An Albian microflora from the Mattagami Formation, James Bay Lowlands, Ontario

Norris, Geoffrey; Telford, P. G.; Vos, M. A.

doi:10.1139/e76-041

Cited by 4 publications

(2 citation statements)

References 5 publications

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“…18A) are functions of poor sampling at higher latitudes. This sampling bias is con firmed by these excluded data sets, which de scribe numerous assemblages with abundant free-sporing plants (e.g., May and Traverse 1973;Skog and Dilcher 1994) or with gym nosperms at lower abundances (e.g, Brideaux and Mclntyre 1975;Norris et al 1976;Ward 1986) before the Turonian-Santonian interval. A second complication is also revealed in these data.…”

Section: Palynological Databases and Limits To Resolumentioning

confidence: 99%

Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation

Lupia

Lidgard²,

Crane³

1999

Paleobiology

199

179

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The Cretaceous radiation of angiosperms initiated a major reorganization of terrestrial plant communities as dominance by pteridophytic and gymnospermic groups eventually gave way to dominance by angiosperms. Previously, patterns of biotic replacement have been assessed using measures based on taxonomic diversity data. However, using measures of both abundance and diversity to investigate replacement patterns provides more information about macroecological change in the fossil record than either can provide alone. Analyses of an updated and expanded database of North American palynological samples from Cretaceous sediments document a rapid increase in angiosperm diversity and abundance within individual fossil palynofloras (represent ing local/subregional vegetation). New analyses of floristic diversity patterns support previous results and indicate that the decline of free-sporing plants is more pronounced than the decline of gymnosperms. In contrast, analyses of abundance data appear to show that the decline of gymnosperms is far more pronounced than the decline of free-sporing plants. Detailed examination of both data sets segregated by paleolatitude shows that this apparent contradiction reflects biogeographical differences in the patterns of vegetational change (e.g., free-sporing plants declined in abundance at lower latitudes) as well as sampling bias (e.g., greater sampling in the northern region in the Late Cretaceous). Analyses accounting for these biases support the conclusion that as an giosperms radiated, free-sporing plants rather than gymnosperms (in this case, mainly conifers) experienced the most pronounced decline. A thorough understanding of the Cretaceous radiation of angiosperms will require both abundance and diversity data. It also will require expanding the analyses presented here into other geographic regions as well as sampling more completely at all spatial scales.

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Section: Palynological Databases and Limits To Resolumentioning

confidence: 99%

Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation

Lupia

Lidgard²,

Crane³

1999

Paleobiology

199

179

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“…They named this river the Esoom river, and showed it flowing in a northwesterly direction and discharging into the Cretaceous Western Interior Seaway (Try et al, 1984). Palynological studies of the Mattagami Formation (e.g., Hopkins and Sweet, 1976;Norris et al, 1976; and others) culminated in the zonation of Norris and Zippi (1991). In their study, the Mattagami Formation was interpreted to range from the Aptian-early Albian to the late Albian, with age determinations easier toward the top of the section because more comparative Albian-Cenomanian studies are available than for earlier Cretaceous stages (Norris and Zippi, 1991).…”

Section: Mattagami Formationmentioning

confidence: 99%

Evidence for an Albian Hudson arm connection between the Cretaceous Western Interior Seaway of North America and the Labrador Sea

White

Witzke

Ludvigson

2000

Geological Society of America Bulletin

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Numerous researchers have alluded to the existence of a Cretaceous Hudson Arm connection between the Labrador Sea and the Western Interior Seaway of North America. However, the evidence for this marine connection has been circumstantial. In this paper we present sedimentary geochemical data that indicate a marine influence in the Albian Mattagami Formation of the Moose River basin, James Bay Lowlands, Ontario. The facies associations between dinoflagellate-bearing laminated mudstones, fluvial sandstones, and early pyrite mineralization are interpreted to indicate deposition in the central basin of an estuary. We use the facies association between the estuarine fill and coeval kaolinitic paleosols in the Moose River basin, and in similar deposits in Quebec and Labrador, to reconstruct a southern shoreline of the Albian Hudson Arm to the Cretaceous Western Interior Seaway. We suggest that development of the Hudson Arm connection between the Labrador Sea and the Cretaceous Western Interior Seaway may be related to a regional extensional regime associated with rifting between Labrador and Greenland, and the passage of eastern North America over Cretaceous hotspots.

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