Geomorphology Commons^™

Megaclasts In Alluvial Fills From The Ogallala Group (Miocene), Banner, Kimball, And Morrill Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Locally derived blocks and boulders (megaclasts) occur in conglomerate and in sand and gravel fills of channels in the Ogallala Group (Miocene) at localities in Banner, Kimball, and Morrill counties in western Nebraska. Some of the megaclasts are up to one or more orders of magnitude larger than the largest distantly derived grains in the sediments surrounding them. A number of these megaclasts probably moved downslope by mass wasting from outcrop sites on paleovalley sides and were later transported by running water. Other blocks and boulders were eroded by streams from bedrock along channel sides and then were transported by …

An Irvingtonian Fauna From The Oldest Quaternary Alluvium In Eastern Pumpkin Creek Valley, Morrill And Banner Counties, Nebraska, R. George Corner, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Vertebrate fossils of Mammuthus meridionalis (Nesti) and Equus sp. cf. E. scotti Gidley occur at two sites in the capping alluvium of the highest strath terrace along the south side of Pumpkin Creek Valley, Nebraska. The presence of these two species supports the conclusion that the age of the capping sediments is probably early Irvingtonian (early Pleistocene).

Asymmetrical Distribution Of Quaternary Alluvial Fills, Pumpkin Creek Drainage Basin, Western Nebraska, Robert F. Diffendal Jr., R. George Corner

Robert F. Diffendal, Jr., Publications

A remnant alluvial fill of early Pleistocene age exposed in Pumpkin Creek Valley, Banner and Morrill counties, Nebraska, has yielded fossils of Mammuthus meridionalis (Nesti) and Equus sp. cf. E. scotti Gidley. Younger fill remnants of trunk and tributary streams allow a refinement of earlier views on the development of the Pumpkin Creek drainage basin during the Quaternary Period. Ancestral Pumpkin Creek both shifted to the north and entrenched its valley several times during the Quaternary Period leaving alluvial fills at three levels or more south of the present creek. Piracy of the headwaters of ancestral Pumpkin Creek took …

Gully, Scour Hole, And Pothole Development At The Base Of The Gering Formation (Miocene?), Southeastern Banner County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Several sediment-filled paleovalleys belonging to the Arikaree Group of Miocene (?) age occur in southeastern Banner County, Nebraska. One gully and a main paleovalley exhibit, respectively, erosional features like those in modern gullies in the area and like those on the bedrock floors of modern straight streams carrying an appreciable sediment load. Scour holes and a pothole on the valley floor of the main paleovalley are similar to those produced experimentally on the bed of a straight stream.

Regional Implications Of The Geology Of The Ogallala Group (Upper Tertiary) Of Southwestern Morrill County, Nebraska, And Adjacent Areas, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

A part of a filled Ogallala Group (upper Tertiary) paleovalley system exhumed by recent stream erosion in southwestern Morrill County, Nebraska, and adjacent areas contains steep gradient gullies filled with locally derived sediments. Younger channels filled with granitic gravels derived by stream erosion of the Rocky Mountains to the west and southwest cut across and through these older filled gullies, indicating that there were at least two periods of downcutting followed by periods of filling during the development of this system.

Individual clasts from younger Ogallala gravels are often as large as or larger than clasts from Quaternary gravels transported …

Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett

Robert F. Diffendal, Jr., Publications

The purpose of this investigation was to extend the area covered by gravity and ground magnetic data related to the Nemaha Uplift and associated structures in eastern Nebraska. Gravity data were collected from Clay, Fillmore, Hamilton, Nuckolls, Polk, Thayer, and York Counties. Additional ground magnetic data and gravity data were collected for central Otoe County.

