MoWIN: North Fork Salt River Basin

North Fork Salt River Basin - Physical Features

Geology

Earth's Early History - The first four billion years or so – is called "Precambrian" (before Cambrian) and is the period during which the earth assumed its current form. The last 544 million years - is divided into eras, periods, and epochs: three eras are identified, Paleozoic, Mesozoic and Cenozoic, each of which is divided into a number of periods which, in turn, are divided into some number of epochs. Each division of geologic time tells its own story.

For a depiction of the Geologic Time Scale in tabular form, see the U.S. Geological Survey's website at http://-vulcan.wr.usgs.gov/Glossary/geo_time_scale.html.

North East Missouri - All Missouri rocks of Cambrian age or younger, including those of the North Fork watershed, are sedimentary – they are formed from the weathered remains of other rocks. Surface rocks in the North Fork watershed were deposited by receding seas 286 – 363 million years ago during the Mississippian and Pennsylvanian periods. Subsequently, the rocks were weathered by wind, temperature and precipitation to provide the foundation for its soils.

An extremely fine grained Late Devonian limestone is found near Louisiana, MO and has been quarried for many years for lithography stones. The same rock is home to Mark Twain and Cameron Caves whose winding galleries so fascinated a young Tom Sawyer.

Mississippian Period: 362 to 320 million years ago. Surface rocks in Knox county and in much of Shelby and Monroe counties are Mississippian: they were laid down at the beginning of the Mississippian period by a return of the Kaskaskia Sea from what is now Illinois. Like the Ordovician, the Mississippian is composed of four series, Kinderhookian, Osageian, Meramecian, and Chesterian. About a quarter of all the rocks exposed in Missouri are from the Mississippian period.

The most typical Mississippian strata is the Burlington Limestone laid down during the Osage incursion. This crystalline limestone covers most of the state and extends into Iowa and Arkansas. Typical characteristics include layers of chert nodules, very hard sedimentary rocks that are probably formed from the remains of ancient sea sponges or other ocean animals that have been fossilized, and a sedimentary structure created by pressure called "stylolites."

At the end of the Mississippian, the retreating Kaskaskian sea overwhelmed the carbonate sequences with silica-rich mud and sand. As the carbonates become exposed, they became subject to weathering on the newly formed land surface.

Pennsylvanian Period: 320 to 286 million years. Surface rocks in Schuyler, Adair, Macon and much of Shelby and Monroe counties are Pennsylvanian, formed by the fourth and final transgression, the Absaroka. The Absaroka came and went five times in the state, leaving as evidence the Morrowan, Akokan, Desmoinsian, Missourian, and Virgilian series of rocks. Most of these rocks are shale, sandstone and clay, although thin limestone and coal layers are also common.

Missouri isn't often thought of as a coal-producing state, but its deposits are quite extensive. Unfortunately, Missouri coal is bituminous and high in sulphur, making it environmentally and economically undesirable.

In truth, underlying clay deposits have proven more economically beneficial for the state. Pennsylvanian clays are often refractory grade, suitable for brick-making and ceramics. The clay pits of Cheltenham in St. Louis county furnished brick for a growing city in the 19th century, and the fireclay works in Audrain county and mid-state have created significant wealth in those areas.

Glossary

Order: Twelve soil orders are recognized. The differences among orders reflect the dominant soil forming processes and the degree of soil formation.

Suborder: Each order is divided into suborders primarily on the basis of properties that influence soil genesis and are important to plant growth or properties that reflect the most important variables within the orders.

Great Group: Each suborder is divided into great groups on the basis of close similarities in kind, arrangement, and degree of development. Each great group is identified by the name of a suborder and by a prefix that indicates a property of the soil.

Subgroup: Each great group has a typic subgroup. Other subgroups are intergrades or extragrades. The typic is the central concept of the great group; it is not necessarily the most extensive. Intergrades are transitions to other orders, suborders, or great groups. Extragrades have some properties that are not representative of the great group but do not indicate transitions to any other known kind of soil.

Family: Families are established within a subgroup on the basis of physical and chemical properties and other characteristics that affect management. Generally, the properties are those of horizons below plow depth where there is biological activity. Among the properties and characteristics considered are particle-size class, mineral content, temperature regime, depth of root zone, consistence, moisture equivalent, slope, and permanent cracks.

Series: A series consists of soils that have similar horizons in their profile. The horizons are similar in color, texture, structure, reaction, consistence, mineral and chemical composition, and arrangement in the profile. The texture of the surface layer or of the substratum can differ within a series.

Topography

The North Fork watershed is characterized by rolling hills and a river that winds slowly in a southeasterly direction toward its confluence with the Mississippi. The watershed is narrower in the north, then broadens as it moves southward. The entire area slopes gradually downward toward the Mississippi.

The origin of the North Fork of the Salt River is in south central Schuyler county at an elevation of about 983 feet above sea level. At this point, it is about 4.9 miles from the border of Schuyler and Adair counties.

At its confluence with Floyd Creek in Adair County, the river has dropped 73 feet to an elevation of about 910 feet, and it is about 10.4 miles south of the border of Schuyler and Adair counties. The watershed continues south-southeast another 10.4 miles across Adair County and intersects the border of Adair and Knox counties at an elevation of 780 feet. Its elevation has dropped about 203 feet since its origin and about 49 feet since its confluence with Floyd Creek.

