Platte River-Medicine Creek drainage divide area landform origins in Lincoln and Frontier Counties, Nebraska, USA

Authors

Abstract:

The Platte River-Medicine Creek drainage divide area in Lincoln and Frontier Counties, Nebraska contains evidence of massive south-oriented flood flow that occurred prior to Platte River valley headward erosion. Flood waters were probably derived from a rapidly melting North American ice sheet and initially flowed across a topographic surface at least as high as the highest Platte River-Medicine Creek drainage divide area elevations today. South-oriented flood flow was moving to what was then an actively eroding east and southeast oriented Republican River valley, which had eroded headward from what was then the newly eroded Kansas River valley to capture the south-oriented flood flow. The southeast oriented Medicine Creek valley eroded headward from the newly eroded Republican River valley and south-oriented tributary valleys then eroded north along south-oriented flood flow channels. Headward erosion of the Platte River valley next beheaded south-oriented flood flow channels to what were then the actively eroding south-oriented Medicine Creek tributary valleys. Flood waters on north ends of beheaded south oriented flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley. The reversed flood eroded north oriented Platte River tributary valleys and created the Platte River-Medicine Creek drainage divide.

Preface:

The following interpretation of detailed topographic map evidence is one of a series of essays describing similar evidence for all major drainage divides contained within the Missouri River drainage basin and for all major drainage divides with adjacent drainage basins. The research project is interpreting evidence in the context of a previously unexplored deep glacial erosion paradigm, which is fundamentally different from most commonly accepted North American glacial history interpretations. Project essays are listed on the sidebar category list under their appropriate Missouri River tributary drainage basin, Missouri River segment drainage basin (by state), and/or state in which the Missouri River drainage basin is located.                        

Introduction:

  • The purpose of this essay is to use topographic map interpretation methods to explore Platte River-Medicine Creek drainage divide area landform origins in Lincoln and Frontier Counties, Nebraska, USA. Map interpretation methods can be used to unravel many geomorphic events leading up to formation of present-day drainage routes and development of other landform features. While each detailed topographic map feature provides detailed evidence to be explained, the solution must be consistent with explanations for adjacent area map evidence as well as solutions to big picture map evidence puzzles. I invite readers to improve upon my solutions and/or to propose alternate solutions that better explain evidence and are also consistent with adjacent map area and big picture evidence. Readers may do so either by making comments here or by writing and publishing their own essays and then by leaving a link to those essays in a comment here.
  • This essay is also exploring a new geomorphology paradigm in which erosional landforms are interpreted as evidence left by immense glacial melt water floods. Implied in that interpretation is the immense floods were derived from a thick North American ice sheet that created a deep “hole” in the North American continent and also melted fast. The previously unexplored paradigm being tested in this and other Missouri River drainage basin landform origins research project essays is a thick North American ice sheet, comparable in thickness to the Antarctic ice sheet, occupied the North American region usually recognized to have been glaciated, and through its weight and erosive actions created a deep North American “hole”. The southwestern rim of that deep “hole” is today preserved in the high Rocky Mountains. The ice sheet through its weight and deep erosion (and perhaps deposition along major south-oriented melt water flow routes) caused significant crustal warping and tectonic change, through its action of melting fast produced immense floods that flowed across the continent, and through its action of melting fast systematically opened up space in the ice sheet created “hole” so headward erosion of newly developed north-oriented drainage systems captured immense south-oriented melt water floods and diverted the floods north into space the ice sheet had once occupied.
  • If this previously unexplored paradigm is correct the geographic region explored by this essay should contain evidence of immense floods that were captured by headward erosion of new valley systems so as to cause the floods to flow in a different direction. Ability of this previously unexplored paradigm to explain Platte River-Medicine Creek drainage divide area landform origins in Lincoln and Frontier Counties, Nebraska will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm. This essay is included in the Missouri River drainage basin landform origins research project essay collection.

Platte River-Medicine Creek drainage divide area location map

Figure 1: Platte River-Medicine Creek drainage divide area location map (select and click on maps to enlarge).

