A geomorphic history based on topographic map evidence

The Lincoln Creek-Turkey Creek drainage divide area in York, Seward, Fillmore, and Saline Counties, Nebraska is a low relief region in the Big Blue River drainage basin. Lincoln Creek and Turkey Creek are the northern and southern of several northeast, east, and southeast oriented streams draining the drainage divide area to the south-southeast oriented Big Blue River. Present day valleys were eroded headward across the region in sequence to capture southeast and south oriented flood flow and to divert the flood flow to what was then the newly eroded south-southeast oriented Big Blue River valley and tributary valley headward erosion. Lincoln Creek valley and tributary valley headward erosion occurred shortly later. Flood water was probably spilling east and south from what was then the developing northeast-oriented Platte River valley, although flood waters were probably derived from a rapidly melting North American ice sheet and probably deeply eroded the York, Seward, Fillmore, and Saline County area prior to Big Blue River valley and Platte River valley headward erosion. The valley headward erosion sequence is determined from present day valley orientations and positions.

• The purpose of this essay is to use topographic map interpretation methods to explore Lincoln Creek-Turkey Creek drainage divide area landform origins in York, Seward, Fillmore, and Saline 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 Lincoln Creek-Turkey Creek drainage divide area landform origins in York, Seward, Fillmore, and Saline 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.

Lincoln Creek-Turkey Creek drainage divide area location map

Figure 1: Lincoln Creek-Turkey Creek 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 Lincoln Creek-Turkey Creek drainage divide area in York, Seward, Fillmore, and Saline Counties, Nebraska location map and illustrates a large area in southeast Nebraska. A thin sliver of northern Kansas is visible along the figure 1 south edge. The south-southeast oriented Missouri River crosses the figure 1 northeast corner and Iowa is the state located east of the Missouri River. East and south of the figure 1 map area the Missouri River continues to flow in a south-southeast direction to Kansas City, Missouri where it turns to flow in an east direction to eventually join the south-oriented Mississippi River. The Platte River flows in a northeast direction from Kearney near the figure 1 west center edge to Columbus and North Bend. At North Bend the Platte River turns to flow in a southeast direction to Fremont and then to flow in a south direction to Ashland. South of Ashland the Platte River turns again to flow in an east-northeast direction to join the south-southeast oriented Missouri River near Plattsmouth. The Big Blue River originates near Marquette and flows in an east-northeast direction to Stromsburg and then east-southeast direction to Ulysses. At Ulysses the Big Blue River turns to flow in a south-southeast direction to Seward, Milford, Crete, Wilber, De Witt, Beatrice, and Wymore before flowing into Kansas. Once in Kansas the Big Blue River continues to flow south to join the east-oriented Kansas River, which joins the Missouri River at Kansas City. Lincoln Creek is an east-northeast and east-southeast oriented Big Blue River tributary located south of the east-northeast and east-southeast oriented Big Blue River headwaters. Lincoln Creek joins the Big Blue River near Seward. Turkey Creek is the unlabeled east, northeast, and south-southeast oriented stream flowing through Geneva and joining the Big Blue River near De Witt. Between Lincoln Creek and Turkey Creek are other east-oriented Big Blue River tributaries. The unlabeled stream flowing through McCool Junction and Beaver is the West Fork Big Blue River. A major West Fork Big Blue River tributary is Beaver Creek, which is the unlabeled east-oriented stream flowing from Hampton to York and joining the West Fork Big Blue River near Beaver. The Platte River-Big Blue River drainage divide area, the Turkey Creek-Little Blue River drainage divide area, and the Platte River-Salt Creek drainage divide area essays describe nearby drainage divide areas and can be found under Platte River or Big Blue River (as appropriate to the rivers involved) on the sidebar category list. Hundreds of published Missouri River drainage basin landform origins research project essays on this website provide overwhelming evidence of immense south-oriented melt water floods, which flowed across southeast Nebraska as present day valleys eroded headward into and across the region.

