Abstract:

This essay uses topographic map evidence to interpret landform origins for the West Nodaway River-Platte River drainage divide area located in Page, Taylor, Ringgold, and Adams Counties, Iowa. The West Nodaway River flows in a south direction across eastern Page County to join the southwest and south oriented East Nodaway River and to form the south oriented Nodaway River, which is a Missouri River tributary. The Platte River is located east of the Nodaway River drainage basin and flows in a south and south-southwest direction in western Ringgold County and then flows in a south direction to eventually join the Missouri River (south of the study region). Between the West Nodaway River and the Platte River are several south, southwest, and south-southwest oriented East Nodaway River tributaries; south, southwest, and southwest oriented One Hundred and Two River headwaters; and south, southwest, and south oriented Honey Creek headwaters; where the south oriented One Hundred and Two River and Honey Creek join the Platte River in Missouri (again south of the study area). The Nodaway River, One Hundred and Two River, Platte River, and their major tributaries have elongate, roughly parallel, and relatively narrow drainage basins. The south and southwest oriented trunk streams and tributaries often have northwest and north oriented (barbed) tributaries from the south and east and south- and southeast oriented tributaries from the north and west. While the region has low relief numerous shallow through valleys cross all major drainage divides between larger south and southwest oriented trunk stream valleys and link north and northwest-oriented tributary valleys with south and southeast oriented tributary valleys. This evidence is interpreted to mean immense southeast and south-oriented floods flowed across the entire region while the deep trunk stream valleys eroded headward into the region from what must have been a newly eroded Missouri River valley. Flood waters are interpreted to have been derived from a rapidly melting thick North American ice sheet located north of the study region. The major southwest and south-oriented trunk stream valleys appear to have been eroded at approximately the same time, although deep valleys in the east eroded headward slightly in advance of deep valleys in the west.

Preface:

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore the West Nodaway River-Platte River drainage divide area landform origins in Page, Taylor, Ringgold, and Adams Counties, Iowa, 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 essays in the Missouri River drainage basin landform origins research project 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 immense melt water 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 West Nodaway River-Platte River drainage divide area landform evidence in Page, Taylor, Ringgold, and Adams Counties, Iowa will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm (see menu at top of page for paradigm related essay). This essay is included in the Missouri River drainage basin landform origins research project essay collection.

West Nodaway River-Platte River drainage divide area location map

Figure 1: West Nodaway River-Platte 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 regional location map for the West Nodaway River-Platte River drainage divide area in Page, Taylor, Ringgold, and Adams Counties, Iowa. Iowa is the state located in the figure 1 north half and Missouri is the state south of Missouri. The south-oriented Mississippi River can be seen near the figure 1 east edge and eventually flows to the Gulf of Mexico. The Missouri River flows in a south-southeast direction from the figure 1 northwest corner to Kansas City located along the figure 1 south edge and then turns to flow in an east-northeast direction to Brunswick, Missouri where it turns again to flow in a southeast direction. South of the figure 1 map area the Missouri River flows in more of an east direction to join the south-oriented Mississippi River. The state west of the Missouri River in the figure 1 southwest quadrant is Kansas and the state north of Kansas is Nebraska. The East Nodaway River is labeled in figure 1 and originates in southwest Iowa north and east of Corning and flows in a southwest and south-southwest direction to join the West Nodaway River near the Iowa-Missouri state line. The Middle Nodaway River, which is a West Nodaway River tributary, begins north of Greenfield (near figure 1 north edge) and flows in a south-southwest direction to  join the south-oriented West Nodaway River near Villisca and then to flow near Clarinda to join the East Nodaway River near the Iowa-Missouri state line. From the state line the Nodaway River flows in a south direction to join the Missouri River. The Platte River begins near Creston in southern Iowa and flows in a south and south-southwest direction to Blockton near the Iowa-Missouri state line. From Blockton the Platte River flows in a south direction to where it is joined by the south-oriented One Hundred and Two River just east of St. Joseph, Missouri and then continues to flow in a south direction to join the Missouri River near Platte City (a short distance upstream from Kansas City). The south-oriented One Hundred and Two River is located between the south-oriented Nodaway River and the south-oriented Platte River and also begins in southern Iowa. The West Nodaway River-Platte River drainage divide area discussed here is located in Page, Taylor, Ringgold, and Adams Counties, Iowa and is located between the West Nodaway River and the Platte River north of Iowa-Missouri state line and south of the railroad line between Villisca and Creston.

