Low-grade metamorphic black slates of Silurian and Lower Devonian ages (from the
Thüringisches Schiefergebirge in Germany) were investigated to identify mineralogical and
geochemical alterations that occur during the oxidative weathering black slates. The slates
exhibit an intense total organic carbon decrease (> 90wt%) due to oxidative weathering. The
organic matter in black slate consists mainly of non-pyrolysable material with only minor
portions of pyrolysable material. In contrast to the non-pyrolysable organic matter, the …