Chronostratigraphy and terrestrial palaeoclimatology of Berriasian–Hauterivian strata of the Cedar Mountain Formation, Utah, USA
Published:April 14, 2020
R. M. Joeckel, G. A. Ludvigson, A. Möller, C. L. Hotton, M. B. Suarez, C. A. Suarez, B. Sames, J. I. Kirkland, B. Hendrix, 2020. "Chronostratigraphy and terrestrial palaeoclimatology of Berriasian–Hauterivian strata of the Cedar Mountain Formation, Utah, USA", Cretaceous Climate Events and Short-Term Sea-Level Changes, M. Wagreich, M. Hart, B. Sames, I. O. Yilmaz
Download citation file:
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.
Figures & Tables
Cretaceous Climate Events and Short-Term Sea-Level Changes
CONTAINS OPEN ACCESS
Sea-level constitutes a critical planetary boundary for both geological processes and human life. Sea-level fluctuations during major greenhouse phases are still enigmatic and widely discussed in terms of changing climate systems. The geological record of the Cretaceous greenhouse period provides a deep-time view on greenhouse-phase Earth system processes that facilitates a much better understanding of the causes and consequences of global, geologically short-term, sea-level changes. In particular, Cretaceous hothouse periods can serve as a laboratory to better understand a near-future greenhouse Earth. This volume presents high-resolution sea-level records from globally distributed sedimentary archives of the Cretaceous involving a large group of scientists from the International Geoscience Programme IGCP 609. Marine to non-marine sedimentary successions were analysed for revised age constraints, the correlation of global palaeoclimate shifts and sea-level changes, tested for climate-driven cyclicities, and correlated within a high-resolution stratigraphic framework of the Geological Timescale. For hothouse periods, the hypothesis of significant global groundwater-related sea-level change, i.e. aquifer-eustasy as a major process, is reviewed and substantiated.