2019/10/17 by R.M. Joeckel, Greg A. Ludvigson, Andreas Möller +6 · 23 citations
Earth and Planetary Sciences · #Geological and Geochemical Analysis #Paleontology and Stratigraphy of Fossils #Geology and Paleoclimatology Research #Chronostratigraphy #Geology #Paleoclimatology #Paleontology #Oceanography #Climate change #Sedimentary rock
paper · doi:10.1144/sp498-2018-133
published in Geological Society London Special Publications 498(1), 75-100 (Geological Society of London)
openalex publication_date 2019/10/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Abstract This paper presents breakthroughs in the chronostratigraphy of the heretofore poorly constrained Yellow Cat Member of the Cedar Mountain Formation, which is an important record of terrestrial environments, ecosystems and global change in the ancient North American Cordilleran foreland. Zircon populations from 10 stratigraphic horizons in the Yellow Cat Member yield youngest single-grain ages ranging from 142.5 ± 2.7 to 133.7 ± 2.7 Ma (Berriasian–late Valanginian); those from one mudstone palaeosol yield a robust Concordia Age of 136.3 ± 1.3 (Valanginian). Additionally, a new palynoflora – one of a few to be published from the Cedar Mountain Formation – is assigned to the middle Berriasian to early Hauterivian stages, based on the presence of Foraminisporis wonthaggiensis and Trilobosporites sp. cf. T. canadensis , and the absence of F . asymmetricus , Appendicisporites spp. and angiosperms. Furthermore, these chronostratigraphic data allow us to interpret part of the so-called ‘Weissert Event’ C-isotope excursion (Valanginian) in a new C-isotope profile through a palaeosol-bearing alluvial succession in the Yellow Cat Member. This research extends a firm understanding of the formation further back into the Early Cretaceous than was the case previously (except for ostracod biostratigraphy) and sets the stage for future advancements.