Paleobotany and paleoecology of Gao Mine, a late Paleocene fossil locality near Red Deer, Alberta, Canada

2013 ◽  
Vol 50 (3) ◽  
pp. 235-248 ◽  
Author(s):  
Ruth A. Stockey ◽  
Georgia L. Hoffman ◽  
Gar W. Rothwell
Keyword(s):  
Leaf Litter ◽  
Plant Community ◽  
Red Deer ◽  
Depositional Environments ◽  
Overbank Sediments ◽  
Fine Grained ◽  
Plant Fossils ◽  
South Central ◽  
Late Paleocene ◽  
Local Plant

In addition to having a rich assemblage of mammalian fossils, the Gao Mine locality in the Paskapoo Formation of south-central Alberta has yielded numerous plant specimens of late Paleocene (late Tiffanian or Ti5) age. The plant fossils are preserved in siltstones and fine-grained sandstones interpreted as overbank sediments that were deposited on an aggrading floodplain. The assemblage is dominated by the cupressaceous conifer Metasequoia foxii and the cercidiphyllaceous dicot Joffrea speirsiae, including their well-preserved seedlings. The flora also contains foliage of the ferns Onoclea and Speirseopteris and the woody dicots Palaeocarpinus, Aphananthe/Celtis, Aesculus, Beringiaphyllum, ?Trochodendron, and Wardiaphyllum, as well as seedlings of unknown dicotyledonous angiosperms. Metasequoia foxii and Speirseopteris are unique to the floras of Gao Mine and the nearby Munce’s Hill site (Tiffanian Ti4). The remainder of the taxa are common in late Paleocene floras of North Dakota, Montana, and Wyoming, all USA. The floras of the nearby Joffre Bridge Roadcut and Blindman River sites (both Tiffanian Ti3) are more diverse, but both of those sites encompass a wider range of depositional environments and may include higher percentages of allochthonous material. Most of the Gao Mine material is autochthonous. The seedlings were buried in place, along with the surrounding leaf litter, preserving a record of the local plant community.

Geological setting and paleobotany of the Joffre Bridge Roadcut fossil locality (Late Paleocene), Red Deer Valley, Alberta

1999 ◽  
Vol 36 (12) ◽  
pp. 2073-2084 ◽  
Author(s):  
Georgia L Hoffman ◽  
Ruth A Stockey
Keyword(s):  
Flood Plain ◽  
Distal Margin ◽  
Plant Fossils ◽  
South Central ◽  
Riparian Trees ◽  
Late Paleocene ◽  
Abandoned Channel ◽  
Death Event ◽  
Crevasse Splay ◽  
Insect Fossils

The Joffre Bridge Roadcut locality (Paskapoo Formation) in south-central Alberta yields plant, mammal, fish, and insect fossils. A Late Paleocene (Tiffanian) age is indicated by mammalian fossils, supported by magnetostratigraphy and palynostratigraphy. This paper summarizes the flora (28 taxa have been identified to date) and describes the sedimentology to provide a paleoenvironmental context. Outcrops at the site are limited, but seven stratigraphic units are recognized and are interpreted to represent five environments of deposition: flood plain, fluvial channel, abandoned channel, swamp, and crevasse splay. The flood-plain mudstones lack identifiable plant material due to bioturbation and pedogenesis. They are capped by a thin, clay-rich paleosol with scattered vertebrate bones. An upward-fining sequence, interpreted as fluvial channel and channel abandonment sediments, rests directly on the paleosol and includes remains of riparian trees. Carbonaceous mudstone, interpreted as a swamp facies, includes remains of only five taxa (taxodiaceous conifers and riparian trees). Light-coloured mudstones on top of the swamp facies include a more diverse assemblage (aquatic and understory plants, taxodiaceous conifers, and riparian trees). Those beds are interpreted as the distal margin of an encroaching crevasse splay. Overlying sediments coarsen upward and are unfossiliferous, except for one occurrence of articulated fish skeletons from a mass-death event. The most productive beds for plant fossils are the top of the channel-abandonment sequence, the swamp horizon, and the base of the crevasse splay. Those beds have also yielded some insect, fish, and mammal remains.

