Republican River drainage basin landform origins, Colorado, Nebraska, and Kansas, USA, overview essay

Authors

A geomorphic history based on topographic map evidence

Abstract:

This essay is an overview of more detailed essays using topographic map evidence to interpret Republican River drainage basin landform origins. The more detailed essays can be found under Republican River on this website’s sidebar category list. All interpretations in this essay and in the more detailed essays are based entirely on topographic map evidence and no effort has been made to introduce evidence from other sources. Major Republican River tributary streams originate in northeast Colorado and flow in a northeast direction across the Kansas northwest corner into southwest Nebraska. Other Republican River tributaries originate in the Colorado northeast corner and flow into southwest Nebraska. The Republican River North and South Forks meet near Benkelman in southwest Nebraska and the Republican River flows in an east-northeast, east-southeast, and east direction to Superior, Nebraska. At Superior the Republican River turns to flow in a south-southeast direction to Concordia, Kansas before flowing in an east and south-southeast direction to join the east-oriented Smoky Hill River near Junction City Kansas and to form the east-oriented Kansas River. The Smoky Hill River, the Republican River, and their major tributaries (including the Solomon and Saline Rivers) all begin in the same region in western Kansas and eastern Colorado and then diverge to flow along different routes only to converge again to form the Kansas River. This divergence and convergence of these multiple drainage routes suggests the Republican River, Smoky Hill River, and their major tributary valleys were eroded as channels in what was once an immense east-oriented anastomosing channel complex. Topographic map evidence presented in the detailed essays suggests the Republican River valley and its tributary valleys eroded headward from what was a newly eroded Kansas River valley to systematically capture immense south- and southeast-oriented flood flow, which was flowing to what were then newly eroded Smoky Hill River tributary valleys. At that time significant southeast-oriented flood flow was moving across western Kansas and eastern Colorado where Republican and Smoky Hill River headwaters are now located. For a time, flood waters from eastern Colorado and western Kansas probably flowed in an east direction along what all of what are now diverging and converging valleys in the Republican and Smoky Hill River anastomosing valley complex. Flood waters were derived from a rapidly melting thick North American ice sheet and flowed in southeast and south directions along the ice sheet’s west and southwest margin and also flowed in south and southeast directions along what are now dismembered flood flow routes in the Rocky Mountains. South and southeast-oriented flood flow to the what were then actively eroding Republican River tributary valleys was beheaded by Platte River and South Platte River valley headward erosion.

Figure 1: Regional map showing Colorado, Nebraska, and Kansas Republican River, major Republican River tributaries, and adjacent rivers and tributaries (select and click on maps to enlarge). National Geographic Society map digitally presented using National Geographic Society TOPO software.

Republican River drainage history

This essay provides an overview of detailed essays using topographic map evidence to interpret Republican River drainage basin landform origins. The detailed essays are found under Republican River on this website’s sidebar category list. The Republican River originates in northeast Colorado with some tributaries flowing in a northeast direction to the Nebraska southwest corner while other tributaries flow in a southeast direction to the Nebraska southwest corner. In Nebraska the Republican River flows in a generally east direction from the southwest corner to near Superior, Nebraska where the Republican River turns to flow in a south-southeast, east and south-southeast direction to join the Smoky Hill River near Junction City. The combined Republican and Smoky Hill Rivers form the east-oriented Kansas River, which joins the Missouri River at Kansas City. North of the Republican River drainage basin east end is the Big Blue River drainage basin with the Big Blue River also flowing to the Kansas River. In western Nebraska the east-oriented Platte River is located north of the Republican River drainage basin and the northeast-oriented South Platte River is located west of the Republican River drainage basin. South of the Republican River drainage basin is the Solomon River drainage basin. The Solomon River originates in western Kansas and roughly parallels the Republican River route as it flows across northern Kansas to join the Smoky Hill River east of Salina, Kansas. South of the east-oriented Solomon River is the east-oriented Saline River, which also originates in western Kansas and which flows across Kansas to join the Smoky Hill River near Salina, Kansas. The east-oriented Smoky Hill River is located south of the Saline River and originates in eastern Colorado, just south and east of Republican River headwaters, and then flows across Kansas to join the Republican River near Junction City. The Republican, Solomon, Saline, and Smoky Hill Rivers all originate in the same general region of eastern Colorado and western Kansas and then have relatively narrow east-oriented drainage basins as they flow across western and central Kansas before converging to form the east-oriented Kansas River. This divergence and convergence of drainage routes suggests the valleys were eroded as channels in what was once a large-scale east-oriented anastomosing channel complex.

