Gasconade River-Bourbeuse River drainage divide area landform origins in Osage, Gasconade, and Franklin Counties, Missouri, USA

Authors

Abstract:

Topographic map interpretation methods are used to determine landform origins for the Gasconade River-Bourbeuse River drainage divide area located in Osage, Gasconade, and Franklin Counties, Missouri. The Gasconade River is a north and north-northeast oriented tributary flowing to the east-northeast, southeast, and northeast oriented Missouri River, which flows to the south oriented Mississippi River as a barbed tributary. East of the Gasconade River are other north and northeast oriented Missouri River tributaries including Big Berger Creek, Boeuf Creek, and St Johns Creek. The Bourbeuse River is a north, northeast, and southeast-oriented tributary to the northeast, east and south-southeast oriented Meramec River, which flows directly to the Mississippi River. Dry Fork is a major north and east-northeast oriented Bourbeuse River tributary. Barbed tributaries, valley orientations (including incised meander valley orientations), alignments of opposing valleys on opposite sides of drainage divides, and through valleys eroded across present day drainage divides provide evidence landforms were eroded by massive south- and southeast-oriented floods as deep valleys eroded headward into the region. North-oriented valleys were eroded by reversals of flood flow on north ends of beheaded south-oriented flood flow routes. Flood waters were probably derived from a rapidly melting thick North American ice sheet located north of the study region.

Preface:

The following interpretation of detailed topographic map evidence is one of a series of essays describing similar evidence for all major drainage divides contained within the Missouri River drainage basin and for all major drainage divides with adjacent drainage basins. The research project is interpreting evidence in the context of a previously unexplored deep glacial erosion paradigm, which is fundamentally different from most commonly accepted North American glacial history interpretations. Project essays available at this site may be found by selecting desired Missouri River tributaries and/or states from this essay’s sidebar category list.

Introduction:

  • The purpose of this essay is to use topographic map interpretation methods to explore the Gasconade River-Bourbeuse River drainage divide area landform origins in Osage, Gasconade, and Franklin Counties, Missouri, 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 essay 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 Gasconade River-Bourbeuse River drainage divide area landform evidence in Osage, Gasconade, and Franklin Counties, Missouri 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.