• Note how the Nodaway River, One Hundred and Two River, and Platte River are three of several south-oriented rivers originating in southern Iowa and flowing to the Missouri River. With the exception of the Grand River, which has a significant southeast oriented segment, almost all Missouri River tributaries in northern Missouri and southern Iowa are oriented in a south direction. Contrast the orientations of these south-oriented Missouri River tributaries with the southeast orientations of Mississippi River tributaries in the figure 1 east half. The Des Moines River is the largest of those Mississippi River tributaries and has some northeast-oriented tributaries in the figure 1 north center area. The difference between the Missouri and Mississippi River tributary orientations is significant and is related to how the different valleys systems were eroded. Both the Mississippi River valley and the Missouri River valley and their tributary valleys were eroded during immense south-oriented floods as a thick North American ice sheet located north of the figure 1 map area rapidly melted. Prior to headward erosion of the Mississippi and Missouri River valleys and their tributary valleys huge south-oriented melt water floods overwhelmed whatever drainage routes existed and flowed in a south direction across the entire figure 1 map area. Headward erosion of the Mississippi River valley permitted southeast and east-oriented tributary valleys to erode headward in sequence (from south to north) across the south-oriented flood flow and to capture the flood waters so as to divert flood flow to the newly eroded and actively eroding Mississippi River valley. South of the figure 1 map area headward erosion of the southeast-oriented Arkansas River valley captured south-oriented flood flow before headward erosion of the southeast-oriented White River (of Arkansas) valley eroded headward to behead flood flow routes to the newly eroded Arkansas River valley. Headward erosion of the Missouri River valley across the state of Missouri next beheaded south-oriented flood flow routes to the newly eroded White River valley. Continuing the sequence, headward erosion of the Des Moines River valley and its northeast-oriented tributary valleys beheaded south-oriented flood flow routes to actively eroding south-oriented Missouri River tributary valleys.

Detailed West Nodaway River-Platte River drainage divide area location map

Figure 2: Detailed West Nodaway River-Platte River drainage divide area 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 West Nodaway River-Platte River drainage divide area in Page, Taylor, Ringgold, and Adams Counties, Iowa. The Missouri River flows in a south-southeast direction from the figure 2 northwest corner to the south edge. The west to east oriented Iowa-Missouri state line is located near the figure 2 south edge and extends from the Missouri River to the figure 2 east edge. All figure 2 map areas north of that state line and east of the Missouri River are located in the state of Iowa. County names and boundaries are shown. Page, Taylor, and Ringgold Counties are located just north of the state line and Adams County is located north of Taylor County. The West Nodaway River originates in southeast Cass County and flows in a southwest direction to the Montgomery County line and then turns to flow in a south direction across eastern Montgomery and Page Counties to join the East Nodaway River in southeast Page County. The Nodaway River then flows in a south direction into northwest Missouri to reach the southeast oriented Missouri River. A major West Nodaway River tributary is the Middle Nodaway River, which originates in Adair County and which flows in a southwest direction across northwest Adams County to join the West Nodaway River near the Montgomery-Page County line. The East Nodaway River has headwaters in southern Adair County and northeast Adams County and flows in a southwest and south-southwest direction to join the West Nodaway River in southeast Page County. East of the East Nodaway River is the south-oriented West One Hundred and Two River which begins in southern Adams County and which flows in a south direction across western Taylor County where it is joined by several southwest and south-southwest oriented tributaries, including the southwest oriented East Fork (just south of the state line) to form the south-oriented One Hundred and Two River. East of the south-oriented One Hundred and Two River drainage basin is the south-oriented Platte River drainage basin. The Platte River originates near Creston in western Union County and flows in a south direction to southwest Ringgold County where it turns to flow in a southwest direction across the Taylor County southeast corner and into Missouri. Once in Missouri the Platte River flows in a south direction and is joined by the One Hundred and Two River near St. Joseph (see figure 1) before continuing to flow in a south direction to eventually join the Missouri River. Honey Creek is a significant southwest and south-oriented Platte River tributary located in the Taylor County southeast quadrant. Southeast-oriented drainage routes in the figure 2 northeast quadrant are headwaters of the south-southeast oriented Thomson River, which flows to the southeast and south-oriented Grand River, which is a Missouri River tributary.

