The international team of geoscientists led by Prof. Silke Voigt from the Goethe University Frankfurt, Prof. Ireneusz Walaszczyk from the University of Warsaw and Dr. André Bornemann from LBEG have thoroughly investigated 40 meters of the geological strata sequence in the former limestone quarry at Hasselberg. The researchers determined that this is only sequence in the transition between Turonian and Coniacian without gaps and it therefore represents a perfect rock sequence to serve geoscientists from all over the world as a reference for their research—a "Global Stratotype Section and Point (GSSP)" or, in the jargon of geosciences, a 'golden nail'.