Mississippi River-Missouri River drainage divide area landform origins in St Charles County, Missouri, USA

Authors

Abstract:

Topographic map interpretation methods are used to interpret landform origins in the Mississippi River-Missouri River drainage divide area located in St Charles County, Missouri. The study region is located north of St Louis and represents the area between the south, southeast, northeast, southeast, and south-southwest oriented Mississippi River and the northeast-oriented Missouri River, which joins the southeast-oriented Missouri River segment as a barbed tributary. Map evidence suggests study region landforms evolved during massive south-oriented glacial melt water floods, which initially flowed across the region on a surface as high or higher than the highest present day study region elevations. The deep Mississippi River valley eroded headward into the study region along and across flood flow channels in what was an immense south-oriented anastomosing channel complex. The north-oriented Mississippi River valley segment was eroded by a reversal of flood flow on the north end of what had been a diverging flood flow channel, which was beheaded by Mississippi River valley headward erosion. That reversal of flood flow also captured flood flow from a major south-oriented flood flow channel further west, which is now the upstream Mississippi River valley location. That capture beheaded southwest-oriented flood flow on what had been a diverging southwest-oriented flood flow route south of the present day Mississippi River valley U-turn and flood waters on the northeast end of the beheaded flood flow channel reversed flow direction to erode the deep northeast-oriented Missouri River valley, which in time became one of the Mississippi River’s most successful tributary valleys in terms of capturing south-oriented melt water flood flow. Map evidence supporting this flood origin interpretation includes valley orientations, barbed tributaries, elbows of capture, asymmetric drainage divides, and shallow through valleys eroded across present day drainage divides.

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 Mississippi River-Missouri River drainage divide area landform origins in St Charles County, 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 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 Mississippi River-Missouri River drainage divide area landform evidence in St Charles County, Missouri will be regarded as evidence supporting the “thick ice sheet that melted fast” paradigm. This essay is included in the Missouri River drainage basin landform origins research project essay collection.

