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This site is maintained by the MARGINS Office. Please share your comments and suggestions with us.
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Browse MARGINS-related
awards in reverse chronological order after start
date (most recent first):
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Collaborative Research: Resolving Mantle, Crustal and Slab Fluxes
to Arc Magmatism in Central America Using Geothermal Fluids and Volcanic
Rocks
| MARGINS Focus Area |
Subduction Factory |
| NSF Org |
EAR |
| Latest Amendment Date |
December 5, 2001 |
| Award Number |
0003668 |
| Award Instrument |
Standard Grant |
| Program Manager |
Sonia Esperanca
EAR DIVISION OF EARTH SCIENCES
GEO DIRECTORATE FOR GEOSCIENCES |
| Start Date |
January 15, 2001 |
| Expires |
November 30, 2003 (Estimated) |
| Expected Total Amount |
$67,281 (Estimated) |
| Investigator |
Tobias P. Fischer (Principal
Investigator current) |
| Sponsor |
University of New Mexico
Sholes Hall
Albuquerque, NM 87131 |
| NSF Program |
1573 PETROLOGY AND GEOCHEMISTRY |
| Field Application |
0000099 Other Applications NEC |
| Abstract |
This proposal is aimed at producing a volatile mass balance for
the Central American subduction zone by quantifying the contributions
from the subducting slab, mantle wedge and overlying crust to the
overall arc budget. The Central American arc was chosen because
it possess a number of unique features which allow explicit linkages
to be forged between systematic variations in volcanic output and
variations in subduction parameters, specifically slab dip, sediment
supply and crustal thickness. Our approach is to couple CO2 and
helium measurements (isotopes and relative abundances) which allows
for identification and quantitative assessment of the various contributors
to the magmatic output. Although a powerful technique, the accuracy
of any flux estimates is limited by uncertainties in the effects
of magmatic degassing on resultant CO2/3He ratios and on assumptions
on the isotopic and abundance characteristics assigned to potential
endmember compositions involved in arc magmagenesis. By analyzing
and comparing the CO2-He relationships in geothermal fluids with
mafic minerals both along and across the Central America arc, we
aim to explore the extent of these limitations and to assess approaches
with the potential to circumvent any difficulties. Additionally,
we will derive present-day CO2 fluxes through combined COSPEC and
gas chemistry studies. This offers the further possibility of deriving
absolute fluxes for N2 and H2O and for also constraining their provenance
in the subduction zone factory. |
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