Author: Morris F. Skinner
Publisher:
ISBN:
Category : Formations (Geology)
Languages : en
Pages : 164
Book Description
"Late Tertiary Valentine and Ash Hollow formations of the Ogallala Group in north-central Nebraska contain two previously unnamed fossiliferous ash-bearing members. These, with four published members, provide a startigraphic framework for large collections of fossils in the Frick Collection in AMNH and other institutions. The Cornell Dam Member (new) in the basal Valentine Formation has salient lithic features and geologic relationships not found in other members of the Valentine. Basal channel sand disconformably overlying the Rosebud Formation contains macro- and microinvertebrate fossils (Norden Fauna, new) that also show the ecological and faunal distinction of this member. Fission track dates suggest that Valentine sediments spanned one and perhaps three million years. The Merritt Dam Member (new) of late Clarendonian to late Hemphillian age, disconformably overlies the Cap Rock Member of the referred Ash Hollow Formation. The Merritt Dam Member is less cliff forming than the Cap Rock Member, contains more volcanic ash and local channel and pond sediments. Tectonic readjustment caused deep channel erosion through the Ogallala into Arikaree rocks on the east flank of the Chadron Arch and eastward into the Cap Rock Member and the Valentine Formation. Sediments filling some of these channels contain vertebrate fossils overlain by vitric tuffs with a fission track date of 9.5 [+ or -] 0.8 Ma. The paleogeomorphology of the Ogallala Group and its depositonal framework is the product of overlapping alluvial fans of at least three paleodrainage systems which filled pre-existing valleys and spread sediments over a vast Great Plains area in Nebraska and South Dakota. In north-central Nebraska widespread aggradation and two short periods of degradation occurred during the Valentinian. Gradual aggradation during the early Clarendonian was followed by intermittent aggradation and degradation during the late Clarendonian and Hemphillian. The stratigraphic allocation and history of 98 collecting localities and documentation of 90 holotypes of fossil vertebrates and 13 plants provide a firm base for continued research. The prinipal aquifer in the Ogallala is the Crookston Bridge Member of the Valentine Formation"--P. 217.
Tertiary Stratigraphy and the Frick Collection of Fossil Vertebrates from North-central Nebraska
Author: Morris F. Skinner
Publisher:
ISBN:
Category : Formations (Geology)
Languages : en
Pages : 164
Book Description
"Late Tertiary Valentine and Ash Hollow formations of the Ogallala Group in north-central Nebraska contain two previously unnamed fossiliferous ash-bearing members. These, with four published members, provide a startigraphic framework for large collections of fossils in the Frick Collection in AMNH and other institutions. The Cornell Dam Member (new) in the basal Valentine Formation has salient lithic features and geologic relationships not found in other members of the Valentine. Basal channel sand disconformably overlying the Rosebud Formation contains macro- and microinvertebrate fossils (Norden Fauna, new) that also show the ecological and faunal distinction of this member. Fission track dates suggest that Valentine sediments spanned one and perhaps three million years. The Merritt Dam Member (new) of late Clarendonian to late Hemphillian age, disconformably overlies the Cap Rock Member of the referred Ash Hollow Formation. The Merritt Dam Member is less cliff forming than the Cap Rock Member, contains more volcanic ash and local channel and pond sediments. Tectonic readjustment caused deep channel erosion through the Ogallala into Arikaree rocks on the east flank of the Chadron Arch and eastward into the Cap Rock Member and the Valentine Formation. Sediments filling some of these channels contain vertebrate fossils overlain by vitric tuffs with a fission track date of 9.5 [+ or -] 0.8 Ma. The paleogeomorphology of the Ogallala Group and its depositonal framework is the product of overlapping alluvial fans of at least three paleodrainage systems which filled pre-existing valleys and spread sediments over a vast Great Plains area in Nebraska and South Dakota. In north-central Nebraska widespread aggradation and two short periods of degradation occurred during the Valentinian. Gradual aggradation during the early Clarendonian was followed by intermittent aggradation and degradation during the late Clarendonian and Hemphillian. The stratigraphic allocation and history of 98 collecting localities and documentation of 90 holotypes of fossil vertebrates and 13 plants provide a firm base for continued research. The prinipal aquifer in the Ogallala is the Crookston Bridge Member of the Valentine Formation"--P. 217.
Publisher:
ISBN:
Category : Formations (Geology)
Languages : en
Pages : 164
Book Description
"Late Tertiary Valentine and Ash Hollow formations of the Ogallala Group in north-central Nebraska contain two previously unnamed fossiliferous ash-bearing members. These, with four published members, provide a startigraphic framework for large collections of fossils in the Frick Collection in AMNH and other institutions. The Cornell Dam Member (new) in the basal Valentine Formation has salient lithic features and geologic relationships not found in other members of the Valentine. Basal channel sand disconformably overlying the Rosebud Formation contains macro- and microinvertebrate fossils (Norden Fauna, new) that also show the ecological and faunal distinction of this member. Fission track dates suggest that Valentine sediments spanned one and perhaps three million years. The Merritt Dam Member (new) of late Clarendonian to late Hemphillian age, disconformably overlies the Cap Rock Member of the referred Ash Hollow Formation. The Merritt Dam Member is less cliff forming than the Cap Rock Member, contains more volcanic ash and local channel and pond sediments. Tectonic readjustment caused deep channel erosion through the Ogallala into Arikaree rocks on the east flank of the Chadron Arch and eastward into the Cap Rock Member and the Valentine Formation. Sediments filling some of these channels contain vertebrate fossils overlain by vitric tuffs with a fission track date of 9.5 [+ or -] 0.8 Ma. The paleogeomorphology of the Ogallala Group and its depositonal framework is the product of overlapping alluvial fans of at least three paleodrainage systems which filled pre-existing valleys and spread sediments over a vast Great Plains area in Nebraska and South Dakota. In north-central Nebraska widespread aggradation and two short periods of degradation occurred during the Valentinian. Gradual aggradation during the early Clarendonian was followed by intermittent aggradation and degradation during the late Clarendonian and Hemphillian. The stratigraphic allocation and history of 98 collecting localities and documentation of 90 holotypes of fossil vertebrates and 13 plants provide a firm base for continued research. The prinipal aquifer in the Ogallala is the Crookston Bridge Member of the Valentine Formation"--P. 217.