  • Figure 1 provides a Platte River-Medicine Creek drainage divide area in Lincoln and Frontier Counties, Nebraska location map. Nebraska is the state occupying much of the figure 1 map area, Kansas is located south of the Nebraska, except in the figure 1 southwest corner area where Colorado is located south of the Nebraska panhandle. The South Platte River flows in a northeast direction to the Colorado northeast corner and then in an east-northeast and east direction to North Platte, Nebraska where it joins the North Platte River to form the southeast-oriented Platte River. The North Platte River flows from the figure 1 west edge (north half) in a southeast direction to North Platte, where it joins the South Platte River. From North Platte the Platte River flows in a southeast direction to Kearney and then turns to flow in a northeast direction to the figure 1 east center edge. East of the figure 1 map area the Platte River flows to join the south-southeast oriented Missouri River, which flows to Kansas City, Missouri, where it joins the east-oriented Kansas River. From Kansas City the Missouri River flows in an east direction to join the south-oriented Mississippi River. South of the Platte River is the Republican River, which flows in an east-northeast direction from the Nebraska southwest corner to Holbrook and Arapahoe, Nebraska before turning flow in a southeast direction to Alma, Nebraska and then in an east direction to Superior (located on Nebraska-Kansas border near figure 1 east edge). Near Superior the Republican River turns to flow in a southeast direction to join the east-oriented Kansas River, which joins the Missouri River at Kansas City. Medicine Creek is an unlabeled southeast-oriented Republican River tributary originating near Wellfleet (located south of North Platte) and flowing to join the Republican River near Cambridge, Nebraska. North Platte and Wellfleet are located in Lincoln County and Curtis and Stockville are located in Frontier County. The south-oriented Medicine Creek tributary joining Medicine Creek downstream from Curtis is probably Fox Creek, which is seen in more detailed maps below.
  • The Platte River-Republican River drainage divide area in Gosper and Furnas Counties essay describes the region located immediately east of the drainage divide area investigated here and can be found under Platte River (NE) or Republican River on the sidebar category list. Hundreds of Missouri River drainage basin landform origins research project essays published on this website collectively provide substantial evidence for massive south-oriented floods, which flowed across Nebraska and into Kansas. Flood waters were probably derived from a rapidly melting thick North American ice sheet. The Republican River valley eroded northwest and west from what was then the newly eroded east-oriented Kansas River valley to capture south-oriented flood flow in western Nebraska. The Medicine Creek valley eroded northwest from the newly eroded Republican River valley to more effectively capture the south-oriented flood flow. Next headward erosion of the Platte River valley, from what was then the newly eroded Missouri River valley, beheaded all south-oriented flood flow routes to the newly eroded Medicine Creek and Republican River valleys. Detailed maps below provide evidence supporting this interpretation.

Platte River-Medicine Creek drainage divide area detailed location map

Figure 2: Platte River-Medicine Creek drainage divide area detailed location map.