  • This overview essay and its related detailed essays interpret Republican River drainage basin landform origins from the perspective of a previously unexplored “thick ice sheet that melted fast” geomorphology paradigm. The paradigm is fundamentally different from most previously published interpretations. The framework of ideas defining the new paradigm includes the presence of a rapidly melting thick North American ice sheet. The ice sheet was comparable in size, if not larger, than the present day Antarctic Ice Sheet and when fully developed had probably stood two or more kilometers above the surrounding non glaciated surface. At the same time the ice sheet “roots” probably extended as much as one kilometer or more below the surrounding non glaciated surface. The deep “hole” in which the ice sheet was located had been formed by a combination of deep glacial erosion under the ice sheet and by crustal warping caused by the ice sheet’s tremendous weight. The crustal warping also affected regions elsewhere on the North American continent and was responsible for uplift of mountain ranges (including the Rocky Mountains) and high plateau areas as the ice sheet melted. Contributing to the uplift of mountain ranges and high plateau areas (as the ice sheet melted) may have been deep flood water erosion of overlying bedrock materials and deposition of those removed materials in new locations. What is important to understanding Republican River drainage basin history is the Rocky Mountains were uplifted as giant melt water floods flowed in a southeast and south direction from western Canada across Montana, Wyoming, and Colorado along routes which roughly parallel the present day east-west continental divide. Present day valley systems eroded headward from east and west in sequence to capture this immense south and southeast-oriented melt water river. The east-west continental divide evolved in a progressive manner, starting in the south and progressing to the north, as headward erosion of deep east- and west-west-oriented valleys reached the region and as Rocky Mountain uplift caused massive flood flow reversals and capture events.
  • At the time of Republican River drainage basin erosion the thick ice sheet was in the process of melting and at least in the south had been significantly reduced in thickness, probably to the extent that only the ice sheet “roots” remained. The remaining ice sheet “roots” were located north and east of the present day Republican River drainage basin, probably north and east of the present day South Dakota Missouri River valley, although at that time the South Dakota Missouri River valley did not exist. Immense melt water floods were flowing directly south from the decaying ice sheet and were being captured in sequence by headward erosion of deep east and southeast-oriented valleys from the deep south-oriented Mississippi River valley. Headward erosion of the deep Arkansas River valley captured flood waters as it eroded in a northwest direction from Arkansas into Kansas and Colorado. The southeast-oriented White River valley next eroded headward and captured south-oriented flood water routes which had been moving flood waters to the newly eroded Arkansas River valley. Next headward erosion of the deep east-oriented Missouri River valley across the state of Missouri beheaded the south-oriented flood flow routes to the newly eroded White River valley. In addition to the large melt water floods moving south from the decaying ice sheet giant southeast-oriented floods were also moving along the ice sheet’s southwest margin and the deep Kansas River valley and its east-oriented tributary valleys eroded headward to capture these southeast-oriented floods as they flowed across Kansas to the newly eroded Arkansas River valley. East-oriented Kansas River tributary valleys eroded headward in sequence with the Smoky Hill River valley eroding headward in advance of the Saline River valley, which eroded headward in advance of the Solomon River valley, which in turn eroded headward in advance of the Republican River valley, which eroded headward in advance of east-oriented Big Blue River tributary valleys. Republican River valley headward erosion beheaded southeast-oriented flood flow routes to what were then actively eroding Solomon and Smoky Hill River valleys (and Solomon River valley headward erosion beheaded flood flow routes to the Saline River valley). Platte River-South Platte River valley headward erosion ultimately beheaded all southeast-oriented flood flow routes to the actively eroding Republican River tributary valleys.