Lincoln Creek-Turkey Creek drainage divide area detailed location map

Figure 2: Lincoln Creek-Turkey Creek drainage divide area detailed location map. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 2 provides a somewhat more detailed location map for the Lincoln Creek-Turkey Creek drainage divide area in York, Seward, Fillmore, and Saline Counties. Merrick, Polk, Butler, Saunders, Hamilton, York, Seward, Lancaster, Clay, Fillmore, and Saline are Nebraska county names and county boundaries are shown. The Platte River flows in a northeast direction across the figure 2 northwest quadrant and forms the boundary between Merrick County and Hamilton and Polk Counties. The Big Blue River originates between Marquette and Aurora in northern Hamilton County and flows in a northeast direction across  the York County northwest corner before entering southern Polk County. Once in Polk County the Big Blue River turns to flow in an east-southeast direction to Ulysses in southern Butler County. From Ulysses the Big Blue River flows in a south-southeast direction to Seward and Milford in Seward County and then to Crete and De Witt in Saline County. From De Witt the Big Blue River turns to flow in a southeast direction to the figure 2 south edge. Lincoln Creek originates in western Hamilton County, almost on the Platte River valley edge, and flows in an east and east-northeast direction across Hamilton County and northern York County and into Seward County, where it turns to flow in a southeast direction to join the Big Blue River near Seward. South of Lincoln Creek is Beaver Creek, which flows in an east direction across Hamilton County to York in York County and then in a southeast direction to join the West Fork Big Blue River in southwest Seward County. The West Fork Big Blue River is located south of Beaver Creek and flows from southern Hamilton County into southwest York County and northwest Fillmore County before flowing in a northeast direction to join southeast-oriented Beaver Creek. After joining Beaver Creek the West Fork Big Blue River flows in a southeast direction to join the south-southeast oriented Big Blue River near the Seward County-Saline County border. Note several northeast-oriented West Fork Big Blue River tributaries including School Creek, Indian Creek, and Johnson Creek. Turkey Creek originates in eastern Clay County and flows in an east and northeast direction into northern Saline County. After flowing in an east direction in northern Saline County Turkey Creek turns to flow in a south-southeast direction to join the Big Blue River near De Witt in southeast Saline County. Squaw Creek is a shorter southeast-oriented Big Blue River tributary located in northeast Saline County. The interpretation provided below is the south-southeast oriented Big Blue River valley and the east- and northeast-oriented Big Blue River tributary valleys eroded headward across the region to capture southeast-oriented flood flow. Headward erosion of the east- and northeast-oriented tributary valleys was in sequence from the southeast to the northwest. Topographic maps below illustrate evidence supporting this interpretation.

West Fork Big Blue River-Squaw Creek drainage divide area

Figure 3: West Fork Big Blue River-Squaw Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the West Fork Big Blue River-Squaw Creek drainage divide area in northern Saline County. Crete is the town located in the figure 3 east half. The Big Blue River flows from the figure 3 north edge in a south-southeast direction to Crete and then to the figure 3 south edge. The West Fork Big Blue River flows in a southeast direction from the figure 3 north edge (west half) into Saline County and then flows in an east-northeast direction to join the Big Blue River near the Seward-Saline County border. Johnson Creek (with a North and South Fork) is the east-southeast and east-northeast oriented West Fork Big Blue River tributary. Turkey Creek flows in an east-southeast direction from the figure 3 west edge to the Pleasant Hill area and then turns to flow in a south-southeast direction to the figure 3 south center edge. Squaw Creek originates in the figure 3 west center (west of Dorchester) and flows in a southeast direction to join the Big Blue River near the figure 3 south edge. Note unnamed southeast oriented Big Blue River tributaries west of Crete and also unnamed Turkey Creek tributaries. Note also northeast and north oriented Turkey Creek, Johnson Creek, and West Fork Big Blue River tributaries. Figure 3 drainage routes are interpreted to have eroded headward into the figure 3 map region to capture massive southeast and south oriented flood flow. Prior to that time flood waters moved across the entire figure 3 map area on a topographic surface at least as high as the highest figure 3 elevations today. Headward erosion of what was then the deep Big Blue River valley permitted headward erosion of the Turkey Creek, Squaw Creek, and West Fork Big Blue River valleys to occur. The deep Turkey Creek valley eroded headward into the figure 3 map area probably at about the same time as deep Big Blue River valley headward erosion reached the map area (see figure 2 to see where south-southeast oriented Turkey Creek joins the Big Blue River). Headward erosion of the Turkey Creek valley then beheaded south-oriented flood flow routes. Flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north and northeast to the newly eroded Turkey Creek valley. This reversed flood flow was responsible for headward erosion of the northeast and north oriented Turkey Creek tributary valleys. Remember the Turkey Creek valley eroded headward from southeast to northwest and beheaded flood flow routes one flow route at a time. Also remember flood flow routes were interconnected, meaning reversed flow on one route could capture flood flow from adjacent yet to be beheaded flood flow routes. The Squaw Creek valley next eroded headward from the actively eroding Big Blue River valley while Big Blue River valley headward erosion continued northward. Squaw Creek valley headward erosion beheaded southeast and south oriented flood flow to the newly eroded Turkey Creek valley. Headward erosion of the West Fork Big Blue River-Johnson Creek valley next beheaded south- and southeast-oriented flood flow to the newly eroded Squaw Creek valley and headward erosion of the West Fork Big Blue River valley beheaded south- and southeast-oriented flood flow routes to what was then the newly eroded Johnson Creek valley.