Gasconade River-Bourbeuse River drainage divide area location map

Figure 1: Gasconade River-Bourbeuse 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 shows a location map for the Gasconade River-Bourbeuse River drainage divide area in Osage, Gasconade, and Franklin Counties, Missouri. Missouri is the state occupying most of the figure 1 map area with Illinois being the state located east of the south-southeast oriented Mississippi River. The Missouri River flows in an east-northeast direction from Kansas City near the figure 1 west edge (north half) to Brunswick. At Brunswick the Missouri River turns to flow in a southeast, south, east, and southeast direction to Jefferson City. From Jefferson City the Missouri River flows in an east-northeast, southeast, and northeast direction to join the south-oriented Mississippi River as a barbed tributary (just downstream from a Mississippi River northward jog to meet the south-oriented Illinois River). The Osage River is an east- and northeast-oriented tributary joining the Missouri River near Jefferson City and the Harry S. Truman Reservoir and the Lake of the Ozarks are large reservoirs flooding the Osage River valley. The Gasconade River is a north-northesat oriented Missouri River tributary located east of the Osage River and flows from the figure 1 south center edge to join the Missouri River near the town of Gasconade (between Jefferson City and Washington). The Bourbeuse River is located east of the Gasconade River and originates near Rolla. For most of its course the Bourbeuse River meanders in a northeast direction before turning to flow in a south direction to join the Meramec River. The Meramec River originates south of Rolla and flows in a north and northeast direction to join the Bourbeuse River and then flows in an east-northest direction to the south side of St Louis where it turns to flow in a south direction to join the south-oriented Mississippi River. The Gasconade River-Bourbeuse River drainage divide area in Osage, Gasconade, and Franklin Counties is located south of the Missouri River, east of the Gasconade River, and west and north of the Bourbeuse River. The region immediately to the east is described in the Missouri River-Meramec River drainage divide area in St Louis and Franklin Counties, Missouri essay. Other regional essays can be found listed under the MO Missouri River or Gasconade River on the sidebar category list.
  • All drainage routes in the figure 1 map area eventually reach the south-oriented Mississippi River, which flows to the Gulf of Mexico. The north-northeast oriented Gasconade River flows to the Missouri River, which in turn flows in an east, southeast and northeast direction to join the south-oriented Mississippi River. The Meramec River flows in north and northeast directions before turning to flow in a south direction to join the south-oriented Mississippi River. The Bourbeuse River flows in a northeast direction before turning to flow in a south direction to join the northeast-oriented Meramec River. These are just a few examples of evidence seen in figure 1 suggesting present day drainage routes provide evidence of earlier drainage patterns. Evidence illustrated and described in this essay and also in other Missouri River drainage basin landform origin research project essays suggests present day figure 1 drainage routes evolved as the deep Mississippi River valley and its deep tributary valleys eroded headward into the region to capture immense south-oriented floods. The south-oriented floods were derived from a rapidly melting thick North American ice sheet, which at the time figure 1 drainage routes were formed was located north of the figure 1 map area.
  • Initially the glacial melt water floods overwhelmed whatever drainage systems existed and flowed in a south direction across the entire figure 1 map area (and a much larger region) directly to the Gulf of Mexico. Headward erosion of the deep Mississippi River valley and its tributary valleys (in sequence from south to north) captured the immense south-oriented floods and flood waters were diverted to the actively eroding Mississippi River valley system. For example, south of the figure 1 map area in the state of Arkansas the southeast-oriented Arkansas River valley and its tributary valleys captured the south-oriented flood flow prior to headward erosion of the southeast-oriented White River valley and its tributary valleys. South-oriented tributary valleys then eroded headward from the newly eroded White River valley north wall. The Black River and the Current River (a Black River tributary in the Ozark Nat. Scenic Riverway near the south edge of the figure 1 southeast quadrant) are south-oriented White River tributaries. Headwaters of other south-oriented White River tributaries are located just south of the figure 1 south edge except in the figure 1 southwest corner area where south-oriented streams flow to the southeast-oriented Arkansas River. Headward erosion of the deep Meramec River valley (which involved a series of flood flow reversals on north ends of beheaded south-oriented flood flow routes) beheaded south-oriented flood flow routes to what were then the actively eroding south-oriented Black River and Current River valleys and their tributary valleys. Flood flow on north ends of the beheaded flood flow routes eroded the north oriented Meramec River headwaters and tributary valleys. Headward erosion of the deep Bourbeuse River valley next beheaded flood flow routes to the newly eroded Meramec River valley (west of where the Bourbeuse River joins it). Missouri River valley headward erosion (also triggered by a reversal of flood flow, but then proceeding headward across and along south-oriented flood flow routes) next beheaded flood flow to the newly eroded Meramec and Bourbeuse River valleys. Missouri River valley headward erosion west of the Meramec and Bourbeuse River valley heads next beheaded and reversed south-oriented flood flow routes that triggered headward of the deep north-northeast oriented Gasconade River valley and north- and northwest-oriented Gasconade River tributary valleys.

