Triassic palynoevents in the circum-Arctic region

Triassic successions of the present-day Arctic contain abundant and diverse assemblages of nonmarine palynomorphs that have provided important biostratigraphic information. Dinoflagellate cyst are biostratigraphically useful in marine intervals in the Upper Triassic. Based on published records, we present a compilation of 78 last occurrences (LOs), first occurrences (FOs), and some abundance events that are anticipated to have correlation potential in the Arctic region. Palynological work has been carried out in many Arctic areas, with extensive palynological research published on the Triassic successions of the Norwegian Barents Sea and Svalbard. An updated, recent palynological zonation scheme exists for that region, integrating previous schemes and illustrating the chronostratigraphic value of palynology in the Triassic. For the Lower and Middle Triassic, good ammonoid control ties the palynological zones to the chronostratigraphic scale. Independent control is sparse, and resolution is lower in the Upper Triassic, so that palynology is commonly the only biostratigraphic discipline available for chronostratigraphic dating and correlation

Permian palynoevents in the circum-Arctic region

Permian palynofloras are recorded around the present-day Arctic and are typically dominated by taeniate and non-taeniate pollen, with intervals of spore domination. The assemblages show close similarities around the Arctic. Based on the published record, we present a compilation of 23 last occurrences (LOs), first occurrences (FOs), and some abundance events. These are anticipated to have regional correlation potential. In general, the Permian palynofloras of the Arctic have not been extensively studied, and the resolution is low due to a general lack of independent age control

Introduction to the “Circum-Arctic Palynological Event Stratigraphy” (CAPE) series of papers

Palynomorphs are one of the few groups of fossils that provide biostratigraphic control in marine to nonmarine rocks and can be applied as proxies for paleoenvironmental and paleoclimatic interpretations. Their utility is enhanced by their microscopic size, which is usually less than 200 micrometres; they are thus easily recovered from small rock samples. They occur throughout the Phanerozoic and are therefore invaluable in refining biostratigraphic control of Arctic successions in Alaska, Arctic Canada, Greenland, northern Europe, and northern Russia. The objective of the Circum-Arctic Palynological Event (CAPE) Stratigraphy series of papers is to integrate data published on Arctic palynomorphs to delineate palynological events (palynoevents) across the Arctic for the Silurian to Cenozoic. Once the series of papers is complete, the data will also be used to compile a TimeScale Creator datapack that can be updated and calibrated on an ongoing basis. Palynoevents include taxon originations (first occurrences or FOs) and extinctions (last occurrences, or LOs) and some abundance events. The palynoevents are correlated with established chronostratigraphic horizons such as bases of ammonoid zones or stages, and hence their chronostratigraphy is independent of the absolute time scale in millions of years. In addition to the palynostratigraphic papers, the series includes a paper detailing the paleogeography of the circum-Arctic regions, including informative maps, as well as a paper providing a palynological perspective of the Cenozoic shift from greenhouse to icehouse conditions

The temporal and spatial distribution of Triassic dinoflagellate cysts

The records of fossil dinoflagellate cysts from the Late Triassic, the time during which they first appear abundantly in the geological record, are reviewed. Most of the Triassic palynological literature pertains to terrestrial palynomorphs, thus it is challenging to establish a global picture of the temporal and spatial distribution of Late Triassic dinoflagellate cyst around the Pangea supercontinent. Moreover, data on Late Triassic dinoflagellate cysts are dispersed, and there are currently no records of dinoflagellate cysts from many marine successions. With the exception of an Australian record of the dinoflagellate cyst Sahulidinium ottii from the upper Mid Triassic, and a possible early Carnian occurrence of, among others, Rhaetogonyaulax in the Swiss Alps, cyst-forming dinoflagellates first appeared relatively synchronously around Pangea from the late Carnian. There are 3–6 species of pre-Norian species globally, whereas species richness exceeded 25 by the end of the Norian. During the Rhaetian, marine seaways had gradually opened due to sustained continental breakup, allowing the expansion of dinoflagellates into many European basins. New species are present, some known only from restricted areas, whereas others like Dapcodinium appear to have a global distribution. The majority of Triassic dinoflagellate cyst taxa do not extend into the Jurassic

Palynological investigations of Permian rocks from Nordaustlandet, Svalbard

Palynological investigations of nine sections covering the upper part of the Nordenskioldbreen Formation, Gipshuken Formation, and the lower part of the Kapp Starostin Formation in the Wahlenbergfjorden area, Nordaustlandet. yielded palynomorphs in three sections. Three assemblages are recognized. A tentative correlation with the Sverdrup Basin suggests a Sakmarian to Artinskian age for the uppermost Nordenskioldbreen and lower Gipshuken Formations. Thermal maturity is low. The palynoflora is dominated by striate pollen suggesting an arid climate throughout the deposition of the Nordenskioldbreen and Gipshuken Formations

Supplement 6. List of specimens

List of figured megaspore and microspore specimens from Hopen with sample heights, localities, Palaeontological Museum Oslo numbers and England Finder slide coordinates

Carboniferous palynoevents in the circum-Arctic region

The Carboniferous of the present-day Arctic yields an abundant and diverse association of terrestrial palynomorphs, particularly from Mississippian successions. Relatively few sections have been studied. However, those published so far demonstrate considerable similarities in the palynofloras between Arctic regions. Based on the published record, we present a compilation of 31 last occurrences (LOs), first occurrences (FOs), and some abundance events that have correlation potential around the Arctic. The chronostratigraphic resolution is relatively low, and the lack of independent age control hampers exact age assignments. But for most of these successions, palynology is the only dating tool available.Le Carbonifère de la région arctique d’aujourd’hui fait état d’une association abondante et diversifiée de palynomorphes terrestres, en particulier de successions du Mississippien. Relativement peu de sections ont été étudiées. Celles publiées jusqu’ici montrent toutefois des similarités considérables des palynoflores entre les régions arctiques. En nous basant sur les documents publiés, nous présentons une compilation des 31 dernières occurrences (DO), des premières occurrences (PO) et de certains phénomènes d’abondance qui pourraient être corrélés dans la région de l’Arctique. La résolution chronostratigraphique est relativement faible et l’absence de critères de datation gêne l’attribution d’âges exacts. La palynologie constitue toutefois le seul outil de datation disponible dans le cas de la majorité de ces successions

Supplement 2. Lyngefjellet range chart

Micropalaeontological and micro-biofacies distribution chart for the Lyngefjellet section. Microfossil occurrences marked with an asterisk were previously reported in Paterson et al. (2016). Relative abundances of palynomorph groups are based on Paterson & Mangerud (2015). Sedimentary log after Mørk et al. (2013)

Supplement 5. Iversenfjellet range chart

Micropalaeontological and micro-biofacies distribution chart for the Iversenfjellet section. Microfossil occurrences marked with an asterisk were previously reported in Paterson et al. (2016). Relative abundances of palynomorph groups are based on Paterson & Mangerud (2015). Sedimentary log after Mørk et al. (2013)