West Nodaway River-West Fork One Hundred and Two River drainage divide area

Figure 3: West Nodaway River-West Fork One Hundred and Two River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 3 provides a reduced size topographic map of the West Nodaway River-West Fork One Hundred and Two River drainage divide area. Bedford, Iowa is the town in the figure 3 southeast corner and the southwest-oriented East Fork One Hundred and Two River flows through Bedford in the southeast corner. Clarinda is the town located just south of the figure 3 west center edge area and is located on the west bank of the south oriented West Nodaway River valley. The south-southwest and south oriented river in the figure 3 west half, but east of the West Nodaway River, is the East Nodaway River, which joins the West Nodaway River a short distance south of the figure 3 map area. Note how the south-oriented West and East Nodaway Rivers both have southeast and northwest oriented tributaries. The northwest-oriented barbed tributary valleys were eroded by reversals of flood flow on northwest and north ends of beheaded south and southeast oriented flood flow channels. The south-southwest and south oriented river located just east of the figure 3 center is the West Fork One Hundred and Two River. New Market is the town located on East Nodaway River-West Fork One Hundred and Two River drainage divide just south of the figure 3 center. The south-southwest oriented tributary joining the West Fork One Hundred and Two River east of New Market is the West Branch One Hundred and Two River and its southwest-oriented tributary flowing from the figure 3 northeast corner is the Middle Branch One Hundred and Two River. Gravity is the town located in the figure 3 east center area and the southwest and south-southwest oriented stream flowing through Gravity is the Middle Fork One Hundred and Two River. Note how the southwest, south-southwest, and south oriented One Hundred and Two River tributaries also have southeast and northwest-oriented tributaries. Further note how the figure 3 drainage routes are elongate, closely spaced, and roughly parallel with each other. The One Hundred and Two River tributaries converge just south of the figure 3 map area to form the south-oriented One Hundred and Two River, which then flows adjacent to and parallel to the Nodaway River. The Nodaway River-One Hundred and Two River drainage divide area in northwest Missouri is described in the Nodaway River-One Hundred and Two River drainage divide area landform origins in Andrew and Nodaway Counties, Missouri essay (see list under MO Missouri River on sidebar category list).

• The closely spaced, elongate, and roughly parallel valleys seen in figure 3 provide evidence of a former south-oriented anastomosing channel complex. Anastomosing channel complexes are formed when massive floods flow moves across a region and erodes ever-changing diverging and converging channels into the underlying surface. Evidence for convergence of figure 3 valleys can be seen where the roughly parallel Nodaway River tributary valleys join to form the south-oriented Nodaway River valley and the roughly parallel One Hundred and Two River tributary valleys join to form the south-oriented One Hundred and Two River. South of the study region the roughly parallel Nodaway River-Missouri River valley eventually converges with the south-oriented One Hundred and Two River-Platte River valley. The divergence of valleys is somewhat more subtle, but can be seen on figure 3 and is even better seen on more detailed topographic maps. Figures 4 and 5 below provide detailed topographic maps of two figure 3 regions, but before looking at the detailed maps look at the bigger picture view in figure 3. First in the figure 3 north center area note a north-northwest oriented East Nodaway River tributary and how it is linked by a through valley with a south-southeast oriented West Fork One Hundred and Two River tributary valley. The through valley provides evidence of a former south-southeast oriented flood flow channel which diverged from the south-oriented channel now used by the East Nodaway River and which converged with the south-oriented channel now used by the West Fork One Hundred and Two River. The second region to look at to see in the big picture view is west and south of the town of New Market. The south and south-southwest oriented stream originating just south of New Market is Buchanan Creek, which south of the figure 3 map area converges with the Nodaway River (south of the West and East Nodaway River confluence). Note how the south-oriented Buchanan Creek valley is linked by a through valley with a northwest, southwest, and west oriented East Nodaway River tributary valley. The through valley provides evidence of a somewhat more complicated diverging and converging south-oriented flood flow channel. The complication arises because the south-oriented Buchanan Creek flood flow initially diverged from what is now the East Nodaway River valley channel further to the north and then was captured by headward erosion of a deep west-oriented East Nodaway River tributary valley.