Detailed location map for Gasconade River-Bourbeuse River drainage divide area

Figure 2: Detailed location map for Gasconade River-Bourbeuse River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 2 provides a more detailed location map for the Gasconade River-Bourbeuse River drainage divide area in Osage, Gasconade, and Franklin Counties. County names and boundaries are shown. The southeast and northeast oriented Mississippi River jog can be seen in the figure 2 northeast corner and the Mississippi River flows in a south direction east of the figure 2 east edge. The Missouri River flows in a southeast direction from the figure 2 west edge (north half) to near Jefferson City where it is joined by the northeast oriented Osage River. From the Osage River confluence the Missouri River flows in a northeast direction to the Osage-Gasconade County line area where it flows in more of and east direction before turning to flow in a southeast direction as the border between Warren and Franklin Counties. Near the Warren County east border the Missouri River turns to flow in a northeast direction to join the south oriented Mississippi River east of the figure 2 east edge. The Gasconade River meanders in a north direction from the figure 2 south edge (west half) across central Maries County and southeastern Osage County and into the Gasconade County northeast corner to join the east-oriented Missouri River. Note how Gasconade River tributaries from the east are generally oriented in northwest directions. The northwest-oriented tributary valleys were eroded by reversals of flood flow along north ends of south oriented flood flow routes beheaded by headward erosion of the deep Gasconade River valley. Another notable feature are its large incised meanders, which were probably eroded by a process of valley headward erosion along and across both south oriented flood flow routes and reversed flood flow routes. Note how some meanders have south or southeast oriented segments and then turn to flow in north or northwest-oriented directions. The Bourbeuse River originates near the figure 2 south edge (near St James, west of center) and flows in a north and northeast direction into southern Gasconade County and then meanders in a northeast direction to Union in Franklin County. East of Union the Bourbeuse River turns to meander in a southeast direction to join the northeast-oriented Meramec River. Figure 2 shows only two named Bourbeuse River tributaries from the north and west. Red Oak Creek in southern Gasconade County first flows in a northeast direction and after joining a southerast-oriented tributary flows in a southeast direction to join the Bourbeuse River in western Franklin County. Dry Fork is a northeast- and east-oriented tributary originating in the Maries County northeast corner and joining the Bourbeuse River in southern Gasconade County. Note how Dry Fork headwaters are located north of northeast-oriented Little Bourbeuse Creek, which joins the Bourbeuse River just east of the Maries County eastern border. Also note how north-oriented Dry Fork headwaters are located just east of a north-oriented Gasconade River meander segment. As already noted Meramec River valley headward erosion occurred first and was followed by Bourbeuse River valley headward erosion which beheaded south and southeast oriented flood flow to the newly eroded Meramec River valley. Dry Fork valley headward erosion headward erosion next beheaded and reversed south and southeast oriented flood flow routes to what were then actively eroding Bourbeuse River headwaters valleys. Next Gasconade River valley headward erosion beheaded and reversed flood flow routes to the actively eroding Dry Fork valley.

Gasconade River-Dry Fork drainage divide area

Figure 3: Gasconade River-Dry Fork drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 3 uses a reduced size topographic map to illustrate the Gasconade River-Dry Fork drainage divide area near the Osage County, Maries County, and Gasconade County common corner (located in the figure 3 southeast quadrant). Belle is the town located in figure 3 south center area and Bland is the town near the Osage, Maries, and Gasconade County common corner. The Gasconade River flows in a northwest, north, east-southeast, and north direction in the figure 3 west half. A large incised and abandoned meander is seen in the figure 3 northwest corner. At one time north-oriented (and reversed) flood flow flowed in a northwest direction before turning to flow in a southeast direction. Today east-oriented Brush Creek drains the southern valley while southeast-oriented Swan Creek drains the northern valley. Note how many Gasconade River tributaries from the east are oriented in northwest directions and how at least some tributaries from the west are oriented in southeast directions. The southeast-oriented Gasconade River tributaries are barbed tributaries and provide evidence the north-oriented Gasconade River valley eroded headward across south and/or southeast-oriented flood flow. The west-northwest oriented stream near the north edge of the figure 3 northeast quadrant is Third Creek, which is a Gasconade River tributary. Note how Third Creek has several north-oriented tributaries with orientations ranging from north-northeast to northwest. The northwest-southeast orientation of many Gasconade River tributary valleys suggests headward erosion of the deep Gasconade River valley may have beheaded and reversed southeast-oriented flood flow routes, with the reversed flood flow eroding the northwest-oriented tributary valleys. The north-oriented Gasconade River valley segments were also eroded by reversals of flood flow on what at one time had been south oriented flood flow channels. Dry Fork flows in a north direction from the figure 3 south center edge (south of Belle) and then meanders across the figure 3 southeast quadrant to the southeast corner. East of the figure 3 southeast corner Dry Fork meanders in an east direction to join the northeast oriented Bourbeuse River, which is located south and east of the figure 3 southeast corner. Note how south and southeast oriented Dry Fork tributaries are much shorter than north-oriented Third Creek tributaries, yet how the tributary valleys are aligned with each other. The alignment of the north-oriented Third Creek tributaries with south-oriented Dry Fork tributaries suggests the valley orientations originated as south-oriented flood flow channels to the newly eroded Dry Fork valley. Headward erosion of the deep Missouri River valley north of the figure 3 map area soon thereafter (before significant south-oriented Dry Fork tributary valleys could be eroded) beheaded and reversed flood flow routes in the figure 3 region so as to cause headward erosion of the north-oriented Gasconade River valley segments and their tributary valleys (including the Third Creek valley and its north-oriented tributary valleys).

