Digital Repository for Área de Conservación Guanacaste, a World Heritage Place.

Nitrogen systematics and gas fluxes of subduction zones: Insights from Costa Rica arc volatiles

Show simple item record Zimmer, Mindy M. Fischer, Tobias P. Hilton, David R. Alvarado, Guillermo E. Sharp, Zachary D. Walker, James A. 2016-06-09T20:41:06Z 2016-06-09T20:41:06Z 2004-05-15
dc.identifier.citation Zimmer, M. M., Fischer, T. P., Hilton, D. R., Alvarado, G. E., Sharp, Z. D., & Walker, J. A. (2004). Nitrogen systematics and gas fluxes of subduction zones: Insights from Costa Rica arc volatiles. Geochemistry, Geophysics, Geosystems Geochem. Geophys. Geosyst., 5(5). es_CR
dc.identifier.issn 1525-2027
dc.identifier.uri 10.1029/2003gc000651
dc.description.abstract Volcanic gases are a powerful tool for assessing magmatic processes in subduction zones. We report gas chemistry and nitrogen isotope compositions of fumaroles, bubbling springs, and geothermal wells from the Costa Rican segment of the Central American volcanic segment (CAVS), and new correlation spectroscopy (COSPEC) SO2 flux measurements of Poa´s and Arenal volcanoes. N2/He ratios (100–8,250) and nitrogen isotope compositions (d 15N = !3.02 to +1.69%) of Costa Rica volatiles are consistent with sources ranging from typical arc-type end-members, with nitrogen addition from the subducting slab, to MORB end-member, having experienced no slab modification. Overall, nitrogen-helium chemistry of Costa Rican material indicates a diminished slab contribution versus other locations along the arc (e.g., Nicaragua and Guatemala). We use SO2 flux measurements of Poa´s and Arenal (1.80*105 ± 4.00*104 and 8.30*103 ± 4.00*103 kg/day, respectively, or 1.30*105 ± 6.25*104 and 2.81*106 ± 6.25*105 mol/day, respectively) to extrapolate a SO2 flux for the Costa Rica segment of 1.09*109 mol/day. Using CO2/St (St = total sulfur) of 2.7 and 5.9, we calculate CO2 fluxes of 1.88*108 and 4.11*108 kg/yr, respectively (2.94*109 and 6.42*109 mol/yr, respectively). Other volatile fluxes (N2, He, H2, Ar, HCl, and H2O) are calculated using CO2/St and regional gas chemistry. For Costa Rica, the output/input ratios of nitrogen are less than unity (0.03 to 0.06 for CO2/St of 2.7 and 5.9, respectively), suggesting more N is subducted than released in the subarc, possibly resulting from sediment offscraping, forearc devolatilization, limited fluid availability in the subarc, or subduction past the subarc. es_CR
dc.language.iso en_US es_CR
dc.publisher Geochemistry, Geophysics, Geosystems es_CR
dc.subject Costa Rica es_CR
dc.subject nitrogen isotopes es_CR
dc.subject recycling es_CR
dc.subject volatile flux es_CR
dc.subject isótopos de nitrógeno es_CR
dc.subject reciclaje es_CR
dc.subject flujo volátil es_CR
dc.title Nitrogen systematics and gas fluxes of subduction zones: Insights from Costa Rica arc volatiles es_CR
dc.type Article es_CR

Files in this item

This item appears in the following Collection(s)

  • Colección Pública
    Artículos de Acceso Abierto y Manuscritos de Investigadores entregados a ACG

Show simple item record

Search COPA


My Account