|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This site is maintained by the MARGINS Office. Please share your comments and suggestions with us.
|
|
|
Browse MARGINS
Awards in reverse chronological order after start
date (most recent first):
|
|
|
 |
MARGINS: Oxygen Isotope Studies of the Central American Arc
| MARGINS Focus Area |
Subduction Factory |
| NSF Org |
OCE |
| Latest Amendment Date |
August 13, 2001 |
| Award Number |
0112132 |
| Award Instrument |
Standard Grant |
| Program Manager |
Rodey Batiza
OCE DIVISION OF OCEAN SCIENCES
GEO DIRECTORATE FOR GEOSCIENCES |
| Start Date |
August 1, 2001 |
| Expires |
July 31, 2004 (Estimated) |
| Expected Total Amount |
$151,315 (Estimated) |
| Investigator |
John M. Eiler (Principal
Investigator current) |
| Sponsor |
California Inst of Tech
1201 E California Blvd
Pasadena, CA 91125 |
| NSF Program |
1620 MARINE GEOLOGY AND GEOPHYSICS |
| Field Application |
0204000 Oceanography |
| Abstract |
In this proposed study the PI and collaborators (Mark
Reagan, Iowa; Mike Carr, Rutgers) propose to measure the oxygen
isotope values (ð18O) in Central America Volcanic Arc (CAVA) lavas
in order to distinguish mantle wedge processes involving subducted
upper crustal materials, from assimilation/contamination of rising
magmas with in situ upper crustal materials. In the former case,
one would expect a correlation between ð18O and proxies of the extent
of melting (e.g. U/Th, Na6) and/or mantle source tracers (e.g. 87Sr/86Sr.
In the latter, one would expect correlation of ð18O with proxies
of contamination, assimilation, and differentiation (like MgO or
Mg#). A pilot study of ~30 samples from CAVA show very surprising
results- there are correlations between d18O and indices of melting,
however large extents of melting and radiogenic 87Sr/86Sr are associated
with low ð18O, not high ð18O as expected for common sources of slab-derived
metasomatizing agents. The PIs propose to collect more d18O data
for more well-characterized samples in order to try to understand
the puzzling results of the pilot study. |
|