  • Figure 2 provides a more detailed location map for the Platte River-Medicine Creek drainage divide area in Lincoln and Frontier Counties, Nebraska. Lincoln, Dawson, Hayes, Frontier, Gosper, Hitchcock, and Furnas are Nebraska county names and the county boundaries are shown. Red Willow County is the county located between Hitchcock and Furnas Counties along the figure 2 south edge. North Platte (city) is located just north of the “C” in Lincoln which is located in the figure 2 northwest quadrant. The Platte River flows in a southeast direction from North Platte (the figure 2 north edge) to the figure 2 east center edge. The Republican River flows in an east-northeast direction from the figure 2 south edge in Hitchcock County across Red Will County to Arapahoe in Furnas County. At Arapahoe the Republican River turns to flow in a southeast direction to the figure 2 south edge. Medicine Creek originates near Somerset in southern Lincoln County and flows in a southeast direction to Wellfleet and then to Maywood, Curtis, and Stockville in Frontier County. From Stockville Medicine Creek flows to Harry Strunk Lake (a reservoir formed by a dam) and then to join the Republican River near Cambridge in northwest Furnas County. Note how in western Lincoln County there is a large area with no identified drainage routes. Figure 3 below provides evidence that Lincoln County may be covered with sand dunes as are areas north of the Platte River. Well developed drainage routes are shown in eastern Lincoln County, with north oriented streams flowing to the southeast-oriented Platte River and south-oriented streams flowing to Medicine Creek or directly to the Republican River. Major north oriented Platte River tributaries include Box Elder Canyon, Cottonwood Canyon, and Snell Canyon. South-oriented Medicine Creek tributaries include Well Canyon, Cut Canyon, Fox Creek, and Curtis Creek Canyon. Deer Creek Canyon is a south-southeast oriented Republican River tributary of importance in the following discussion. The name “Canyon” implies these north and south oriented streams have eroded deep valleys into the landscape. Note on figure 2 how the north and south oriented streams flow on similar alignments. Eastern Lincoln County drainage routes were developed during a massive south-oriented flood, which flowed across the entire figure 2 map area prior to Platte River valley headward erosion. Sand deposits in eastern Lincoln County and also north of the Platte River are probably flood deposited sediments, perhaps where flood waters were temporarily ponded. Headward erosion of what was then a deep east-oriented Republican River valley captured the south-oriented flood flow and diverted the flood waters east and southeast to the newly eroded Kansas River and Missouri River valleys. The deep Deer Creek Canyon and Medicine Creek valleys next eroded headward from the newly eroded Republican River valley to capture south-oriented flood flow and divert the water more directly to the newly eroded Republican River valley. South-oriented Medicine Creek tributary valleys next eroded north along major south-oriented flood flow channels. Headward erosion of the Platte River valley then beheaded the south-oriented flood flow channels to what were then the actively eroding south-oriented Medicine Creek tributary valleys (and the Deer Creek Canyon valley). Flood waters on north ends of the beheaded flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley.

Platte River-Medicine Creek drainage divide area south of North Platte, Nebraska

Figure 3: Platte River-Medicine Creek drainage divide area south of North Platte, Nebraska.

  • Figure 3 uses reduced size maps to illustrate the Platte River-Medicine Creek drainage divide area south of North Platte, Nebraska. North Platte is located just north of the figure 3 map area on highway 83 (the north-south highway in figure 3). The southeast-oriented Platte River is located in the figure 3 northeast corner.Somerset is the small town located in the figure 3 south center edge. Medicine Creek originates a short distance northwest of Somerset and flows in a southeast direction to the figure 3 south edge. South of figure 3 Medicine Creek continues to flow in a southeast direction to join the east and southeast oriented Republican River.  South oriented streams near the figure 3 east edge join Medicine Creek south of the figure 3 map area. Lake Maloney, which is located just west of the north-south highway and a short distance south of the figure 3 north edge is a reservoir associated with the regional irrigation system and a southeast-oriented irrigation canal is located near the figure 3 north edge. Other than the irrigation canal and Lake Maloney the drainage divide area between the Platte River and the Medicine Creek headwaters appears to be devoid of any surface drainage pattern, and appears to be a relatively level plain covered by what is probably a veneer of wind deposited sediments. Near the figure 3 east edge there is a region where north-oriented Platte River tributaries and south-oriented Medicine Creek tributaries have eroded deep valleys to create a badland type landscape. North and south oriented valleys in this badland region were eroded into the upland surface, which further west represents a nearly featureless plain. Evidence near the figure 3 east edge suggests the north-oriented Platte River tributary valleys are linked to south oriented Medicine Creek tributary valleys. The valley orientations and north-south oriented through valleys linking the opposing tributary valleys provide evidence of massive south oriented flood flow, which once moved across the entire figure 3 map area. South-oriented Medicine Creek tributary valleys eroded headward into the figure 3 map area along those south oriented flood flow channels prior to Platte River valley headward erosion. Platte River valley headward erosion beheaded south oriented flood flow channels to what were then actively eroding Medicine Creek tributary valleys. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley. Reversed flood flow eroded north-oriented Platte River tributary valleys and created the Platte River-Medicine Creek drainage divide. While topographic map evidence is not adequate to determine underlying sediment characteristics it is probable the topographic surface into which the north- and south-oriented tributary valleys were eroded had been formed at least in part by deposition of flood transported sediments. Dunes located west of the north and south oriented tributary valley area probably formed on what were once flood deposited deltaic sediments, although field evidence is needed to confirm the interpretation.