Detailed map of Gasconade River-Dry Fork drainage divide area

Figure 4: Detailed map of Gasconade River-Dry Fork 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 Gasconade River-Dry Fork drainage divide area south of Belle, which was seen in less detail in figure 3. The Gasconade River flows in a northeast and northwest direction from the figure 4 west edge (south half) to the figure 4 northwest corner. Mill Creek is a west-northwest oriented Gasconade River tributary in the figure 4 southwest quadrant and flows through the small town of Paydown. Note north and northwest-oriented Mill Creek tributaries. Hallaway Hollow is the west and west-southwest Gasconade River tributary located north of Mill Creek. The west-oriented stream near the figure 4 northwest quadrant north edge is a tributary to southwest and west-oriented Hatchee Creek, which joins the Gasconade River near the figure 4 northwest corner. Note the northwest-oriented through valley in section 35 linking the Hatchee Creek valley with the Hallaway Hollow valley. South of Halfway Hollow a higher level through valley can be seen in the west center area of section 1 linking a northwest-oriented Hallaway Hollow tributary with a south-southwest oriented Mill Creek tributary valley. Other shallower through valleys linking the Hallaway Hollow valley and Mill Creek valley can be seen in sections 2 and the section 1 southeast quadrant. These through valleys provide evidence of former south-oriented flood flow routes which were beheaded and reversed as headward erosion of the deep Gasconade River valley and its tributary valleys captured flood flow. Dry Fork drains in a north-northeast direction from the figure 4 south edge (east half) into section 32 and then turns to flow in an east direction to the figure 4 east edge (north half). Note how in the figure 4 northeast corner Dry Fork has two south-oriented tributaries. Also note the southwest and southeast-oriented Dry Fork tributary in section 31 and how that tributary is linked by a shallow through valley with a west- and northwest-oriented Hatchee Creek tributary valley. The map contour in the section 31 eastern two-thirds is 10 feet, although it changes to 20 feet in the section 31 western third. The through valley floor elevation is between 980 and 1000 feet. South of the through valley elevations rise to more than 1060 feet in the section 6 southwest quadrant. North of the through valley a spot elevation of 1042 feet can be seen near the road just north of the section 31 northeast corner. These elevations suggest the through valley is between 40-60 feet deep and may be two or more miles wide. The through valley formed as south-oriented flood waters flowed across what is now the Gasconade River-Dry Fork drainage divide. Remember the Gasconade River flows in a north direction to the Missouri River while Dry Fork flows to the northeast-oriented Bourbeuse River, which then flows to the northeast, east, and south-southeast oriented Meramec River.

