Very low-grade metamorphism of Rheno-Hercynian allochthons (Variscides, Germany): facts and tectonic consequences

The Horre Belt in the SE part of the Rhenish Massif has been regarded as autochthonous because of the apparent lack of metamorphic inversion. We have performed a K-white mica study using powder X-ray diffraction derived Kubler Index (KI) and K-white mica b cell dimension, and the spectrally derived wavelength of the 2,200 nm absorption feature (“2200wvl”) of supposedly allochthonous units and the underlying par-autochthon. KI reveals a slight,...