A geomorphic history based on topographic map evidence

The Little Blue River-Republican River drainage divide area in Kearney, Adams, Franklin, and Webster Counties, Nebraska was eroded by massive south and southeast oriented floods, which initially flowed to what was then the newly eroded Republican River valley, which had eroded headward into the region from what was also then the newly eroded Kansas River valley. South and southeast oriented flood flow to what were then actively eroding south-oriented Republican River tributary valleys was beheaded by Little Blue River valley headward erosion. The Little Blue River valley eroded headward into the region from what was then the newly eroded Big Blue River valley, which had eroded headward from the newly eroded Kansas River valley. Flood waters on north ends of beheaded south-oriented flood flow routes reversed flow direction to flow north to the newly eroded Little Blue River valley. South and southeast oriented flood flow to the actively eroding Little Blue River valley and tributary valleys was beheaded by headward erosion of the Platte River valley, which had eroded headward from what was then the newly eroded Missouri River valley.

Preface:

• The purpose of this essay is to use topographic map interpretation methods to explore Little Blue River-Republican River drainage divide area landform origins in Kearney, Adams, Franklin, and Webster 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 Little Blue River-Republican River drainage divide area landform origins in Kearney, Adams, Franklin, and Webster 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.

Little Blue River-Republican River drainage divide area location map

Figure 1: Little Blue River-Republican River drainage divide area location map(select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

Figure 1 provides a Little Blue River-Republican River drainage divide area in Kearney, Adams, Franklin, and Webster Counties, Nebraska location map. The state occupying the figure 1 northern half is Nebraska and Kansas is the state south of Nebraska. The Platte River is the major west to east oriented Nebraska river and flows in a southeast direction from North Platte (in the figure 1 northwest corner area) to Kearney and then in a northeast direction to the figure 1 northeast corner area, where the Platte River turns to flow in a south-southeast direction. East of the figure 1 map area the Platte River turns to flow in an east-northeast direction to join the south-southeast oriented Missouri River (not seen in figure 1). The Kansas River is the major east-oriented Kansas River and can be seen in the figure 1 southeast corner as the east-northeast oriented river flowing through Junction City and Manhattan. The Big Blue River is a Kansas River tributary originating near Marquette, Nebraska (almost next to the northeast-oriented Platte River near Grand Island) and flowing in an east direction to Ulysses and then in a south-southeast direction to Seward, Crete, and Beatrice, Nebraska and to Marysville and Blue Rapids, Kansas before joining the Kansas River near Manhattan. The Little Blue River is an important Big Blue River tributary and also originates near the Platte River (south and east from Kearney, Nebraska) and flows in a southeast direction to Hebron and Fairbury, Nebraska before joining the south-southeast oriented Big Blue River near Blue Rapids, Kansas. The Republican River is located south and west of the Little Blue River-Big Blue River and flows from the figure 1 west edge in southern Nebraska to McCook, Holbrook, Oxford, Alma, Republican City, Red Cloud, and Superior, Nebraska and to Republic, Concordia, Clyde, and Clay Center, Kansas before joining the Kansas River near Junction City.

The Little Blue River-Republican River drainage divide area in Kearney, Adams, Franklin, and Webster Counties, Nebraska is generally north of the Republican River between Republican City and Superior, Nebraska and includes the Little Blue River headwaters area near Minden, Nebraska. The Little Blue River-Republican River drainage divide area in Nuckolls and Thayer Counties, Nebraska and Republic County, Kansas essay addressed the region located directly east from the region studied here and can be located under Big Blue River 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 southeast and south oriented floods, which flowed across Nebraska and Kansas. Flood waters were probably derived from a rapidly melting North American ice sheet and were captured by headward erosion of the east-oriented Kansas River valley. The Big Blue River valley and the Republican River valley eroded headward from the actively eroding Kansas River valley. Little Blue River valley headward erosion was slightly behind Republican River headward erosion and beheaded southeast and south oriented flood flow to the newly eroded Republican River valley. Headward erosion of the Platte River valley beheaded all southeast and south oriented flood flow to the Little Blue River valley and to the Republican River valley (west of the Little Blue River valley head).

