Sedimentology Commons^™

The Inapplicability Of The Concept Of The "Sidney Gravel" To The Ogallala Group (Late Tertiary) In Part Of Southern Banner County, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

A series of geologic maps of counties in western Nebraska was prepared for the Nebraska Geological Survey during the mid-1 930s. These maps showed the distribution of rock units of Tertiary age including a formation designated as the “Sidney.” The Sidney Gravel was described as a widespread sheetlike complex of channel deposits, but with small areas where it is not developed. In southern Banner County, Nebraska, there are several channels filled with sand and gravel that were mapped as Sidney in this series. Recently one of these channel fills has been observed to cut across the other. The fills are …

Further Comments On The Nature And Developmental History Of Quaternary Pumpkin Creek, Banner, And Morrill Counties, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

The occurrence of Quaternary anorthosite-rich sand and gravel deposits in south-central Morrill County, Nebraska, supports the idea that Pumpkin Creek formerly flowed farther east than it does today. This eastern extension of the creek was abandoned when another headward cutting tributary of the North Platte River cut through the divide between Pumpkin Creek and the North Platte just east of Jail and Courthouse rocks and captured Pumpkin Creek.

Unusual clast types found in Quaternary deposits along Pumpkin Creek in Banner County may be used to determine some characteristics of the streams that carried them. For example, armored mud balls and …

Geometries And General Features Of Some Cenozoic Valleys And Valley Fills, Western Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

Portions of Tertiary and Quaternary valleys and valley fills have been exhumed by recent stream erosion at many sites in western Nebraska. Paleovalleys vary from narrow, steep-sided, high gradient tributary gullies less than 0.1 km wide to broad, flat-floored valleys produced by lateral erosion. Segments of valley floors may be nearly smooth in the case of a Quaternary example, or may be very irregular with potholes and other deep scour features. Paleovalley sides, when exposed, are often steeply sloping, and approaching or possibly going beyond the vertical where the valleys have been eroded into the Brule Formation. Paleovalleys range in …

A Gering Formation (Miocene) Pumice Conglomerate And Associated Beds From Broadwater, Nebraska, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

The Mitchell Pass Member of the Gering Formation was defined by Vondra, Schultz, and Stout in 1969 on the basis of exposures in the Wildcat Ridge area of western Nebraska. The basal part of the member in many areas of Wildcat Ridge is a pumice-pebble conglomerate bed. A newly discovered pumice-pebble conglomerate locality occurs north of Broadwater, Nebraska, some twenty miles east of the easternmost previously reported exposure of the pumice conglomerate at Redington Gap on Wildcat Ridge. Pumice samples from Redington Gap and Broadwater have the same index of refraction and similar inclusions. Beds above the conglomerate and below …

The Ord River Catchment Regeneration Project. 1. The Nature, Extent And Causes Of Erosion In The Ord River Catchment Area, K Fitzgerald

Journal of the Department of Agriculture, Western Australia, Series 4

OF the 17,800 square miles of Ord River catchment area, an estimated 1,450 square miles of country is subject to varying degrees of erosion.

This lies astride the Ord River and its major tributaries, the Elvire, Negri, Stirling, Panton, Turner, Nicholson and RB rivers.

The bulk of the eroded country lies in W.A. but part projects into the Northern Territory.