Gravity And Ground Magnetic Investigations In Eastern Nebraska, Robert F. Diffendal Jr., R. R. Burchett

Robert F. Diffendal, Jr., Publications

The purpose of this investigation was to extend the area covered by gravity and ground magnetic data related to the Nemaha Uplift and associated structures in eastern Nebraska. Gravity data were collected from Butler, Jefferson, Saline, and Seward counties. Additional ground magnetic data and gravity data were collected for eastern Sarpy and northeastern Cass counties in Nebraska and gravity data were collected from parts of Mills and Fremont counties in Iowa.

Ash Hollow Historical Park, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ash Hollow Creek is an intermittent stream forming a southern tributary to the North Platte River. The creek flows only in response to precipitation from locally heavy thunderstorms or to heavy runoff from melting snow in the spring. Western Nebraska has a semi-arid climate and receives less than 20 inches of rainfall per year. Vegetation in the park and surrounding area is typical of the short grass prairie of the Great Plains. Native short grasses grow abundantly on undisturbed tablelands, valley sides, and along principal flood plains of streams and rivers. Prickly pear, barrel cactus, yucca and sagebrush are common …

Broadwater Ne Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 37'30" — 41° 45'

102° 45' — 102° 52'30"

Scale 1:24,000

Completed June 6, 1979

High resolution .tif file attached below as supplemental file

Broadwater Nw Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 37'30" — 41° 45'

102° 52'30" — 103° 00'

Scale 1:24,000

Completed June 25, 1979

High resolution .tif file attached below as supplemental file

Martin Quadrangle, Nebraska—Keith County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Martin Quadrangle, Nebraska—Keith County

7.5 minute series (topographic), scale 1:24,000

101°37'30" to 101°45'

41°15' to 41°22'30"

Ogallala Group

Completed September 20, 1978

Ogallala Sw Quadrangle, Nebraska—Keith And Perkins Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ogallala SW Quadrangle, Nebraska—Keith and Perkins Counties

7.5 minute series (topographic), scale 1:24,000

101°37'30" to 101°45'

41°00' to 41°07'30"

Post-Ogallala sand and gravel

September 20, 1978

Brule Se Quadrangle, Keith And Perkins Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 00' — 41° 07'30"

101° 45' — 101° 52'30"

Scale 1:24,000

High resolution .tif file attached below as supplemental file

Brule (Sw) Quadrangle, Keith And Perkins Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 00' — 41° 07'30"

101° 52'30" — 102° 00'

Scale 1:24,000

High resolution .tif file attached below as supplemental file

Sutherland Reservoir Nw Quadrangle, Nebraska—Lincoln County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Sutherland Reservoir NW Quadrangle, Nebraska—Lincoln Co.

7.5 minute series (topographic), scale 1:24000

101°07'30" to 101°15'

41°07'30" to 41°15'

Ql = Loess, Post-Ogallala Sand and Gravel, Ogallala Outcrop

July 11, 1978

Nevens Quadrangle, Nebraska—Keith County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nevens Quadrangle, Nebraska—Keith County

7.5 minute series (topographic), scale 1:24,000

101°22'30" to 101°30'

41°07'30" to 41°15'

Ql = Loess

Post-Ogallala sand and gravels

Ogallala Outcrop

Volcanic ash

July 11, 1978

Paxton North Quadrangle, Nebraska—Keith And Lincoln Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Paxton North Quadrangle, Nebraska—Keith and Lincoln Counties

7.5 minute series (topographic), scale 1:24000

101°15' to 101°22'30"

41°07'30" to 41°15'

Ql=loess, Qsa=sand; Post-Ogallala sand and gravel; Ogallala Outcrop

July 7, 1978

Maxwell Quadrangle, Nebraska—Lincoln County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Maxwell Quadrangle, Nebraska—Lincoln County

7.5 minute series (topographic), scale 1:24,000

100°30' to 100°37'30"

41°00' to 41°07'30"

Ogallala Outcrop

Completed June 7, 1978

Twin Buttes Quadrangle, Nebraska—Garden County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Twin Buttes Quadrangle, Nebraska—Garden Co.

