[Müller] Transmission electron microscopy of deformed eclogite from the Chinese Continental Scientific Drilling project at Donghai
German Title: Transmission electron microscopy of deformed eclogite from the Chinese Continental Scientific Drilling project at Donghai
Current Status: completed with report
Main Applicant:Prof. Dr. Wolfgang Friedrich Müller
Eclogite, especially deformed eclogite (and eventually other ultrahigh pressure metamorphic rocks), from the Chinese Continental Scientific Drilling project in Dabie Shan will be studied by methods of transmission electron microscopy (TEM). The study shall contribute to the knowledge of formation and exhumation of ultrahigh pressure metamorphic rocks. Nature, density, distribution and orientation of crystal defects, phase- and grain-boundaries of the eclogite minerals present (garnet, omphacite, amphiboles, epidote group, Fe-Ti-Oxides, cyanite, micas, etc.) have to be characterized. They are generated during crystal growth, by phase transformations - including mineral reactions - and by deformation. In principle, they permit conclusions regarding the pressure, temperature and deformation history of the rocks. However, the basis of data and knowledge is weak so far. E.g., the slip systems of omphacite, which is the main constituent and the mineral carrying the deformation of eclogite, are not sufficiently well known, especially not as function of pressure and temperature.Comparison with eclogites from other localities, which experienced lower pressures, should reveal eventual peculiarities of the behaviour of ultrahigh pressure metamorphic eclogites. The TEM study will be performed on samples also investigated by other groups in order to obtain integral information from eclogites whose mineralogy, petrology and geochemistry is well characterized.
Müller, Wolfgang Friedrich, Xu, Zhiqin, Brenker, Frank E (2011). "Transmission electron microscopy of omphacite and other minerals in eclogites from the CCSD borehole, China: indications for their deformation and temperature history" European Journal of Mineralogy 23 p645-659