A geomorphic history based on topographic map evidence

The Moreau River-Belle Fourche River drainage divide area discussed here is located in western South Dakota, USA. Although detailed topographic maps of the Moreau River-Belle Fourche River drainage divide area have been available for more than fifty years detailed map evidence has not previously been used to interpret the region’s geomorphic history. The interpretation provided here is based entirely on topographic map evidence. The Moreau River-Belle Fourche River drainage divide area is interpreted to have been eroded during immense southeast-oriented flood events, the first of which flowed on a topographic surface at least as high as the highest points in the present-day drainage divide area. Flood erosion across the Moreau River-Belle Fourche River drainage divide ended when headward erosion of the Moreau River valley captured all southeast-oriented flood flow, although flood waters from west of the Black Hills probably continued to erode the Belle Fourche River valley.

Preface:

The following interpretation of detailed topographic map evidence is provided as evidence in the Missouri River drainage basin landform origins research project, which is compiling similar evidence for all major drainage divides contained within the Missouri River drainage basin and for all major drainage divides with and within certain adjacent drainage basins. The research project is interpreting evidence in the context of a previously unexplored geomorphology paradigm, which is briefly described in the introduction below. Project essays are listed on the sidebar category list under their appropriate Missouri River tributary drainage basin, Missouri River segment drainage basin (by state), and/or state in which the Missouri River drainage basin is located.

Introduction:

• The purpose of this essay is to use topographic map interpretation methods to explore South Dakota Moreau River-Belle Fourche River drainage divide area landform origins. 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 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 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 similar essays is a thick North American ice sheet, comparable in thickness to the present day Antarctic ice sheet, occupied approximately the North American region usually recognized to have been glaciated and through its weight and erosive actions created a “deep” North American “hole”, 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 Moreau River-Belle Fourche River drainage divide area landform evidence will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm.

Moreau River-Belle Fourche River drainage divide area general location map

Figure 1: Moreau River-Belle Fourche River drainage divide area general 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 general location map for the Moreau River-Belle Fourche River drainage divide area. The Belle Fourche River begins in Wyoming west of the Black Hills and flows northeast almost to Alzada, Montana and then turns southeast to flow into South Dakota and flows along the Black Hills northeast flank before turning northeast to join the northeast-oriented Cheyenne River. The South Fork Moreau River begins along the South Dakota west edge near the Montana border and flows southeast before turning northeast to join the southeast-oriented North Fork Moreau River and to form the east-northeast oriented Moreau River. West of the northeast-oriented Belle Fourche River segment and the southeast-oriented Moreau River headwaters is the northeast-oriented Little Missouri River. The Moreau River-Belle Fourche River drainage divide area addressed by this essay is located between of the South Fork Moreau River and southeast-oriented Belle Fourche River segment including drainage divides associated with southeast-oriented Elm Creek, which flows to the Belle Fourche River (and will include evidence related to Sulphur Creek-Elm Creek drainage divide where Sulphur Creek flows to Cherry Creek and the Cheyenne River). The North Fork-South Fork Moreau River drainage divide area essay, Little Missouri River-Belle Fourche River drainage divide area essay, and Cherry Creek-Cheyenne River drainage divide area essay address nearby drainage divide areas and can be found under appropriate river names on the sidebar category list. Evidence presented in this essay is interpreted in the context of an immense southeast-oriented flood that was systematically captured by headward erosion of deep northeast-oriented valleys and diverted east and northeast of the present day Missouri River (not shown in figure 1). Detailed evidence presented here will show the southeast and northeast-oriented Belle Fourche River valley eroded headward to capture the southeast-oriented flood flow and subsequently the east-northeast-oriented Moreau River eroded west-southwest to capture southeast-oriented flood water moving to the newly eroded Belle Fourche River valley and to create the Moreau River-Belle Fourche River drainage divide.

