Low-latitude climate variability in the Heinrich frequency band of the Late Cretaceous greenhouse world

• Published in: Climate of the past Vol. 10; no. 3
• Main Authors: de Winter, N. J, Zeeden, C, Hilgen, F. J
• Format: Journal Article
• Language: English
• Published: Copernicus GmbH 22.05.2014
• Subjects: Climate; Cretaceous period
• ISSN: 1814-9332; 1814-9332
• DOI: 10.5194/cp-10-1-2014

Deep marine successions of early Campanian age from DSDP (Deep Sea Drilling Project) site 516F drilled at low paleolatitudes in the South Atlantic reveal distinct sub-Milankovitch variability in addition to precession, obliquity and eccentricity-related variations. Elemental abundance ratios point to a similar climatic origin for these variations and exclude a quadripartite structure as an explanation for the inferred semi-precession cyclicity in the magnetic susceptibility (MS) signal as observed in the Mediterranean Neogene for precession-related cycles. However, semi-precession cycles as suggested by previous work are likely an artifact reflecting the first harmonic of the precession signal. The sub-Milankovitch variability, especially in MS, is best approximated by a ~7 kyr cycle as shown by spectral analysis and bandpass filtering. The presence of sub-Milankovitch cycles with a period similar to that of Heinrich events of the last glacial cycle is consistent with linking the latter to low-latitude climate change caused by a non-linear response to precession-induced variations in insolation between the tropics.