Petrotectonic evolution of the high- to ultrahigh-pressure Maksyutov Complex, Karayanova area, south Ural Mountains: structural and oxygen isotope constraints

Lithos ◽  
2000 ◽  
Vol 52 (1-4) ◽  
pp. 235-252 ◽  
Author(s):  
Mary L Leech ◽  
W.G Ernst
Keyword(s):  
Oxygen Isotope ◽  
Ultrahigh Pressure ◽  
Ural Mountains ◽  
Maksyutov Complex

Petrotectonic origin of mafic eclogites from the Maksyutov subduction complex, south Ural Mountains, Russia

2021 ◽  
Author(s):  
Valentin V. Fedkin ◽  
Theodore D. Burlick ◽  
Mary L. Leech ◽  
Andrey A. Shchipansky ◽  
Peter M. Valizer ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Oceanic Island ◽  
Ultrahigh Pressure ◽  
Late Paleozoic ◽  
Bulk Rock ◽  
Ural Mountains ◽  
Physical Conditions ◽  
Thermal Maximum ◽  
Maksyutov Complex ◽  
Island Basalt

ABSTRACT The Maksyutov complex is a mid- to late-Paleozoic high- to ultrahigh-pressure (HP-UHP) eclogite-bearing subduction zone terrane in the south Ural Mountains. Previous reports of radial fractures emanating from quartz inclusions in garnet, omphacite, and glaucophane, cuboid graphite pseudomorphs after matrix diamond, and microdiamond aggregates preserved in garnet identified by Raman spectroscopy indicate that parts of the complex were subjected to physical conditions of ∼600 °C and >2.8 GPa for coesite-bearing rocks, and >3.2 GPa for diamond-bearing rocks. Peak UHP eclogite-facies metamorphism took place at ca. 385 Ma, and rocks were exhumed through retrograde blueschist-facies conditions by ca. 360 Ma. Bulk analyses of 18 rocks reflect the presence of mid-oceanic-ridge basalt (MORB), oceanic-island basalt (OIB), and island-arc tholeiite (IAT) basaltic and andesitic series plus their metasomatized equivalents. To more fully constrain the petrotectonic evolution of the complex, we computed isochemical phase equilibria models for representative metabasites in the system Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2 based on our new bulk-rock X-ray fluorescence (XRF) data. Both conventional Fe-Mg exchange thermometry and phase equilibrium modeling result in higher peak equilibrium temperatures than were previously reported for the complex. Pseudosection analysis provides minimum P-T conditions of 650–675 °C and 2.4–2.6 GPa for peak assemblages of the least retrogressed Maksyutov eclogites, whereas Fe-Mg exchange thermometry yields temperatures of 750 ± 25 °C for a pressure of 2.5 GPa. We interpret our new P-T data to reflect a thermal maximum reached by the eclogites on their initial decompression-exhumation stage, that defines a metamorphic field gradient; the relict coesite and microdiamond aggregates previously reported testify to pressure maxima that define an earlier prograde subduction zone gradient. The eclogitic Maksyutov complex marks underflow of the paleo-Asian oceanic plate and does not represent subduction of the Siberian cratonal margin.

Tectonic Setting and Petrology of Ultrahigh-Pressure Metamorphic Rocks in the Maksyutov Complex, Ural Mountains, Russia

1996 ◽  
Vol 38 (2) ◽  
pp. 136-160 ◽  
Author(s):  
N. L. Dobretsov ◽  
V. S. Shatsky ◽  
R. G. Coleman ◽  
V. I. Lennykh ◽  
P. M. Valizer ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Ultrahigh Pressure ◽  
Metamorphic Rocks ◽  
Ural Mountains ◽  
Maksyutov Complex

scholarly journals In Situ Oxygen Isotope Determination in Serpentine Minerals by Ion Microprobe: Reference Materials and Applications to Ultrahigh-Pressure Serpentinites

2018 ◽  
Vol 42 (4) ◽  
pp. 459-479 ◽  
Author(s):  
Maria Rosa Scicchitano ◽  
Daniela Rubatto ◽  
Jörg Hermann ◽  
Tingting Shen ◽  
José Alberto Padrón-Navarta ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Reference Materials ◽  
Ultrahigh Pressure ◽  
Ion Microprobe ◽  
Serpentine Minerals ◽  
Isotope Determination
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