Platte River-Medicine Creek drainage divide area in eastern Lincoln County

Figure 4: Platte River-Medicine Creek drainage divide area in eastern Lincoln County.

  •  Figure 4 illustrates the Platte River-Medicine Creek drainage divide area east of the figure 3 map area and includes overlap areas with figure 3. The southeast-oriented Platte River valley is located in the figure 4 northeast quadrant. Named north-oriented Platte River tributaries from west to east are Moran Canyon, Box Elder Canyon, Cottonwood Canyon, Snell Canyon, Conroy Canyon (in which Jeffery Reservoir is located), and Jeffery Canyon. Note how north-northeast oriented Jeffery Canyon is linked by a west-east oriented through valley with the north-northwest and north oriented Snell Canyon. South of north-oriented Moran Canyon is south-oriented Well Canyon, south of north-oriented Box Elder Canyon is south-oriented Cut Canyon, south of north-oriented Cottonwood Canyon is south-oriented Fox Creek, south of north-oriented Snell Canyon is south-oriented Curtis Canyon (not labeled in figure 4), and south of north-oriented Jeffery Canyon is south-oriented East Deer Creek Canyon (not labeled in figure 4). Well Canyon, Cut Canyon, Fox Creek, and Curtis Canyon all drain to southeast-oriented Medicine Creek, which flows in a southeast direction to the east-oriented Republican River. Deer Creek Canyon flows in a south-southeast direction directly to the Republican River. A close look at figure 4 reveals multiple north-south oriented through valleys linking the north-oriented Platte River tributaries with the south-oriented Medicine Creek tributaries. Figure 5 below provides a detailed map of the Box Elder Canyon-Cut Canyon drainage divide area, figure 6 provides a detailed map of the Cottonwood Canyon-Fox Creek drainage divide area, figure 7 provides a detailed map of the Snell Canyon-Jeffery Canyon drainage divide area, and figure 8 provides a detailed map of the Jeffery Canyon-Deer Creek Canyon drainage divide area. What has happened in the figure 4 map area is prior to Platte River valley headward erosion massive south-oriented flood flow moved across the figure 4 map area on a topographic surface at least as high as the highest figure 4 elevations today. As noted in the figure 3 discussion the sediments on the topographic surface on which those flood waters flowed may have been deposited earlier during flood history. Flood waters were flowing south to what was then the newly eroded southeast-oriented Medicine Creek valley, which had eroded headward from what was then the newly eroded Republican River valley. South-oriented Medicine Creek tributary valleys then eroded deep valleys north along south-oriented flood flow channels. These flood flow channels were beheaded by Platte River valley headward erosion. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley and in doing so eroded the north oriented Platte River tributary valleys and created the Platte River-Medicine Creek drainage divide. Detailed maps below provide further evidence. 


Detailed map of Box Elder Canyon-Cut Canyon drainage divide area

Figure 5: Detailed map of Box Elder Canyon-Cut Canyon drainage divide area.

