| Titre | Ichnology and paleoenvironmental interpretations of the Cretaceous-Paleocene rift succession of northeast Baffin Island region, Nunavut, Canada |
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| Auteur | Dafoe, L ;
Haggart, J; Williams, G; Stimson, M |
| Source | AAPG - Annual Convention and Exhibition, abstracts; American Association of Petroleum Geologists, Annual Meeting Abstracts 2019, 2019 p. 1-2 |
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| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180428 |
| Éditeur | American Association of Petroleum Geologists |
| Réunion | AAPG - Annual Convention and Exhibition; San Antonio; US; mai 19-22, 2019 |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; numérique |
| Formats | pdf (Adobe® Reader®) |
| Province | Nunavut |
| SNRC | 38A; 38B; 38C; 38D; 48D |
| Région | île de Baffin; Pond Inlet; Bylot Island |
| Lat/Long OENS | -81.0000 -72.0000 74.0000 72.5000 |
| Sujets | Paléogène; Paléocène; ichnologie; ichnofossiles; ichnofaciès; empreintes fossiles; palynologie; paléoenvironnement; cadre tectonique; antécédents tectoniques; décrochement horizontal; expansion océanique;
antecedents de sedimentation; milieu sédimentaire; structures sédimentaires; débit de sedimentation; géologie du substratum rocheux; lithologie; roches sédimentaires; roches clastiques; mudstones; grès; Dinoflagellés; paléontologie; sédimentologie;
stratigraphie; tectonique; Sciences et technologie; Phanérozoïque; Cénozoïque; Tertiaire; Mésozoïque; Crétacé |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des strates crétacées du territoire de Baffin |
| Diffusé | 2019 06 30 |
| Résumé | (disponible en anglais seulement)
Clastic strata cropping out along northeast Baffin Island, Canada, preserve an onshore stratigraphic record of rifting that formed the adjacent Baffin Bay
region, beginning in the Early Cretaceous with seafloor spreading ceasing near the end of the Eocene. Cretaceous through Paleocene strata of this succession are preserved in the area around Pond Inlet, in Eclipse Trough along southwest Bylot Island,
and in North Bylot Trough on north Bylot Island. Analysis of the ichnology and sedimentology of 35 stratigraphic sections of these strata was undertaken, in conjunction with palynological study, to better understand their evolving depositional
environments and to provide an analogue for the associated offshore section in Baffin Bay. Lower Cretaceous syn-rift strata of Eclipse Trough include primarily fluvial facies. However, a unique interval containing wave ripples and mud-crack casts, as
well as surface trails, trackways, resting traces, shallow dwellings, and microbial-induced sedimentary structures reflecting the Scoyenia Ichnofacies, is interpreted as lake-margin in origin. In another synrift section, Ophiomorpha characterize
middle shoreface strata, and wave-rippled to hummocky cross-stratified beds contain a diverse, but opportunistic, archetypal Cruziana Ichnofacies within storm-dominated lower shoreface deposits. Overlying Upper Cretaceous transgressive mudstones
reflect more distal marine deposition and are dominated by Phycosiphon. Shallower, proximal outer-shelf settings with distal Cruziana Ichnofacies assemblages are also seen in the mudstones where they transition to sandstones. These sandstones consist
of progradational, storm-dominated, inner shelf through foreshore deposits, with alternating stratified and bioturbated beds containing either archetypal Cruziana Ichnofacies or Macaronichnus-dominated suites. Overlying Paleocene sandstones generally
show evidence of high sedimentation rates suggesting deltaic deposition. Paleocene mudstones are rarely bioturbated, primarily by diminutive, marine, grazing traces. Palynological analysis indicates a lack of dinocysts in these rocks, supporting a
brackish estuarine or prodeltaic setting. Seafloor sampling from Baffin Bay reveals similar facies to those seen onshore, demonstrating that the onshore record provides a vital analogue for understanding the adjacent offshore succession. These
analyses help to document depositional complexities within an evolving rift system. |
| Sommaire | (Résumé en langage clair et simple, non publié)
La stratigraphie du Crétacé et du Paléogène du littoral de l'île Bylot (Nunavut) constitue un analogue essentiel pour la compréhension des
successions du plancher océanique voisin de la baie de Baffin, dont l'échantillonnage est très limité. Des analyses détaillées de la sédimentologie et des ichnofossiles de 35 coupes stratigraphiques offrent de nouvelles perspectives sur les
paléoenvironnements sédimentaires des unités lithostratigraphiques. Plus précisément, l'ensemble de la succession témoigne de la prédominance des dépôts marins et des tempêtes avec des paléomilieux sédimentaires semblables à ceux relevés entre les
deux zones structurelles isolées de l'île Bylot. |
| GEOSCAN ID | 314519 |
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