During the ice-free Cretaceous, the tropics have been proposed as key drivers of global climate, yet direct mid- to high-latitude evidence remains absent. Here, we present centennial-resolution geochemical records of hydroclimatic variability from early Campanian (83.62？83.14 Ma) midlatitude lacustrine successions. The records exhibit significant sub-precessional cycles at 10？12 k.y. and 5？5.4 k.y., and other millennial-scale cycles, primarily at ～3.6 k.y., ～2.6？2.5 k.y., and ～2.3 k.y. High-precision chronology, phase locking of different proxies, and eccentricity-modulated amplitudes identify these sub-precessional signals as semi- and quarter-precession cycles. As these signals are most consistent with a tropical origin, their footprints in midlatitude hydroclimate records highlight the tropical control on climate during this greenhouse interval. Such low- to high-latitude teleconnection would provide efficient poleward heat and moisture transport, helping to reconcile the anomalously warm Cretaceous poles under a weak meridional temperature gradient. We further show that the ～3.6 k.y. and ～2.6？2.5 k.y. cycles arise from semi- and quarter-precession cycles via combination of tones and harmonics, whereas the ～2.3 k.y. cycles are most likely linked to solar activity, underscoring their persistence throughout geological history.
Article link: https://doi.org/10.1130/G54399.1
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