Crooked Creek-Coon Creek drainage divide area

Figure 4: Crooked Creek-Coon Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 4 illustrates the Crooked Creek-Coon Creek drainage divide area north of the figure 3 map area. Milford is the town located in the figure 4 east half. The Big Blue River flows in a south-southeast direction from the figure 4 north edge to Milford and then to the figure 4 east edge. Coon Creek is the southeast and northeast oriented tributary joining the Big Blue River at Milford. Beaver Crossing is the town near the figure 4 west edge. The West Fork Big Blue River flows in a southeast direction from the figure 4 west edge to Beaver Crossing and then to the figure 4 south center edge. Walnut Creek is the south, southeast, and south oriented tributary joining the West Fork Big Blue River east of Beaver Crossing. Goehner is the town northeast of Walnut Creek and near the figure 4 north edge. The stream originating north of Goehner is the North Branch Crooked Creek, which flows in an east direction to join the north and northeast oriented South Branch Crooked Creek and then to flow to the south-southeast oriented Big Blue River. Figure 4a below provides a detailed map of the South Branch Crooked Creek-Coon Creek drainage divide area. South Branch Crooked Creek flows north, east, and north in the figure 4a north center area. Coon Creek flows in a north, northeast, and southeast direction toward the figure 4 southeast corner area. South-oriented drainage in the figure 4 southwest corner flows to the southeast-oriented West Fork Big Blue River located south of the figure 4a map area. Northeast drainage in the figure 4a east center area flows to the Big Blue River as does southeast-oriented drainage in the figure 4a northeast corner. What has happened in the figure 4a map area is south-oriented flood water moved across the entire region on a topographic surface as high as the highest figure 4a elevations today. Headward erosion of the deep Big Blue River valley and the West Fork Big Blue River valley permitted the southeast-oriented Coon Creek valley and the south-oriented West Fork tributary valleys to erode headward into the figure 4a map area. Headward erosion of the Coon Creek valley beheaded south-oriented flood flow routes. Flood waters on the north end of a beheaded flood flow route reversed flow direction to create the north-oriented Coon Creek headwaters valley. The Crooked Creek valley then eroded headward (west from the newly eroded Big Blue River valley) and beheaded south-oriented flood flow to the actively eroding Coon Creek valley. Flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north to the newly eroded east-oriented Crooked Creek valley. The figure 4 and 4a evidence suggests a more complicated pattern of headward erosion and beheading of flood flow routes than what I have described. What I have tried to do is to explain the process, which was repeated multiple times as the illustrated valley system evolved.

Figure 4a: Detailed map of South Branch Crooked Creek-Coon Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Lincoln Creek-West Fork Big Blue River drainage divide area