The Hayes Tephra Deposits, and Upper Holocene Marker Horizon in South-Central Alaska

1990 ◽  
Vol 33 (3) ◽  
pp. 276-290 ◽  
Author(s):  
James R. Riehle ◽  
Peter M. Bowers ◽  
Thomas A. Ager
Keyword(s):  
Cook Inlet ◽  
Radiocarbon Dates ◽  
Fine Grained ◽  
South Central ◽  
Inlet Region ◽  
Tephra Deposits ◽  
Phenocryst Content

AbstractThe most widespread of all Holocene tephra deposits in the Cook Inlet region of south-central Alaska is a set of deposits from Hayes volcano. Because of their unique phenocryst content—biotite in rare amounts and a high proportion of amphibole to pyroxene—the deposits are readily identifiable at all but the most distant sites where they are very fine grained. Eighteen radiocarbon dates from eight upland sites limit the age of the tephra set to between about 3500 and 3800 yr. The set originated at Hayes volcano in the Tordrillo Mountains 150 km northwest of Anchorage; seven or possibly eight closely succeeding deposits, low-silica dacite in composition, compose two main lobes that extend northeast for 400 km and south for at least 250 km from the vent. We estimate the total tephra volume to be 10 km3; multiple layers imply four to six larger and two or three smaller eruptions. The deposits are a nearly isochronous marker horizon that should be useful in future archeologic, geologic, and palynologic studies in the region.

Eudaemonema webbi sp. nov. (Mammalia, Mixodectidae) from the late Paleocene of western Canada: the youngest known mixodectid

2010 ◽  
Vol 47 (12) ◽  
pp. 1451-1462 ◽  
Author(s):  
Craig S. Scott
Keyword(s):  
New Species ◽  
North American ◽  
Western Canada ◽  
South Central ◽  
Late Paleocene ◽  
Early Paleocene ◽  
Stratigraphic Ranges ◽  
A New Species ◽  
Stratigraphic Range

Mixodectidae (Mammalia, Archonta) are an unusual, poorly known family of dermopteran-like mammals that have been discovered at several North American localities of primarily early Paleocene age. Among the three or four recognized mixodectid genera, Eudaemonema Simpson is perhaps one of the least understood, being known from only a few localities of late Torrejonian and earliest Tiffanian age. This paper reports on a new species of Eudaemonema from the late Paleocene of Alberta, Canada, that significantly extends the geographic and stratigraphic ranges of the genus. Eudaemonema webbi sp. nov. is known from middle and late Tiffanian localities in central and south central Alberta, and it represents the youngest and northernmost species of Eudaemonema so far discovered. E. webbi differs from the genotypic species E. cuspidata in being larger and in having a suite of dental characters (e.g., molariform posterior premolars, enlarged molar protocone and hypocone, development of a second grinding platform on the lower molars) that suggests an increased emphasis on grinding during mastication. E. webbi possesses several dental features (e.g., broad, shelf-like molar paraconid–paracristid, lingually shifted molar hypoconulid) that resemble those of cynocephalids (Mammalia, Dermoptera), with these resemblances interpreted herein as convergent. The occurrence of E. webbi at Gao Mine extends the stratigraphic range of Eudaemonema into the late Tiffanian (Ti5) and represents the youngest known record of Mixodectidae.

The benefits of being in a bad neighbourhood: plant community composition influences red deer foraging decisions

Oikos ◽  
2009 ◽  
Vol 118 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Jennie N. Bee ◽  
Andrew J. Tanentzap ◽  
William G. Lee ◽  
Roger B. Lavers ◽  
Alan F. Mark ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Red Deer ◽  
Plant Community Composition ◽  
Foraging Decisions

ECOLOGICAL AND TAPHONOMIC FIDELITY IN FOSSIL CRINOID ACCUMULATIONS

Palaios ◽  
2019 ◽  
Vol 34 (11) ◽  
pp. 575-583 ◽  
Author(s):  
DAVID L. MEYER ◽  
WILLIAM I. AUSICH
Keyword(s):  
Depositional Environments ◽  
Biological Processes ◽  
Post Mortem ◽  
Eastern Flank ◽  
South Central ◽  
Middle Mississippian ◽  
Symmetrical Distribution ◽  
Close Proximity ◽  
Marine Facies ◽  
Taphonomic Analysis

