New geologic time scale yardstick
Earth Science is based on understanding the geologic, climactic, and astronomic events that radically altered living conditions throughout prehistory. Such events are dated on a geologic time scale (GTS) – the ultimate ʺyardstickʺ by which continent formation, ancient asteroid impacts, dinosaur extinctions, and calamitous volcanic eruptions are measured. Researchers from nine countries collaborated in the GTSNEXT project. Fundamentally, GTSNEXT aimed to train and mentor the next generation of scientists who will study Earth systems. GTSNEXT also undertook an ambitious multi-faceted effort in order to equip these young researchers with the most accurate GTS available. The first step was intercalibrating the three existing methods for measuring geologic time, based on samples from mineral sanidine (Fish Canyon tuff). Doing so resulted in the most precise dates ever established for the dinosaur extinctions caused by asteroid impacts (Cretaceous-Paleogene boundary). With these dates, GTSNEXT analysed deep-marine samples from Spain; the results extend the known GTS through the Paleocene and into the Maastrichtian (the earliest Cretaceous period). GTSNEXT also analysed Monte dei Corvi (Italy) and deep-sea (equatorial Atlantic) cores, further refining the GST to account for prehistoric impacts of tides and astronomic pull. GTSNEXT has thereby produced the first calculations describing how extraterrestrial gravity and tidal forces affected Miocene climate change. Finally, GTSNEXT honed the isotope dating techniques and accepted ratios for fields such as uranium-lead geochronology and cosmochronology. GTSNEXT has expanded and refined the GST dating back 100 million years, a novel contribution which the consortium expects to stand undisputed. Young researchers have been trained in updated methods for astronomical, Ar/Ar (Argon/Argon) and U-Pb (Uranium/lead) dating. GTSNEXT’s definitive time scale and improved methodology promise to reconstruct Earth history, trace mineral resources, and predict global impacts of future climate shifts. The outcome will be a more precise and viable picture of for all involved with Earth Science.
Keywords
Earth Science, geologic time, climate change impacts, palaeontology
