A Quantitative Foraminiferal Biozonation of the Late Jurassic and Early Cretaceous of the East Newfoundland Basin

Williamson, M. A.

doi:10.2307/1485526

Cited by 27 publications

(5 citation statements)

References 21 publications

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“…At the conjugate western Atlantic margin, several basins offshore Newfoundland, including the Jeanne d'Arc, Flemish Pass, Orphan and Carson-Salar basins, have depositional histories similar to western Iberia (e.g. Stam 1986;Williamson 1987;McAlpine 1990). Being active hydrocarbon exploration areas, as increasing amounts of well materials become available from these basins, biofacies analysis may help to interpret their evolution.…”

Section: Control Of Diapirism On Facies Pattern and Benthic Communitiesmentioning

confidence: 99%

Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

Fürsich

Schneider²,

Werner

et al. 2021

Palaeobio Palaeoenv

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The Kimmeridgian Alcobaça Formation of the Lusitanian Basin forms a mixed carbonate–siliciclastic unit between basinal deposits of the Abadia Formation, and fluvial–terrestrial strata of the Lourinhã Formation. This study presents >2.5 km of detailed logs of nine outcrop sections of the Alcobaça Formation in its type region. Eight of these sections encircle the Caldas da Rainha Diapir, which was a prominent, emergent, passive salt diapir during the time of deposition. Palaeoenvironments of the unit form a complex mosaic of low- to high-energy, carbonate- or siliciclastic-dominated shallow shelf settings; coastal embayments and lagoons; and coastal plains with rivers, lakes and playas. In the strata, abundant microfauna is often joined by a rich macrofauna, usually dominated by bivalves. Locally, corals, calcareous sponges or oysters form meadows or patch reefs. These autochthonous to parautochthonous remnants of former communities are assigned to 35 benthic macrofaunal associations. The integration of palaeoecological analysis of these associations with microfaunal and sedimentological data provides constraint on their salinity ranges, which range from slightly hypersaline to freshwater. Frequent temporal and spatial salinity fluctuations are attributed to variations in relative sea-level, salt tectonics or climate. The NNE-trending Caldas da Rainha Diapir induced pronounced facies differentiation. Predominantly, non-marine siliciclastic facies in the northwest and carbonate to siliciclastic, marine to brackish facies in the southwest are contrasted by shallow-marine carbonate facies east of the diapir. Comprehensive exposure and well-preserved fossils make the Alcobaça Formation an excellent showcase to demonstrate how biofacies analysis can help to disentangle the interplay of climate changes, sea-level fluctuations and salt tectonics. Based on the improved characterisation of the unit, the Alcobaça Formation is formally defined, and seven members are established.

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Section: Control Of Diapirism On Facies Pattern and Benthic Communitiesmentioning

confidence: 99%

Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

Fürsich

Schneider²,

Werner

et al. 2021

Palaeobio Palaeoenv

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“…In the Paleogene Labrador Margin and North Sea zonations, the missing intervals correspond to hia tuses caused by basinward shifts in shoreline (Gradstein, 1987). Reviews of the methodology used in constructing and interpret ing RASC zonations can be found in Gradstein et al (1985), D'lorio (1986), Gradstein (1987), and Williamson (1987).…”

Section: Comparison Of Site 647 Assemblages With Regional Zonationsmentioning

confidence: 99%

Paleogene Benthic Foraminifer Biostratigraphy and Paleoecology at Site 647, Southern Labrador Sea

Kaminski¹,

Gradstein²,

Berggren³

1989

Proceedings of the Ocean Drilling Program, 105 Scientific Results

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Benthic foraminifers were examined from the Paleogene of Ocean Drilling Program (ODP) Site 647 and Deep Sea Drilling Program (DSDP) Site 112 in the southern Labrador Sea. The Paleogene sequence of the deep Labrador Sea can be subdivided into seven assemblages, based on the ranges and relative abundance of characteristic taxa. The first oc currences (FOs) and last occurrences (LOs) of important benthic taxa are calibrated to a standard biochronology, by in terpolating from our age model for Site 647. The biostratigraphy of Site 647 is used to improve the age estimates of Site 112 cores. Fifteen microfossil events in Site 647 also are found in the sedimentary wedge along the Labrador Margin. A comparison of the probabilistic microfossil sequence from the Labrador Margin with that at Site 647 yields four isoch ronous benthic foraminifer LOs. Two new species are described from Sites 647 and 112: Hyperammina kenmilleri, Kaminski n.sp., and Ammodiscus nagyi Kaminski n.sp.Significant faunal turnovers are observed at the Ypresian/Lutetian and Eocene/Oligocene boundaries. The Ypresian/Lutetian boundary is characterized by a Glomospira-facies and is attributed to a rise in the CCD (carbonate com pensation depth) associated with the NP14 lowstand in sea level. The Eocene/Oligocene boundary is delimited by the LO of Spiroplectammina spectabilis and Reticulophragmium amplectens. The change from an Eocene agglutinated as semblage to a predominantly calcareous assemblage in the early Oligocene took place gradually, over a period of about 4 Ma, but the rate of change accelerated near the boundary. This faunal turnover is attributed to changes in the preser vation of agglutinated foraminifers, as delicate species disappeared first. Increasingly poorer preservation of aggluti nated foraminifers in the late Eocene to earliest Oligocene reflects the first appearance of cool, nutrient-poor deep wa ter in the southern Labrador Sea. The approximately coeval disappearance of agglutinated assemblages along the Lab rador Margin was caused by a regional trend from slope to shelf environments, accentuated by the "mid"-Oligocene lowstand in sea level.