Tertiary Stratigraphy and the Frick Collection of Fossil Vertebrates from North-Central Nebraska
North-Central Section of the Geological Society of America
Author: Donald L. Biggs
Publisher: Geological Society of America
ISBN: 0813754038
Category : Science
Languages : en
Pages : 460
Book Description
Publisher: Geological Society of America
ISBN: 0813754038
Category : Science
Languages : en
Pages : 460
Book Description
Geological Survey Bulletin
The Niobrara
Author: Paul A. Johnsgard
Publisher: U of Nebraska Press
ISBN: 9780803259812
Category : Nature
Languages : en
Pages : 396
Book Description
Although its history is etched on canyon walls reaching back twenty million years, the Niobrara is very much a river of today. Stretching 535 miles from its headwaters to the Missouri River, it is one of Nebraska?s least altered waterways and is designated as a national scenic river. Its waterfalls and wildlife make it a haven for outdoor enthusiasts, but pressures from development still threaten its scenic and ecological wonders. ø This first book-length study of the Niobrara is a comprehensive look at an ecological treasure. Paul A. Johnsgard reviews the river?s history from its geologic past through prehistoric settlement to the present and highlights its historical and biological features. ø Writing from this crossroads of eastern and western species, Johnsgard also describes the Niobrara?s varied plants and animals, providing extensive information on bird populations. He offers portraits of sixteen species of special conservation concern, such as the black-tailed prairie dog and the olive-backed pocket mouse. Drawings by Johnsgard, information tables on various species, plus site lists make the book an invaluable reference. It conveys the Niobrara?s value as a recreational and scientific resource to help visitors better appreciate this riparian paradise while offering specialists an unimpeachable guide to its scientific riches. The Niobrara includes chapters by Jon Farrar and Duane Gudgel.
Publisher: U of Nebraska Press
ISBN: 9780803259812
Category : Nature
Languages : en
Pages : 396
Book Description
Although its history is etched on canyon walls reaching back twenty million years, the Niobrara is very much a river of today. Stretching 535 miles from its headwaters to the Missouri River, it is one of Nebraska?s least altered waterways and is designated as a national scenic river. Its waterfalls and wildlife make it a haven for outdoor enthusiasts, but pressures from development still threaten its scenic and ecological wonders. ø This first book-length study of the Niobrara is a comprehensive look at an ecological treasure. Paul A. Johnsgard reviews the river?s history from its geologic past through prehistoric settlement to the present and highlights its historical and biological features. ø Writing from this crossroads of eastern and western species, Johnsgard also describes the Niobrara?s varied plants and animals, providing extensive information on bird populations. He offers portraits of sixteen species of special conservation concern, such as the black-tailed prairie dog and the olive-backed pocket mouse. Drawings by Johnsgard, information tables on various species, plus site lists make the book an invaluable reference. It conveys the Niobrara?s value as a recreational and scientific resource to help visitors better appreciate this riparian paradise while offering specialists an unimpeachable guide to its scientific riches. The Niobrara includes chapters by Jon Farrar and Duane Gudgel.
U.S. Geological Survey Professional Paper
Neogene Mammals
Author: Spencer G. Lucas
Publisher: New Mexico Museum of Natural History and Science
ISBN:
Category : Science
Languages : en
Pages : 450
Book Description
Neogene Mammals: New Mexico Museum of Natural History and Science Bulletin 44
Publisher: New Mexico Museum of Natural History and Science
ISBN:
Category : Science
Languages : en
Pages : 450
Book Description
Neogene Mammals: New Mexico Museum of Natural History and Science Bulletin 44
U.S. Geological Survey Professional Paper
Author: Geological Survey (U.S.)
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 60
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 60
Book Description
Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate Like Mammals
Author: Christine M. Janis
Publisher: Cambridge University Press
ISBN: 9780521355193
Category : Science
Languages : en
Pages : 712
Book Description
This book is designed as a source and reference for people interested in the history and fossil record of North American tertiary mammals. Each chapter covers a different family or order, and includes information on anatomical features, systematics, the distribution of the genera and species at different fossil localities, and a discussion of their paleobiology. Many of these groups have never been covered in this fashion before.
Publisher: Cambridge University Press
ISBN: 9780521355193
Category : Science
Languages : en
Pages : 712
Book Description
This book is designed as a source and reference for people interested in the history and fossil record of North American tertiary mammals. Each chapter covers a different family or order, and includes information on anatomical features, systematics, the distribution of the genera and species at different fossil localities, and a discussion of their paleobiology. Many of these groups have never been covered in this fashion before.
Distribution and Stratigraphic Correlation of Upper Paleocene and Lower Eocene Fossil Mammal and Plant Localities of the Fort Union, Willwood, and Tatman Formations, Southern Bighorn Basin, Wyoming
Author: Thomas M. Bown
Publisher:
ISBN:
Category : Bighorn Basin (Mont. and Wyo.)
Languages : en
Pages : 120
Book Description
Publisher:
ISBN:
Category : Bighorn Basin (Mont. and Wyo.)
Languages : en
Pages : 120
Book Description