The effects of astronomically forced climate change on hemipelagic carbonate sedimentation in a tectonically active setting: the Albian Mioño Formation in Castro Urdiales (Cantabria, N Spain)

Abstract Our understanding of the stratigraphic expression astronomically driven climate-change cycles in Milankovitch frequency band has improved significantly recent decades. However, several aspects have been little studied to date, such as nature climatically regulated environmental processes that ultimately control cyclic sedimentation. Similarly, relatively is known about successions accumulated tectonically active basins. In order fill this knowledge gap, Albian hemipelagic deposits Mioño Formation exposed Castro Urdiales (Basque-Cantabrian Basin) are herein. These were during a rifting phase with strong tectonic activity. The sedimentological, petrographic and cyclostratigraphic analysis demonstrates that, despite synsedimentary instabilities some diagenetic overprinting, carbonate alternation was forced 110.68–110.47 Ma. Seasonality fluctuations by precession caused periodic (20 ky) variations rate productivity (abundance pelagic calcareous plankton micrite exported from adjacent shallow-water areas) and/or siliceous dilution (terrestrially derived siliciclastic sediment supply particle production sponges). resulted formation marly limestone beds when annual seasonality low (i.e., boreal summer at aphelion, winter perihelion) accumulation marlstones increased perihelion, aphelion). incidence these decreased line modulation short-eccentricity 100 ky. conclusion, study shows can be reliably recorded settings if gravity flows or other disturbances do not affect autochthonous