7.5 minute series (topographic), scale 1:24000

102°07'30" to 102°15'

41°07'30" to 41°30'

Qsa, Ql, Qg, Ogallala Outcrop, Ogallala Volcanic Ash, Pre-Ogallala (Brule) Outcrop, Pre-Ogallala (Brule) White Horizons, QF=Pleist Fossil, BF=Brule Fossil, F-Ogallala Fossil

August 28, 1977

Lisco Se Quadrangle, Nebraska—Garden And Cheyenne Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lisco SE Quadrangle, Nebraska—Garden and Cheyenne Counties

7.5 minute series (topographic), scale 1:24,000

102°30' to 102°37'30"

41°15' to 41°22'30"

Ql = Loess

Qsa = Sand

Volcanic ash

Completed August 27, 1977

Oshkosh Quadrangle, Nebraska—Garden County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Oshkosh Quadrangle, Nebraska—Garden County

7.5 minute series (topographic), scale 1:24000

102°15' to 102°22'30"

41°22'30" to 41°30'

Ogalalla Outcrop, Pre-Ogallala Outcrop, Brule-Whitney

August 5, 1977

Lisco Quadrangle, Nebraska—Garden And Cheyenne Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lisco Quadrangle, Nebraska—Garden and Cheyenne Counties

7.5 minute series (topographic), scale 1:24,000

102°30' to 102°37'30"

41°22'30" to 41°30'

Quarternary sand and gravel (Broadwater)

Ogallala Outcrop

Volcanic ash

Ogallala fossil

Completed August 5, 1977

Coumbe Bluff Quadrangle, Garden County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 22'30" — 41° 30'

102° 22'30" — 102° 30'

Scale 1:24,000

High resolution .tif file attached below as supplemental file

Oshkosh Sw, Nebraska—Garden County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Oshkosh SW, Nebraska—Garden County

7.5 minute series (topographic), scale 1:24,000

102°22'30" to 102°30'

41°15' to 41°22'30"

Tmo Ogalalla, Tφb Brule, Ash Hollow, Devil's Washbasin, Wild Horse Canyon

June 1977

Big Springs Ne Quadrangle, Garden And Deuel Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 07'30" — 41° 15'

102° 00' — 102° 07'30"

Scale 1:24,000

Completed July 16, 1976

High resolution .tif file attached below as supplemental file

Ruthton Quadrangle, Nebraska—Garden And Keith Counties, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Ruthton Quadrangle, Nebraska—Garden and Keith Counties

7.5 minute series (topographic), scale 1:24000

103°07'30" to 103°15'

41°15' to 41°22'30"

Ql=loess, Qsa=sand; Ogallala & Post-Ogallala Gravels (Blancan?), Ogallala Outcrop; Pre-Ogallala Outcrop (Brule), Faunal site

July 16, 1976

Lewellen Quadrangle, Nebraska--Garden County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lewellen Quadrangle, Nebraska--Garden County

7.5 minute series (topographic), scale 1:24,000

102°07'30" to 102°15'

41°22'30" to 41°15'

Ql = loess

Qsa = sand

Volcanic ash

Ogallala and post-Ogallala gravels

Ogallala Outcrop

Pre-Ogallala Outcrop (Brule)

Faunal site

Completed July 16, 1976

Big Springs Nw Quadrangle, Garden And Deuel Counties, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 07'30" — 41° 15'

102° 07'30" — 102° 15'

Scale 1:24,000

Completed July 16, 1976

High resolution .tif file attached below as supplemental file

Belmar Quadrangle, Keith County, Nebraska, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.

41° 15' — 41° 22'30"

101° 52'30" — 102° 00'

Scale 1:24,000

Completed August 14, 1975

High resolution .tif file attached below as supplemental file

Lemoyne Quadrangle, Nebraska--Keith County, 7.5 Minute Series (Topographic), Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Lemoyne Quadrangle, Nebraska--Keith County

7.5 minute series (topographic), scale 1:24,000

101°45' to 101°52'30"

41°15' to 41°22'30"

Ogallala Outcrop (in pencil)

Completed August 14, 1975