Little Blue River-Republican River drainage divide area detailed location map

Figure 2: Little Blue River-Republican River drainage divide area detailed location map. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 2 provides a slightly more detailed location map for the Little Blue River-Republican River drainage divide area in Kearney, Adams, Franklin, and Webster Counties, Nebraska. Buffalo, Hall, Hamilton, Kearney, Adams, Clay, Franklin, Webster, and Nuckolls are Nebraska county names and the county boundaries are shown. The Platte River flows from the figure 2 west edge along the Buffalo County south boundary to the figure 2 north edge just east from Grand Island. Hastings is the city located in Adams County south of Grand Island. The Republican River flows in an east and east-southeast direction from Harlan County Lake (in the figure 2 southwest corner) to Franklin (in Franklin County), Red Cloud (in Webster County), and Superior (in Nuckolls County) before flowing south of the figure 2 map area. The Little Blue River originates in southern Kearney County (south of Minden) and flows in a southeast direction to the Franklin County northeast corner and then turns to flow in a northeast direction across the Webster County northwest corner into southern Adams County. In Adams County the Little Blue River flows in an east-southeast direction before turning to flow in a north-northeast direction and then turning to flow in a southeast direction across the Clay County southwest corner and the Nuckolls County northeast corner. Note the large number of southeast and south oriented Republican River tributaries in Franklin and Webster Counties. The east-oriented Republican River valley eroded headward across southern Webster and Franklin Counties to capture south and southeast oriented flood flow. The south and southeast oriented tributary valleys eroded headward from what was then the actively eroding Republican River valley head along captured south and southeast oriented flood flow routes. The Little Blue River valley eroded headward into the figure 2 map area to capture south and southeast oriented flood flow which had been moving to the newly eroded Republican River valley and to those actively eroding south-oriented Republican River tributary valleys. In Kearney County Little Blue River tributaries from the south are northeast oriented, although in Adams County the tributaries from the south are north or north-northeast oriented. The north and northeast oriented tributary valleys, and the north-northeast oriented Little Blue River valley segment in Adams County, were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes. Flood flow routes were beheaded one flood flow route at a time (from east to west). Because flood flow routes (or channels) were interconnected reversed flood flow in a newly beheaded south-oriented flood flow channel could capture yet to be beheaded flood flow from routes further to west. Such captures of yet to be beheaded flood flow provided the water volumes required to erode significant north-oriented tributary valleys. Headward erosion of the northeast-oriented Platte River valley and its northeast-oriented Dry Creek tributary valley beheaded all southeast and south-oriented flood flow routes to the newly eroded Little Blue River valley. Topographic maps below begin with the Platte River-Little Blue River headwaters drainage divide area and then proceed to the Little Blue River-Republican River drainage divide.