Mississippi River-Missouri River drainage divide area location map

Figure 1: Mississippi River-Missouri 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 is a location map for the Mississippi River-Missouri River drainage divide area located in St Charles County, Missouri. The Mississippi River is the south-southeast oriented river flowing from the figure 1 north center edge area to the south edge (near southeast corner) and forms the border between Illinois to the east and Missouri to the west. The Missouri River flows in an east-northeast direction from the figure 1 west edge (north of center) to Brunswick, Missouri and then turns to flow in a southeast, south, east, and southeast direction to Jefferson City. From Jefferson City the Missouri River flows in an east  and northeast direction to join the Mississippi River a short distance upstream from St Louis. Note how near St Louis the Mississippi River turns to flow in a north direction for a short distance and then turns to flow in a south-southwest direction before resuming its south-southeast orientation and how the Missouri River flows in a northeast direction to join the south-oriented Mississippi River as a barbed tributary. The Mississippi River-Missouri River drainage divide area in St Charles County illustrated and described in this essay is located south of the south, north, and southeast oriented Mississippi River valley segment and north of the northeast-oriented Missouri River valley segment seen north of St Louis and includes the towns of St Charles and O’Fallon. The Peruque Creek-Missouri River drainage divide area landform origins in Warren and St Charles Counties, Missouri essay addresses the region directly west of this essay’s study region and is included in the essays listed under MO Missouri River on the sidebar category list.
  • Topographic map evidence presented in this essay and in other essays in the Missouri River drainage basin landform origins research project suggests the Mississippi River-Missouri River drainage divide area was eroded by immense south-oriented glacial melt water floods. Flood waters were derived from a rapidly melting thick North American ice sheet, which at the time valleys in the figure 1 map area were eroded was located north of the figure 1 map area. Initially the massive south-oriented glacial melt water floods overwhelmed whatever drainage systems existed and flowed directly 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 deep tributary valleys in sequence from south to north gradually captured much of the south-oriented flood flow and diverted the flood waters to what was then the actively eroding Mississippi River valley. In the figure 1 map area headward erosion of the deep Missouri River valley captured south-oriented flood flow routes to what were then actively eroding White River tributary valleys located south of the figure 1 map area (the White River is a southeast-oriented Mississippi River tributary in Arkansas). Flood waters on north ends of beheaded flood flow routes reversed flow direction to erode north-oriented Missouri River (and Osage River) tributary valleys.
  • Probably some of the most intriguing figure 1 drainage features are where the south-southeast oriented Mississippi River turns to flow in a north direction and then in a southeast and south-southwest direction before resuming its south-southeast flow direction and the northeast-oriented Missouri River course just before the Missouri River enters the Mississippi River valley, which makes the Missouri River a barbed tributary. Why would the south-oriented Mississippi River flow in a north direction and why would one of the Mississippi River’s major tributaries flow in a northeast direction to join a south-oriented river? When the deep Mississippi River valley eroded headward into the figure 1 map area it was eroding headward along just one of many south-oriented flood flow channels crossing the figure 1 map area. The numerous south-oriented flood flow channels made up an immense south-oriented anastomosing channel complex where flood flow channels diverged from each other and then converged again. These south-oriented flood flow channels were located on an erosion (and/or deposition?) surface comparable in elevation to present day drainage divide elevations. While many of these features are outside the study region and figure 1 does not provide much detail, I will try to use figure 1 map evidence to briefly explain how these unusual geomorphic features evolved.
  • The deep Mississippi River valley and its deep tributary valleys eroded headward along and across major flood flow channels carved into a high level topographic surface and in doing so beheaded diverging south-oriented flood flow routes. Flood waters on north ends of these beheaded flood flow channels reversed flow direction to erode north-oriented tributary valleys, which now are used by north-oriented and barbed tributaries flowing to the south-oriented Mississippi River. For example near St Marys (south of St Louis) a north-oriented tributary flows to the south-oriented Mississippi River. Also, as deep Mississippi River valley headward erosion captured converging flood flow routes it eroded headward fastest along the most successful of the captured flood flow channels. Note how in the Alton and Wood River, Illinois area (north of St Louis) there are south-southwest oriented Mississippi River tributaries aligned with the south-southwest Mississippi River segment near St Louis. These tributaries provide evidence headward erosion of the deep Mississippi River valley captured major south-southwest oriented flood flow channels and eroded headward along them. Note also how the south-oriented Illinois River joins the Mississippi River at the north end of the north-oriented Mississippi River segment. The south-oriented Illinois River route and the south-oriented Mississippi River route immediately to the west were parallel south-oriented flood flow channels in the large anastomosing channel complex. Prior to headward  erosion of the deep Mississippi River valley these south-oriented flood flow channels were located on a topographic surface as high as regional drainage divides today and probably were relatively shallow channels that had diverging flood flow channels to both the east and the west.
  • When deep Mississippi River valley headward erosion reached the Wood River-Alton, Illinois area a deep valley eroded headward along a southeast-oriented flood flow channel diverging from the south-oriented Illinois River flood flow channel and that valley captured the south-oriented Illinois River flood flow channel. Flood waters on the north end of the beheaded flood flow channel then reversed flow direction to erode the north-oriented Mississippi River valley segment, which then captured the south-oriented flood flow channel on the present day south-oriented Mississippi River alignment and the deep Mississippi River valley then continued to erode headward along that channel (a deep valley also eroded headward on the Illinois River alignment). But south of the newly eroded Mississippi River valley U-turn were additional southwest-oriented diverging flood flow channels to what were then actively eroding south-oriented White River tributary valleys south of the figure 1 map area. Flood flow on the northeast ends of those beheaded flood flow channels also reversed flow direction and began to erode northeast-oriented valleys, one of which was the northeast-oriented Missouri River valley segment, which captured massive flood flow from west of the actively eroding Mississippi River valley and eventually became one of the most successful of the Mississippi River tributary valleys in terms of capturing flood flow. As the deep Mississippi River valley eroded headward additional east and southeast-oriented tributary valleys eroded from it and beheaded flood flow routes to the newly eroded Missouri River valley. However, the Missouri River valley eroded headward fast enough that it’s actively eroding valley head was always west of the beheaded flood flow routes.

