@misc{10481/91040,
year = {2024},
month = {1},
url = {https://hdl.handle.net/10481/91040},
abstract = {Multiple studies have applied zoned garnet geochronology to place temporal constraints on
the rates of metamorphism and deformation during orogenesis. We report new high-resolution
isotope dilution–thermal ionization mass spectrometry Sm-Nd isochron ages on concentric
growth zones from microstructurally and thermodynamically characterized garnets from
the Betic Cordillera, southern Spain. Our ages for the garnet core (13.64 ± 0.31 Ma), mantle
(13.41 ± 0.37 Ma), and rim (13.34 ± 0.45 Ma) indicate rapid garnet growth and are consistent
with published garnet ages interpreted to reflect high-pressure metamorphism in the
region. Thermodynamic analysis indicates garnets grew during subduction at ∼1.5–2.0 GPa
and 570–600 °C. The core to rim duration of spiral garnet growth was just a few hundred
thousand years. While other zoned garnet studies have shown similar rapid growth in subduction
zone settings, this is the first documentation of such rapid growth of a spiral garnet.
Combining this garnet growth duration with the magnitude of spiral inclusion trail curvature,
we compute a strain rate of ∼10−13 s−1, an order of magnitude faster than all previous spiral
garnet studies. We interpret that these spiral garnets recorded a rapid pulse of deformation
and strain during the final stages of subduction and incipient exhumation.},
organization = {Spanish grants CGL2015–65602-R (AEI-FEDER), P18-RT-3275, and B-RNM-301-UGR18 (Junta de Andaucía/FEDER)},
organization = {U.S. National Science Foundation grants PIRE-1545903 and EAR-1946651},
publisher = {Geological Society of America},
title = {Rapid development of spiral garnets during subduction zone metamorphism revealed from high-resolution Sm-Nd garnet geochronology},
doi = {10.1130/G51882.1},
author = {Farrell, Thomas P. and Aerden, Domingo Gerard and Baxter, Ethan F. and Starr, Paul G. and Williams, Mike L.},
}