Sikeston Ridge is a two-mile (3 km) wide topographic terrace with an average height of deposited by the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it ...

. It was formed when the Mississippi River flowed west of Sikeston, United States. This Southeast

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

ridge runs from the area of Haywood City south through Sikeston towards the Mississippi River town of

New Madrid, Missouri New Madrid ( es, Nueva Madrid) is a city in New Madrid County, Missouri, United States. The population was 2,787 at the 2020 census. New Madrid is the county seat of New Madrid County. The city is located 42 miles (68 km) southwest of Cair ...

. The most dominant ridge in the area is

Crowley's Ridge Crowley's Ridge (also Crowleys Ridge) is a geological formation that rises 250 to above the alluvial plain of the Mississippi embayment in a line from southeastern Missouri to the Mississippi River near Helena, Arkansas. It is the most prom ...

which is long and with an average height of . In 1789, the King of Spain ordered that an overland route be laid out to connect the cities of

St. Louis St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the bi-state metropolitan area, which e ...

and

New Orleans New Orleans ( , ,New Orleans

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ...

Origin

Sikeston Ridge was once mapped as a part of the early to middle Wisconsin Valley Train. Further observations and studies in the area found that the surface deposits on and around the ridge consist of medium to fine sand, muddy sand, and sandy mud. This finding showed that the loess cap was very thin, leading geomorphologists to believe the ridge was much younger than previously thought. After this discovery, they suggested the

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluv ...

sands on the ridge were deposited during the Peoria Loess deposition. This is consistent with Sikeston Ridge being a remnant of the late Wisconsin Valley Train. The fluvial deposits on Sikeston Ridge and more surfaces downstream match up and have been interpreted as a part of the same late Wisconsin full

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

and early late glacial valley train course. The relative ages of the terraces in the area were determined by coring and by comparing the heights of the terraces. Surfaces with very little loess covering indicate that they were formed in the full glacial to early late glacial period. While the relative age of the ridge has been agreed upon, it still remains unclear whether the sediment underlying Sikeston Ridge and the corresponding surfaces were deposited by the

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

or Mississippi River. Slackwater

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...

, which are mostly clay and silt carried as suspended load and deposited from floodwaters backfilled into the system, found in the area suggest that the Mississippi River was actively aggrading during the late Wisconsin full glacial period and that Sikeston Ridge represents a valley train constructed by the Mississippi River flowing through the Bell City– Oran Gap. Valley train surfaces to the east of Sikeston Ridge may have resulted from deposition by the Ohio River. Sikeston Ridge was also thought to have

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...

origins because of its orientation in the

New Madrid Seismic Zone The New Madrid Seismic Zone (), sometimes called the New Madrid Fault Line, is a major seismic zone and a prolific source of intraplate earthquakes (earthquakes within a tectonic plate) in the Southern and Midwestern United States, stretching to ...

. Trenching, drilling, and satellite imaging along the western scarp of Sikeston ridge showed slight subsurface deformation of less than 0.25 m, which is negligible compared to the 3 to 5 m height of the ridge at the spots where data was collected. Sikeston Ridge has been determined to have been

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

al in origin and has been associated with

colluvial Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combinati ...

deposition and channel incision during the latest Wisconsin glacial period, during the

Pleistocene The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed ...

. Scalloped patterns along the ridge margins point towards erosional trimming in the past.

Location

Sikeston Ridge is a prominent topographic feature of the in southeastern Missouri. It is located within the New Madrid Seismic Zone, but it is not tectonic in origin. New_Madrid_and_Wabash_seizmic_zones-USGS

New_Madrid_and_Wabash_seizmic_zones-USGS

The

Geographic Names Information System The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of ...

(GNIS) provides three location points running along the ridge: * * *

References

Sikeston Ridge: Pleistocene Erosional Remnant or Quaternary Fault-Bounded Block within the New Madrid Seismic Zone?
{{reflist Ridges of Missouri Historical geology Landforms of New Madrid County, Missouri Landforms of Scott County, Missouri

Origin

Location

See also

References