The Triassic Timescale
The Mesozoic Era begins with the approximately 50-million-year-long Triassic Period, a major juncture in Earth history when the vast Pangaean supercontinent completed its assembly and began its fragmentation, and the global biota diversified and modernized after the end-Permian mass extinction, the most extensive biotic decimation of the Phanerozoic. The temporal ordering of geological and biotic events during Triassic time thus is critical to the interpretation of some unique and pivotal events in Earth history. This temporal ordering is mostly based on the Triassic timescale, which has been developed and refined for nearly two centuries. This book reviews the state of the art of the Triassic timescale and includes comprehensive analyses of Triassic radio-isotopic ages, magnetostratigraphy, isotope-based and cyclostratigraphic correlations and timescale -relevant marine and non-marine biostratigraphy.
The Triassic timescale: new constraints and a review of geochronological data
Published:January 01, 2010
A review of geochronological data underlying the geological timescale for the Triassic yields a significantly different timescale calibration than that published in the most recent compilation (Geologic TimeScale 2004). This is partly due to the availability of new radio–isotopic data, but mostly because strict selection criteria are applied and complications arising from biases (both systematic and random) are accounted for in this contribution. The ages for the base and the top of the Triassic are constrained by U–Pb ages to 252.3 and 201.5 Ma, respectively. These dates also constrain the ages of major extinction events at the Permian–Triassic and...