the influence of nutrient forms (nitrogen/phosphorous forms) and parameters like pH and organic carbon in the distributional characteristics of two important trace metals, viz. iron and manganese, ... -
Aeolian deposition of Arabia and Somalia sediments on the southwestern continental margin of India
(Current Science Association, Bangalore, India, 1996)Kaolinite, smectite, illite and chlorite as major clay minerals and palygorskite and gibbsite in minor quantities have been recorded from the slope of southwestern continental margin of India. Contribution of kaolinite, ... -
Alteration of basaltic glasses from the Central Indian Ocean
(Geological Society of India, 1999)Textural, mineralogical and compositional characteristics of basaltic glasses from the Central Indian Ocean show them to be altered to varying extents through their interaction with the seawater, resulting in the formation ... -
Alterations in geochemical associations in artificially disturbed deep-sea sediments
(Taylor and Francis, 2005)In view of the role of sediment geochemistry in regulating the benthic ecosystem, diagenetic remobilization of dissolved constituents, bottom water redox, and regeneration of benthic fluxes, surficial sediments in and ... -
Analysis of sup(210)Pb in sediment trap samples and sediments from the northern Arabian Sea: Evidence for boundary scavenging
(Pergamon, 2002)The concentrations of sup(210)Pb were measured in particles intercepted by sediment traps deployed at 1024 m and 3024 m in the northern Arabian Sea for a period of 1 year from November 1986 to October 1987. The sup(210)Pb ... -
Anomalous behaviour of uranium isotopes in backwater sediments of Zuari river
(Elsevier, 1983)The surface leaching of the labile component of uranium has been carried out in estuarine sediments of Zuari River in Goa, India The measurements of alpha activities of sup(238) U, sup(235) U and sup(234) U in the leachates ... -
Atypical ferromanganese micronodules from middle fan-valley system, Bay of Bengal
(Current Science Association, 1994)Ferromanganese micronodules having botryoidal and spheroidal morphogroups have been observed over a 0.22 million km@u2@@ area from the middle fan region of the Bay of Bengal. The bulk micronodules have 26.26% Mn, 1.02% Fe, ... -
Australasian microtektites from the Central Indian Basin: Implications for ejecta distribution patterns
(Current Science Association, Bangalore, India, 1996)Microtektites belonging to the Australasian tektite strewn field have been recovered in one (SK-16/176) out of three cores examined from the Central Indian Basin. The microtektites have been identified based on their ... -
Australasian microtektites in a substrate: A new constraint on ferromanganese crust accumulation rates
(Elsevier, 1994)Microtektites belonging to the Australasian tektite strewn field are found in the substrate of a ferromanganese crust dredged from the Central Indian Basin. They are identified on their physical appearance, geographic ... -
Australian minitektites discovered in the Indian Ocean
(Meteoritical Society, Fayetteville, USA, 1999)Large area sampling with a box core in the Indian Ocean has led to the discovery of minitektites (> 1-3.75 mm long) and a tektite fragment (approx 1.25 mm) occuring with microtektites belonging to the Australasian tektite ... -
Bacterial response to contrasting geochemistry in the sediments of central Indian Ocean basin
(Regional Research laboratory, Bhubaneswar, 2005)The latitudinal differences in geochemical and physiographic nature could evoke varied biological/microbiological response in the deep-sea benthic ecosystem of the Central Indian Ocean. Sediment cores have been examined ... -
Barium as a productivity proxy in continental margin sediments: A study from the eastern Arabian Sea
(Elsevier, 2002)Barium, aluminium, cadmium and uranium were analyzed in 112 surface sediment samples from the western continental margin, of India. Excess Ba (Ba sub(xs)) concentrations are high at the SW margin of India, an area of high ... -
Buried nodules from the central Indian Ocean basin
(Regional Research laboratory, Bhubaneswar, 2005)The occurrence of buried nodules is rare compared to surface nodule abundance in the deep sea. Surface nodules are collected with freefall grab, vanveen /peterson grabs, dredges and sediment cores whereas buried nodules ... -
Clay mineralogy of the mud banks of Cochin
(Current Science Association, 1968)The mineralogy of the sediments constituting the mud banks formed off Cochin, Kerala, India was studied. The clay mineral composition was used as a means of understanding the nature and source of origin of the muds. Fine ... -
Clay minerals as palaeomonsoon proxies: Evaluation and relevance to the late Quaternary records from SE Arabian Sea
(NCAOR, Goa, 2005)Palaeoclimatic studies are largely dependent on the quality of records and a prudent use of environmental proxy indicators. In this study, the factors affecting the detrital clay minerals in marine environment and their ... -
Coexistence of pumice and manganese nodule fields-evidence for submarine silicic volcanism in the Central Indian Basin
(Pergamon, 1993)Pumice, of various shapes and sizes, uncoated or coatEd. by ferromanganese oxides, have been recovered from deeper parts of the Central Indian Basin (CIB). The pumice field covers an area of 600,000 km sup(2), approximately ... -
Constraints in using Cerium-animaly of bulk sediments as an indicator of paleo bottom water redox environment: A case study from the Central Indian Ocean Basin
(Elsevier, 2005)The total rare earth elements (Sigma REE) abundance along with major and a range of trace element chemistry of twenty-eight sub-sections in a 5 m long sediment core (AAS-05/GC-02) from the Central Indian Ocean Basin shows ...