Detailed location map for Mississippi River-Missouri River drainage divide area

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

 

Figure 2 provides a detailed location map for the Mississippi River-Missouri River drainage divide area in St Charles County, Missouri. County names and boundaries are shown and Illinois is the state east of south-oriented Mississippi River and Missouri the state to the west. Note how the Mississippi River flows in a south direction between Lincoln County (Missouri) and Calhoun County (Illinois) and then makes a U-turn to flow in a north-northeast direction before turning again to flow in a southeast and then a south-southwest direction. The Illinois River flows in a south direction from the figure 2 north center edge between Calhoun and Jersey Counties in Illinois to join the Mississippi River at the north end of its northward jog. The Missouri River flows in a southeast direction along the Warren County southern border and then turns to flow in a northeast direction along the St Charles County southern border. The Missouri River does turn to flow in a southeast direction before joining the southeast-oriented Mississippi River, although for most of that distance the Missouri River channel is located in the southeast-oriented Mississippi River valley. The Cuivre River is the east oriented Missouri River tributary forming the Lincoln-St Charles County border and Big Creek is an east oriented Cuivre River tributary flowing from northern Warren County. Big Creek headwaters and tributaries in Warren County are oriented in north directions and appear to be aligned with south-oriented Missouri River tributaries. Peruque Creek is an east-oriented Mississippi River originating in northeast Warren County (south of Big Creek) and which flows across northwest St Charles County to near O’Fallon where it turns to flow in a north direction to meet the south-oriented Mississippi River. South of Peruque Creek is east-oriented Dardenne Creek, which originates just west of the Warren-St Charles County line and which also turns to flow in a north direction to meet the south-oriented Mississippi River just east of Peruque Creek. Note how the Mississippi River-Missouri River drainage divide in St Charles County is an asymmetric drainage divide with the east- and north-oriented Mississippi River tributaries being located almost next to the northeast-oriented Missouri River. This lack of a Missouri River drainage basin north of the Missouri River is evidence the flood flow reversal that created the north-oriented Mississippi River valley segment also reversed flood flow moving to the newly eroded Missouri River valley, which was also being eroded by reversed flood flow on a flood flow route beheaded by Mississippi River valley headward erosion. Another example of a northeast-oriented river formed by a reversal of what had been southwest-oriented flood flow is seen in St Louis and Franklin Counties where the Meramec River first flows in a northeast direction (parallel to the northeast-oriented Missouri River) and then in the St Louis urban area turns to flow in a southeast direction to join the Mississippi River.

Mississippi River-Missouri River drainage divide area

Figure 3: Mississippi River-Missouri River 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 Mississippi River-Missouri River drainage divide area north of St Louis. The Mississippi River flows in a southeast direction from the figure 3 west edge (north of center) and then turns to flow in a northeast direction to join the south-oriented Illinois River, which flows from the figure 3 north edge (west half). After joining the Illinois River the Mississippi River flows in a southeast direction to the figure 3 east center edge. At the figure 3 east center edge the Missouri River turns still again to flow in a south-southwest direction to the figure 3 south edge (east half). The Missouri River flows in a northeast direction to enter the southeast-oriented Mississippi River valley just north of Pelican Island (east of the figure 3 center). The Missouri River channel is then located on the southwest side of the southeast-oriented Mississippi River valley and the Mississippi River channel is located on the valley’s northeast side until the valley changes direction near the figure 3 east edge and the two channels become one. Alton is the city on the northeast side of the Mississippi River near the figure 3 east edge and Wood River is the city straddling the east edge on the east side of the Mississippi River where it turns to flow in a south-southwest direction. Note how the northeast-oriented Missouri River valley and the south-southwest oriented Mississippi River valley in the figure 3 southeast quadrant appear to be roughly parallel valleys with the two rivers flowing in opposite directions. Both valleys originated as relatively shallow southwest or south-southwest oriented flood flow channels carved into a topographic surface as high as the highest figure 3 elevations today. At that time flood waters were probably flowing across the entire figure 3 map area on that higher level topographic surface and flood waters from high level flood flow channels on the south-oriented Illinois and Mississippi River alignments north and west of figure 3 were being captured by the south-southwest oriented flood flow channels, with the southwest-oriented flood flow channel on the Missouri River alignment flowing to actively eroding south-oriented White River tributary valleys (south of figure 1 map area). The deep south-oriented Mississippi River valley then eroded headward along the eastern flood flow channel to the Wood River-Alton area where it then eroded its southeast-oriented valley segment so as to capture the south-oriented flood flow channel on the Illinois River alignment. Flood waters on the north end of the beheaded flood flow channel then reversed flow direction to not only erode the north-oriented Mississippi River valley segment (which captured the south-oriented flood flow channel on the Mississippi River alignment west and north of the figure 3 map area), but which reversed flood flow on the northeast end of the flood flow channel on the Missouri River alignment, which then eroded the northeast-oriented Missouri River valley.