Moreau River-Belle Fourche River drainage divide area detailed location map

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

Figure 2 provides a detailed location map for the Moreau River-Belle Fourche River drainage divide area addressed here. The southeast oriented Belle Fourche River flows just to the southwest of the highway between Bentonite Spur, Wyoming and Belle Fourche, South Dakota and then flows to Fruitdale and Nisland before turning southeast to flow to Vale and Volunteer and finally turning east and east-northeast to join the Cheyenne River in the figure 2 southeast corner. Note how nearly all Belle Fourche River tributaries from the north are southeast oriented. Tributaries important to the discussion here, among others, include North Indian Creek and Indian Creek, Willow Creek, and Elm Creek and its tributary Soft Water Creek. The South Fork Moreau River flows southeast in the figure 2 north center and then turns northeast to join the east-northeast-oriented Moreau River in the figure 2 northeast corner. South Fork Moreau River tributaries important here include southeast and northeast-oriented Battle Creek, just west of Castle Rock Butte and southeast and northeast-oriented Antelope Creek, which is a tributary to Battle Creek. Also discussed in this essay is South Sulphur Creek, which flows to Sulphur Creek (figure 2 east center) and then to Cherry Creek and the Cheyenne River. The predominance of southeast-oriented tributaries to the Belle Fourche River and in the Moreau River headwaters area is evidence the Belle Fourche River valley was eroded headward to capture multiple southeast-oriented flood flow routes and to divert the flood waters to the northeast-oriented Cheyenne River valley and that subsequently the east-northeast-oriented Moreau River valley eroded headward to behead the southeast-oriented flood flow routes to the newly eroded Belle Fourche River valley and to divert the flood water further to the north and east. Evidence presented in this and adjacent area essay is not adequate to determine the flood water source, although by using numerous Missouri River drainage basin landform origins research project essays published on this website it is possible to trace flood waters headward to southern Alberta and a North American ice sheet location. Rapid melting of a thick North American ice sheet would be a logical flood water source. Nor is evidence in this and adjacent area essays adequate to determine why flood waters were being progressively captured and diverted further and further to the northeast, although the opening up of space by a rapidly melting thick North American ice sheet, which had created a deep “hole,” would explain the captures.

Little Missouri River-Moreau River-Belle Fourche River drainage divide area

Figure 3: Little Missouri River-Moreau River-Belle Fourche River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 3 illustrates the northwest end of the Moreau River-Belle Fourche River drainage divide where the north-oriented Little Missouri River drainage basin truncates it. The discussion here proceeds southeast along the Moreau River-Belle Fourche River drainage divide with some brief looks at locations where major tributaries join the Belle Fourche River. Northwest-oriented streams along the figure 3 west edge flow to the northeast-oriented Little Missouri River. North Indian Creek and Crooked Creek (which is a North Indian Creek tributary and is located in figure 3 south center) flow to the Belle Fourche River. Southeast-oriented drainage in the figure 3 southeast corner flows to southeast and northeast-oriented Battle Creek, which flows to the South Fork Moreau River. The unnamed northeast-oriented stream west of Gustave Butte is the South Fork Moreau River. Note how the northeast-oriented South Fork Moreau River valley eroded southwest to capture multiple southeast-oriented flood flow routes and note headwaters of the beheaded southeast-oriented flood flow routes southeast of the northeast-oriented South Fork Moreau River valley segment, which are today southeast-oriented tributaries to the South Fork Moreau River. Events recorded by this figure 3 evidence begin with multiple southeast-oriented flood flow routes moving across a topographic surface at least as high as the highest figure 3 elevations today in what was probably an immense southeast-oriented anastomosing channel complex. Following headward erosion of what was then the deep Belle Fourche River valley, headward erosion of deep southeast-oriented tributary valleys eroded northwest from the newly eroded Belle Fourche River valley north wall along the southeast-oriented flood flow routes. Headward erosion of northeast-oriented tributaries to what was then the actively eroding and deep east-northeast-oriented Moreau River valley then began to capture southeast-oriented flood flow routes to the newly eroded Belle Fourche River valley (and also to capture flood flow routes the Moreau River valley had already captured as seen here in figure 3). Subsequently the deep northeast-oriented Little Missouri River valley eroded headward to capture all southeast-oriented flood water moving to the newly eroded Moreau and Belle Fourche River valleys and to create the Little Missouri River- Moreau River and the Little Missouri-Belle Fourche River drainage divides.