Platte River-Sand Creek drainage divide area

Figure 3: Platte River-Sand Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the Platte River-Sand Creek drainage divide area in Kearney County. Minden is the larger town located in the figure 3 southwest quadrant. The northeast-oriented Platte River can just barely be seen in the figure 3 northwest corner. The Platte River is flowing near the southeast margin of a broad, but shallow northeast-oriented valley. The valley is much better illustrated and described in the Loup River-Platte River drainage divide area between Kearney and Columbus essay (see essay lists under Platte River or Loup River on sidebar category list). South of the Platte River is what appears to be an area of sand dunes and flowing through that area is northeast-oriented Dry Creek, which is a Platte River tributary (Dry Creek is north of the northeast-oriented irrigation canal located just south of the sand dune area). Sand Creek originates north of Minden as a northeast-oriented stream and then turns to flow in a southeast direction to the figure 3 southeast corner and south and east of figure 3 joins the Little Blue River. Heartwell is the smaller town located on the highway northeast from Minden. North of Heartwell is east and east-northeast oriented Cottonwood Creek, which near the figure 3 east edge makes an abrupt turn to flow in a south-southeast direction to join the Little Blue River (south and east of the figure 3 map area). Southeast-oriented drainage in the figure 3 southeast quadrant flows to southeast oriented Sand Creek south of the figure 3 map area. Note the extremely low relief in the figure 3 map area. The Sand Creek valley in the figure 3 southeast quadrant is lower in elevation than the Platte River valley floor in the figure 3 northwest corner. The Platte River is not flowing in a well-defined valley. In fact, the northeast-oriented Dry Creek route could probably be considered an abandoned Platte River channel. What has happened here is massive southeast and south oriented flood flow moved across the figure 3 map area prior to Platte River valley headward erosion. Flood waters were moving to what was then the actively eroding Little Blue River valley and tributary valleys (including the Sand Creek and Cottonwood Creek valleys). Southeast-oriented Sand Creek valley segments and tributary valleys and southeast oriented Cottonwood Creek tributaries and the south-southeast oriented Cottonwood Creek valley segment all provide evidence of the southeast and south oriented flood flow. Headward erosion of the shallow northeast-oriented Platte River valley captured the southeast and south-oriented flood flow and beheaded all flood flow routes to what had been the actively eroding Little Blue River valley and tributary valleys. At the time of the flood flow capture water volumes were probably great enough that the northeast-oriented Platte River route included the northeast-oriented Dry Creek valley location. As water volumes decreased the Dry Creek channel was stranded in its position south of the Platte River.

Sand Creek-Little Blue River drainage divide area

Figure 4: Sand Creek-Little Blue River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 4 illustrates the Sand Creek-Little Blue River drainage divide area south and slightly east of the figure 3 map area and includes overlap areas with figure 3. Minden is the town located in the figure 4 northwest corner. Holstein is the smaller town in the figure 4 northeast corner area and Norman is the even smaller town located between Minden and Holstein. Cottonwood Creek is the south-southeast oriented stream flowing across the figure 4 northeast corner and Sand Creek flows in a southeast direction across the figure 4 northeast quadrant  to the west of Cottonwood Creek. The South Branch Sand Creek flows in a northeast direction from the figure 4 center area to join southeast-oriented Sand Creek west of Holstein. Note southeast-oriented South Branch tributaries, which provide evidence the northeast-oriented South Branch valley eroded headward to capture southeast-oriented flood flow moving south and west of what was then the actively eroding Sand Creek valley head. Northeast-oriented Sand Creek tributaries in the figure 4 northwest quadrant eroded headward in sequence (from southeast to northwest) to capture southeast-oriented flood flow to what were then the actively eroding southeast-oriented South Branch tributary valleys. North-oriented headwaters valleys of some of those northeast-oriented Sand Creek tributaries were eroded by reversals of flood flow on north ends of beheaded flood flow routes. The Little Blue River originates in the figure 4 west enter area (south of Minden) and flows in a southeast direction before turning to flow in an east direction and then south-southeast direction to figure 4 south center edge. Southeast-oriented drainage routes in the figure 4 southeast quadrant flow to the east-oriented Little Blue River valley south of the figure 4 map area. Headward erosion of the northeast-oriented South Branch Sand Creek valley beheaded southeast-oriented flood flow to what were then actively eroding Little Blue River tributary valleys. The Little Blue River headwaters area is slightly higher in elevation than the southeast-oriented Sand Creek valley region to the northeast. This evidence suggests flood waters deeply eroded the figure 4 map area with erosion greatest in the Sand Creek valley area. Had the Platte River valley not beheaded flood flow to the figure 4 map area it is possible Sand Creek valley and tributary valley headward erosion would have beheaded all flood flow routes to the actively eroding Little Blue River valley.