Mississippi River Dardenne Creek drainage divide area

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

 

Figure 4 illustrates the Mississippi River-Dardenne Creek drainage divide area at the south end of the Mississippi River U-turn, which was seen in less detail in figure 3 above. The southeast and northeast oriented Mississippi River is seen in the figure 4 north half. The northeast oriented Missouri River can be seen in the figure 4 southeast corner. St Charles is the city located on higher ground between the Mississippi River valley and the Missouri River valley in the figure 4 southeast quadrant. St Peter is the city in the figure 4 south center area and O-Fallon is the city in the figure 4 southwest quadrant. Mississippi River tributaries from the south (from west to east) include Peruque Creek, which flows in an east-northeast direction from the figure 4 west edge (south of center) to the O’Fallon northern limits and then turns to flow in a north-northeast direction to join the south-oriented Mississippi River as a barbed tributary. Dardenne Creek flows in a north direction to and through St Peter to enter the Mississippi River valley and then turns to flow in a northeast and north direction to join the northeast-oriented Mississippi River. Spencer Creek flows in a north-northwest direction to enter the Mississippi River valley at St Peter and then turns to flow in a north-northeast oriented channel to join northeast- and north-oriented Dardenne Creek. Sandfort Creek flows in a north direction along the west edge of St Charles to join north-oriented Dardenne Creek. Cole Creek flows in a northeast direction in St Charles and then on entering the Mississippi River valley turns to flow in a northwest direction to join north-oriented Dardenne Creek. The north-oriented tributary valleys were eroded by reversals of flood flow on the north ends of south-oriented flood flow routes beheaded by headward erosion of the deep Mississippi River valley. As already mentioned the Mississippi River valley U-turn was eroded when headward erosion of the southeast-oriented Mississippi River north of the figure 4 map captured south-oriented flood flow on the present day Illinois River alignment. That capture beheaded south-oriented flood flow routes across the figure 4 east half (which were flowing on a topographic surface at least as high as the highest figure 4 elevations today). Flood waters on the north end of the beheaded flood flow routes reversed flow direction to erode the northeast-oriented Mississippi River valley segment, which then captured south-oriented flood flow on the south-oriented Mississippi River alignment north of the figure 4 west half. Capture of south-oriented flood flow in the figure 4 west half beheaded south-oriented flood flow routes south of the newly eroded Mississippi River valley U-turn, which caused flood flow reversals that eroded the north-oriented tributary valleys.

Cole Creek-Missouri River drainage divide area

Figure 5: Cole Creek-Missouri River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

Figure 5 illustrates the Cole Creek-Missouri River drainage divide area located south of the figure 4 map area and includes overlap areas with figure 4. The south edge of the Mississippi River valley where it makes its U-turn is located along the figure 5 northern margin. The northeast-oriented Missouri River valley extends from the south edge of the figure 5 southwest quadrant to join the Mississippi River valley near the figure 5 north edge (east half). St Charles is the city located north of the figure 5 center area on the high ground between the Mississippi River valley and the northeast-oriented Missouri River valley. Urban areas east and south of the Missouri River valley are included in the St Louis urban area. Note how there are several north-oriented tributaries in the region east and south of the northeast-oriented Missouri River valley. The north-oriented Missouri River tributary valleys were eroded by reversals of flood flow on north ends of beheaded south oriented flood flow routes. St Peters is the city located south of the Mississippi River valley near the west of the figure 5 northwest quadrant. Dardenne Creek flows in a northeast direction from St Peters to the figure 5 north edge. Note north-northwest oriented Dardenne Creek tributaries flowing near the figure 5 west edge south of St Peters and how some of the tributaries originate almost at Jacobs, which is a place-name on the north side of the Missouri River valley in the figure 5 southwest corner. These north-northwest oriented tributaries are linked by shallow through valleys with the Missouri River valley and provide evidence of former south-oriented flood flow routes reversed by headward erosion of the deep Mississippi River valley. Spencer Creek is the north-northwest oriented tributary joining Dardenne Creek near the St Peters north edge and is also flowing in a valley eroded by reversed flood flow on the north end of a beheaded flood flow route. Cole Creek flows in a northeast direction through St Charles to enter the Mississippi River valley between Gardnerville and Elm Point (place names in the Mississippi River valley just north of St Charles) and then turns to flow in a northwest direction to the figure 5 north edge. While difficult to see on figure 5 the Cole Creek valley is linked by shallow through valleys with south-southeast oriented tributary valleys to the northeast-oriented Missouri River valley. These shallow through valleys provide evidence of what were once southwest and south oriented flood flow channels which were beheaded and reversed by Mississippi River valley headward erosion. Figure 6 below provides a detailed topographic map to better illustrate evidence.

