[en] 44 delta¹³C-values for carbonaceous matter in a metamorphic profile from the Swiss Alps have been determined. The analyzed samples range from unmetamorphosed sediments to staurolite schists. The carbon isotopic composition is more-or-less constant with delta-values around - 25 parts per thousand in the unmetamorphosed sediments, but shifts towards higher ¹³C-content with increasing grade of metamorphism. delta¹³C values of around - 11 parts per thousand were measured in the rocks of the highest metamorphic grade. (author)