Little Blue River-Republican River drainage divide area west end

Figure 5: Little Blue River-Republican River drainage divide area west end. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 uses reduced size maps to illustrate the west end of the Little Blue River-Republican River drainage divide area south and east of the figure 4 map area (there is an area of overlap, compare county boundary along the figure 5 north edge with county boundary near figure 4 south edge). The Republican River is the east-oriented river located near the figure 5 south edge. Red Cloud is the larger town located in the Republican River valley in the figure 5 southeast quadrant. Upland is the much smaller town located in the figure 5 northwest corner. Campbell is the slightly larger town located east of Upland and adjacent to the county boundary line. Blue Hill is the town near the figure 5 northeast corner. The Little Blue River flows in an east direction along the figure 5 north edge area just east of Upland and then turns to flow in a southeast direction to Campbell. From Campbell the Little Blue River flows in an east-northeast direction and then turns to flow in north direction to the figure 5 north edge (just east of the figure 5 north center edge). North of the figure 5 map area the Little Blue River turns again to flow in an east direction and north of Blue Hill it turns to flow in a north direction before turning to flow in a southeast direction. This figure 5 Little Blue River-Republican River drainage divide area provides excellent evidence the Republican River valley eroded headward across the region to capture what was then south-oriented flood flow. The numerous south-oriented Republican River tributary valleys eroded headward from the actively eroding Republican River valley head along south-oriented flood flow routes. Headward erosion of the Little Blue River valley then beheaded the south-oriented flood flow routes. North-oriented Little Blue River valley segments were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes. North-oriented Little Blue River tributary valleys were eroded in the same way. Remember, Little Blue River valley headward erosion beheaded south-oriented flood flow routes one flood flow route at a time (from east to west). Flood flow routes were interconnected, meaning reversal of flood flow on a newly beheaded flood flow route could capture yet to beheaded flood flow from flood flow routes further to the west. Such captures of yet to be beheaded flood flow were what caused the Little Blue River valley to continue eroding west from the south ends of its north-oriented valley segments. Also such captures of yet to be beheaded flood flow provided the water volumes required to erode the north-oriented Little Blue River tributary valleys. Figure 6 below provides a detailed map of the drainage divide area near Campbell.

Detailed map of Little Blue River-Republican River drainage divide area

Figure 6: Detailed map of Little Blue River-Republican River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 provides a detailed map of the Little Blue River-Republican River drainage divide area south of Campbell, which is seen in less detail in figure 5 above. Campbell is located near the figure 5 north center edge and is located just west of the north-south oriented Franklin County-Webster County boundary. The Little Blue River flows along the figure 6 north edge area from just west of Campbell to the figure 6 northeast corner. Note extensive north-oriented headwaters valleys for most Little Blue River tributaries shown. South-oriented figure 6 drainage flows to the Republican River and continues south in lengthy south-oriented tributary valleys, which in figure 5 can be compared in length with the north-oriented Little Blue River tributary valleys (note how south-oriented valleys are much longer than the north-oriented valleys). A close look at the figure 6 Little Blue River-Republican River drainage divide reveals shallow north-south through valleys linking at least some of the north-oriented Little Blue River tributary valleys with south-oriented Republican River tributary valleys. The deepest of the north-south oriented through valleys is located in section 34 near the figure 6 west center area. A shallower north-south oriented through valley can be seen in section 1 in the figure 6 south center area. Still other through valleys can be found in sections 5 and 4 in the figure 6 southeast quadrant. The through valleys provide evidence of multiple south-oriented flood flow routes or channels across what is today the Little Blue River-Republican River drainage divide. Flood waters were flowing to what were then the actively eroding south-oriented Republican River tributary valleys. At that time the present day Little Blue River valley and tributary valleys did not yet exist and flood waters were flowing on a topographic surface at least as high as the present day Little Blue River-Republican River drainage divide. Headward erosion of the deep Little Blue River valley then beheaded the south-oriented flood flow channels. Flood waters on north ends of the beheaded flood flow routes reversed flow direction to flow north to the newly eroded Little Blue River valley. Reversed flow probably captured significant yet to be beheaded flood flow from channels further to the west and the captured flood flow probably aided in eroding the north-oriented tributary valleys.

