High-precision U–Pb ages in the early Tithonian to early Berriasian and implications for the numerical age of the Jurassic–Cretaceous boundary

Abstract

Abstract. The numerical age of the Jurassic–Cretaceous boundary has\nbeen controversial and difficult to determine. In this study, we present\nhigh-precision U–Pb geochronological data around the Jurassic–Cretaceous\nboundary in two distinct sections from different sedimentary basins: the Las\nLoicas, Neuquen Basin, Argentina, and the Mazatepec, Sierra\nMadre Oriental, Mexico. These two sections contain primary and secondary\nfossiliferous markers for the boundary as well as interbedded volcanic ash\nhorizons, allowing researchers to obtain new radioisotopic dates in the late Tithonian\nand early Berriasian. We also present the first age determinations in the\nearly Tithonian and tentatively propose a minimum duration for the stage as\na cross-check for our ages in the early Berriasian. Given our radioisotopic\nages in the early Tithonian to early Berriasian, we discuss implications\nfor the numerical age of the boundary.