DIRECT ISOTOPE DATING OF A NORTHERN SCHWARZWALD QTZ-BA-HEM VEIN

An epigenetic quartz-barite-hematite vein (Schrotloch, Northern Schwar zwald), located predominantly in the Buhlertal granite, has been dated with the (U+Th)/He-4 method to Late Triassic. Field relations constra in the age to between Hercynian and Tertiary. The result shows that th e entire vein is of post-Bunter age, including the part which cross-cu ts the overlying Lower Bunter and which was hypothesized to be younger . The isotopic age precludes a late-magmatic origin for the vein.