Most of the island consists of pervasively overprinted, greenschist-facies sequences.
Two generations of folds can be distinguished by overprinting relations.
Several brittle extensional micro-faults bear a ductile overprint expressed in the folding of both foliation and fault surfaces.
In highly sheared regions of the phyllonite, the only evidence preserved is for extension, with any strike-slip fabrics having been entirely re-worked and overprinted.
This is mainly due to the penetrative last overprint under greenschist-facies conditions, which erased all relic features of foregoing events.
Exact metamorphic conditions during the last overprint are difficult to constrain, due to the lack of suitable petrological tools for greenschist-facies mineral assemblages.
Such anomalously low values can be attributed to overprinting by isotopically light cements precipitated during diagenesis of the organic-rich intervals.
Our studied samples were most likely affected by several metamorphic overprints, such as burial, regional and/or contact metamorphism.