Moreau River-Belle Fourche River drainage divide near Battle Creek Butte

Figure 4: Moreau River-Belle Fourche River drainage divide near Battle Creek Butte. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 4 illustrates the Moreau River-Belle Fourche River drainage divide southeast of the figure 3 map area and includes overlap areas. Southeast-oriented Antelope Creek in the figure 4 southeast corner turns northeast (see figures 2 and 5) and flows to southeast-oriented Battle Creek, which turns northeast and flows to the southeast-oriented South Fork Moreau River, which turns northeast to flow to east-northeast-oriented Moreau River valley (see figure 2). Today all southeast-oriented drainage at the figure 4 east edge flows to the east-northeast-oriented Moreau River, however these were originally southeast-oriented flood flow routes to the newly eroded Belle Fourche River valley and were captured by headward erosion of northeast-oriented tributary valleys from the newly eroded east-northeast-oriented Moreau River valley. Porcupine Creek flows southeast and south to join North Indian Creek and Indian Creek, which flows to the Belle Fourche River. All south-oriented drainage routes west of Porcupine Creek flow to the Belle Fourche River and were eroded by southeast-oriented flood flow routes that were captured by what was then the newly eroded Belle Fourche River. Headward erosion of the Porcupine Creek valley beheaded a southeast-oriented flood flow route to what is now the beheaded Antelope Creek valley. That same southeast-oriented flood flow route was captured further to the northwest by headward erosion of the North Indian Creek and Crooked Creek valleys to behead the Porcupine Creek valley. This process of ever-changing flood flow routes or channels is characteristic of what happens in large flood formed anastomosing channel complexes, which suggests the newly eroded east-northeast-oriented Moreau River valley was capturing an ever-changing southeast-oriented anastomosing channel complex and in the process was redirecting that channel complex to flow east-northeast.

Moreau River-Belle Fourche River drainage divide near Two Top Butte

Figure 5: Moreau River-Belle Fourche River drainage divide near Two Top Butte. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 5 illustrates the Moreau River-Belle Fourche River drainage divide area southeast of the figure 4 map area and includes overlap areas. Southeast-oriented Willow Creek flows to the Belle Fourche River (see figure 6 below). Antelope Creek flows southeast and turns northeast to flow to what will be northeast-oriented Battle Creek and the northeast-oriented South Fork Moreau River (see figure 2). The Antelope Creek elbow of capture illustrates how headward erosion of northeast-oriented tributary valleys to the newly eroded east-northeast-oriented Moreau River valley captured southeast-oriented flood flow routes to what was then the newly eroded Belle Fourche River valley. Note how through valleys link the southeast-oriented Antelope Creek valley with headwaters of southeast-oriented Willow Creek.Those through valleys are evidence flood water once flowed southeast from the Antelope Creek valley to the Willow Creek valley and were captured by headward erosion of the northeast-oriented Antelope Creek valley. Note south-southeast-oriented Horse Creek flowing from the Willow Creek headwaters source area (it will be seen again in figure 6). Events recorded by figure 5 evidence begin with flood waters flowing across a topographic at least as high as the Two Top Buttes top. Following headward erosion of the deep Belle Fourche River valley to the south deep southeast-oriented valleys, such as the Willow Creek valley eroded headward from newly eroded Belle Fourche River north valley wall. About the same time headward erosion of deep northeast-oriented valleys from the actively eroding east-northeast-oriented Moreau River valley eroded into the region and began to capture southeast-oriented flood flow routes such as the flow route to the southeast-oriented Willow Creek valley. Flood flow routes continued to be progressively captured until headward erosion of the northeast-oriented Little Missouri River valley captured all southeast-oriented flood flow and the figure 5 region has changed little since.

Belle Fourche River and Willow Creek near Newell

Figure 6: Belle Fourche River and Willow Creek near Newell. United States Geological Survey map digitally presented using National Geographic Society TOPO software. 

Figure 6 illustrates where south-southeast oriented Willow Creek joins the Belle Fourche River near Newell, South Dakota and does not include overlap areas with other figures used here. The southeast-oriented Belle Fourche River flows along the figure 6 south edge. Willow Creek flows south-southeast from the figure 6 north center to the Belle Fourche River. Southeast-oriented Dry Creek flows from the figure 6 northwest corner to the Belle Fourche River and southeast-oriented Horse Creek flows from the figure 6 west center to the Belle Fourche River. Horse Creek headwaters were seen in figure 5 and began in the same general area as the Willow Creek headwaters. A major Horse Creek tributary is Indian Creek and a major Indian Creek tributary is North Indian Creek, both of which were seen in figures 3 and 4. Irrigation canals from the Belle Fourche Reservoir west of the figure 6 map area have altered the figure 6 drainage pattern somewhat, but the original pattern of southeast and south-oriented drainage from the Moreau River-Belle Fourche River drainage divide area to the Belle Fourche River valley should still be evident. The Belle Fourche River valley was initially eroded headward into a topographic surface at least as high as the tops of the Two Top Buttes in figure 5 and flood waters lowered the regional topographic surface to the level seen today prior to being captured by headward erosion of the northeast-oriented Little Missouri River valley. No remnants of what must have been a significant Belle Fourche River valley north wall remain today.

Moreau River-Belle Fourche River drainage divide near Castle Rock Butte