Third Creek-Red Oak Creek drainage divide area

Figure 5: Third Creek-Red Oak Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 5 illustrates the Third Creek-Red Oak Creek drainage divide area located east and north of the figure 3 map area and includes overlap areas with figure 3. Belle is the town located in the figure 5 southwest corner. Bland is located near the Osage, Maries, and Gasconade  County corner east and slightly north from Belle. Owensville is the larger town located in the figure 5 east center. The Gasconade River flows in a north, east-southeast and northeast direction in the figure 5 northwest corner. Third Creek is the northwest, west, and northwest-oriented tributary originating north of Owensville and joining the Gasconade River at the elbow of capture where it turns from flowing in an east-southeast direction to flowing in a northeast direction. The east-southeast oriented Gasconade River valley segment was eroded headward along a captured southeast-oriented flood flow route while the northwest-oriented Third Creek valley was eroded by a reversal of flood flow on the northwest end of the beheaded flood flow route. Dry Fork meanders across the south edge of the figure 5 southeast quadrant and joins the meandering Bourbeuse River just south of the figure 5 southeast corner. A Bourbeuse River meander can be seen along the figure 5 east edge just north of the southeast corner. Red Oak Creek is a northeast-oriented stream in the figure 5 southeast quadrant located between Owensville and Dry Fork and just east of the figure 5 map area turns to flow in a southeast direction to join the Bourbeuse River. Note how Dry Fork tributaries are oriented in southeast directions and also how Red Oak Creek tributaries from the north are oriented in southeast directions. Further, note how southeast-oriented Red Oak Creek tributaries are aligned with northwest-oriented Third Creek tributaries and headwaters valleys. The figure 5 map contour interval is 20 meter and does not provide enough detail to show shallow through valleys. The Third Creek-Red Oak Creek drainage divide has a very gradual slope toward the northeast and appears to be a remnant of what was once a relatively smooth erosion and/or deposition surface. The smooth surface was probably developed as large volumes of south and/or southeast-oriented flood flow moved across the region. Flood waters were first captured by headward erosion of the deep Bourbeuse River valley south of the figure 5 map area. Next headward erosion of the deep Dry Fork valley captured the flood flow and beheaded flood flow routes to the newly eroded Bourbeuse River valley. Red Oak Creek valley headward erosion next beheaded flood flow routes to the newly eroded Dry Fork valley. Headward erosion of the deep Gasconade River next beheaded flood flow routes across the figure 5 map area causing a massive reversal of flood flow which eroded the northwest-oriented Third Creek valley and its tributary valleys.

Detailed map of Cedar Branch-Red Oak Creek drainage divide area

Figure 6: Detailed map of Cedar Branch-Red Oak Creek drainage divide area.United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 6 illustrates a detailed topographic map of the Cedar Branch-Red Oak Creek drainage divide area seen in less detail in figure 5. Cedar Branch is a northwest-oriented Third Creek tributary flowing across section 29, the section 30 northeast corner, and into section 19 where it makes a short westward jog before resuming its northwest direction west of the figure 6 map area. The north-northwest oriented stream originating in section 21 (just north of Owensville) is Third Creek, which north of the figure 6 map area turns to flow in a northwest direction to join the north-oriented Gasconade River. Red Oak Creek flows in a northeast direction across the figure 6 southeast corner and east of the figure 6 map area turns to flow in a southeast direction to join the northeast-oriented Bourbeuse River. The northeast-oriented stream following the railroad in the figure 6 northeast corner area is Long Branch, which joins southeast-oriented Soap Creek, which then joins Red Oak Creek where Red Oak Creek turns from flowing in a northeast direction to flowing in a southeast direction. The map contour interval west of Owensville is 20 feet and east of Owensville is 10 feet. Several shallow through valleys can be seen crossing the Gasconade River-Bourbeuse River drainage divide, which extends in a northeast direction from the figure 6 southwest corner region to the northeast corner region. A through valley in Owensville links the northwest-oriented Cedar Branch valley with the valley of an east-southeast oriented Red Oak Creek tributary. The through valley crosses the drainage divide right at the point where the map contour interval changes so a precise valley floor elevation is difficult to obtain. However, my best guess is the through valley floor elevation is in the 910-920 foot range. Northeast of the through valley elevations rise to more than 950 feet and southwest of the through valley elevations rise even higher. Another shallow through valley is seen in the section 21 southeast quadrant and links the northwest-oriented Third Creek valley with a southeast-oriented Red Oak Creek tributary valley. The through valley floor elevation is between 920 and 930 feet. Elevations rise to more than 940 feet to the northeast and even more to the southwest. Similar through valleys can be found crossing drainage divides elsewhere in the Owensville region. The through valleys provide evidence of what were once southeast-oriented flood flow channels to the actively eroding Red Oak Creek valley. At that time the deep Gasconade River valley did not exist and flood waters could freely move to and across the figure 6 map area. Headward erosion of the deep Gasconade River valley beheaded the southeast-oriented flood flow and triggered a massive flood flow reversal.