Detailed topographic map of West Nodaway River-West Fork One Hundred and Two River drainage divide area.

Figure 4: Detailed topographic map of West Nodaway River-West Fork One Hundred and Two River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 4 provides a detailed topographic map of the through valley crossing the East Nodaway River-West Fork One Hundred and Two River drainage divide area seen in less detail in the figure 3 north center area. The south-southwest East Nodaway River flows in the large valley extending from the figure 4 north center edge area to the figure 4 south edge (west half). The south-southwest oriented West Fork One Hundred and Two River flows in a somewhat smaller valley from the figure 4 east edge (north half) to the figure 4 south edge (east half). Note in section 9 the north-south oriented through valley linking a north-northwest oriented East Nodaway River tributary valley with a south-southeast oriented West Fork One Hundred and Two River tributary valley. The map contour interval is ten feet and the through valley floor elevation is between 1170 and 1180 feet. Elevations on both sides of the through valley rise to more than 1230 feet. While not deep the through valley is a water eroded feature and provides evidence of a former south-southest oriented flood flow channel across what is now the East Nodaway-West Fork One Hundred and Two River drainage divide. The through valley floor elevation also provides evidence the deep East Nodaway River valley seen today did not exist at the time flood waters were flowing across the present day drainage divide. Study of the figure 4 map area reveals many other shallower through valleys linking northwest and west oriented East Nodaway River tributary valleys with the south-southeast oriented West Fork One Hundred and Two River tributary valley. These multiple southeast and south-southeast oriented through valleys provide evidence of multiple flood flow channels which once crossed the region, which suggests headward erosion of the south-oriented West Fork One Hundred and Two River valley captured flood waters flowing in a south-southeast or southeast oriented anastomosing channel complex and subsequently headward erosion of the south-oriented East Nodaway River valley beheaded those flood flow channels with flood waters on northwest ends of beheaded flood flow channels reversing flow direction to erode the northwest and west oriented East Nodaway tributary valleys. Also note in figure 4 the large incised meanders carved into the East Nodaway River valley.

Detailed topographic map of East Nodaway River-Buchanan Creek drainage divide area

Figure 5: Detailed topographic map of East Nodaway River-Buchanan Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 5 provides a detailed topographic map of the East Nodaway River-Buchanan Creek drainage divide area west and south of New Market which was seen in less detail in figure 3 above. New Market is located in the figure 5 northeast corner area. The south-southwest oriented East Nodaway River flows across the figure 5 northwest corner. Note the southwest-northwest oriented stream in section 31 which then flows in a southwest and west direction across sections 36 and 35 to join the East Nodaway River in section 34. South of the section 31 southwest-northwest elbow of capture is the south-oriented Buchanan Creek valley extending from the abbreviated section 1 across section 12 and 13 to the figure 5 south edge. Note how the south-oriented Buchanan Creek valley is linked by a shallow through valley with the southwest-northwest oriented valley in section 31. The map contour interval is ten feet and the through valley natural floor elevation appears to have been between 1160 and 1170 feet before road construction. Elevations to the east rise to more than 1230 feet while elevations to the west are not as high they do rise to at least 1200 feet. The through valley is evidence south-oriented flood water once flowed to the Buchanan Creek valley along what are today the section 31 southwest- and northwest-oriented valley alignments and converged in section 31 to flow along what is today the south-oriented Buchanan Creek alignment. Southeast-oriented flood flow on what is to today the northwest-oriented Section 31 valley alignment was beheaded and reversed by headward erosion of the deep west and southwest oriented East Nodaway River tributary valley in sections 35 and 36. Note how that tributary valley has multiple north-oriented tributary valleys and how those north-oriented tributary valleys are linked by shallow through valleys with south-oriented tributary valleys (the southwest-oriented drainage routes in sections 10, 11, and 15 flow to the East Nodaway River). Many of these shallow through valleys are defined by only one or two contour lines on each side, but again they exist and provide evidence of former flood flow channels. The evidence suggests flood waters diverged from a major south-oriented flood flow channel on the present day East Nodaway River alignment (north of the figure 5 map area) and were then captured by headward erosion of the deep East Nodaway River valley and its deep southwest- and west-oriented tributary valley in sections 35 and 36. Flood waters on north ends of beheaded flood flow channels then reversed flow direction to erode the north-oriented tributary valleys seen today.

