Geology and Geomorphology

Physiographic Regions

Missouri has been divided into six Natural Divisions based on natural features including: soils, geology, topography, and plant and animal distributions (Thom and Wilson 1980). These six divisions are further divided into regions. The Watershed is located entirely within the Ozark Natural Division and the vast majority lies within the Springfield Plateau region (Figure Ge01).

Geology

The geology of the Watershed is dominated by Ordovician dolomites and Mississippian limestones (Figure Ge02). Most of the water movement is through the surface stream network. Water that does reach the subsurface will likely resurface locally where a stream valley incises the confining rock layer (MDNR 1996). Eleven springs have been located in the Watershed (Table Ge01 and Figure Ge02). Karst topography is limited to the extreme headwater area in Greene and Webster counties and most (7) of the springs are located there.

The surface of the Watershed consists mainly of Jefferson City-Cotter dolomite, with some occurrences of early Mississippian limestones on upland areas. Movement of water from the surface to subsurface is minimal throughout most of the Watershed. This is due to the stony red clay residue overlying much of the Jefferson City-Cotter and the presence of thin shale units within the formation.

Soil Types (Allgood and Persinger 1979).

The primary soils (Figure Ge03) in the area were formed in cherty limestone, dolomite, or sandstone and are well to moderately well drained. Soils with fragipans are common. Alluvial soils on the floodplains along major streams are deep and well drained.

Barco Series

Moderately deep, well drained, moderately permeable soils on uplands. Formed in acid limestone. Slopes in the 2 to 9 percent range. Solum and depth to soft sandstone bedrock usually 20 to 40 inches.

Barden Series

Deep, moderately well drained, slowly permeable soils on uplands. Formed in loess or silty material and shale residuum. Slopes from 1 to 5 percent. Solum ranges from 30 to 60 inches, with the depth to shale bedrock typically exceeding 60 inches.

Bardley Series

Moderately deep, well drained permeable soils on uplands. Formed in cherty sediments and dolomite and limestone residuum. Slopes from 3 to 35 percent. Solum and depth to bedrock range from 20 to 40 inches. Chert and flagstone fragments range from 15 to 70 percent in surface layers.

Bolivar Series

Moderately deep, well drained, moderately permeable soils on uplands. Formed in acid limestone residuum. Slopes range from 5 to 14 percent. Solum and depth to weathered sandstone bedrock range from 20 to 40 inches. Depth to hard bedrock greater than 60 inches. Chert makes up 20 to 70 percent in the A horizon and 35 to 85 percent in Bt.

Clarksville Series

Deep, somewhat excessively drained, moderately rapid permeable soils on uplands. Formed in cherty limestone. Slope from 9 to 35 percent. Solum and depth to bedrock greater than 60 inches. Chert makes up 20 to 70 percent in the A horizon and 35 to 85 percent in Bt.

Collinsville Series

Moderately shallow, well drained, moderately rapid permeable soils on uplands. Formed under prairie grasses in sandstone residuum. Slopes from 5 to 14 percent. Solum and depth to sandstone bedrock less than 20 inches. Sandstone fragments present throughout the profile.

Creldon Series

Deep, moderately well drained soils on uplands with a fragipan. Above the fragipan, permeability is moderately slow. Formed in loess and loamy or clayey cherty limestone residuum. Slopes range from 2 to 9 percent. Solum and depth to bedrock are greater than 60 inches. Fragipan depth is in the 18 to 36 inch range. Chert fragments in the A horizon 0 to 5 percent, 0 to 10 percent in the Bt horizon, and from to 60 percent in and below the 2Btx horizon.

Doniphan Series

Deep, well drained, moderately permeable soils on uplands. Formed in cherty sediments and in the underlying material weathered from clay shale and dolomite or cherty limestone. Slopes from 3 to 14 percent. Solum from 60 to more than 100 inches. Chert fragments range from 25 to 75 percent in the A horizon, and 0 to 15 percent in the 2Bt horizon.

Eldon Series

Deep, well drained, moderately permeable soils on uplands. Formed in cherty material weathered from limestone interbedded with shale and sandstone. Slopes in the 3 to 14 percent range. Solum is more than 60 inches thick. Coarse fragments up 8 to 40 percent of the A horizon, and from 8 to 15 percent in the Bt horizon.

Gasconade Series

Shallow, somewhat excessively drained, moderately slowly permeable soils on uplands. Formed in limestone residuum. Slopes from 2 to 50 percent. Solum and depth to limestone bedrock range from 4 to 20 inches.

Gerald Series

Deep, somewhat poorly drained soils, with a fragipan on uplands. Permeability is very slow in fragipan and moderately slow below. Formed in loess and underlying dolomite residuum. Slopes from 0 to 2 percent. Solum and depth to bedrock more than 60 inches. Depth to fragipan is 20 to 40 inches. Chert comprises less than 5 percent by volume above fragipan.

Goss Series

Deep, well drained, moderately permeable soils on uplands. Formed in cherty limestone residuum. Slopes from 14 to 45 percent. Solum from 55 inches to 8 feet, with coarse fragments in the 10 to 80 percent range throughout the profile.