Gasconade River-Big Berger Creek drainage divide area

Figure 7: Gasconade River-Big Berger Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 7 uses a reduced size topographic map to illustrate the Gasconade River-Big Berger Creek drainage divide area north of the figure 5 map area (there is a gap between figure 5 and figure 7). Hermann is the town straddling the figure 7 north center edge and is located on the Missouri River valley south side. The Missouri River valley in figure 7 is oriented in an east and northeast direction west of Hermann and in a southeast direction in the figure 7 northeast corner. The Gasconade River meanders in a southeast and then north direction from the figure 7 southwest corner to Clausner Bend where it turns to flow in a southeast, northeast, north-northwest, and west direction before finally flowing in a northeast direction to join the Missouri River. The north-northwest and west oriented valley segments were eroded by reversals of flood flow on northwest ends of beheaded southeast-oriented flood flow routes while the southeast-oriented valley segment was eroded headward along a southeast-oriented flood flow route. Evidence for the southeast-oriented flood flow route can be seen in the form of northwest-southeast oriented through valleys directly to the southeast of the elbow of capture (where the southeast-oriented river segment turns to flow in a northeast and then north-northwest direction). The through valley links the northwest-oriented Puncheon Creek valley  and northwest-oriented Second Creek valley with the southeast-oriented Gasconade River valley segment. Puncheon Creek flows in a northwest and southwest direction to join northwest-oriented Second Creek, which joins the Gasconade River near the same elbow of capture. Gasconade is the town located where the Gasconade River flows into the Missouri River valley. The northwest-oriented tributary joining the Gasconade River south of Gasconade is First Creek. Like Third Creek to the south First Creek also has north- and northwest-oriented tributaries. Proceeding east from Gasconade the next named Missouri River tributary is northeast and north-oriented Cole Creek and the next named tributary is northwest and northeast oriented Frene Creek, which joins the Missouri River at Hermann. Note the northwest-southeast oriented through valley (used by a road) southwest of Hermann linking a northwest-oriented Cole Creek tributary valley with an east-oriented Frene Creek tributary valley. Continuing east from Frene Creek is northeast oriented Little Berger Creek, which enters the Missouri River valley near the Gasconade County-Franklin County line. Still further east is northeast oriented Big Berger Creek, which originates north and west of the word BOEUF and joins the Missouri River east the figure 7 map area. Fork Creek is a northeast, east-southeast, and northeast oriented Big Berger Creek tributary flowing through sections 1 and 6 just south of the figure 7 center area and will be seen again in figure 8. The northeast- and north-oriented Missouri River tributary valleys were eroded in sequence from east to west as Missouri River valley headward erosion beheaded and reversed south and southeast-oriented flood flow routes. Tributary valleys eroded by reversed flood flow often erode headward to the southwest so as to capture yet to be beheaded flood flow from west of the actively eroding Missouri River valley head. Study of the figure 7 map area reveals additional through valleys, although detailed topographic maps provide much better evidence of the former southeast-oriented flood flow routes.

