| Title | Mesozoic event-stratigraphy of the Scotian Margin, offshore Nova Scotia: preliminary palynological results from the Upper Member of the Missisauga Formation in Panuke B-90 |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Correia, V ;
Fensome, R A; MacRae, R A; Dafoe, L T; Williams, G L |
| Source | Geological Survey of Canada, Open File 8981, 2023, 37 pages, https://doi.org/10.4095/331910  Open Access |
| Image |  |
| Year | 2023 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | digital; on-line |
| File format | readme
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| File format | pdf |
| Province | Nova Scotia; Eastern offshore region |
| NTS | 10O/13; 20P; 11D; 11E; 11F; 11G; 21A; 21H |
| Lat/Long WENS | -66.0000 -54.0000 46.0000 42.0000 |
| Subjects | Science and Technology; general geology; stratigraphy; palynology; stratigraphic analyses; palynostratigraphy; paleoenvironment; Missisauga Formation; Panuke B-90; Scotian Margin; Scotian Basin;
Mesozoic |
| Illustrations | photographs; location maps; stratigraphic column; photomicrographs |
| Program | Energy Geoscience Program Coordination |
| Released | 2023 05 31 |
| Abstract | Conceived as a continuation of the previous multidisciplinary event stratigraphy studies of the Late Cretaceous to Neogene of the Scotian Margin in the 2000s, the "Mesozoic eventstratigraphy of the
Scotian Margin" project proposes a similar study for the Late Triassic to Early Cretaceous interval. The first stage of this project comprises a detailed multidisciplinary study of the composite Lower Cretaceous section from Panuke B-90 and Cohasset
A-52 conventional cores. The present work reports initial palynologic data from the formal Upper Member of the Missisauga Formation in Panuke B-90. These data, combined with preliminary insights from sedimentary facies, macrofossil, and trace fossil
analyses, suggest that from the base of the studied section upwards involves a transition from a neritic/shelfal to a mainly estuarine-brackish setting. This was followed by a transgressive cycle through the Upper Member of the Missisauga Formation,
which culminated in a return of more fully marine environments near the base of the overlying Naskapi Member of the Logan Canyon Formation. It is apparent that this transgression is not continuous, but intercalated with smaller cycles, well
documented by the fluctuations in dominance between terrestrial (pollen and spore abundance) versus marine (mainly dinoflagellate-cyst abundance and richness) palynomorph trends through this succession, presented here in three main intervals. The
dinoflagellate-cyst assemblages and key bioevents recorded in this initial study indicate a Barremian age for the Upper Member of the Missisauga Formation in Panuke B-90. The overlying Naskapi Member is expected to be of early Aptian age based on
previous reports of the presence of the age-diagnostic ammonite Deshayesites sp. Ongoing work on the conventional cores from Panuke B-90, and subsequently Cohasset A-52 and other wells, will contribute to a comprehensive Mesozoic event-stratigraphic
framework for the Scotian Margin. |
| Summary | (Plain Language Summary, not published)
Age determinations for rocks of the Scotian Margin have largely been determined through analysis of microfossils, using events (mainly originations and
extinctions of species). Palynomorphs (organic-walled microfossils), especially dinoflagellate cysts of marine origin and spores and pollen of terrestrial origin, are important tools in dating deposits, and are also indicators of past environments.
The present project involves palynologic, paleoenvironmental and sedimentary analysis of the Triassic to Lower Cretaceous cored sections of offshore wells on this Margin. Preliminary results from samples from Panuke B-90 core indicate, at the base, a
transition from a marine to an estuarine setting, culminating in evidence from the middle part of the core of a normal marine environment. The palynologic assemblages from the lower and middle part of this core are characteristic of the Early
Cretaceous, most likely of Barremian age (131 to 126 million years ago). Ongoing work on this Lower Cretaceous core and coeval wells will contribute to a comprehensive event-stratigraphic framework, critical for more applied studies, for example
related to carbon capture. |
| GEOSCAN ID | 331910 |
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