ABSTRACT Among fossiliferous marine facies, deposits rich in stalked echinoderms, particularly encrinites, have long been suspected to be susceptible to taphonomic biases because intact calyxes are under-represented or masked by disarticulated skeletal debris. In the middle Mississippian Fort Payne Formation of south-central Kentucky, penecontemporaneous crinoid-rich facies are exposed in close proximity along the shores of Lake Cumberland. Crinoidal packstone buildups preserve a broad preservational spectrum, with articulated crinoid calyxes with arms and columns attached, intact calyxes, holdfasts, and long articulated columns, in a matrix of entirely disarticulated crinoidal fragments. Along a 250 m transect across the flanks and crest of this buildup, identification of 563 specimens of crinoids and blastoids revealed a symmetrical distribution of taxa in which the crest was dominated by disparid and camerate crinoids and the flanks were dominated by camerates. Taphonomic analysis of the same transect showed that intact crinoid calyxes with or without attached arms and column occurred across the entire buildup, but nearly complete specimens with attached arms and column were most common on the western flank and less common on the crest and eastern flank. Taxonomic and taphonomic distributions demonstrate a primary ecologic zonation across the buildup with only localized post-mortem dispersal of crinoids. This is the first demonstration of primary ecologic zonation of a crinoid community preserved within a single lithofacies. Depending on depositional and taphonomic circumstances, crinoids are preserved intact close to their living site; understanding these physical and biological processes provides a significant feedback in reconstructing these ancient depositional environments.

Volcaniclastic lithostratigraphy and paleoenvironment of the lower Eocene McAbee fossil beds, Kamloops Group, British Columbia, Canada

2018 ◽  
Vol 55 (8) ◽  
pp. 923-934 ◽  
Author(s):  
Alexander J. Lowe ◽  
Christopher K. West ◽  
David R. Greenwood
Keyword(s):  
British Columbia ◽  
Forest Ecology ◽  
Lower Eocene ◽  
Main Site ◽  
Plant Fossils ◽  
South Central ◽  
Lithostratigraphic Units ◽  
Near Shore ◽  
Spatio Temporal ◽  
Depositional Setting

The lower Eocene McAbee fossil beds (∼53 Ma), in south-central British Columbia, Canada, represent a lacustrine sequence deposited during a time of pervasive regional volcanism. Previous studies on fossil assemblages at the McAbee fossil beds consist of amalgamated collections of plants from several disjunct and stratigraphically unconstrained exposures and horizons, with limited knowledge of the spatio-temporal variation in depositional and taphonomic setting. This study presents a high-resolution lithostratigraphic analysis of the McAbee main site to provide stratigraphic, paleoenvironmental, and taphonomic context to fossil collections. A lithostratigraphic framework was developed for the McAbee main site by correlating tuff marker beds. The sequence was divided into eight lithostratigraphic units on the basis of systematic lithologic trends, a result of varying degrees of volcanic influences. An absence of shallow water indicators, bioturbation, and evidence for fluvio–deltaic influence, and the nonrestricted presence of highly abundant and diverse well-preserved plant fossils indicates a deep water, yet relatively near shore facies, suggesting steep sided lake margins. This taphonomic regime imparts minimal transport- and degradation-induced biases in fossil plant assemblages and suggests plant fossils represent local vegetation growing near the point of deposition. The new lithostratigraphic framework coupled with a refined understanding of depositional setting and taphonomic regime demonstrates the opportunity to document conditions of forest ecology within a dynamic volcanic environment over millennial and multi-millennial time scales.

APPROACHES TO PALAEOGEOGRAPHIC RECONSTRUCTIONS OF THE LATROBE GROUP, GIPPSLAND BASIN, SOUTHEASTERN AUSTRALIA

2005 ◽  
Vol 45 (1) ◽  
pp. 581 ◽  
Author(s):  
T. Bernecker ◽  
A.D. Partridge
Keyword(s):  
Co2 Storage ◽  
Depositional Environments ◽  
Petroleum Systems ◽  
Fine Grained ◽  
Southeastern Australia ◽  
Depositional System ◽  
Facies Associations ◽  
Marine Fossils ◽  
Coal Accumulation ◽  
Gippsland Basin

In the Gippsland Basin, the seaward extent of paralic coal occurrences can be mapped in successive time slices through the Paleocene and Eocene to provide a series of straight to gently arcuate surrogate palaeoshorelines within the petroliferous Latrobe Group. Palaeogeographic reconstructions that incorporate this information provide a unique perspective on the changes affecting a siliciclastic depositional system on a passive continental margin where basin development has been primarily controlled by thermal sag. In contrast, the absence of calcareous marine fossils and lack of extensive, widespread and thick fine-grained sediments on the marine shelf and continental slope, beyond the seaward limits of coal accumulation, have contributed to the false impression that the Latrobe Group accumulated in a largely non-marine basin. Based on the proposed model for palaeoshoreline delineation, seismic data, sequence analysis, petrography and palynology can be integrated to subdivide the main depositional environments into distinct facies associations that can be used to predict the distribution of petroleum systems elements in the basin. The application of such palaeogeographic models to the older section of the Latrobe Group can improve the identification of these petroleum systems elements in as yet unexplored parts of the Gippsland Basin. Given the recent attention paid to the basin as a CO2 storage province, palaeogeographic interpretations may be able to assist with the selection of appropriate injection sites.