Detailed map of First Creek-Fork Creek drainage divide area

Figure 8: Detailed map of First Creek-Fork Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 8 provides a detailed map of the First Creek-Fork Creek drainage divide area seen in less detail in figure 7 above. First Creek flows in a northwest and north direction from the figure 8 south edge (just west of center) and then flows in a southwest direction to the figure 8 west edge (south half). West of the figure 8 map area First Creek turns to flow in a north direction and can be seen again in the figure 8 northwest corner area. North and west of figure 8 First Creek turns to flow in a west-northwest direction to join the Gasconade River as seen in figure 7. The northwest-oriented stream flowing to the figure 8 northwest corner is a First Creek tributary and joins First Creek just north of the figure 8 northwest corner. Note how First Creek makes a north-south oriented U-turn along the section 29-28 boundary in the figure 8 northwest quadrant. The U-turn probably reflects headward erosion of the valley first along a south oriented flood route and then along the north end of a beheaded flood flow route, although the entire northwest-oriented valley system was probably eroded by reversed flood flow on the northwest ends of beheaded flood flow routes. Little Berger Creek is the northeast-oriented stream in the figure 8 northeast quadrant and roads are located along its drainage divides. The northeast and east-southeast oriented stream south of the Little Berger Creek drainage basin is Fork Creek, which flows to the figure 8 east edge (south half). East of the figure 8 map area Fork Creek turns to flow in a northeast direction to join northeast-oriented Big Berger Creek. As already noted the major roads are located on the drainage divides suggesting the drainage divides are relatively even ridge tops. But, a close look at the drainage divides reveals shallow through valleys linking the various the various Missouri River tributary valleys. For example, near the corner of sections 2, 3, 34, and 35 a shallow through valley links the northwest-oriented First Creek tributary valley with a southeast-oriented Fork Creek tributary valley. The map contour interval is 20 feet and the through valley floor elevation is between 840 and 860 feet (a spot elevation at a road intersection reads 848 feet). Elevations in section 35 rise to more than 920 feet while in section 3 elevations rise to 947 feet (see Bench Mark elevation). The through valley is at least 60-80 feet deep and may have been deeper when it was eroded. A shallower through valley is located in the section 10 northwest quadrant (figure 8 south center area) and has a floor elevation of between 880 and 900 feet. Elevations on either side rise to more than 920 feet. Following drainage divides surrounding the Little Berger Creek drainage basin reveals similar shallow through valleys. The through valleys provide evidence of flood flow channels that once moved south and southeast-oriented flood waters across the figure 8 map area prior to headward erosion of the present day deep valleys. At that time the flood flow channels were eroded into an erosion (deposition?) surface at least as high as the present day drainage divides. Headward erosion of the deep Missouri River valley and its tributary valleys (in sequence from east to west) captured the south and southeast oriented flood flow and triggered flood flow reversals to erode north oriented valleys.

Boeuf Creek-St Johns Creek drainage divide area

Figure 9: Boeuf Creek-St Johns Creek drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 9 uses a reduced size topographic map to  illustrate the Boeuf Creek-St Johns Creek drainage divide area located east and south of the figure 7 map area and includes overlap areas with figure 7. Washington is the larger town straddling the east edge of the figure 9 northeast quadrant and is located on the southwest side of the southeast-oriented Missouri River valley. Casco is a much smaller town located in the figure 9 south center and south of Casco is St Johns Creek. From the Casco area St Johns Creek flows in an east direction and then meanders in a north and northeast direction to join the Missouri River just west of Washington. Note how St Johns Creek has south and southeast-oriented tributaries from the north and west and north and northwest oriented tributaries from the south and east and has northwest and southeast oriented valley segments. The north-northeast-oriented stream meandering from the figure 9 southwest corner into the figure 9 northwest quadrant and then turning to meander in an east and north direction to join the Missouri River near the small town of Dundee (south of the east-oriented Missouri River segment seen along the figure 9 north edge). The north-oriented tributary meandering immediately to the east of Boeuf Creek is Cedar Fork and Middle Fork is the north and north-northwest oriented tributary flowing to Cedar Fork. West and slightly south of Casco is the small town of Port Hudson, which is located on the Middle Fork-St Johns Creek drainage divide. Note how northwest-oriented Middle Fork headwaters valleys are aligned with southeast-oriented St Johns Creek headwaters valleys in the Port Hudson region. The figure 9 map contour interval is 20 meters which does not show shallow through valleys well, although evidence for shallow through valleys can be seen north of Port Hudson. More detailed topographic maps, not illustrated in this essay, show the through valleys much better. On the more detailed maps where contour intervals are in feet there is an isolated high point greater than 890 feet on the drainage divide about three miles north of Port Hudson (grid lines on the figure 9 map define one mile squares). Proceeding south from that high point towards Port Hudson the drainage divide elevation drops to less than 830 feet and then fluctuates, although it never exceeds 860 feet until south of Port Hudson where it rises to more than 900 feet. The low drainage divide elevations between the isolated 890 plus foot elevation in the north and the 900 foot elevations south of Port Hudson define what was once the floor of a southeast-oriented flood flow channel to what was then the actively eroding St Johns Creek valley. Southeast-oriented flood flow in that channel was beheaded and reversed by headward erosion of the east-oriented Boeuf Creek valley, which triggered the flood flow reversal responsible for headward erosion of the north-oriented Middle Fork, Cedar Fork, and Boeuf Creek valleys.

