An introduction to causes and consequences of Cretaceous sea-level changes (IGCP 609)

• Published in: Geological Society, London, Special Publications
• Main Authors: Wagreich, Michael, Sames, Benjamin, Hart, Malcolm, Yılmaz, İsmail Ömer
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Geological Society of London 2020
• Subjects: Geology; Ocean Engineering; Water Science and Technology; Ice Sheet
• Online Access: https://hdl.handle.net/11511/45899; https://doi.org/10.1144/sp498-2019-156

The International Geoscience Programme Project IGCP 609 addressed correlation, causes and consequences of short-term sea-level fluctuations during the Cretaceous. Processes causing several ka to several Ma (third- to fourth-order) sea-level oscillations during the Cretaceous are so far poorly understood. IGCP 609 proved the existence of sea-level cycles during potential ice sheet-free greenhouse to hothouse climate phases. These sea-level fluctuations were most probably controlled by aquifer-eustasy that is altering land-water storage owing to groundwater aquifer charge and discharge. The project investigated Cretaceous sea-level cycles in detail in order to differentiate and quantify both short- and long-term records based on orbital cyclicity. High-resolution sea-level records were correlated to the geological timescale resulting in a hierarchy of sea-level cycles in the longer Milankovitch band, especially in the 100 ka, 405 ka, 1.2 Ma and 2.4 Ma range. The relation of sea-level highs and lows to palaeoclimate events, palaeoenvironments and biota was also investigated using multiproxy studies. For a hothouse Earth such as the mid-Cretaceous, humid-arid climate cycles controlling groundwater-related sea-level change were evidenced by stable isotope data, correlation to continental lake-level records and humid-arid weathering cycles.