A continental-scale Eurasian ice sheet 2.4 million years ago.

Wagner, Kaleb; Ylä-Mella, Lotta; Margold, Martin; Knudsen, Mads F; Sørensen, Aske L; Larsen, Nicolaj K; Anderson, Robert S; Eriksen, Birte L et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Understanding when ice sheets first developed over the continents is essential for attributing ice volume to marine records of global sea-level change. We resolve a long-standing terrestrial-marine mismatch in the timing of the first Eurasian Ice Sheet (EIS) expansion by dating the earliest glaciogenic unit in northwest Europe, the Hattem Bed Complex (HBC). Paired cosmogenic <sup>26</sup>Al-<sup>10</sup>Be burial dating and detrital zircon fingerprinting indicate that glacially-derived Fennoscandian gravels reached the Netherlands <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mrow><mn>2.41</mn></mrow><mrow><mo>-</mo><mn>0.29</mn></mrow><mrow><mo>+</mo><mn>0.51</mn></mrow></msubsup></math> Ma, while ages from the overlying Appelscha Formation record a second EIS advance and attendant shutdown of the Baltic River System <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mrow><mn>1.72</mn></mrow><mrow><mo>-</mo><mn>0.25</mn></mrow><mrow><mo>+</mo><mn>0.25</mn></mrow></msubsup></math> Ma. Cyclic stratification of the HBC could reflect freshwater discharge to the North Atlantic associated with episodic disruption of meridional overturning circulation. The timing of the first trans-Baltic EIS overlaps the Laurentide Ice Sheet maximum (<math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mrow><mn>2.42</mn></mrow><mrow><mo>-</mo><mn>0.14</mn></mrow><mrow><mo>+</mo><mn>0.14</mn></mrow></msubsup></math>Ma), underscoring substantial Northern Hemisphere ice growth more than a million years prior to the Mid-Pleistocene Transition.