Figure 2: More detailed regional map (than figure 1) showing Republican River-Smoky Hill River drainage divide area in eastern Colorado. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Looking specifically at the Republican River drainage basin let us begin at the west end in eastern Colorado. Detailed essays for eastern Colorado Republican River drainage divide areas have not yet been written, although figure 2 provides a more detailed map (than figure 1) showing the Republican River-Smoky Hill River drainage divide area in eastern Colorado. The north-south Colorado-Kansas state line is located along the east edge of Kit Carson County, Colorado. The South Fork Republican River flows to the figure 2 northeast corner and the northeast-oriented stream north of the South Fork is the Arikaree River, also a Republican River tributary. Northeast-oriented streams flowing to the figure 2 east edge (north half) are Beaver Creek headwaters, with Beaver Creek also being a Republican River tributary. The Arikaree River, South Fork Republican River, and Beaver Creek flow in parallel northeast and east directions before joining in southern Nebraska (see figure 1). East-oriented streams flowing to the figure 2 east edge (south half) are Smoky Hill River headwaters, with the Smoky Hill River being located near the figure 2 south edge and the North Fork Smoky Hill River being the northern east-northeast and east oriented stream. Southeast-oriented streams in the figure 2 southwest corner are Arkansas River tributaries, with the southeast-oriented Arkansas River being located south and west of the figure 2 map area. Note how the Smoky Hill River, North Fork Smoky Hill River, South Fork Republican River, and Arikaree River have some southeast-oriented tributaries. Also note there is no evidence of the east-oriented Solomon River or Saline River located between the northeast-oriented Republican River headwaters and the east-northeast and east-oriented Smoky Hill River headwaters in the figure 2 map area.

  • What happened to develop the figure 2 drainage pattern is initially immense southeast-oriented floods flowed across the entire figure 2 map area. Flood waters probably flowed in a large southeast-oriented anastomosing channel complex with headward erosion of the Arkansas River valley capturing the southeast-oriented flood flow. Following the flood flow routes headward today leads to the high Rocky Mountains, however at the time flood waters crossed the figure 2 map area that mountain barrier did not exist. The flood water source was the rapidly melting North American ice sheet and the flood waters flowed in a southeast and south direction along what is now the east-west continental divide to eventually reach the figure 2 map area and then to the newly eroded Arkansas River valley. Headward erosion of the east-oriented Smoky Hill River valley from what was then the newly eroded Kansas River valley, which had eroded headward from what was then the newly eroded east-oriented Missouri River valley (in the state of Missouri), next beheaded southeast-oriented flood flow channels to the newly eroded Arkansas River. North Fork Smoky Hill River valley headward erosion then beheaded southeast-oriented flood flow routes to the newly eroded Smoky Hill River valley. Beaver Creek valley headward erosion from the actively eroding Republican River valley in southern Nebraska next beheaded southeast-oriented flood flow to the newly eroded North Fork Smoky Hill River valley. Following Beaver Creek valley headward erosion South Fork Republican River valley headward erosion beheaded southeast-oriented flood flow to the newly eroded Beaver Creek valley. Finally (in figure 2) Arikaree River valley headward erosion beheaded southeast-oriented flood flow to the newly eroded South Fork Republican River valley. Looking at figure 1 the next major northeast-oriented valley to be eroded across the region north and west of the figure 2 map area was the South Platte River valley, which beheaded southeast-oriented flood flow routes to the newly eroded Arikaree River valley. Rocky Mountain uplift combined with headward erosion of the southwest-oriented Colorado River valley next ended southeast-oriented flood flow to the newly eroded South Platte River valley and subsequently major flood flow reversals caused by Rocky Mountain uplift resulted in the north-oriented Laramie River and North Platte River valley segments further to the northwest.

