After establishing the NL oils as a single type, Clayton and Koncz<ref name=ch08r6 /> determined the source potential for the available sedimentary section using 26 core samples and attempted to correlate the NL oils to each of the possible sources. Just as the first screening step for the oil–oil correlation involved δ<sup>13</sup>C values of the aliphatic and aromatic hydrocarbons, the first screening step for the oil–source rock correlation effort involved comparing δ<sup>13</sup>C of the whole oils and bitumens from the source candidates. Their results indicate that two potential sources [the Upper Triassic Kössen Marl and the Sarmatian (middle Miocene) shales] have very similar δ<sup>13</sup>C values. When these carbon isotope data are combined with oleanane–hopane ratios and C<sub>27</sub>–C<sub>29</sub> sterane distributions, cluster analysis comparison supports a dominantly Upper Triassic source for the NL oils, with possibly a minor contribution from the Sarmatian (middle Miocene) shales. | After establishing the NL oils as a single type, Clayton and Koncz<ref name=ch08r6 /> determined the source potential for the available sedimentary section using 26 core samples and attempted to correlate the NL oils to each of the possible sources. Just as the first screening step for the oil–oil correlation involved δ<sup>13</sup>C values of the aliphatic and aromatic hydrocarbons, the first screening step for the oil–source rock correlation effort involved comparing δ<sup>13</sup>C of the whole oils and bitumens from the source candidates. Their results indicate that two potential sources [the Upper Triassic Kössen Marl and the Sarmatian (middle Miocene) shales] have very similar δ<sup>13</sup>C values. When these carbon isotope data are combined with oleanane–hopane ratios and C<sub>27</sub>–C<sub>29</sub> sterane distributions, cluster analysis comparison supports a dominantly Upper Triassic source for the NL oils, with possibly a minor contribution from the Sarmatian (middle Miocene) shales. |