We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The transgression history of the Saxonian Cretaceous revisited or: the imperative for a complete stratigraphic reappraisal (Cenomanian, Elbtal Group, Germany).
- Abstract
Until a few years ago, the onset of continental to deeper marine deposition in the Saxonian Cretaceous Basin (SCB) was largely assigned to the naviculare transgression of the early Late Cenomanian. Based on the integrated investigation of 39 Cenomanian surface and subsurface sections, a completely revised stratigraphic framework for the lower Elbtal Group is presented herein. The new data show that Cretaceous sedimentation started already in the early Early Cenomanian, indicated by the contemporaneous onlap of non-marine (Niederschöna Formation) and marine strata (Oberhäslich Formation). The Cenomanian transgressions proceeded on a broad front from the north, at first following the course of roughly south--north-discharging palaeovalleys of a fluvial palaeodrainage system dewatering an elevated principal source area in the southwest. The sequence stratigraphic analysis demonstrates the presence of four complete, unconformity-bounded Cenomanian depositional sequences (DS) and a fifth one, DS Ce-Tu 1, which started in the mid-Late Cenomanian and lasted into the Early Turonian. The depositional sequences comprise six major transgressive phases that overstepped each other and enlarged the depositional realm by means of non-marine and/or marine onlap: A, early Early Cenomanian (equivalent to the "ultimus/Aucellina Transgression"), DS Ce 1+2; B, late Early Cenomanian, DS Ce 3; C, early Middle Cenomanian (primus Transgression), reflecting the most prominent sea-level rise within the SCB, DS Ce 4; D, early Late Cenomanian (naviculare Transgression), DS Ce 5; E, late Late Cenomanian (plenus Transgression), DS Ce-Tu 1; F, earliest Turonian (Lohmgrund Horizon), maximum flooding of DS Ce-Tu 1. The marine Oberhäslich Formation was accompanied by collateral fluvial deposits of the Niederschöna Formation during the early Early to early Late Cenomanian, respectively. The marine transgressions reached the Úštěk-Bad Schandau Sea Bight, the deepest of the north-sloping palaeovalleys, first and produced an up to 120-m-thick marine sedimentary record (Oberhäslich and Pennrich formations), subdivided into five almost equally thick depositional sequences. This maximum thickness is in the order of the accommodation generated during the Cenomanian age and corresponds to a rather low sedimentation rate of 20 m/myr. Therefore, the thickness changes observed within the lower Elbtal Group can be explained quite simply by the pre-transgression topography and sequence stratigraphic onlap patterns onto the elevated palaeotopography in the southwest. The new stratigraphic framework of the lower Elbtal Group thus shows that tectonic inversion in the SCB was essentially a post-Cenomanian process.
- Subjects
MARINE transgression; ALLUVIUM; SEQUENCE stratigraphy; ABSOLUTE sea level change; SEQUENCE analysis
- Publication
Journal of Applied & Regional Geology / Zeitschrift der Deutschen Gesellschaft für Geowissenschaften (ZDGG), 2023, Vol 174, Issue 1, p69
- ISSN
1860-1804
- Publication type
Article
- DOI
10.1127/zdgg/2023/0376