Hector Series

Moderately shallow, well drained, rapidly permeable soils on uplands. Formed under timber in sandstone residuum. Slopes from 5 to 14 percent. Solum and depth to sandstone bedrock less than 20 inches. Sandstone fragments present throughout the profile.

Huntington Series

Deep, well drained, moderate permeability on floodplains along major streams. Formed in silty alluvium. Slope from 0 to 2 percent. Solum and depth to nonconforming cherty layers between 40 to 60 inches. Course fragments comprise less than 5 percent throughout.

Lebanon Series

Deep, moderately well drained soils with a fragipan. Permeability above the fragipan is moderate, and slow at the fragipan. Formed in loess and dolomite residuum. Slopes from 2 to 5 percent. Solum and depth to bedrock 60 inches, with a fragipan at a depth of 18 to 36 inches.

Mandeville Series

Moderately deep, well drained, moderately permeable soils on uplands. Formed in acid shale residuum. Slopes from 2 to 5 percent. Solum and depth to soft shale bedrock range from 20 to 40 inches. Depth to hard bedrock is greater than 60 inches.

Nolin Series

Deep, well drained, moderately permeable soils on floodplains. Formed in alluvium. Slopes from 1 to 3 percent.

Pembroke series

Very deep, well drained, moderately permeable soils on uplands. Formed in loess. Slopes from 2 to 16 percent. Solum as deep as 60 inches.

Peridge Series

Deep, well drained, moderately permeable soils on uplands. Formed in loess and limestone residuum. Slope from 1 to 9 percent. Chert from 0 to 10 percent in upper 40 inches and 0 to 35 percent below 40 inches.

Scholten Series

Deep, moderately well drained soils, with a fragipan on uplands. Permeability very slow in the fragipan, moderate above, and moderate below. Formed in cherty limestone. Slope from 2 to 9 percent. Depth to fragipan is 18 to 27 inches. Chert comprises 15 to 40 percent in the A and E horizons, 35 to 65 percent in Bt, and 15 to 70 percent in 2Btx and 3Bt.

Tonti Series

Deep, moderately well drained soils, with a fragipan on uplands. Permeability is moderate above and slow within the fragipan. Formed in loess and underlying cherty limestone. Slope from 2 to 5 percent. Depth to the fragipan is 15 to 25 inches. Chert exists 10 to 25 percent above and 60 to 65 percent in the fragipan.

Viraton Series

Deep, moderately well drained soils, with a fragipan on uplands. Permeability is moderate above and very slow in the fragipan. Formed in loess and cherty dolomite. Slope from 2 to 9 percent. Depth to fragipan is 16 to 33 inches. Chert ranges from 0 to 35 percent above, 25 to 70 percent in, and 5 to 60 percent below the fragipan.

Stream Orders and Gradients

For this report, the following information on Watershed streams was limited to those that drain into the Pomme de Terre River upstream of the normal pool level of Harry S. Truman Lake. There is a total of 357.5 miles of third and higher order (Strahler 1957) stream segments in the Watershed including 188.0 miles of third order, 85.3 miles of fourth order, 62.9 miles of fifth order and 21.3 miles of sixth order (Table Ge02). Average gradients of third order streams ranged from 15.5 (Ingalls Creek) to 104.7 (Unnamed #4) feet per mile (Table Ge02). Third order streams in the northern portion of the Watershed have steeper average gradients than those in the rest of the Watershed (Figure Ge04). Average gradients for fourth order streams range from 14.6 (Piper Creek) to 110.0 (Vanderman Branch; Table Ge02) feet per mile. The only sixth order stream segment in the Watershed, a 21.3 mile segment Pomme de Terre River stretching from Harry S. Truman Lake normal pool level upstream to Pomme de Terre Dam, has a gradient of 1.7 feet per mile. Third and higher order stream subwatersheds are listed in (Table Ge03). Locations and gradient plots for all third and higher order streams were calculated using USGS 7.5 minute topographic maps (Figure Ge05), and are available from the Missouri Department of Conservation's (MDC) office in Clinton, MO.

Figure Ge01: Location of the Pomme de Terre River watershed

Location map of the Pomme de Terre River watershed within the Upper Ozark and Springfield Plateau regions of Missouri Natural Divisions

Figure Ge02: Geology and springs of the Pomme de Terre River watershed

Map of Geology and springs of the Pomme de Terre River watershed

Table Ge01: Springs in the Pomme de Terre River watershed

Springs in the Pomme de Terre River watershed.

Figure Ge03: Soils of the Pomme de Terre River watershed

Soils of the Pomme de Terre River watershed

Table Ge02: Attributes of third and higher order stream segments in the Pomme de Terre River watershed

Attributes of third and higher order stream segments in the Pomme de Terre River watershed

Figure Ge04: Average gradients for third and higher order streams in the Pomme de Terre River

Average gradients for third and higher order streams in the Pomme de Terre River watershed plotted by hydrologic unit number and the median value for each hydrologic unit.

Table Ge03: Third and higher order stream subwatersheds within the Pomme de Terre River watershed

Third and higher order stream subwatersheds within the Pomme de Terre River watershed

Figure Ge05: USGS topographic map (1:24,000 scale) coverage for the Pomme de Terre River watershed

USGS topographic map (1:24,000 scale) coverage for the Pomme de Terre River watershed