Contribution of ductile flow to exhumation of low-temperature, high-pressure metamorphic rocks: San Juan-Cascade nappes, NW Washington State

1999 ◽  
Vol 104 (B5) ◽  
pp. 10883-10902 ◽  
Author(s):  
Jeffrey G. Feehan ◽  
Mark T. Brandon
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Washington State ◽  
Metamorphic Rocks ◽  
San Juan ◽  
Ductile Flow

scholarly journals Exhumation Paths of High-Pressure–Low-Temperature Metamorphic Rocks from the Lycian Nappes and the Menderes Massif (SW Turkey): a Multi-Equilibrium Approach

2004 ◽  
Vol 46 (3) ◽  
pp. 641-669 ◽  
Author(s):  
GAËTAN RIMMELÉ ◽  
TEDDY PARRA ◽  
BRUNO GOFFÉ ◽  
ROLAND OBERHÄNSLI ◽  
LAURENT JOLIVET ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Metamorphic Rocks ◽  
Menderes Massif ◽  
Sw Turkey ◽  
Equilibrium Approach

scholarly journals Insights from elastic thermobarometry into exhumation of high-pressure metamorphic rocks from Syros, Greece

Solid Earth ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 1335-1355
Author(s):  
Miguel Cisneros ◽  
Jaime D. Barnes ◽  
Whitney M. Behr ◽  
Alissa J. Kotowski ◽  
Daniel F. Stockli ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Oxygen Isotope ◽  
Thermal Conditions ◽  
Garnet Growth ◽  
Metamorphic Rocks ◽  
Core Complex ◽  
Pressure Groups ◽  
Mineral Growth ◽  
Metamorphic Terranes

Abstract. Retrograde metamorphic rocks provide key insights into the pressure–temperature (P–T) evolution of exhumed material, and resultant P–T constraints have direct implications for the mechanical and thermal conditions of subduction interfaces. However, constraining P–T conditions of retrograde metamorphic rocks has historically been challenging and has resulted in debate about the conditions experienced by these rocks. In this work, we combine elastic thermobarometry with oxygen isotope thermometry to quantify the P–T evolution of retrograde metamorphic rocks of the Cycladic Blueschist Unit (CBU), an exhumed subduction complex exposed on Syros, Greece. We employ quartz-in-garnet and quartz-in-epidote barometry to constrain pressures of garnet and epidote growth near peak subduction conditions and during exhumation, respectively. Oxygen isotope thermometry of quartz and calcite within boudin necks was used to estimate temperatures during exhumation and to refine pressure estimates. Three distinct pressure groups are related to different metamorphic events and fabrics: high-pressure garnet growth at ∼1.4–1.7 GPa between 500–550 ∘C, retrograde epidote growth at ∼1.3–1.5 GPa between 400–500 ∘C, and a second stage of retrograde epidote growth at ∼1.0 GPa and 400 ∘C. These results are consistent with different stages of deformation inferred from field and microstructural observations, recording prograde subduction to blueschist–eclogite facies and subsequent retrogression under blueschist–greenschist facies conditions. Our new results indicate that the CBU experienced cooling during decompression after reaching maximum high-pressure–low-temperature conditions. These P–T conditions and structural observations are consistent with exhumation and cooling within the subduction channel in proximity to the refrigerating subducting plate, prior to Miocene core-complex formation. This study also illustrates the potential of using elastic thermobarometry in combination with structural and microstructural constraints, to better understand the P–T-deformation conditions of retrograde mineral growth in high-pressure–low-temperature (HP/LT) metamorphic terranes.

Zircon U-Pb and geochemical signatures in high-pressure, low-temperature metamorphic rocks as recorders of subduction zone processes, Sikinos and Ios islands, Greece

2021 ◽  
pp. 120447
Author(s):  
Eirini M. Poulaki ◽  
Daniel F. Stockli ◽  
Megan E. Flansburg ◽  
Michelle L. Gevedon ◽  
Lisa D. Stockli ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Subduction Zone ◽  
Metamorphic Rocks ◽  
Subduction Zone Processes
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