Figure 5: Lincoln Creek-West Fork Big Blue River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 uses reduced size maps to illustrate the Lincoln Creek-West Fork Big Blue River drainage divide west of Seward and is located north of the figure 4 map area and includes overlap areas with figure 4. Seward is the larger town located near the figure 5 east edge. Staplehurst is the smaller town located northwest from Seward and near the figure 5 north edge. The Big Blue River flows from Staplehurst to Seward and then south-southeast along the figure 5 east edge and then flows east of the figure 5 map area. Lincoln Creek is the east-southeast and southeast oriented Big Blue River tributary flowing from the figure 5 northwest corner to join the Big Blue River near Seward. Crooked Creek is the east-oriented Big Blue River tributary located in the figure 5 southeast quadrant. The West Fork Big Blue River is located in the figure 5 southwest corner area and is flowing in an east-southeast direction. Utica is the town in the figure 5 west center (just east of York-Seward County line). Walnut Creek is the south and southeast oriented stream located in the figure 5 south center area and is a West Fork Big Blue River tributary. Sleepy Hollow Creek is the southeast and south oriented West Fork Big Blue River tributary located south of Utica. Headward erosion of the West Fork Big Blue River valley south of the figure 5 map area and into the figure 5 map area captured south and southeast oriented flood flow. South and southeast oriented tributary valleys, including the Walnut Creek valley and the Sleepy Hollow Creek valley, then began to erode headward from the newly eroded West Fork Big Blue River valley. Headward erosion of the Big Blue River-Lincoln Creek valley and tributary valleys then began to behead south oriented flood flow to the newly eroded West Fork Big Blue valley and the actively eroding south and southeast oriented West Fork Big Blue River tributary valleys. Note north-oriented Lincoln Creek tributary valleys and valley segments. North-oriented Lincoln Creek tributary valleys and valley segments were eroded by flood flow reversals on north ends of beheaded flood flow routes. These reversals of south-oriented flood flow were responsible for creating the present day Lincoln Creek-West Fork Big Blue River drainage divide. Northeast-oriented Lincoln Creek tributary valleys may have been eroded by reversed flood flow or they may have eroded headward from the actively eroding Lincoln Creek valley head to capture yet to be beheaded south- and southeast-oriented flood flow located southwest from the Lincoln Creek valley head.

Lincoln Creek-Beaver Creek drainage divide area east of York

Figure 6: Lincoln Creek-Beaver Creek drainage divide area east of York. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 illustrates the Lincoln Creek-Beaver Creek drainage divide area east of York and is located west of the figure 5 map area. Lincoln Creek is the northeast, southeast, northeast oriented stream located in the figure 6 northwest quadrant and north of York. The Lincoln Creek tributary flowing east along the figure 6 north edge and then turning in a southeast direction to join northeast-oriented Lincoln Creek is Coon Branch, which has southeast and south oriented headwaters north of the figure 6 map area. North of the figure 6 map area Lincoln Creek turns to flow in an east-southeast direction to the figure 5 map area. North-oriented drainage in the figure 6 northeast quadrant flows to Lincoln Creek. Beaver Creek flows in an east direction from the figure 6 west edge to the south edge of York and then into the figure 6 southeast quadrant where it flows in a south direction to the figure 6 south edge. South of figure 6 Beaver Creek joins the West Fork Big Blue River, which flows to the south oriented Big Blue River. Figure 6 drainage routes evolved as valleys eroded headward into the region. The Beaver Creek valley eroded north and west from the West Fork Big Blue River valley and beheaded south and southeast-oriented flood flow routes to the newly eroded West Fork Big Blue River valley located south of the figure 6 map area. South and southeast oriented Beaver Creek tributary valleys eroded headward from the newly eroded Beaver Creek valley. Flood flow to these actively eroding Beaver Creek tributary valleys was beheaded by headward erosion of the Lincoln Creek valley. In the figure 6 east half flood waters on north ends of beheaded flood flow routes reversed flow direction to flow north to the newly eroded east-southeast oriented Lincoln Creek valley located north of the figure 6 map area. The northeast-oriented Lincoln Creek valley segment then eroded southwest to capture southeast-oriented flood flow moving on the Coon Branch alignment and also on the southeast-oriented Lincoln Creek valley segment alignment. Note how the southeast-oriented Lincoln Creek valley segment is aligned with a southeast-oriented Beaver Creek tributary located just east of York. Headward erosion of the northeast-oriented Lincoln Creek valley beheaded the southeast-oriented flood flow route supplying water to what was then the actively southeast-oriented Beaver Creek tributary valley. Note the northeast-oriented Lincoln Creek jog to the northwest and the short northwest-oriented Lincoln Creek tributary near the figure 6 north edge. The northwest-oriented tributary valley and the short northwest-oriented Lincoln Creek valley segment were created by reversals of beheaded flood flow.

