geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Sr-Nd isotopic studies of Narcondam Volcanics, India; constraints on Andaman-Indonesian arc magmatism


, : Sr-Nd isotopic studies of Narcondam Volcanics, India; constraints on Andaman-Indonesian arc magmatism. Mineralogical Magazine 75.3: 525

Narcondam island, part of Andaman group of islands of India is a dormant volcano of Andaman-Indonesia island arc related to oblique subduction of Indian plate beneath the SE Asian plate. Unlike the active Barren Island volcano of Andaman arc, which erupts basaltic to basaltic-andesite lavas, Narcondam samples, studied during the present study, range from basaltic- andesites to dacites with majority of them plotting in andesitic field of Total Alkali Silica (TAS) classification diagram. Origin of andesitic lavas has been explained variably, ranging from models of hydrous melting of mantle-wedge to models of mixing of basaltic magma with rhyolitic magma at shallower depths [1]. Narcondam andesites show mineral textures, such as resorbed rims of plagioclase phenocrysts, Na rich layers sandwiched between Ca rich layers of plagioclase crystals and at least two generations of phenocrysts, indicating compositional changes in magma not related to fractional crystallization. Presence of rhyolitic glass inclusions, and olivine and quartz crystals together are reported from Narcondam samples in an earlier study [2]. It is therefore suggested that andesitic lavas are not primary melt but probably resulted from mixing of basaltic and rhyolitic magmas. Sr and Nd isotope ratios are used to quantify the mixing and it appears that andesites of Narcondam and also other andesitic volcanoes of Sunda arc may have resulted from variable but small inputs of sediments (<5%) to the mixed magma which has 70 to 80% contribution from Barren Island type basaltic melt and 15-20% of rhyolitic melt similar to that erupted in Sunda arc elsewhere [3]. [1] Kent et. al. (2010) Nature Geoscience 3, 632-636. [2] Pal et. al. (2007) Journal Volcano. Geotherm. Res. 168, 93-113. [3] Turner and Foden (2001) Contrib. Min. Pet., 142, 43-57.

US$29.90


Other references

Shakofsky S.M.; Nimmo J.R., 1994: Improved laboratory and field techniques for measuring unsaturated flow at the Idaho National Engineering Laboratory. Abstracts with Programs - Geological Society of America 26(7): 442

Grävinghoff, J.; Hanson, H., 1969: Effect of light and reducing substances on the reaction of tyrosine with 1-nitroso-2-naphthol. Acta Biologica et Medica Germanica 22(3): 461-471

Sysa P.S.; Hohn H.; Schmidt I., 1977: Nucleolus organizers in chromosomes of some domestic animals. Annales de Genetique et de Selection Animale 9(4): 540-541

Aoyagi, M.; Yamazaki, Y.; Yokota, M.; Fuse, T.; Suzuki, Y.; Itoh, S.; Watanabe, T., 1996: Frequency specificity of 80-Hz amplitude-modulation following response. The usefulness of 80-Hz amplitude-modulation following response (AMFR) detected by phase coherence to predict the hearing threshold during sleep was evaluated in 90 ears of 53 children with hearing impairment. The threshold of 80-Hz AMFR at carrie...

Gómez-Restrepo, C.; Bohórquez Peñaranda, A.Patricia.; Ávila, M.J.; Jaramillo González, L.Eduardo.; Vélez Fernández, C.; Vélez Traslaviña, Ángela.; García Valencia, J.; Pinzón-Amado, A., 2014: Pharmacological Treatment for Adult Diagnosed With Schizophrenia With Agitation or Violent Behavior. To determine the most effective pharmacological intervention and to bring recommendations for decision-making in the management of adults with schizophrenia with violent behavior or agitation. A clinical practice guideline was elaborated under the...

Karaca, A.; Kevseroglu, K., 1999: The research of some important agricultural characters of coriander (Coriandrum sativum L.) and fennel (Foeniculum vulgare Mill.) varieties of Turkish origin. During a study conducted at Samsun, Turkey, in 1996/97, 8 coriander varieties originating from Erzurum (large and small), Burdur, Tokat, Hatay, Usak, Carsamba and Kbrs, and 2 fennel varieties originating from Hatay and Denizli were used to examine...

Oberg, G.; Mellander, O., 1955: Antibody formation and nutrition. 2. Antibody titre in lambs and goats fed on homologous and heterologous milk using influenza and diphtheria vaccine as antigens. For part I see Abet. 3807, Vol. 23. 2. The experiment reported in the earlier paper was repeated with 5 more pairs of twin lambs, with similar results. Ten goat kids were removed from their dams when 2 days old and bottle-fed with fresh cow's...

Andrieu, J.; Barny, S.; Colardelle, P.; Maisonneuve, P.; Giraud, V.; Robin, E.; Bréart, G.; Coste, T., 1995: Prevalence and risk factors of hepatitis C virus infection in a hospitalized population in a gastroenterology unit. Role of endoscopic biopsies. In order to study the prevalence and risk factors of HCV infection in a population hospitalized in a Gastroenterology Unit, 3,767 patients were tested for serum anti-HCV, and 2,607 filled out a questionnaire about risk factors. With the RIBA 2 tes...

Spangler, E.L.; Goodney, P.P.; Schanzer, A.; Stone, D.H.; Schermerhorn, M.L.; Powell, R.J.; Cronenwett, J.L.; Nolan, B.W., 2015: Outcomes of carotid endarterectomy versus stenting in comparable medical risk patients. In medically high-risk patients the choice between carotid artery stenting (CAS) and carotid endarterectomy (CEA) can be difficult. The purpose of this study was to compare risk-stratified outcomes of CAS and CEA. Patients who underwent isolated p...

Palacios, M.C.; Haros, M.; Rosell, C.M.; Sanz, Y., 2004: Characterization of an acid phosphatase from Lactobacillus pentosus: regulation and biochemical properties. Aims: To screen for phosphatase and phytase activities in Lactobacillus isolated from diverse ecosystems and to determine the biochemical properties and the factors that regulate the synthesis of the enzyme responsible for these activities in the...