Detailed map of Cole Creek-Missouri River drainage divide area

Figure 6: Detailed map of Cole Creek-Missouri River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

Figure 6 is a detailed topographic map of the Cole Creek-Missouri River drainage divide area seen in less detail in the figure 5 map area above. The northeast-oriented Missouri River flows across the figure 6 southeast quadrant. Cole Creek flows a north and northeast direction from the figure 6 center region to the figure 6 north center edge. South of the north-oriented Cole Creek headwaters are unnamed Missouri River tributaries. The map contour interval is ten feet and elevations along the Missouri River channel edge are 440 feet. North of the figure 6 map area elevations adjacent to the Mississippi River channel are 420 feet. Near the figure 6 west center edge elevations along the Mississippi River-Missouri River drainage divide are as high as 622 feet (see spot elevation). Follow the drainage divide in an east-northeast direction and elevations drop to between 600 and 610 feet before another spot elevation is found with an elevation of 645. The lower elevations between the 622 foot elevation and the 645 foot elevation represent a former south-oriented flood flow channel defined by the north-northwest oriented Spencer Creek valley to the north and south-southeast oriented Duckett Creek valley to the south. Headward erosion of the deep Mississippi River valley to the north beheaded the south-oriented flood flow channel and flood waters on the north end of the beheaded flood flow route reversed flow direction to erode the north-northwest oriented Spencer Creek valley.From the 645 foot spot elevation there is another drop in elevation and then a Bench Mark labeled BM 625. The shallow channel between the 645 foot elevation and the 625 foot elevation links a northeast-oriented Cole Creek headwaters valley with an unnamed south-oriented Missouri River tributary valley. East of the 625 foot spot elevation is a second north-oriented Cole Creek headwaters valley and the drainage divide makes a significant south jog around that north-oriented valley head. Note how at that south end of the south jog the north-oriented Cole Creek headwaters valley is linked by a shallow through valley with a southwest-oriented tributary valley draining to a south-oriented Missouri River tributary. The shallow through valley is defined by at least two contour lines on each side. While the evidence is subtle the drainage divide is crossed by multiple shallow through valleys which provide evidence of former flood flow channels. Those flood flow channels cross a drainage divide approximately 180 feet higher than the present day Missouri River valley floor. and approximately 200 feet higher than the Mississippi River valley floor to the north. These elevations provide a minimum measure of the amount of erosion which occurred as the deep Mississippi River valley eroded headward into the region and then beheaded south-oriented flood flow moving to what was then the newly eroded northeast-oriented Missouri River valley.

Cuivre River-Peruque Creek drainage divide area

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

 


