Department of Geosciences, Eberhard Karls University, Tübingen, 72076, Tübingen, Germany.
Senckenberg Centre for Human Evolution and Palaeoenvironment, Tübingen, Germany.
Sci Rep. 2021 Oct 11;11(1):19427. doi: 10.1038/s41598-021-98618-0.
We present an updated time frame for the 30 m thick late Miocene sedimentary Trachilos section from the island of Crete that contains the potentially oldest hominin footprints. The section is characterized by normal magnetic polarity. New and published foraminifera biostratigraphy results suggest an age of the section within the Mediterranean biozone MMi13d, younger than ~ 6.4 Ma. Calcareous nannoplankton data from sediments exposed near Trachilos and belonging to the same sub-basin indicate deposition during calcareous nannofossil biozone CN9bB, between 6.023 and 6.727 Ma. By integrating the magneto- and biostratigraphic data we correlate the Trachilos section with normal polarity Chron C3An.1n, between 6.272 and 6.023 Ma. Using cyclostratigraphic data based on magnetic susceptibility, we constrain the Trachilos footprints age at ~ 6.05 Ma, roughly 0.35 Ma older than previously thought. Some uncertainty remains related to an inaccessible interval of ~ 8 m section and the possibility that the normal polarity might represent the slightly older Chron C3An.2n. Sediment accumulation rate and biostratigraphic arguments, however, stand against these points and favor a deposition during Chron C3An.1n.
我们提出了克里特岛 Trachilos 厚达 30 米的晚中新世沉积剖面的更新时间框架，该剖面包含可能最古老的人类足迹。该剖面的特征是正常的磁极。新的和已发表的有孔虫生物地层学结果表明，该剖面的年龄在 MMi13d 地中海生物带内，比6.4Ma 年轻。来自 Trachilos 附近暴露的沉积物的钙质超微化石数据属于同一子流域，表明沉积发生在钙质超微化石生物带 CN9bB 期间，在 6.023 和 6.727 Ma 之间。通过整合磁和生物地层学数据，我们将 Trachilos 剖面与正常极性 Chron C3An.1n 相关联，该剖面的年龄在 6.272 和 6.023 Ma 之间。利用基于磁化率的旋回地层学数据，我们将 Trachilos 足迹的年龄约束在6.05 Ma，比之前认为的要早大约 0.35 Ma。与无法访问的~8 m 剖面间隔以及正常极性可能代表稍老的 Chron C3An.2n 有关的不确定性仍然存在。然而，沉积速率和生物地层学论点反对这些观点，并支持在 Chron C3An.1n 期间进行沉积。
