Metamorphic data from global subduction zones do not call for excessive
overpressures
Dazhi Jiang
Department of Earth Sciences, Western University, Canada, Department of Earth Sciences, Western University, Canada, Department of Earth Sciences, Western University, Canada
Corresponding Author:[email protected]
Author ProfileAbstract
Yamato and Brun (Nature Geoscience 10, 46-50, 2017) claimed that
metamorphic data from global (ultra)high-pressure ((U)HP) rocks exhibit
an unusual linear relation, between peak pressure and pressure drop,
which challenges current interpretation of P-T-t paths but supports
their model invoking excessive overpressures. If their model holds, most
research on (U)HP rocks since their discovery would require serious
reconsideration. Here, I demonstrate that their model requires critical
assumptions that are neither justified by the principles of rock
mechanics in the context of realistic geologic settings nor consistent
with microstructures of (U)HP rocks. Furthermore, contrary to their
claim, the global (U)HP data can be readily explained in the current
framework but are inconsistent with their model prediction.