Tertiary fluvial gravels and evolution of the Western Canadian Prairie Landscape

Leckie, Dale A.

doi:10.1016/j.sedgeo.2006.05.019

Cited by 21 publications

(8 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Cypress Hills Formation ichthyofauna indicates a lowland fluvial environment consistent with the braided river floodplain environment suggested by the sedimentary geology of the formation (Leckie and Cheel, 1989;Leckie, 2006). The presence of silcretes forming in situ in some layers and silcrete fragments forming part of the flood-deposited breccias that bear many of the fossils of the formation had been interpreted by Leckie and Cheel (1990) as evidence of strongly seasonal rainfalls and locally arid conditions.…”

Section: Paleoenvironmental Reconstructionmentioning

confidence: 67%

“…The western part of the formation has relatively more large clasts, whereas average grain size is smaller in the eastern part of the formation (Vonhof, 1969;Leckie and Cheel, 1989;Leckie, 2006), in an area corresponding to where the fossils described here were recovered (Leckie and Cheel, 1989). In this area, lacustrine marlstones and fossil-bearing debris-flow deposits are interbedded with the deposits of braided channels up to 9 m deep, occasionally cutting into the lake deposits (Leckie and Cheel, 1989).…”

Section: Geologic Settingmentioning

confidence: 90%

“…The Cypress Hills Formation is represented by erosional remnants of fluvially deposited and weakly cemented gravels, conglomerates, and sandstones, along with volcanic ashes, bentonite, silt, clay, and marl (Vonhof, 1969;Leckie and Cheel, 1989;Leckie, 2006). The western part of the formation has relatively more large clasts, whereas average grain size is smaller in the eastern part of the formation (Vonhof, 1969;Leckie and Cheel, 1989;Leckie, 2006), in an area corresponding to where the fossils described here were recovered (Leckie and Cheel, 1989).…”

Section: Geologic Settingmentioning

confidence: 98%

“…The formation ranges in thickness between approximately 30 and 50 m in the area north of Eastend (Vonhof, 1969; reported as 100 to 160 feet). These sediments represent the distal areas of a wide braidplain, with low-sinuosity rivers flowing north-northeast towards what is now the Hudson Bay (Leckie and Cheel, 1989;Leckie, 2006). Sediments were derived from the Rocky Mountains of western Montana, with tributaries coming from the Sweetgrass Hills, Highwood Mountains, and Bearpaw Mountains, as indicated by the lithology of the Cypress Hills pebbles (Vonhof, 1969) and the proximal-distal eastward trend of relative clast sizes (Leckie and Cheel, 1989;Leckie, 2006).…”

Section: Geologic Settingmentioning

confidence: 99%

“…These sediments represent the distal areas of a wide braidplain, with low-sinuosity rivers flowing north-northeast towards what is now the Hudson Bay (Leckie and Cheel, 1989;Leckie, 2006). Sediments were derived from the Rocky Mountains of western Montana, with tributaries coming from the Sweetgrass Hills, Highwood Mountains, and Bearpaw Mountains, as indicated by the lithology of the Cypress Hills pebbles (Vonhof, 1969) and the proximal-distal eastward trend of relative clast sizes (Leckie and Cheel, 1989;Leckie, 2006). Several of the fossiliferous beds in the study area correspond to Leckie and Cheel's (1989) conglomeratic breccias and associated sandstones, which they interpreted as representing debris-flow deposits resulting from flooding episodes.…”

Section: Geologic Settingmentioning

confidence: 99%

See 4 more Smart Citations

The late Eocene–early Oligocene ichthyofauna from the Eastend area of the Cypress Hills Formation, Saskatchewan, Canada

Divay

2015

Journal of Vertebrate Paleontology

View full text Add to dashboard Cite

The Eocene through Miocene Cypress Hills Formation of Saskatchewan and Alberta has been the basis of studies on sedimentology, paleobotany, herpetofauna, avifauna, and mammalian local faunas. We describe the ichthyofauna from the Eastend area of the formation, representing late Eocene Chadronian to early Oligocene Whitneyan deposits. This fauna is diverse, including at least 14 fish taxa: Lepisosteus, Amiinae, aff. Hiodon, at least three cypriniforms among which is a Ptychocheilus-like leuciscine and at least one catostomid, two ictalurids, both ascribed to Astephus, a probable salmoniform, an amblyopsid-like percopsiform, Mioplosus, a probable moronid, a centrarchid, and at least one other perciform of uncertain affinity. The formation may therefore represent the first fossil record of the Amblyopsidae, and the first North American occurrence of the Moronidae. The composition of the ichthyofauna suggests higher temperatures during the Eocene-Oligocene transition than at present. Paleotemperatures similar to those of the Gulf Coast of the United States are indicated by the present ranges of several taxa, as well as by the large sizes attained by some of these fishes. The high relative abundance of abraded ictalurid material representing small individuals suggests that much of the formation was deposited in shallow, hypoxic floodplain pools that may have seasonally dried out. However, the large sizes attained by some taxa and the diversity of the fauna as a whole indicate that the neighboring aquatic environments were diverse, with welloxygenated, vegetated, permanent, and deep-water environments. This suggests the presence of a mosaic of conditions, such as is found in large floodplains.

show abstract

Section: Paleoenvironmental Reconstructionmentioning

confidence: 67%