Lincoln Creek-Beaver Creek drainage divide area west of York

Figure 7: Lincoln Creek-Beaver Creek drainage divide area west of York. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 7 illustrates the Lincoln Creek-Beaver Creek drainage divide area west of York and of the figure 6 map area and includes overlap areas with figure 6. Lincoln Creek is located in the figure 7 north half and flows from the figure 7 west edge to the east edge. Beaver Creek is located in the figure 7 south half and also flows from the west edge to the east edge. South of Beaver Creek is northeast and east-northeast oriented Bear Creek which flows to join Beaver Creek. Note how Beaver Creek tributaries from the north are generally oriented in a southeast direction and Lincoln Creek tributaries from the north are generally oriented in a south-southeast direction. Also Bear Creek has a southeast-oriented tributary in the figure 7 southwest corner area. The figure 7 drainage routes were eroded in sequence. The Beaver Creek valley was first to enter the figure 7 map area and eroded headward into the figure 7 southeast quadrant and captured southeast-oriented flood flow which had been moving to the actively eroding West Fork Big Blue River valley located south of the figure 7 map area. The West Fork Big Blue River valley was eroding headward slightly in advance of the Beaver Creek valley, although both valleys were eroding headward at approximately the same time. Southeast-oriented Beaver Creek tributaries in the figure 7 east half provide evidence that headward erosion of the Beaver Creek valley captured southeast-oriented flood flow. The Bear Creek valley eroded headward from the newly eroded Beaver Creek valley and captured southeast-oriented flood flow not yet beheaded by the Beaver Creek valley headward erosion, although headward erosion of the Beaver Creek valley followed so rapidly that southeast-oriented Bear Creek tributary valleys were not eroded. Beaver Creek valley headward erosion captured southeast-oriented flood waters moving to the newly eroded Bear Creek valley and in time Beaver Creek valley headward erosion overtook Bear Creek valley headward erosion, meaning the Beaver Creek valley headward erosion captured all flood flow moving to what had been the actively eroding Bear Creek valley. Without a flood flow source Bear Creek valley headward erosion ceased while Beaver Creek headward erosion continued west of the figure 7 map area. The Lincoln Creek valley eroded headward across the figure 7 map area slightly behind Beaver Creek valley and captured flood flow moving to what were then the actively eroding Beaver Creek tributary valleys. Lincoln Creek valley headward erosion continued to lag slightly behind Beaver Creek valley headward for the entire distance across the figure 7 map area. Southeast-oriented Lincoln Creek tributary valleys eroded headward from the newly eroded Lincoln Creek valley and flood flow to those actively eroding valleys was beheaded by Big Blue River valley headward erosion north of the figure 7 map area.

Beaver Creek-West Fork Big Blue River drainage divide area

Figure 8: Beaver Creek-West Fork Big Blue River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 8 illustrates the Beaver Creek-West Fork Big Blue River drainage divide area south and west of York and south of the figure 7 map area and includes overlap areas with figure 7. York is located near the figure 8 north edge (east half). The smaller town south of York in the figure 8 southeast quadrant is McCool Junction. Henderson is the smaller town located near the figure 8 west center area. Beaver Creek is located in the figure 8 north half and flows from the west edge to the east edge. East of the figure 8 map area Beaver Creek turns to flow in a south and southeast direction to join the West Fork Big Blue River. Bear Creek is the northeast and east-northeast oriented stream south of Beaver Creek and flows to join Beaver Creek near the figure 8 north center area. The West Fork Big Blue River is located in the figure 8 south half and in the southwest quadrant flows in a northeast and southeast direction to the figure 8 south center edge. South of figure 8 the West Fork Big Blue River turns to flow in a northeast and north direction and then east to the figure 8 east edge. Galaway Creek is the southeast and east oriented stream joining the West Fork Big Blue River near McCool Junction. Note south and southeast oriented West Fork Big Blue River and Galaway Creek tributaries. The West Fork Big Blue River valley was the first of the present day deep valleys to erode headward into the figure 8 map area. North-oriented West Fork Big Blue River tributary valleys in the figure 8 southeast quadrant were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes. When West Fork Big Blue River valley headward erosion reached the McCool Junction area it beheaded a major south-oriented flood flow route. Flood waters on the north end of the beheaded flood flow route reversed flow direction to erode the north-oriented West Fork Big Blue River valley segment near McCool Junction. The West Fork Big Blue River valley then eroded headward (southwest and northwest) from a more southern location while the Galaway Creek valley eroded headward on approximately the same alignment as the West Fork Big Blue River valley to the east. Because the southern West Fork Big Blue River valley was far enough south and west from the Galaway Creek valley it was able to erode headward before Galaway Creek valley headward erosion beheaded southeast and south oriented flood flow to the actively eroding West Fork Big Blue River valley head. Headward erosion of the Beaver Creek and Bear Creek valleys followed soon after and beheaded all southeast-oriented flood flow routes to what was then the actively eroding Galaway Creek valley system.

