P-T-t constraints on exhumation following subduction in the Rheic Ocean from eclogitic rocks in the Acatlan Complex of southern Mexico
P-T-t constraints on exhumation following subduction in the Rheic Ocean from eclogitic rocks in the Acatlan Complex of southern Mexico (in The evolution of the Rheic Ocean; from Avalonian-Cadomian active margin to Alleghenian-Variscan collision, Ulf Linnemann (editor), R. Damian Nance (editor), Petr Kraft (editor) and Gernold Zulauf (editor))
Special Paper - Geological Society of America (2007) 423: 489-509
- absolute age
- Acatlan Complex
- chemical composition
- crystal chemistry
- dates
- deformation
- eclogite facies
- exhumation
- facies
- faults
- geochemistry
- Gondwana
- intrusions
- ion probe data
- mass spectra
- metamorphic rocks
- Mexico
- mineral composition
- nesosilicates
- Ordovician
- orthosilicates
- P-T-t paths
- paleogeography
- Paleozoic
- Pangaea
- petrography
- petrology
- plate tectonics
- plutons
- Puebla Mexico
- Rheic Ocean
- SHRIMP data
- silicates
- spectra
- structural analysis
- subduction
- tectonics
- textures
- thrust faults
- U/Pb
- zircon
- zircon group
- Tecomate Formation
- Cosoltepec Formation
- Patlanoaya Formation
- Totoltepec Pluton
- Piaxtla Suite
- Esperanza Granite
- Petlalcingo Suite
The Piaxtla Suite of the Acatlan Complex (southern Mexico) has previously been considered a vestige of the Iapetus Ocean that underwent eclogite-facies metamorphism during Late Ordovician subduction and exhumation. Study of granitoid, mafic, and metasedimentary rocks of the Asis Lithodeme of the Piaxtla Suite reveals a complex tectonothermal history involving: (1) eclogite-facies syntectonic metamorphism preserved as aligned omphacite in mafic lenses dated at 346+ or -3 Ma (concordant U-Pb zircon age), which is inferred to result from subduction; (2) polyphase deformation involving WSW-ENE tectonic transport under amphibolite-facies conditions accompanied by migmatization due to decompression melting dated at ca. 347-330 Ma (SHRIMP [sensitive high-resolution ion microprobe] zircon ages); (3) continued deformation under greenschist facies; and (4) development of several phases of late folds and crenulation cleavage.