Figure 3: More detailed regional map (than figure 1) showing Republican River-Smoky Hill River drainage divide area in western Kansas and its relationship to Solomon and Saline River headwaters. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the Republican River-Smoky Hill River drainage divide area immediately east of the figure 2 map area and includes an overlap strip with figure 2. Beaver Creek is the northeast oriented stream flowing across the figure 3 northwest corner area and other northeast oriented streams flowing to the figure 3 north edge are also Republican River tributaries. Prairie Dog Creek is the southeastern of the northeast-oriented Republican River tributaries and crosses the figure 3 north edge near Jennings (near the northeast corner). The Republican River tributaries flow in a northeast direction to join the east oriented Republican River in southern Nebraska (see figure 1). The northeast and east oriented streams flowing to the north half of the figure 3 east edge are Solomon River tributaries and include the North and South Forks of the Solomon River. The North and South Forks of the Solomon River flow along roughly parallel routes across northern Kansas before joining to form the southeast-oriented Solomon River (see figure 1). The east oriented stream flowing near the Sheridan-Gove County border to the figure 3 east edge is the Saline River. East of the figure 3 map area the Saline River flows in an east and east-southeast direction to eventually join the Smoky Hill River. South of the Saline River in northern Gove Cove is east-southeast oriented Big Creek and south of Big Creek is Hackberry Creek. Big Creek, Hackberry Creek, and other east- and southeast-oriented streams south of the Saline River are tributaries to the Smoky Hill River, which flows in an east direction across Wallace County and into Logan County before turning to flow in a southeast direction to the figure 3 south edge. Note how the Smoky Hill River and Saline River and to a lesser extent the South and North Forks of the Solomon River  and the northeast-oriented Republican River tributaries have southeast-oriented tributaries.

  • Each of the detailed essays found under Republican River on the sidebar category list includes eight or more topographic maps which illustrate drainage routes in much greater detail than seen in this overview essay. The topographic maps illustrate additional evidence suggesting headward erosion of the east and northeast oriented valleys progressively captured multiple southeast-oriented flood flow channels such as might be found in a large-scale southeast-oriented anastomosing channel complex. In addition to southeast-oriented tributaries there are northwest and north-oriented tributaries flowing in valleys eroded by reversed flood flow on northwest and north ends of beheaded flood flow routes. Further, shallow through valleys crossing present day drainage divides provide evidence of the southeast-oriented flood flow channels that predate the present day northeast and east-oriented valleys. Based on this evidence the Smoky Hill River valley eroded headward across the figure 3 map area first to capture southeast-oriented flood flow that was moving to what were then the actively eroding Arkansas River tributary valleys located south and east of the figure 3 map area. Hackberry Creek valley headward erosion next beheaded flood flow routes to the newly eroded Smoky Hill River valley with Big Creek valley headward erosion next beheading flood flow routes to the newly eroded Hackberry Creek valley. The Saline River valley beheaded flow routes to the newly eroded Big Creek valley and South Fork Solomon River valley headward erosion beheaded flood flow routes to the newly eroded Saline River valley. North Fork Solomon River valley headward erosion subsequently beheaded flood flow routes to the newly eroded South Fork Solomon River valley and the Prairie Dog Creek valley next beheaded flood flow routes to the newly eroded North Fork Solomon River valley. Beaver Creek valley headward erosion beheaded flood flow routes to the newly eroded northeast-oriented Republican River tributary valleys between Beaver Creek and Prairie Dog Creek and South Fork Republican River valley headward erosion beheaded flood flow routes to the newly eroded Beaver Creek valley. Note how northeast-oriented Republican River tributary valley headward erosion beheaded all southeast-oriented flood flow routes to the Solomon River, Saline River, Big Creek, and Hackberry Creek headwaters, located in southern Thomas County and the Sherman County southeast corner.

Figure 4: More detailed regional map (than figure 1) showing convergence of Smoky Hill River, Solomon River, Saline River, and Republican River to form east-oriented Kansas River. United States Geological Survey map digitally presented using National Geographic Society TOPO software.  

Figure 4 illustrates the region in north central Kansas where the diverging valleys seen in figures 2 and 3 converge again to form the east-oriented Kansas River. Salina, Kansas is the city located near the figure 4 south center edge (look at figure 1 to see the distance between figures 2 and 3 and figure 4 and routes the diverging and converging valleys use). The Smoky Hill River flows in a north direction to Salina and then in a an east-northeast to Junction City near the figure 4 east edge (south half) . Near Junction City the east-northeast oriented Smoky Hill River joins the south-southeast oriented Republican River to form the northeast-oriented Kansas River, which flows to the figure 4 east edge. East of figure 4 the Kansas River turns to flow in an east direction to join the Missouri River at Kansas City (see figure 1). The Republican River flows in a south-southeast and east direction from the figure 4 north center edge to Concordia in Cloud County and then flows in an east direction to the Clay County northeast corner. From the Clay County northeast corner the Republican River flows in a south-southeast direction to join the Smoky Hill River. The Saline River is the east-oriented river in Lincoln County, which then turns to flow in a southeast direction and to join the Smoky Hill River just east of Salina in Saline County. The North and South Forks Solomon River combine at Waconda Lake (the reservoir located in northwest Mitchell County) to form the Solomon River which flows in an east-southeast and southeast direction to join the Smoky Hill River at Solomon (located in the Saline County northeast corner next to the Dickinson County border). Note how the Solomon River has numerous south-oriented tributaries and the Saline River has north oriented tributaries. Study of the figure 4 map area reveals many other north and south-oriented steams. The south-oriented valleys were eroded headward along south-oriented flood flow routes while the north-oriented valleys were eroded by flood flow reversals along the north ends of beheaded south-oriented flood flow routes. The north-south orientation of these figure 4 streams suggests the initial flood flow in the figure 4 map area was predominately oriented in a south direction.