Detailed map of St Johns Creek-Bourbeuse River drainage divide area

Figure 10: Detailed map of St Johns Creek-Bourbeuae River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

  • Figure 10 provides a detailed topographic map of the St Johns Creek-Bourbeuse River drainage divide area located along the south edge of the figure 9 map area. The west to east oriented red highway in figure 10 is seen along the south margin of figure 9. The northeast-oriented highway in section 28 leads to Port Hudson, which is located just north of the figure 10 map area. Leslie is the town located just east of the figure 10 center and Beaufort is the town located at the highway intersection east of Leslie and near the figure 10 east edge. St Johns Creek is the northeast-oriented stream flowing to the figure 10 north edge in section 25 and as seen in figure 9 flows to the Missouri River. Highways roughly follow drainage divides surrounding the St Johns Creek drainage basin. West-oriented streams in the figure 10 northwest corner region flow to a northwest oriented Cedar Fork tributary, with Cedar Fork flowing to Boeuf Creek, which in turn flows to the Missouri River. Big Creek is the southeast oriented stream flowing across the figure 10 southwest corner region and makes a north-south U-turn in the figure 10 south center edge area before flowing in a south and east direction to join the Bourbeuse River (south of figure 10). The southwest and southeast oriented stream joining the north-oriented Big Creek valley segment (near figure 10 south edge) is Skinner Creek. Little Creek is the southeast- and south oriented stream flowing through the word BOONE to the figure 10 south edge and then to the Bourbeuse River. A northwest and southeast oriented Bourbeuse River incised meander can be seen in the figure 10 southeast corner area. Note how the northeast-oriented St Johns Creek headwaters valley is linked by a through valley with the southwest-oriented Skinner Creek headwaters valley in section 33. The railroad crosses the drainage divide at a point where the elevation is between 800 and 810 feet. In section 4 to the south elevations rise to more than 900 feet and in section 28 to the north (near the radio tower) a bench mark has an elevation of 930 feet. The through valley is at least 100 feet deep and is a water eroded feature, and was probably formed by south oriented flood flow moving to the actively eroding Bourbeuse River valley. Headward erosion of the deep Missouri River valley to the north beheaded the south-oriented flood flow and the flood flow on the north end of the beheaded flood flow routes reversed flow to erode the north-oriented St Johns Creek valley (I have simplified here what was really a much more complicated process). Other interesting shallow through valleys can be seen by following the drainage divide elevations westward from Beaufort. At Beaufort elevations rise to at least 840 feet. Proceeding west along the drainage divide elevations fall to between 800 and 810 feet in the section 6 northwest corner then rise slightly before falling to less than 800 in the section 1 northeast corner. Continuing to the section 36 southwest corner elevations rise to more than 860 feet. The shallow through valley defined by these elevations links a north-oriented St Johns Creek tributary valley with a a south- and southeast-oriented Bourbeuse River tributary valley. The through valley is a water eroded feature and was eroded by south-oriented flood flow moving to what was then the actively eroding Bourbeuse River valley. Flood flow to the Bourbeuse River valley was beheaded and reversed by headward erosion of the deep Missouri River valley (north of figure 10).

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.

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