  • Figure 5 provides a detailed map of the Box Elder Canyon-Cut Canyon drainage divide area seen in less detail in the figure 4 map area. Box Elder Canyon is the labeled north-oriented valley near the figure 5 north central edge and Upper Box Elder School is located in Box Elder Canyon. North-oriented valleys west of Box Elder Canyon all drain to north oriented Box Elder Canyon. The north-oriented valley in the figure 5 northeast corner area drains to north-oriented Cottonwood Canyon. The south-oriented stream draining to the figure 5 south center edge (in which the road is located) is south oriented Cut Canyon, which drains to southeast-oriented Medicine Creek. South-southwest oriented valleys in the figure 5 southwest corner area drain to south-oriented Well Canyon. Other figure 5 south-oriented valleys drain to south-oriented Cut Canyon. Note the well-developed north-south oriented through valley located in section 15 east center area. Also note through valleys in the section 14 southwest corner area, the section 23 northeast quadrant, and the section 24 northwest corner. These and other through valleys provide evidence of multiple south-oriented flood flow channels across the figure 5 map area prior to Platte River valley headward erosion. Flood waters were flowing to what were then actively eroding south-oriented Medicine Creek tributary valleys, such as the Cut Canyon valley, and were eroding headward into the figure 5 map area from the newly eroded Medicine Creek valley. Flood waters were probably flowing in a south-oriented anastomosing channel complex, with headward erosion of the deep Medicine Creek tributary valleys beheading flood flow to adjacent south-oriented flood flow channels. Headward erosion of the deep Platte River valley beheaded the south-oriented flood flow channels. Flood flow on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley. The reversal of flood flow eroded the north-oriented Box Elder Creek valley and tributary valleys and created the Box Elder Canyon-Cut Canyon drainage divide.

Detailed map of Cottonwood Canyon-Fox Creek drainage divide area

Figure 6: Detailed map of Cottonwood Canyon-Fox Creek drainage divide area.
  • Figure 6 provides a detailed map of the Cottonwood Canyon-Fox Creek drainage divide area located east of the figure 5 map area and includes overlap areas with figure 5. Cottonwood Canyon drains in a north-northeast and north direction from the figure 6 center to the figure 6 north center edge. Note how in section 30 the north oriented Cottonwood Creek valley has captured southeast oriented drainage from a valley draining from the section 24 northeast quadrant across the section 19 southwest quadrant to the section 30 northeast quadrant. That capture occurred at the time south oriented flood flow across the figure 6 map area was reversed by Platte River valley headward erosion north of the figure 6 map area. Note how in the section 30 southwest corner there is a through valley linking the north oriented Cottonwood Canyon valley with headwaters of a southwest and south oriented valley. That south oriented valley is a Cut Canyon tributary and was eroded headward by south oriented flood flow moving south on the present day north-oriented Cottonwood Canyon alignment and also moving southeast on the alignment of the southeast-oriented Cottonwood Canyon headwaters valley. Also note the north oriented Cottonwood Canyon headwaters valley in the section 29 southwest corner and how that north oriented valley is linked by a through valley near the figure 6 south edge with a south oriented valley. The south oriented valley is a Fox Creek tributary. South-oriented Fox Creek is labeled in the figure 6 southeast quadrant and is a Medicine Creek tributary.  Note how in section 20 the Fox Creek headwaters are linked by a through valley with a northwest-oriented Cottonwood Canyon tributary. Prior to Platte River valley headward erosion south oriented flood flow moved south from the Cottonwood Canyon alignment to what was then the actively eroding Fox Creek valley. When Platte River valley headward erosion beheaded south-oriented flood flow moving along the Cottonwood Canyon alignment, flood waters were reversed and the flow reversal eroded the northwest-oriented Cottonwood Canyon tributary valley. Note how the early flood flow channels were diverging and merging, which is characteristic of an anastomosing channel complex. This entire badland area along the Platte River-Medicine Creek drainage divide was crossed by a south-oriented anastomosing channel complex, into which deep south-oriented Medicine Creek tributary valleys eroded headward from the newly eroded Medicine Creek valley. At that time the Platte River valley did not exist and flood water were flowing on a high level topographic surface at least as high the highest figure 6 elevations today. Then Platte River valley headward erosion beheaded the south-oriented flood flow channels (one channel at a time from east to west) and flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded Platte River valley. Because flood flow channels were interconnected reversed flood flow on a newly beheaded flood flow channel could capture yet to be beheaded flood flow from channels further to the west. Capture of such yet to be beheaded flood flow provided the water volumes required to deep north-oriented Platte River tributary valleys.

Detailed map of Snell Canyon-Jeffery Canyon drainage divide area

Figure 7: Detailed map of Snell Canyon-Jeffery Canyon drainage divide area.