East Fork One Hundred and Two River-Platte River drainage divide area

Figure 6: East Fork One Hundred and Two River-Platte River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 6 provides a topographic map of the East Fork One Hundred and Two River-Platte River drainage divide area south and east of the figure 3 map area. Bedford, Iowa is the town located near the figure 6 northwest corner and is located on the northwest banks of the south-southwest oriented East Nodaway River. Note the west to east oriented county line located near the figure 6 south edge, which also is the Iowa-Missouri state line. Blockton is the smaller town located near the figure 6 east center edge and is located on the east bank of the southwest-oriented Platte River. Athelstan is the small town located along the Iowa-Missouri state line and on the Platte River north bank. The Platte Branch joins the Platte River near Athelstan and the figure 6 south edge. Honey Creek is the south-southwest stream flowing through the word “CLAYTON” near the north edge and then turning to flow in a south direction to the figure 6 south edge (west half). South of figure 6 the Platte River turns to flow in a south direction flows parallel to Honey Creek, which eventually joins the Platte River. The south- and southwest-oriented stream in the figure 6 southwest corner is Norvey Creek which flows to the One Hundred and Two River. Note how the south, south-southwest, and southwest oriented trunk streams have short southeast-oriented tributaries from the west and at least some short northwest-oriented tributaries from the east. These tributary valley orientations provide evidence the south, south-southwest, and southwest oriented valleys eroded headward across southeast-oriented flood flow, with the valleys in the east eroding headward first and the valleys in the west eroding headward last. A close look at the figure 6 drainage divides reveals some through valleys, although most through valleys in the figure 6 map area are not deep enough to be seen (the map contour interval is ten meters). Figure 7 below provides a detailed topographic map of the East Fork One Hundred and Two River-Honey Creek (Platte River) drainage divide area near Bedford to illustrate the shallow through valleys crossing that drainage divide.

Detailed topographic map of East Fork One Hundred and Two River-Honey Creek drainage divide area

Figure 7: Detailed topographic map of East Fork One Hundred and Two River-Honey Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 7 provides a detailed topographic map of the East Fork One Hundred and Two River-Honey Creek (Platte River) drainage divide area north and east of Bedford and seen in less detail in figure 6. Bedford is located in the figure 7 southwest corner and the East Fork One Hundred and Two River flows in a southwest direction from the figure 7 north center edge to the southwest corner. Honey Creek flows from the figure 7 east edge (near northeast corner) in a southwest direction to the figure 7 south center edge. Note how the East Fork One Hundred and Two River has north and northwest oriented tributaries from the southeast in addition to south and southeast oriented tributaries from the northwest. The barbed tributaries provide evidence headward erosion of the deep southwest-oriented East Fork One Hundred and Two River valley beheaded multiple south and southeast oriented flood flow routes. Note also how Honey Creek tributaries from the northwest are generally oriented in a southeast direction and how tributaries from the southeast are oriented in northwest directions or have northwest-oriented tributaries. Follow the East Fork One Hundred and Two River-Honey Creek drainage divide in a southwest direction from the figure 7 northeast quadrant to the southwest quadrant and note the numerous shallow through valleys crossing that drainage divide. For example in the section 9 southeast quadrant (near the north edge) a shallow northwest-southeast oriented through valley links a northwest-oriented East Fork One Hundred and Two River tributary valley with a southeast-oriented Honey Creek tributary valley. The map contour interval is ten feet and the through valley floor elevation is between 1220 and 1230 feet. On either side elevations rise to more than 1260 feet. The through valley provides evidence of a southeast-oriented flood flow channel beheaded by East Fork One Hundred and Two River valley headward erosion. The northwest-oriented tributary valley was eroded by a reversal of flood flow on the northwest end of the beheaded flood flow channel. Continuing in a southwest direction along the drainage divide there are additional through valleys, although somewhat shallower. Each of these through valleys provides evidence of a southeast-oriented flood flow channel. Headward erosion of the southwest-oriented Honey Creek valley and subsequently the southwest-oriented East Fork One Hundred and Two River valley captured southeast-oriented flood flow moving across the figure 7 map area.