Figure 7 illustrates the Cuivre River-Peruque Creek drainage divide area located west and slightly north of the figure 4 map area and includes overlap areas with figure 4. The Mississippi River flows in a southeast direction from the figure 7 north edge to the east center edge. The Cuivre River flows in a southeast direction from the figure 7 northwest corner area and then turns to flow in a north and east-northeast direction to the figure 7 north center edge where it enters the Mississippi River valley. Once in the Mississippi River valley the Cuivre River meanders in a southeast and northeast direction before finally joining southeast-oriented Cuivre Slough, which drains to the main Mississippi River channel. Note how near the figure 7 west margin there are several north-northwest oriented Cuivre River tributaries. Also note Whites Branch, which originates near the figure 7 center and which flows in a north, northwest, and west-southwest direction to join the north-oriented Cuivre River segment. Peruque Creek flows in an east direction from the figure 7 southwest corner to Lake St Louis and then jogs to the north before flowing in an east direction to the north edge of O’Fallon. From O’Fallon Perugia Creek flows for a short distance in a north direction before turning to flow in a north-northeast direction to join the southeast-oriented Mississippi River. What is remarkable about the figure 7 map area are the numerous north-oriented barbed tributaries adjacent to what is one of North America’s major south-oriented rivers. The barbed tributaries provide evidence of flood flow reversals caused not only by headward erosion of the deep southeast-oriented Mississippi River valley segment but also of flood flow reversals caused by headward erosion of the Cuivre River valley. Remember, north of the figure 7 map area the Mississippi River valley is oriented in a south direction and pointed almost directly at the location of O’Fallon. To get reversals of flood flow near the figure 7 west margin means flood waters were not confined  to the south-oriented Mississippi River valley alignment, but flowed across the western half of figure 7. Elevations in the Mississippi River valley area are less than 130 meters (the map contour interval is 10 meters). Elevations in the figure 7 west half are greater than 160 meters, meaning they are at least 30 meters higher than on the Mississippi River valley floor. These elevations provide a minimum measure of how much erosion flood waters accomplished as they eroded headward along the present day Mississippi River valley.

Detailed map of Cuivre River-Peruque Creek drainage divide area

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

 

Figure 8 provides a detailed topographic map of the Cuivre River-Peruque Creek drainage divide area seen in less detail in the figure 7 southwest quadrant above. The north-northwest oriented stream flowing to the figure 8 northwest corner is Enon Branch, which north of the figure 8 joins east-oriented Big Creek just before Big Creek joins the Cuivre River (see figure 7). The unnamed north-northwest oriented streams flowing to the figure 8 north edge (west half) just east of Enon Branch flow directly to the Cuivre River, which has turned to flow in a north direction. Peruque Creek flows in a northeast direction across the figure 8 southeast corner. Note southeast-oriented Peruque Creek tributaries originating in the figure 8 center area and how in the section 10 southwest quadrant a southeast-oriented Peruque Creek tributary valley is linked by a shallow through valley with the easternmost of the north-northwest oriented Cuivre River tributary valleys. The map contour interval is 20 feet and the through valley floor elevation is between 600 and 620 feet. Elevations on either side of the through valley rise to more than 640 feet. A similar through valley in the figure 8 southwest corner links the north-northwest oriented Enon Branch valley with the valley of a southeast-oriented Peruque Creek tributary. The through valleys are subtle features and are not deep, but they are water eroded features and provide evidence of what were once south-southeast oriented flood flow channels to what were at that time actively eroding southeast-oriented Peruque Creek tributary valleys. At that time the Cuivre River valley did not exist and flood waters flowed across the region on an erosion (deposition?) surface at least as high as the highest figure 8 elevations today. Headward erosion of the east orienetd Cuivre River valley segment (near the figure 7 north edge) then beheaded the south-oriented flood flow moving across the figure 8 map area. The resulting flood flow reversal not only eroded the north-northwest oriented valleys seen in the figure 8 west half, but also eroded the north-oriented Cuivre River valley seen in the figure 7 northwest quadrant.

Dardenne Creek-Missouri River drainage divide area

Figure 9: Dardenne Creek-Missouri River drainage divide area. United States Geological Survey map digitally presented using National Geographic Society TOPO software.