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“…In the Paleogene Labrador Margin and North Sea zonations, the missing intervals correspond to hiatuses caused by basinward shifts in shoreline (Gradstein, 1987). Reviews of the methodology used in constructing and interpreting RASC zonations can be found in Gradstein et al (1985), D'Iorio (1986), Gradstein (1987) and Williamson (1987).…”

Section: Geroch Andmentioning

confidence: 99%

Cenozoic deep-water agglutinated foraminifera in the North Atlantic

Kaminski¹

1987

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Cenozoic (predominantly Paleogene) "flysch-type" agglutinated foraminiferal assemblages and their modern analogs in the North Atlantic and adjacent areas have been studied to provide an overview of their spatial and temporal distribution and utility for paleoenvironmental analysis. Over 200 species of agglutinated foraminifera have been recognized in Paleogene sediments from North Atlantic and Tethyan basins. This unified taxonomic data base enables the first general synthesis of biostratigraphic, paleobiogeographic and paleobathymetric patterns in flysch-type agglutinated assemblages from upper Cretaceous to Neogene sediments in the North Atlantic. The majority of taxa are cosmopolitan, but latitudinal, temporal and depth-related trends in diversity and species composition are observed among flysch-type assemblages.Modern deep-sea agglutinated foraminiferal faunas provide an analog to fossil flysch-type assemblages and serve as models for paleoecologic studies. Core-top samples from the Panama Basin, Gulf of Mexico and Nova Scotian continental rise were examined in order to determine the habitats of modern species of agglutinated foraminifera. The ecology of modern taxa provides constraints on the paleoenvironmental significance of fossil agglutinated assemblages in the North Atlantic, and their utility for paleoceanography.Towards this end, spade core samples from a 3912 m deep station in the Panama Basin were studied to determine abundance and microhabitat partitioning among living agglutinated foraminiferal populations and the preservation of dead assemblages. The genera Dendrophrya, Cribrostomoides and Ammodiscus have epifaunal habitats and the genus Reophax is predominantly infaunal. Species of Reophax are probably responsible for fine reticulate burrows observed in xradiographs. An experiment using recolonization trays in the Panama Basin was designed to identify opportunistic species of benthic foraminifera, and to assess the rate at which a population can colonize an abiotic substrate. The most successful colonizer at this site is Reophax, while Dendrophrya displays the lowest capability for dispersal. After nine months the abundance of living individuals in sediment trays was one-tenth to one-third that of background abundance, but the faunal diversity did not differ greatly from control samples. Recolonization by benthic foraminifera is more rapid than among macrofaunal invertebrates.Modern agglutinated assemblages from the Louisiana continental slope were examined to determine changes in species composition associated with hydrocarbon seeps. Organic-rich substrates are characterized by a decrease in astror--iihizids and an increase in trochamminids and textulariids. Highly organicenriched substrates with chemosynthetic macrofauna are dominated by Trochammina glabra and Glomospira charoides.The biostratigraphy of fossil agglutinated foraminifera in the North Atlantic is based on detailed analysis of 670 samples from 14 wells and one outcrop section, and examination of additional picked faunal...

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A Quantitative Foraminiferal Biozonation of the Late Jurassic and Early Cretaceous of the East Newfoundland Basin

Cited by 27 publications

References 21 publications

Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

Life at the continental–marine interface: palaeoenvironments and biota of the Alcobaça Formation (Late Jurassic, Central Portugal), with a formal definition of the unit appended

Paleogene Benthic Foraminifer Biostratigraphy and Paleoecology at Site 647, Southern Labrador Sea

Cenozoic deep-water agglutinated foraminifera in the North Atlantic

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