Once out of Adair County, it gradually broadens as it continues to run south-southeast across the corner of Knox County for another 8.6 miles to its border with Shelby County. At this point, its elevation has dropped another 40 feet to about 740 feet above sea level.

The watershed broadens as it turns east-southeast across Shelby County for another 8.6 miles to its confluence with Bear Creek.
From there to the border of Shelby and Monroe counties is about 20.5 miles over which its elevation will drop another 100 feet.

From its origin in Schuyler County, the watershed's elevation has now dropped a total of about 323 feet.

From the border of Shelby and Monroe counties to the North Fork's confluence with Clear Creek where Bouvet built his salt lick is another 6.5 miles and the river has dropped another foot to 619 feet above sea level.
From its confluence with Clear Creek to the border of Monroe and Ralls counties is another 11.4 miles, and it will drop another 20 feet to 599 feet.

Maps from: U.S. Geological Survey, "The National Map."

Soils

Prime farmland is of major importance in meeting the Nation's short- and long-range needs for food. Agricultural production land is limited and requires best management practices to maintain productivity.

Prime farmland has adequate and dependable moisture from precipitation or irrigation. The temperature and growing season are favorable. The level of acidity or alkalinity is acceptable. Prime farmland has few or no rocks and is permeable to water and air. It is not excessively subject to erosion or saturated with water for long periods and is not frequently flooded during the growing season. The slope ranges mainly from zero to six percent.

About 65,000 acres in Schuyler County, or about 33 percent of the total acreage, meets the soil requirements for prime farmland. Areas of prime farmland are scattered throughout the North Fork Salt Watershed. Crops grown include soybeans, corn, winter wheat, and grain sorghum.

Four combinations of soil series, called 'associations', are identified:

Lamoni-Seymour-Leonard Association: Very deep, gently sloping and moderately sloping, somewhat poorly drained and poorly drained soils that formed in loess, sediments, and glacial till on uplands. This association consists of soils on upland ridges that have long backslopes and small, branching drainage ways. These ridges generally are uniform in elevation and are in the upper reaches of watershed basins. Slopes range from two to nine percent. This association makes up about 19 percent of the county. It is about 43 percent Lamoni and similar soils, 43 percent Seymour and similar soils, 11 percent Leonard and similar soils, and 3 percent soils of minor extent.
Gara-Armstrong Association: Very deep, moderately sloping to moderately steep, well drained and moderately well drained soils that formed in glacial till; on uplands. This association consists of soils on upland convex ridges and backslopes adjacent to minor drainage ways. Slopes range from 5 to 20 percent. This association makes up about 50 percent of the county. It is about 45 percent Gara soils, 35 percent Armstrong and similar soils, and 20 percent soils of minor extent.

Winnegan-Keswick Association: Very deep, moderately sloping to steep, moderately well drained soils that formed in glacial till on uplands. This association consists of soils on long, narrow, convex ridgetops and steep valley backslopes adjacent to major drainage ways. Slopes range from 5 to 35 percent. This association makes up about 19 percent of the county. It is about 80 percent Winnegan and similar soils, 12 percent Keswick soils, and 8 percent soils of minor extent.
Zook-Kennebec-Fatima Association: Very deep, nearly level, moderately well drained and poorly drained soils that formed in alluvium; on flood plains. This association is found on flood plains and on slopes that range from zero to two percent, and constitutes about 12 percent of the county. It is about 63 percent Zook and similar soils, 33 percent Kennebecand Fatima and similar soils, and 4 percent soils of minor extent.

Source: Missouri Cooperative Soil Survey, "Soil Survey of Schuyler County, Missouri,"

Climate

The North Fork watershed has cold winters and long, hot summers. Heavy rains occur mainly in spring and early summer, when moist air from the Gulf of Mexico interacts with drier continental air. Snow falls nearly every winter and often stays on the ground for a few weeks. The annual precipitation is normally adequate for corn, soybeans, and all grain crops.

The average temperature is about 27 degrees F and the average daily minimum temperature is about 18 degrees. In summer, the average temperature is about 74 degrees and the average daily maximum temperature is about 85 degrees.

The total annual precipitation is about 35 inches. Of this, about 24 inches, or 69 percent, usually falls in April through September. The growing season for most crops falls within this period.

The average seasonal snowfall is 23.2 inches. On the average, 17 days of the year have at least one inch of snow on the ground but the number of such days varies greatly from year to year.

The average relative humidity in mid-afternoon is about 60 percent. Humidity is higher at night, and the average at dawn is about 80 percent. The sun shines about 70 percent of the time possible in summer and 55 percent in winter. The prevailing wind is from the south-southeast and average wind speed is highest in spring.

Elk River | James River | Sac River | Spring River | North Fork Salt River

Missouri Department
of Natural Resources

Missouri Watershed Information Network (MoWIN)
Send comments to: mowin1@missouri.edu
205 Agricultural Engineering
Columbia, MO 65211
Phone: (573) 882-0085
Toll Free: (MO only): 1-877-H20-shed (426-7433)
Fax: (573) 884-5650

Page last updated August 26, 2008