Palynostratigraphic zonation of Paleocene strata in the central and south-central Alberta Plains

1990 ◽  
Vol 27 (10) ◽  
pp. 1263-1269 ◽  
Author(s):  
Thomas D. Demchuk
Keyword(s):  
Coal Seam ◽  
River Basin ◽  
Red Deer ◽  
River Valley ◽  
Lower Portion ◽  
Wind River Basin ◽  
South Central

Paleocene strata of the Scollard and Paskapoo formations in the central and south-central Alberta Plains can be subdivided into five formal biostratigraphic zones, based in part on a Momipites–Caryapollenites palynofloral lineage. A similar zonation previously identified from strata of the Wind River basin in Wyoming displays similar palynomorph occurrences. However, differences that are present are likely a result of latitudinal climatic zonation between Alberta and Wyoming during Paleocene time.Lowermost Paleocene strata of Alberta (Wodehouseia fimbriata Zone) are barren of Momipites species, which subsequently first appear in the Momipites wyomingensis Zone. These two zones include strata from the Cretaceous–Tertiary boundary (Nevis coal seam) to the top of the Scollard Formation. A diverse assemblage of Momipites spp. plus Aquilapollenites spinulosus, Caryapollenites prodromus, and Tiliaepollenites danei are present in the Aquilapollenites spinulosus Zone within the lowermost Paskapoo Formation. Two more species of Caryapollenites appear in the Caryapollenites wodehousei Zone. The Pistillipollenites mcgregorii Zone is characterized by the presence of Pistillipollenites mcgregorii, Insulapollenites rugulatus, and Caryapollenites inelegans. Momipites leffingwellii is absent from the lower portion of this zone, with Momipites waltmanensis, Momipites actinus, and Momipites triorbicularis absent from the upper portion. Lower P. mcgregorii Zone strata are the youngest strata encountered in the vicinity of the Red Deer River valley. Upper P. mcgregorii Zone strata include strata of the Obed–Marsh coal zone within the uppermost part of the Paskapoo Formation adjacent to the Alberta Foothills.

scholarly journals Grain size statistics and depositional pattern of the Ecca Group sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Christopher Baiyegunhi ◽  
Kuiwu Liu ◽  
Oswald Gwavava
Keyword(s):  
South Africa ◽  
Grain Size ◽  
Depositional Environments ◽  
Energy Conditions ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Equal Proportion ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Fine Grained

AbstractGrain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicate the dominance of low energy environment. The bivariate plots show that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are lacustrine or deltaic deposits. The C-M plots indicated that the sediments were deposited mainly by suspension and saltation, and graded suspension. Visher diagrams show that saltation is the major process of transportation, followed by suspension.

Origins and engineering hazards of Swedish glaciomarine and marine clays

1991 ◽  
Vol 7 (1) ◽  
pp. 257-264 ◽  
Author(s):  
R. L. Stevens ◽  
M. S. Rosenbaum ◽  
L. G. Hellgren
Keyword(s):  
Urban Areas ◽  
Urban Expansion ◽  
Three Dimensional ◽  
Depositional Environments ◽  
Coarse Grained ◽  
Land Uplift ◽  
Fine Grained ◽  
Depositional Settings ◽  
Late Weichselian ◽  
Three Dimensional Models

AbstractThis paper relates the Engineering features of fine-grained clays in the Göteborg area to their glacial sources, depositional settings and postdepositional changes. These deposits occupy valley and coastal areas where urban expansion has been concentrated, despite the considerable problems with settlement and quick-clay behaviour. Both mineralogical and permeability trends are largely determined by the textural characteristics of the deposits. The depositional environments, which have largely controlled the textural trends, are known to have evolved during late Weichselian times due to glacial retreat, isostatic land uplift and climatic changes. A generalized lithostratigraphical model has been produced and this is used here to help understand and predict the variability of the geotechnical properties. The stratigraphical trends in texture, mineralogy and structure are considered within four broad genetic categories: 1) coarse-grained glacial deposits, 2) glaciomarine deposits, 3) very distal glaciomarine deposits, and 4) shallow-marine deposits. These divisions can often be recognized within the logs of geotechnical reports, which suggested that they could provide the basis for development of three-dimensional models which have both geological and geotechnical predictive power within the vicinity of Göteborg. They could also act as a guide for the development of similar models in urban areas elsewhere.

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