Biostratigraphy and Related Studies

Williams, Graham L.; Ascoli, P; Barss, M S; Bujak, J P; Davies, E.R.; Fensome, Robert A.; Williamson, M. A.

doi:10.1130/dnag-gna-i1.87

Cited by 17 publications

(4 citation statements)

References 36 publications

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“…The timescale of Gradstein et al (2012) Palaeontological evidence used to interpret the evolution of the Labrador-Baffin Seaway region has been derived primarily from the study of Cretaceous-Neogene microfossil (including palynological) assemblages recovered from offshore wells on the Labrador Margin and on the West Greenland Margin. Papers, reports and two theses on the palynomorphs from Labrador Margin and Davis Strait wells, all drilled in the 1970s and 1980s, have been produced by Williams (1975), Gradstein & Williams (1976), Barss et al (1979), Ioakim (1979), Gradstein & Williams (1981), Wil liams (1986), Bujak Davies Group (1987, Bell (1989), Williams et al (1990), Nøhr-Hansen (2004a, Nøhr-Hansen (in Sønderholm et al 2003b), Williams (2007a-f), Ainsworth et al (2014) and Fensome (2015). Foraminiferal studies were undertaken by Grad stein & Williams (1976), Gradstein & Srivastava (1980), Grad stein & Agterberg (1982, Gradstein et al (1994) and Ainsworth et al (2014).…”

Section: North-eastern Canadamentioning

confidence: 99%

Biostratigraphic correlation of the western and eastern margins of the Labrador–Baffin Seaway and implications for the regional geology

2016

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New analyses of the palynological assemblages in 13 offshore wells on the Canadian margin and six on the West Greenland Margin, in conjunction with onshore data, have led to a new biostratigraphic framework for the Cretaceous–Cenozoic strata of the Labrador Sea – Davis Strait – Baffin Bay (Labrador–Baffin Seaway) region and the first broad biostratigraphic correlation of the Canadian and Greenland margins. This framework is based on 167 last occurrences and 18 local/regional peak/common-occurrence events for dinocysts, miospores, fungal spores and Azolla. Detailed biostratigraphic evidence has confirmed the following hiatuses: pre-Aptian in the Hopedale Basin; pre-Albian in the Saglek Basin; Albian–Turonian in some wells of the Hopedale Basin; Turonian–Santonian/Campanian in some areas; pre-Campanian and late Campanian – Thanetian on the Greenland Margin; late Maastrichtian and Danian in some wells of the Hopedale Basin and in the Saglek Basin; Selandian in part of the Hopedale Basin, in all the Saglek Basin wells and in two wells on the West Greenland Margin; late Ypresian and/or Lutetian on both sides; Oligocene to middle Miocene of considerable variability on both margins, with all of the Oligocene and the lower Miocene missing in all the West Greenland Margin wells; and middle to late Miocene on the western side. On the Canadian margin, the hiatuses can be partially matched with the five previously recognised regional unconformities; on the Greenland margin, however, the relationship to the five unconformities is more tenuous. Palynomorph assemblages show that most Aptian to Albian sediments were deposited in generally non-marine to marginal marine settings, interrupted by a short-lived shallow marine episode in the Aptian. A marine transgression started in the Cenomanian–Turonian and led to the most open-marine, oceanic conditions in the Campanian–Lutetian; shallowing probably started in the late Lutetian and continued into the Rupelian, when inner neritic and marginal marine palaeoenvironments predominated. Throughout the rest of the Cenozoic, inner neritic palaeoenvironments alternated with marginal marine conditions on the margins of the Labrador–Baffin Seaway. These observations broadly reflect the tectonic evolution of the seaway, with rift conditions prevailing from Aptian to Danian times, followed by drift through much of the Paleocene and Eocene, and post-drift from Oligocene to the present. Dinocysts indicate that climatic conditions in the Labrador–Baffin Seaway region were relatively temperate in the Cretaceous, but varied dramatically through the Cenozoic. The Danian was a time of increasingly warmer climate, a thermal maximum being reached around the Paleocene–Eocene boundary reflecting the global thermal event at this time. Warm to hot conditions prevailed throughout the Ypresian, but the climate began to cool in the Lutetian, a trend that accelerated through the Priabonian and Rupelian. Throughout the Neogene, temperatures generally declined, culminating in the Quaternary.

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Section: North-eastern Canadamentioning

confidence: 99%

Biostratigraphic correlation of the western and eastern margins of the Labrador–Baffin Seaway and implications for the regional geology

2016

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“…1). The sandstone‐rich Missisauga Formation, up to 3·5 km thick, is of Berriasian to Barremian age (Williams et al. , 1990) and passes seawards into shales of the Verrill Canyon Formation.…”

Section: Geological Settingmentioning

confidence: 99%

Relationship of diagenetic chlorite rims to depositional facies in Lower Cretaceous reservoir sandstones of the Scotian Basin

Gould¹,

Pe‐Piper²,

Piper

2010

Sedimentology

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The relationship between diagenetic chlorite rims and depositional facies in deltaic strata of the Lower Cretaceous Missisauga Formation was investigated using a combination of electron microprobe, bulk geochemistry and X-ray diffraction data. The succession studied comprises several stacked parasequences. The delta progradational facies association includes: (i) fluvial or distributary channel sandstones (some with tidal influence); (ii) thick-bedded delta-front graded beds of sandstone interpreted as resulting from fluvial hyperpycnal flow during floods and storms; and (iii) more distal muddier delta-front and prodeltaic facies. The transgressive facies association includes lag conglomerate, siderite-cemented muddy sandstone and mudstone, and bioclastic sandy limestone. Chlorite rims are absent in the fluvial facies and best developed in thick sandstones lacking mudstone baffles. Good quality chlorite rims are well correlated with Ti in bulk geochemistry. Ti is a proxy for Fe availability, principally from the breakdown of abundant detrital ilmenite (FeTiO 3 ). Under conditions of sea floor diagenesis, the abrupt decrease in sedimentation rate at transgressive surfaces caused progressive shallowing of the sulphate-depletion level and of the overlying Eh-controlled diagenetic zones, resulting in conditions suitable for diagenetic formation of berthierine to migrate upwards through the packet of reservoir sandstones. This early diagenetic berthierine suppressed silica cementation and later recrystallized to chlorite. Thick euhedral outer chlorite rims were precipitated from formation water in sandstone lacking muddy baffles on this chlorite substrate and inhibited late carbonate cementation. This study thus shows that the preservation of porosity by chlorite rims is a two-stage process. Rapidly deposited delta-front turbidite facies create early diagenetic conditions that eventually lead to the formation of chlorite rims, but the best quality chlorite rims are restricted to sandstones with high permeability during burial diagenesis.

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“…The Upper Cretaceous dinoflagelIate cyst assemblages from offshore eastern Canada were described by Barss et al (1979), Bujak & Williams (1978), Williams (1975), Williams & Brideaux (1975), Williams & Bujak (1977a, l 977b), Williams et al (1974) and Williams et al (1990).…”

Section: Svartenhuk Halvømentioning

confidence: 99%