Calibrating geologic strata, dinosaurs, and other fossils at Dinosaur Provincial Park (Alberta, Canada) using a new CA-ID-TIMS U–Pb geochronology
نویسندگان
چکیده
The 100 m thick stratigraphic section exposed at Dinosaur Provincial Park (DPP, southern Alberta) contains bentonites that have been used for more than 30 years to date DPP's rocks and fossils using the K-Ar decay scheme. Limited reproducibility among different vintages of 40Ar/39Ar ages inhibited development a high resolution chronostratigraphy. Here we employ further test recently completed CA-ID-TIMS U–Pb geochronology associated age-stratigraphy model update temporal constraints on Park’s bentonites, formational contacts, other markers. In turn, document rock accumulation rates, calibrate durations informal megaherbivore dinosaur assemblage zones biozones. Weighted mean 206Pb/238U from five range 76.718 ± 0.020 Ma 74.289 0.014 (2σ internal uncertainties) through an interval 88.75 m, indicating duration ~2.43 Myr overall rate 3.65 0.04 cm/ka. An increase in above Oldman-Dinosaur contact conforms regionally expressed pattern increased accommodation ~76.3 across Alberta Montana. Palynological biozone data suggest condensed section/hiatus uppermost portion Oldman Formation. exhibit ~600–700 kyr are significantly shorter those overlying Horseshoe Canyon A decreased dinosaur-assemblage turnovers last eight million Mesozoic western Canada may be explained by withdrawal Western Interior Seaway expansion ecologically homogenous lowlands its wake.
منابع مشابه
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ژورنال
عنوان ژورنال: Canadian Journal of Earth Sciences
سال: 2023
ISSN: ['1480-3313', '0008-4077']
DOI: https://doi.org/10.1139/cjes-2023-0037