 

Figure 9 illustrates the Dardenne Creek-Missouri River drainage divide area located west and slightly south of the figure 5 map area and south and slightly east of the figure 7 map area and includes overlap areas with figures 5 and 7. The northeast oriented Missouri River valley extends from the figure 9 south edge to the east edge. Dardenne Creek flows from the figure 9 west center edge through the reservoir just north of the August A. Busch Memorial Wildlife Area in an east and east-northeast direction until just east of the figure 8 center area where it turns to flow in a north direction to the figure 8 north edge and then to the Mississippi River valley. Lake St Louis in the figure 9 northwest corner is located in the Peruque Creek valley, with Peruque Creek also flowing in an east, northeast, and north direction to the Mississippi River valley. Weldon is the place-name at the north end of the Daniel Boone Bridge across the Missouri River. Jacobs is a place-name downstream from Weldon and is just north of Bonhomme Island. Note how in the region from Weldon to beyond Jacobs the Missouri River has very short south-oriented tributaries which are aligned with much longer north-oriented Dardenne Creek tributaries. The lack of any Missouri River drainage area to the north suggests the Missouri River valley eroded headward along just one of several northeast- and north-oriented flood flow routes that developed after deep Mississippi River valley headward erosion beheaded southwest oriented flood flow routes in the region. The east- and northeast-oriented Dardenne Creek and Peruque Creek valley segments are roughly parallel with the Missouri River valley and probably were eroded by massive volumes of reversed flood flow at the same time the deep Missouri River valley eroded headward across the region. The figure 9 map is not easy to read, but elevations in the Missouri River valley are in the 140 meter range (the map contour interval is 20 meters). Elevations along the Dardenne Creek-Missouri River drainage divide in the Weldon Spring State Wildlife Area (in figure 8 southwest quadrant) exceed 200 meters (which is the dark contour line). Several shallow through valleys crossing the drainage divide can be located between the isolated areas higher than 200 meters which can be seen along the drainage divide from the figure 8 west edge to areas east of Jacobs. Similar through valleys can be seen crossing the Peruque Creek-Dardenne Creek drainage divide in the figure 9 northwest quadrant. These shallow through valleys provide evidence of multiple south-oriented flood flow routes which flowed across the region prior to headward erosion of the Dardenne Creek valley, which captured the flood flow and diverted the flood waters north probably to what was then the actively eroding Mississippi River valley head. Peruque Creek valley headward erosion captured the flood flow probably at almost the same time, although slightly later than the Dardenne Creek valley headward erosion and also diverted flood waters to the actively eroding Mississippi River valley head.

Detailed map of Crooked Creek-Missouri River drainage divide area

Figure 10: Detailed map of Crooked Creek-Missouri 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 Crooked Creek-Missouri River drainage divide area, which was seen in less detail in figure 9 above. The Missouri River valley and Missouri River can be seen along the south edge of the figure 10 southeast quadrant. Crooked Creek is a north-northeast oriented Dardenne Creek tributary originating near Weldon Spring Heights (the small lake south of the major highway interchange is located in the Crooked Creek valley) and flows to the figure 10 north edge (just west of center). Note how the north-northeast oriented Crooked Creek valley is linked by a shallow through valley (located under the words “Weldon Spring Heights”) with a south-oriented Missouri River tributary valley. The map contour interval is ten feet and the through valley floor elevation is between 580 and 590 feet. Elevations to the west rise to more than 660 feet. West of the figure 10 map area elevations rise even higher to more than 750 feet. Immediately to the east of the through valley elevations rise to at least 620 feet in the town of Weldon Springs Heights, which suggests the through valley may only be 30-40 feet deep and may be a relatively narrow flood flow channel. But continue east along the Dardenne Creek-Missouri River drainage divide to south of the town of Weldon Spring where elevations rise to more than 660 feet (slightly higher elevations are found just east of the figure 10 map area). Instead of seeing a relatively narrow 30-40 foot deep valley we are seeing evidence for a through valley at least three miles in width (and maybe much wider) and which was at least 70 feet deep and probably much deeper. Note how east of the highway going to the bridge over the Missouri River a south-oriented Missouri River tributary valley is linked by what appears to be another relatively narrow through valley with a north-northwest oriented Dardenne Creek tributary valley draining to the figure 10 north edge (just east of center). Again the through valley floor elevation is between 580 and 590 feet. The narrow north-south oriented through valleys were eroded as deeper channels on the floor of the much broader through valley. The broad through valley between the 660 foot plus elevations (near the figure 10 west and east edges) documents how massive south-oriented floods moving to the actively eroding Missouri River valley stripped significant thicknesses of surface material from present day drainage divide areas. Probably significantly more than 70-80 feet of material was stripped from the drainage divide, however there are no higher markers in the figure 10 map area to document greater erosion.

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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