West Branch One Hundred and Two River-Platte River drainage divide area

Figure 8: West Branch One Hundred and Two River-Platte River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 8 provides a topographic map of the West Branch One Hundred and Two River-Platte River drainage divide area. Lenox is the town in the figure 8 north center area. Note the west to east Adams-Taylor County line north of Lenox. Clearfield is the town located in the figure 8 east center area. The north-south highway at Clearfield is located on the Taylor-Ringgold county line. The Platte River flows in a south direction near the figure 8 east edge. The southwest oriented stream flowing across the figure 8 northwest corner is the West Branch One Hundred and Two River. The southwest and west-southwest oriented stream originating near Lenox and flowing to the figure 8 west edge is the Middle Branch One Hundred and Two River. Gravity is the town located near the figure 8 southwest corner and the unlabeled stream flowing to the west edge near Gravity is the Middle Fork of the West Fork One Hundred and Two River. Merle Junction is the labeled railroad junction in the figure 8 south center area. The south-southwest and southwest oriented stream originating south of Lenox and flowing through Merle Junction to Conway and the figure 8 south edge (west half) is the East Fork One Hundred and Two River. Note the labeled southwest oriented East Fork tributaries in the figure 8 center area (Hog Branch and East Branch). The unlabeled southwest-oriented stream originating near Clearfield and flowing to the figure 8 south center edge is Honey Creek, which as mentioned in the figure 6 discussion flows eventually to the Platte River. The figure 8 map contour interval is ten meters and relief is low meaning it is difficult to see through valleys. However, orientations of tributary valleys, including barbed tributary valleys, to the larger south and southwest oriented trunk stream valleys suggest the deep south and southwest oriented valleys eroded headward across south and/or southeast oriented flood flow. The low relief surface seen in the figure 8 map area was probably formed by flood erosion (and/or deposition). Figure 9 below provides a more detailed topographic map of the Clearfield area to better illustrate drainage divides in that region. Gard Branch is a northeast, east-northeast, and east-southeast oriented Platte River tributary north of Clearfield. Note how headward erosion of the southwest-oriented East River valley would have beheaded southeast and south oriented flood flow routes to the Gard Branch valley. Turkey Creek is a south-southeast and southeast oriented Platte River tributary located south and east of Clearfield. Note how Gard Branch valley headward erosion would have beheaded south-oriented flood flow to the Turkey Creek valley.

