Astronomical time keeping of earth history: An invaluable contribution of scientific ocean drilling

Abstract

The mathematically predictable cyclic movements of Earth with respect to the sun provides the basis for constructing highly accurate and precise age models for Earth’s past. Construction of these astronomically calibrated timescales is pivotal to placing major transitions and events in the geological record in their temporal context. Understanding the precise nature and timing of past events is of great societal relevance as we seek to apply these insights to constrain near-future climate scenarios. Scientific ocean drilling has been critical in this endeavor, as the recovery and analysis of high-quality and continuous marine sedimentary archives underpin such high-resolution age models for paleoclimate records. This article identifies key astronomically calibrated records through the past 66 million years (the Cenozoic) collected during multiple Deep Sea Drilling Project, Ocean Drilling Program, Integrated Ocean Drilling Program, and International Ocean Discovery Program expeditions, highlights major achievements, and suggests where future work is needed.