  • Figure 7 provides a detailed map of the Snell Canyon-Jeffery Canyon drainage divide area located east and north of the figure 6 map area. Snell Canyon is a labeled north and north-northwest valley extending from section 1 near the figure 7 southwest corner to section 24 near the figure 7 northwest corner. South-oriented drainage routes in section 1 (near the figure 7 southwest corner) flow to south-oriented Curtis Canyon and southeast-oriented Medicine Creek. Note how the north-oriented Snell Canyon headwaters valley and north-oriented Snell Canyon tributary valleys are linked by high level through valleys with the south-oriented Curtis Canyon tributary valleys. Jeffery Canyon is a north-northwest and north-northeast oriented valley extending from section 10 along the figure 7 south edge (east half) to the figure 7 northeast corner. Note how Snell Canyon and a northeast-oriented Jeffery Canyon tributary valley are linked by a west to east oriented through valley in sections 6, 5, and 4. Also note north of the Jeffery Queen School location (located in the west to east oriented through valley) is north-oriented Conroy Canyon, which drains to the figure 7 north edge. Note how the Conroy Canyon Road is located in a north-south oriented through valley linking the north-oriented Conroy Canyon valley with the west to east oriented Snell Canon-Jeffery Canyon through valley. Study of figure 7 reveals other similar through valleys linking north-oriented Conroy Canyon tributary valleys with the Snell Canyon-Jeffery Canyon through valley. How did the west to east oriented Snell Canyon-Jeffery Canyon through valley form? As with previous figures prior to Platte River valley headward erosion flood waters moved south across the figure 7 map area on a topographic surface at least as high as the highest figure 7 elevations today. Flood waters were flowing in a south oriented anastomosing channel complex. Headward erosion of the deep southeast oriented Medicine Creek valley captured the south oriented flood flow channels and diverted the flood waters to the newly eroded east and southeast oriented Republican River valley. Deep south oriented Medicine Creek tributary valleys then eroded north along south oriented flood flow channels. Headward erosion of deeper channels beheaded shallower flood flow channels and headward erosion of the deeper channels eventually reached into and across the figure 7 map area. Headward erosion of the deep Platte River valley then beheaded south oriented flood flow channels one channel at a time from east to west. In the figure 7 map area south-oriented flood flow on the Jeffery Canyon alignment was beheaded first. Flood waters on the north end of the beheaded flood flow route reversed flow direction to flow north. Because flood flow channels were interconnected reversed flow on the Jeffery Canyon alignment captured yet to be beheaded flood flow from south oriented flood flow channels further to the west. The west to east oriented Snell Canyon-Jeffery Canyon through valley and northeast-oriented Jeffery Canyon tributary valley were eroded by yet to be beheaded south-oriented flood flow on the Snell Canyon alignment that had been captured by reversed flood flow on the Jeffery Canyon alignment. In time headward erosion of the Platte River valley beheaded and reversed flood flow on the Snell Canyon alignment. Reversed flood flow on the Snell Canyon alignment then eroded the north-oriented Snell Canyon valley and created the Snell Canyon-Jeffery Canyon drainage divide.

Detailed map of Jeffery Canyon-East Deer Creek Canyon drainage divide area

Figure 8: Detailed map of Jeffery Canyon-East Deer Creek Canyon drainage divide area.