Detailed topographic map of Gard Branch-Turkey Creek drainage divide area

Figure 9: Detailed topographic map of Gard Branch-Turkey Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 9 provides a detailed topographic map of the Gard Branch-Turkey Creek drainage divide area east of Clearfield and seen in less detail in figure 8 above. The south-oriented Platte River can be seen along the figure 9 east edge (north half). Clearfield is located in the figure 9 southwest quadrant and the south-oriented stream originating in section 1 just west of Clearfield is Honey Creek, which flows parallel to the Platte River for a significant distance before joining the Platte River. Turkey Creek is the south-oriented stream originating in section 6 just east of Clearfield. Note how the Turkey Creek valley is linked by shallow through valleys with a north-oriented Gard Branch tributary valley. The through valley floors have elevations of between 1240 and 1250 feet and the highest elevations on either side rise to somewhere between 1260 and 1270 feet, meaning the through valleys are shallow. However, the through valleys are deep enough to show up on the topographic map and provide evidence of south-oriented flood flow from the present day Gard Branch drainage basin to the south-oriented Turkey Creek valley. No through valley is visible linking the north-northeast oriented Gard Branch tributary valley in section 36 with the south-oriented Honey Creek valley, although the proximity of that section 1 drainage divide to the section 6 Gard Branch-Turkey Creek drainage divide and the lack of any barriers between the two strongly suggests south-oriented flood flow also moved into the Honey Creek valley as well. At the time south-oriented flood waters flowed across sections 1 and 6 to what were then actively eroding south-oriented Honey Creek and Turkey Creek valleys the deep Gard Branch valley did not exist, which implies the deep south-oriented Platte River valley was also eroding headward at the same time. As the deep south-oriented Platte River valley eroded headward it beheaded and reversed south-oriented flood flow routes, with the reversed flood flow eroding the northeast and east oriented tributary valleys seen in the figure 9 east half. Headward erosion of the deep Gard Branch valley then beheaded and reversed flood flow routes to the south-oriented Turkey Creek and Honey Creek valleys, with the reversed flood flow eroding the north and north-northeast oriented Gard Branch tributary valleys. Flood flow movements were probably much more complicated than I have described and future work will probably better interpret this region.

West Nodaway River-West Branch One Hundred and Two River drainage divide area

Figure 10: West Nodaway River-West Branch One Hundred and Two River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

• Figure 10 illustrates the West Nodaway River-West Branch One Hundred and Two River drainage divide area located north of the figure 3 map area and includes overlap areas with figure 3. The West Nodaway River flows in a south direction near the figure 10 west edge. The south-southwest oriented Middle Nodaway River joins the West Nodaway River just south of the town of Villisca near the figure 10 west center edge. The town located just north of the figure 10 northeast corner is Corning, Iowa. The East Nodaway River flows in a west-southwest direction from the figure 10 northeast corner to the town of Nodaway and then turns to flow in a south direction to the figure 10 south edge (just west of center). Note north and northwest oriented East Nodaway River tributaries and tributaries to southwest-oriented Long Branch, which is an East Nodaway River tributary. East and southeast of the East Nodaway River is the West Fork of the East Nodaway River, which flows from the figure 10 east edge (north half) in a southwest direction and then parallels the East Nodaway River by turning to flow in south direction before turning to flow in a south-southwest direction to the figure 10 south center edge. Note northwest-oriented West Fork tributaries in the figure 10 northeast quadrant. The Rose Branch is the southwest-oriented tributary joining the West Fork East Nodaway River near the Bycroft Landing Field in the figure 10 southeast quadrant. The West Branch One Hundred and Two River flows in a southwest direction across the figure 10 southeast corner. The north and northwest oriented (and barbed) tributary valleys seen in the figure 10 map area were eroded by reversals of south and southeast oriented flood flow routes beheaded by headward erosion of the deep south- and southwest-oriented valleys. Shallow through valleys can be seen crossing many of the drainage divides. Some of the easiest to see through valleys in the figure 10 map area are north and east of Villisca. For example a through valley near the railroad line crossing the Middle Nodaway River-East Nodaway River drainage divide just east of Villisca is defined by three ten-meter contour lines on each side and provides evidence of an east-southeast oriented channel linking the south-oriented Middle Nodaway River valley with the south-oriented East Nodaway River valley. Other through valleys are shallower, but provide evidence of south- and southeast oriented flood flow routes which once crossed all of the present day figure 10 drainage divides.

Additional information and sources of maps studied

This essay has provided only a sample of the detailed topographic map evidence supporting the flood erosion interpretation. Many additional illustrations could be provided. Readers are encouraged to look at mosaics of detailed topographic maps to see the abundance of available data. Maps used in this study were created and published by the United States Geologic Survey and can be obtained directly from the United States Geological Survey and/or from dealers offering United States Geological Survey maps. Hard copy maps can also be observed at United States Geological Survey map depositories which are located throughout the United States and elsewhere. Illustrations used here were created using National Geographic Society TOPO software and digital map data. TOPO software and map data can be obtained from the National Geographic Society and/or dealers offering National Geographic Society digital map data.