Little Blue River-Republican River drainage divide area near Blue Hill

Figure 7: Little Blue River-Republican River drainage divide area near Blue Hill. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 uses a less reduced size map to illustrate the Little Blue River-Republican River drainage divide area near Blue Hill. Much of the figure 7 map area is seen is less detail in figure 5. Blue Hill is the largest town and is located east of the figure 7 north center area. Bladen is the smaller town located in the figure 7 northwest quadrant. Rosemont is the small town located near the figure 7 east center edge. North-oriented figure 7 drainage all flows to the Little Blue River, located north of the figure 7 map area. South-oriented figure 7 drainage flows to the Republican River, located south of the figure 7 map area. Note how many of the north-oriented Little Blue River tributaries are located on similar alignments to the alignments of south-oriented Republican River tributaries. Also follow the Little Blue River-Republican River drainage divide eastward across the figure 7 map area. A close look reveals several north-south oriented through valleys, even though the figure 7 map is not a detailed map. The similar alignments and the shallow through valleys provide evidence the south-oriented Republican River tributary valleys were eroded by multiple south-oriented flood flow channels, which flowed across the present day Little Blue River valley location (north of the figure 7 map area). Headward erosion of the Little Blue River valley then beheaded the south-oriented flood flow routes to the figure 7 map area. Flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north to the newly eroded Little Blue River valley. The reversal of flood flow was responsible for eroding the north-oriented Little Blue River tributary valleys and also for creating the Little Blue River-Republican River drainage divide. Figure 8 provides a detailed map of the Little Blue River-Republican drainage divide area near Blue Hill.

Detailed map of Little Blue River-Republican River drainage divide area near Blue Hill

Figure 8: Detailed map of Little Blue River-Republican River drainage divide area near Blue Hill. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 8 provides a detailed map of the Little Blue River-Republican River divide area located south and east from the town of Blue Hill. The figure 8 map area can be seen in less detail in figure 7 above. North-oriented figure 8 drainage flows to the Little Blue River, which is located north of the figures 7 and 8 map areas. South-oriented figure 8 drainage flows to the Republican River, which is located south of the figures 7 and 8 map areas. Note how north-oriented Little Blue River tributary valleys are aligned with south-oriented Republican River tributary valleys. Also close study of the figure 8 drainage divide reveals shallow through valleys link most of those opposing tributary valleys. The north-south oriented railroad line in section 28 is located in one such through valley. Other north-south oriented through valleys can be seen in sections 29, 27, 26, and 36. The alignment of the opposing tributary valleys and the north-south oriented through valleys provide evidence of multiple south-oriented flood flow channels moving large volumes of flood water to what were then the actively eroding south-oriented Republican River tributary valleys. At that time the Little Blue River valley and the north-oriented Little Blue River tributary valleys did not exist. Nor did the northeast-oriented Platte River valley exist. Flood waters were moving freely in a south direction from wherever the flood source area was to this region in south central Nebraska, where flood waters had been captured by headward erosion of the Republican River valley, which had eroded headward from what was then the newly eroded east-oriented Kansas River valley. Headward erosion of the Little Blue River valley north of the figure 7 and 8 map areas captured the south-oriented flood flow and diverted the flood waters to what was then the newly eroded Big Blue River valley, which had also eroded headward from the newly eroded east-oriented Kansas River valley. Flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north and in doing so eroded the north-oriented Little Blue River tributary valleys and created the Little Blue River-Republican River drainage divide. Headward erosion of the northeast-oriented Platte River valley then captured all south-oriented flood flow to the newly eroded Little Blue River valley, as seen in figures 3 and 4 above.