  • The figure 4 map area is located directly south of where the decaying ice sheet in South and North Dakota was located at the time Republican River valley headward erosion occurred. At that time huge south oriented melt water rivers were emerging from giant ice-walled canyons carved into the decaying ice sheet’s surface. The Missouri River valley and tributary valleys such as the Platte River, Niobrara,River, White River, and Cheyenne River valleys did not yet exist and flood waters flowed south across Nebraska and Kansas to what was then the actively eroding Arkansas River valley (prior to Arkansas River valley headward erosion flood waters flowed even further south). Kansas River and Smoky Hill River valley headward erosion beheaded the south oriented flood flow routes while the south-southeast oriented Republican River valley segments were eroded headward along south-oriented flood flow routes and east-oriented Republican River valley segments were eroded across south-oriented flood flow routes. As Republican River valley headward erosion proceeded westward Rocky Mountain uplift was diverting south- and southeast-oriented flood flow eastward creating the southeast-oriented flood flow routes captured by headward erosion of the multiple northeast-oriented and parallel Republican River tributary valleys (seen in figure 2 and 3). At the time the northeast-oriented Republican River tributary valleys began to behead flood flow routes to what were then actively eroding Solomon, Saline, and Smoky Hill River valleys flood waters were flowing east to the figure 4 map in all of the major Kansas River tributary valleys. At that time the Republican, Solomon, Saline, and Smoky Hill River valley complex was for all practical purposes a giant east-oriented anastomosing channel complex. Approximately 140 topographic maps illustrated in the 17 Republican River drainage basin landform origins detailed essays provide much more evidence than the regional maps shown in this brief overview essay provide.

Introduction to Missouri River drainage basin research project essay series

  • This Republican River drainage basin landform origins overview essay and its related detailed essays is one of a series of overview essays and related detailed essays in the Missouri River drainage basin landform origins research project. The research project goal is to use topographic map evidence to describe the evolution of drainage divides separating each significant present day Missouri River tributary valley and also to describe the evolution of drainage divides separating the present day Missouri River drainage basin from adjacent drainage basins. Each overview essay and its related detailed essays pertains to a specific Missouri River tributary, tributary to a present day Missouri River tributary, or a present day Missouri River valley segment. Each detailed essay illustrates and discusses topographic map evidence describing the evolution of a secondary drainage divide separating specified Missouri River tributary valleys. The Missouri River drainage basin research project series is being developed one essay at a time and overview essays are added as significant tributaries are reached.
  • The Missouri River drainage basin research project introduces a new regional geomorphology paradigm. An essay titled “About the ‘thick ice sheet that melted fast’ geomorphology paradigm” provides a brief introduction to the new paradigm and how the new paradigm emerged. Detailed evidence illustrated and discussed in the Missouri River drainage basin research project builds a strong case for (1) deep glacial erosion of the North American continent by a thick North American ice sheet that created and occupied a deep “hole”, (2) rapid melting of that thick North American ice sheet, (3) immense floods of south-oriented melt water, (4) headward erosion of deep east, northeast and north-oriented valley systems to capture the south-oriented melt water floods and to divert the melt water further and further northeast into space the ice sheet had once occupied, (5) deep flood water erosion of the North American continent surface, and (6) crustal warping that resulted in uplift of mountain ranges as flood waters were deeply eroding what are now high mountain regions. This interpretation is fundamentally different from most previous interpretations. The Republican River drainage basin evidence in this overview essay and its related detailed essays is presented for review and discussion by qualified research geomorphologists and geologists.

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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