  • Figure 8 provides a detailed map of the Jeffery Canyon-East Deer Creek Canyon drainage divide area located east and south of the figure 7 map area and includes overlap areas with figure 7. North-northwest oriented Jeffery Canyon is labeled and is located in the figure 8 center area and extends from the figure 8 south center to the figure 8 north edge. South-southeast oriented East Deer Creek Canyon drains to the figure 8 south center edge. South of figure 8 Deer Creek flows in a south-southeast direction to join the east and southeast oriented Republican River and is not a Medicine Creek tributary. Note how in the figure 8 south center area a south oriented East Deer Creek Canyon tributary is linked by a north-south through valley with the north-northwest oriented Jeffery Canyon valley. Other through valleys in sections 9 and 16 link north- and northeast-oriented Jeffery Canyon tributary valleys with headwaters of the south-southeast-oriented East Deer Creek Canyon valley. These and other figure 8 through valleys provide evidence of major south oriented flood flow channels, which carried large quantities of south oriented flood water to what was then the actively eroding East Deer Creek Canyon valley. These flood flow channels were eroded at a time when the Platte River valley north of the figure 8 map area did not exist. South-oriented flood waters had been captured by headward erosion of the east and southeast oriented Republican River valley located south and east of the figure 8 map area. The deep (East) Deer Creek Canyon valley then eroded headward from the newly eroded Republican River valley north wall along south-oriented anastomosing flood flow channels and into and north of the figure 8 map area. Headward erosion of the southeast oriented Platte River valley north of the figure 8 map area then beheaded the south-oriented flood flow channels providing flood waters to what were then the south oriented East Deer Creek Canyon valley and tributary valleys. Flood waters on north ends of beheaded flood flow channels reversed flow direction to flow north to the newly eroded and deeper Platte River valley. The reversal of flood flow eroded the north-oriented Jeffery Canyon valley and tributary valleys and also captured yet to be beheaded flood flow from south-oriented flood flow channels further to the west (Snell Canyon for example). The flood flow reversal also created the Jeffery Canyon-East Deer Creek Canyon drainage divide. Headward erosion of the Platte River valley next beheaded south oriented flood flow channels further west, which had been supplying the newly reversed Jeffery Canyon valley with large volumes of yet to be beheaded flood flow. The figure 8 landscape has not significantly changed since all flood routes were beheaded.

Medicine Creek valley area between Curtis and Stockville, Nebraska

Figure 9: Medicine Creek valley area between Curtis and Stockville, Nebraska.

  • Figure 9 illustrates the Medicine Creek valley between Curtis and Stockville and is located south of the figure 4 map area. Curtis is the town located near the figure 9 west center edge. Stockville is the town located just west of the figure 9 south center edge, Medicine Creek flows in a southeast direction from Curtis to Stockville and then to the figure 9 south edge. South of figure 9 Medicine Creek flows to the east and southeast oriented Republican River (see figure 10 below). Fox Creek is the south-southeast oriented stream flowing from the figure 9 northwest corner to join Medicine Creek near Curtis. Curtis Creek Canyon is the south oriented stream east of Fox Creek. Moorefeld is the town located west of the figure 9 north center area. Mitchell Creek Canyon is the south-southeast oriented stream originating near Moorefield and flowing across the figure 9 center to the figure 9 south edge. South of figure 9 Mitchell Creek Canyon joins southeast oriented Medicine Creek. East of Mitchell Creek Canyon is south-southeast oriented Deer Creek Canyon, which extends from the figure 9 north edge to the figure 9 south edge. South of figure 9 Deer Creek flows parallel to Medicine Creek and directly joins the east-oriented Republican River (see figure 10). Farnam is the town located in the figure 9 northeast corner area. Note how Farnam is located on what appears to be a high level erosion surface into which the south-southeast oriented Republican and Medicine Creek tributary drainage basins have been eroded. Note the south- and southwest-facing escarpment marking the south and southwest boundaries of that upland erosion surface. Note how the southwest facing escarpment is the south-southeast oriented Deer Creek valley wall. Figure 9a below illustrates the region north and east of Farnam, which is the Plum Creek-Platte River drainage divide area. Farnam is the town located in the figure 9a south center area. The southeast-oriented Platte River is located in the figure 9a northeast corner and is located in the large southeast-oriented Platte River valley. The southeast-oriented stream draining the upland erosion on which Farnam is located is Plum Creek. Plum Creek originates in the figure 9a northwest quadrant and flows to the figure 9a south edge (east half). South and east of figure 9a Plum Creek eventually joins the Platte River (Plum Creek downstream from figure 9a is illustrated and discussed in the Platte River-Republican drainage divide area in Gosper and Furnas Counties essay). The Plum Creek valley eroded headward from what was then the actively eroding Platte River valley head slightly in advance of Platte River valley headward erosion.Plum Creek valley headward erosion beheaded south-oriented flood flow channels to what were then actively eroding south-oriented Republican River tributary valleys and diverted flood water east to the newly eroded Platte River valley. Headward erosion of the East Deer Creek Canyon valley (extending in a south-southeast direction from the figure 9a northwest corner along the southwest margin of the Plum Creek drained upland erosion surface) to the figure 9a south edge beheaded some southeast-oriented flood flow routes to the Plum Creek valley. Headward erosion of the deeper Platte River valley eventually beheaded all south-oriented flood flow routes from the north, which were moving water to the actively eroding Plum Creek valley. North-oriented Platte River tributary valleys were eroded by reversal of flood flow on north ends of south-oriented flood flow channels.

