[Grimmer] Magnetofabrics of shear zones and ultrahigh-pressure rocks from the Chinese Continental Scientific Drilling (CCSD)
German Title: Magnetofabrics of shear zones and ultrahigh-pressure rocks from the Chinese Continental Scientific Drilling (CCSD)
Current Status: completed
Main Applicant:Dr. Jens Carsten Grimmer
The Chinese Continental Scientific Drilling (CCSD) in Donghai intersected crustal and mantle ultrahigh-pressure (UHP) rocks from the Triassic-Jurassic Sulu-UHP-orogen in eastern China. The CCSD provides a 5.1 km vertical section of stacked UHP-rocks separated by shear zones. The intersected rocks mainly comprise eclogites, amphibolites, gneisses, and minor peridotites. Coesite inclusions in garnet and zircon from eclogites and gneisses indicate that the intersected rocks were subducted to upper mantle depths (>80 km) and subsequently exhumed. Rock magnetic studies on drill core samples provide a unique chance to monitor vertical changes of structural elements, strain gradients, fluid-rock interactions, and changes of oxygen fugacities especially across ductile shear zones. A focus will be placed on rock magnetic properties (anisotropy of and temperature dependent magnetic susceptibility, magneto-mineralogy) of peridotites, eclogites, and high-grade shear zones in gneisses. The susceptibility tensor comprises two fabric components which can be isolated and which recorded the same or different and thus possible polyphase or progressive deformation. Rock magnetic studies contribute to questions related with structural geology, petrology, mineralogy, and geochemistry, and thus may contribute to a better understanding of exhumation processes by its multidisciplinary approach.
Grimmer, JC, Qi, X, Xu, Z (2009). "Magnetofabrics of eclogites and ultramafic rocks from the Chinese Continental Scientific Drilling (CCSD) project: evidence for ultrahigh-pressure (UHP) texture inheritance throughout retrogression" Geotectonic Research Number 0 p59-61
Xuexiang, Qi, Grimmer, Jens C, Zhiqin, Xu (2009). "Ultrahigh-pressure texture inheritance during retrogression: Evidence from magnetofabrics in eclogites and ultramafic rocks (Chinese Continental Scientific Drilling project)" Tectonophysics 475 p267-278