West Fork Big Blue River-Turkey Creek drainage divide area

Figure 9: West Fork Big Blue River-Turkey Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 9 illustrates the West Fork Big Blue River-Turkey Creek drainage divide area south of the figure 8 map area. Sutton is the town located in the figure 9 west center edge area. Geneva is the located in the figure 9 southeast quadrant and Fairmont is the town north of Geneva and located in the figure 9 northeast quadrant. Grafton is the smaller town located between Sutton and Fairmont. The West Fork Big Blue River is the east-southeast and northeast oriented stream located in the figure 9 north center edge area (see figure 8 for West Fork Big Blue River route north of the figure 9 map area). School Creek is the northeast oriented West Fork Big Blue River tributary flowing from near Sutton across the figure 9 northwest quadrant. Turkey Creek is the northeast and southeast oriented stream flowing from the figure 9 south center edge to near Geneva. From Geneva Turkey Creek flows in a northeast and then southeast direction to reach the figure 9 east edge. Indian Creek is the north and northeast oriented West Fork Big Blue River tributary located in the figure 9 northeast corner. Elk Run is the north, northeast, east, and northeast oriented West Fork Big Blue River tributary located west and north of Grafton. Turkey Creek valley headward erosion reached the figure 9 map area first and eroded headward along southeast-oriented flood flow routes and then across southeast-oriented flood flow routes several times to produce its present day northeast and southeast oriented valley route. Southeast-oriented tributary valleys eroded headward from the newly eroded Turkey Creek valley and one such tributary valley then eroded west into the figure 9 southwest quadrant area to capture multiple southeast-oriented flood flow routes. Headward erosion of the West Fork Big Blue River valley beheaded south-oriented flood flow to the newly eroded Turkey Creek valley and its actively eroding tributary valleys. North-oriented West Fork Big Blue River tributary valleys were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes. Northeast and east oriented West Fork Big Blue River tributary valley segments may have been eroded by yet to be beheaded flood flow west of the actively eroding West Fork Big Blue River valley head moving to actively eroding reversed flow (north-oriented) West Fork Big Blue River tributary valleys. The northeast-oriented School Creek valley eroded headward across southeast-oriented flood flow routes and beheaded flood flow routes to the newly eroded Turkey Creek and tributary valleys.

School Creek-Turkey Creek drainage divide area

Figure 10 illustrates the School Creek-Turkey Creek drainage divide area south and west of the figure 9 map area and includes overlap areas with figure 9. Sutton is the town located in the figure 10 northwest quadrant. School Creek is the northeast-oriented stream flowing through Sutton and across the figure 10 northwest quadrant. Turkey Creek originates in the figure 10 southwest quadrant as a southeast-oriented stream and after making some northeast-southeast jogs in the figure 10 south center area turns to flow in a northeast direction to the figure 10 east center edge. The North Fork Turkey is located north of Turkey Creek in the figure 10 center area and has southeast-oriented headwaters and then flows in an east-northeast direction and southeast direction to join Turkey Creek near the figure 10 east edge. Note southeast-oriented Turkey Creek and North Fork Turkey Creek tributaries and headwaters. Headward erosion of the northeast-oriented School Creek valley beheaded southeast-oriented flood flow moving to what was the actively eroding Turkey Creek valley system. Headward erosion of the east-oriented Big Blue River tributary valleys probably occurred very late in the massive south oriented flood history. Water responsible for eroding the Lincoln Creek-Turkey Creek drainage divide area was probably spilling south and southeast from what was then an actively eroding northeast-oriented Platte River valley north and west of the Lincoln Creek-Turkey Creek drainage divide area. This spillage was captured by headward erosion of the south-southeast oriented Big Blue River valley and its east- and southeast-oriented tributary and headwaters valleys. Headward erosion of the Platte River valley ended all flood flow across the Lincoln Creek-Turkey Creek drainage divide area. The Lincoln Creek-Turkey Creek drainage divide area geomorphic history interpreted here has largely been based on the positions and orientations of present day valleys and streams. Evidence for through valleys is of little assistance in this region due the limited topographic relief. It is possible the low topographic relief is in some way related to flood deposited sediments in the region. Regardless, the limited topographic relief limits the ability of map interpretation methods to determine how much material if any has been eroded from this drainage divide area. Based on evidence from nearby drainage divide areas where there is more topographic relief it seems reasonable to assume the Lincoln Creek-Turkey Creek drainage divide area was deeply eroded by immense south- and southeast-oriented flood flow prior to development of the present day drainage network.

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.