Author: North Central Nebraska Resource Conservation and Development ProjectPublisher:
ISBN:
Category : Conservation of natural resources
Languages : en
Pages : 80
Book Description
A Promise for the Future in North Central Nebraska
Author: North Central Nebraska Resource Conservation and Development ProjectPublisher:
ISBN:
Category : Conservation of natural resources
Languages : en
Pages : 80
Book Description
Agrindex
Author: Educational Press Bulletin
Author: Illinois. Office of the Superintendent of Public InstructionPublisher:
ISBN:
Category :
Languages : en
Pages : 1308
Book Description
The Nebraska Farmer
Author: Oildom
Author: Publisher:
ISBN:
Category : Petroleum industry and trade
Languages : en
Pages : 728
Book Description
Technical Note
Author: Proceedings of the ... Conference of the North Central States Entomologists
Author: North Central States Entomologists. ConferencePublisher:
ISBN:
Category : Beneficial insects
Languages : en
Pages : 784
Book Description
Upper Mississippi River Comprehensive Basin Study: Appendix A-Q
Author: Upper Mississippi River Comprehensive Basin Study Coordinating CommitteePublisher:
ISBN:
Category : Mississippi River Valley
Languages : en
Pages : 760
Book Description
Tertiary Stratigraphy and the Frick Collection of Fossil Vertebrates from North-central Nebraska
Author: Morris F. SkinnerPublisher:
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.
The Physical and Economic Foundation of Natural Resources
Author: United States. Congress. House. Committee on Interior and Insular AffairsPublisher:
ISBN:
Category : Photosynthesis
Languages : en
Pages : 256
Book Description