Figure 9a: Platte River-Plum Creek drainage divide northeast of Farnam.

Republican River valley between Cambridge and Arapahoe, Nebraska

Figure 10: Republican River valley between Cambridge and Arapahoe, Nebraska.

  • Figure 10 illustrates the Republican River valley downstream from Cambridge to Arapahoe, Nebraska and is located south and east of the figure 9 map area. Arapahoe is the town located near the figure 10 southeast corner. The Republican River flows in an east direction along the east half of the figure 10 south edge. The lake located along the figure 10 west edge is Harry Strunk Lake, which is a reservoir flooding the Medicine Creek valley. Medicine Creek Dam is located near the figure 10 west center edge. Medicine Creek flows from the dam location in a south-southeast direction to join the Republican River at Cambridge, which is located slightly south of the figure 10 south edge. Deer Creek Canyon is the southeast-oriented stream flowing from near the figure 10 northwest corner to join the Republican River near Holbrook, which is located just east of the figure 10 south center edge. Muddy Creek is the southeast-oriented stream east of Deer Creek Canyon, which flows from the figure 10 north center edge area to join the Republican River just west of Arapahoe. Note how south-oriented food flow to what were then actively eroding south-oriented Deer Creek Canyon tributaries was beheaded by Muddy Creek valley headward erosion. Also note how Deer Creek Canyon valley headward erosion beheaded south-oriented flood flow channels to what were then actively eroding south-oriented Republican River tributary valleys. What has happened in this figure 10 map area is prior to Republican River valley headward erosion flood waters moved south across the figure 10 map area on a topographic surface at least as high as the highest figure 10 elevations today. Headward erosion of the deep east and southeast oriented Republican River valley from what was then the newly eroded Kansas River valley captured the south oriented flood flow and diverted the flood waters east and southeast to the newly eroded Kansas River valley. South oriented Republican River valley tributary valleys began to erode north from the newly eroded Republican River valley north wall. At the same southeast oriented tributary valleys began to erode northwest to capture the multiple south-oriented flood flow channels and divert the flood waters more directly to the newly eroded east-oriented Republican River valley. The Muddy Creek valley, Deer Creek Canyon valley, and Medicine Creek valley were three of the southeast oriented valleys that eroded headward across the south oriented flood flow routes. Figure 10 evidence suggests Muddy Creek valley headward erosion beheaded south oriented flood flow to the Deer Creek Canyon valley, which suggests the Deer Creek Canyon valley was being eroded headward slightly in advance of the Muddy Creek valley, which probably means the two valleys were being eroded at approximately the same time.

Additional information and sources of maps

This essay has only provided a sample of the drainage divide evidence supporting the “thick ice sheet that melted fast” geomorphology paradigm. Many additional examples could be provided, especially by using more detailed topographic maps. Readers are encouraged to look at mosaics of detailed topographic maps to see the abundance of supporting data. Maps used in this study were created by the United States Geological Survey and can be purchased in hard copy from the United States Geological Survey or from dealers offering United States Geological Survey maps. Hard copy maps can also be observed at United States Geological Survey map depositories located in major research libraries and elsewhere throughout the United States and in other countries. Illustrations used in this essay were created using National Geographic Society TOPO software and digital data. National Geographic Society digital maps can be purchased from the National Geographic Society or from dealers offering National Geographic Society digital maps.

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