Liberty Creek-Republican River drainage divide area

Figure 9: Liberty Creek-Republican River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 9 illustrates the Liberty Creek-Republican River drainage divide area east of the figure 7 map area and includes overlap areas with figure 7. Rosemont is the small town west of the figure 9 north center area. Lawrence is the somewhat larger town located east of the figure 9 north center area. St. Stephens is the place-name located south of Lawrence. Mount Clare is the place-name in the figure 9 southeast quadrant and figure 10 below provides a detailed map of the Liberty Creek-Republican River drainage divide area near Mount Clare. North-northeast oriented streams on either side of Rosemont flow to the southeast-oriented Little Blue River, which is located north of the figure 9 map area. The north-oriented stream located east of Lawrence is Liberty Creek, which north of figure 9 turns to flow in a northeast direction to join the southeast-oriented Little Blue River. The southeast oriented stream in the figure 9 east center area is Elk Creek, which east of the figure 9 map area flows in an east and east-northeast direction to join the Little Blue River. South-oriented drainage in the south half of the figure 9 map area all flows to the east-oriented Republican River located south of the figure 9 map area. Note how the southeast-oriented Liberty Creek tributary originating in the figure 9 north center area and flowing to near St. Stephens before joining north-oriented Liberty Creek is aligned with the southeast-oriented Elk Creek headwaters. Also note how north-oriented tributary valleys to that southeast-oriented Liberty Creek tributary are linked to south-oriented Republican River tributary valleys. Apparently that southeast-oriented tributary alignment was used by a southeast-oriented flood flow channel moving flood waters to the actively eroding Elk Creek valley prior to being captured by reversed flow on the Liberty Creek alignment. South-oriented flood flow on the Liberty Creek alignment was beheaded by headward erosion of the deep Little Blue River-Liberty Creek valley north of the figure 9 map area and flood waters on the north end of the beheaded flood flow route reversed flow direction to erode the north-oriented Liberty Creek valley. That north-oriented valley was able to capture south-oriented flood flow west of what was then the actively eroding Little Blue River valley head (and northeast-oriented Liberty Creek valley head) and captured flood waters eroded northeast-oriented Liberty Creek tributary valleys north of St. Stephens. Flood flow volumes were great enough the reversed flow was able to erode its deep north-oriented Liberty Creek valley far enough south so as to capture the southeast-oriented flood flow moving to what was then the actively eroding Elk Creek valley.

Liberty Creek-Republican River drainage divide area

Figure 10: Liberty Creek-Republican River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 10 provides a detailed map of the Liberty Creek-Republican River drainage divide area near Mount Clare, which was seen in less detail in figure 9 above. Mount Clare is located in the figure 10 southeast quadrant near the figure 10 south edge. The north-oriented valley in the figure 10 north center area is north-oriented Liberty Creek. The south-oriented valley in the figure 10 south center area is a south-oriented Republican River tributary. Note how the north-oriented Liberty Creek headwaters valley is linked by a shallow through valley with the south-oriented Republican River tributary valley (see sections 20 and 29).  The through valley linking the two opposing valleys provides evidence of south-oriented flood flow to the actively eroding Republican River tributary valley prior to headward erosion of the Little Blue River and northeast-oriented Liberty Creek valley north of the figure 10 map area. Headward erosion of the Little Blue River and northeast-oriented Liberty Creek valley north of the figure 10 map area beheaded the south-oriented flood flow, which resulted in a reversal of flood flow on the north end of the beheaded flood flow route. East-oriented drainage flowing to the figure 10 east edge flows to east and east-northeast oriented Elk Creek, which is a Little Blue River tributary. Note shallow through valleys linking the north-oriented Liberty Creek headwaters valley with the east-oriented Elk Creek tributary valleys (e.g. see section 21). Also note shallow through valleys linking the Elk Creek tributary valleys with the south-oriented Republican River tributary valleys (e.g. see section 28). A much broader, but also shallow through valley can be seen in the section 19 area of the figure 10 northwest quadrant, which links north-oriented Liberty Creek tributary valleys with south-oriented Republican River tributary valleys. This much broader through valley, which as a slightly higher valley floor elevation than the through valleys further east, suggests large sheets of south-oriented flood water may have flowed south across the region. Erosion apparently was greater toward the east, where both the Republican River valley and the Little Blue River valley are deeper. The figure 10 evidence suggests flood waters deeply eroded the region and the depth of erosion of was related to the depths of valleys eroding headward into the region.

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.