Crowley's Ridge

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Crowley's Ridge runs through the Mississippi embayment in this shaded-relief map. Crowleys Ridge relief v1.jpg
Crowley's Ridge runs through the Mississippi embayment in this shaded-relief map.

Crowley's Ridge (also Crowleys Ridge) is a geological formation that rises 250 to 550 feet (170 m) above the alluvial plain of the Mississippi embayment in a 150-mile (240 km) line from southeastern Missouri to the Mississippi River near Helena, Arkansas. It is the most prominent feature in the Mississippi Alluvial Plain between Cape Girardeau, Missouri, and the Gulf of Mexico.

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This narrow rolling hill region rising above the flat plain is the sixth, and smallest, natural division of the state of Arkansas. It is protected within Ozark–St. Francis National Forest.

Most of the major cities of the Arkansas Delta region lie along Crowley's Ridge. It was named after Benjamin Crowley, known as the first American settler to reach the area, sometime around 1820. The Civil War Battle of Chalk Bluff was fought on Crowley's Ridge on May 1–2, 1863.

Composition and origin

The ridge is primarily composed of the windblown glacially derived sediment known as loess. It contrasts greatly with the flat table land around it and with the black soil that makes up the delta. The ridge varies from half a mile to 12 miles (19 km) wide and reaches an elevation of 550 feet (170 m) near its northern extremity. The highest point on the ridge in Arkansas is "Legacy Mountain" at the Craighead County solid waste site south of Jonesboro. The formation is generally thought to have originally been an island between the Mississippi River and Ohio River that was isolated as a long low hilly ridge after the rivers changed course millions of years ago. [1] Recent seismic evidence, however, questions the fluvial origin by focusing on uplift along ridge bounding faults. [2]

Loess deposits are found along both sides of the Mississippi River Alluvial Valley. These loess deposits are a classic example of periglacial loess. [3] [4] Crowley's Ridge is a natural loess accumulation point. A comparable example of this type of deposit is the Loess Hills in northwestern Missouri and southwestern Iowa.

There is evidence that the area's elevation has increased over the years, suggesting that uplift is still taking place. This alternative explanation posits a link between the ridge and the nearby New Madrid Seismic Zone. [2]

Soils and vegetation

The flora and fauna of the ridge seem more closely related to the Tennessee hills to the east than to the Ozark Mountains to the west. This unique habitat has been protected by the establishment of several state and city parks, the St. Francis National Forest, recreational lakes, and in 1997 a national scenic byway, the Crowley's Ridge Parkway. [5] [6]

The soils in this area are moderately fertile and sometimes rich. The land is moderately rugged, discouraging row-crop agriculture. These soils are easily eroded. There is some commercial agriculture in the loessal plains area of the ridge. The ridge is surrounded by the fertile lands of the delta region. The vegetation is predominantly oak and hickory forests, similar to vegetation found in the Appalachian Mountains. Examples are the tulip tree (a yellow poplar) and the American beech. Ferns and flowers abound here, including the American bellflower, fire pink, butterfly weed, cardinal flower, blue lobelia, phlox, verbena, wild hydrangea, hibiscus, aster and yellow jasmine. The low-lying areas around the ridge were once much swampier, and the ridge provided a natural and more healthful place for settlers to establish homes. The ridge became a natural north-south communications link for the region, since travel along the ridge was much easier than through the swampy lowlands. [7]

Fossils

The region adjacent to the ridge is covered with thick deltaic soils, and few fossils are found except in gravel pits. These pits sometimes reveal the teeth of large mastodons, mammoths and horses, which roamed the continent as recently as 10,000 years ago. Crowley's Ridge contains important exposures of fossiliferous Tertiary sediments and contains the only documented Miocene exposures in the state. A silicified conifer stump weighing several tons was unearthed near Wittsburg, and many more were found around Piggott. Mastodon bones were found within the city limits of Helena at the southern end of the ridge. Near Forrest City, in the bed of Crow Creek, a deposit of oyster shells estimated to be nearly 7,000,000 cubic yards in size was discovered. [7]

Namesake

Grave of Benjamin Crowley in Shiloh Cemetery at Crowley's Ridge State Park south of Paragould, Arkansas. The inscription reads "Benjamin Crowley - 1758-1842 - The man for whom Crowley's Ridge is named" Crowleys Ridge State Park Shiloh Cemetery Paragould AR 05.jpg
Grave of Benjamin Crowley in Shiloh Cemetery at Crowley's Ridge State Park south of Paragould, Arkansas. The inscription reads "Benjamin Crowley - 1758-1842 - The man for whom Crowley's Ridge is named"

Crowley's Ridge is named after Benjamin Crowley (1758–1842), the first American settler of the Ridge near Paragould, Arkansas. Crowley is buried in the Shiloh Cemetery in Greene County, Arkansas, and a monument marks the spot. The cemetery is part of Crowley's Ridge State Park. Next to Crowley's grave, other early settlers of the ridge are buried in unmarked graves.

Crowley's Ridge Nature Center

The Forrest L. Wood Crowley’s Ridge Nature Center in Jonesboro, Arkansas features self-guided exhibits about area's topography and natural history and wildlife of Crowley’s Ridge. [8] Operated by the Arkansas Fish and Game Commission (AGFC) and opened in 2004, the Center includes an exhibit area, discovery room, observation tower, meeting rooms, auditorium, and gift shop. [9] Outside there are trails through trails through wetlands, forest and prairie, and a 1/4 mile universally accessible trail and boardwalk around a pond. The Center offers many activities and nature education programs. It is named after Forrest L. Wood, a former commissioner and supporter of the AGFC.

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Loess A predominantly silt-sized clastic sediment of accumulated wind-blown dust

Loess is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of the Earth's land area is covered by loess or similar deposits.

Ozark–St. Francis National Forest

The Ozark – St. Francis National Forest is a United States National Forest that is located in the state of Arkansas. It is composed of two separate forests, Ozark National Forest in the Ozark Mountains; and St. Francis National Forest on Crowley's Ridge. Each forest has distinct biological, topographical, and geological differences.

Cane Creek State Park

Cane Creek State Park is a 2,053-acre (831 ha) Arkansas state park in Lincoln County, Arkansas in the United States. Straddling the Gulf Coastal Plain and the Mississippi Delta, the park includes the 1,675-acre (678 ha) Cane Creek Lake, a wooded lake which borders Bayou Bartholomew, the world's longest bayou. The park became a reality when the U.S. Department of Agriculture’s Soil Conservation Service said it would provide federal funds to the project in 1973, prompting the Arkansas Game and Fish Commission (AGFC) to pledge to build and maintain the lake within the park. The park is characterized by rolling wooded hills, deep draws, and steeply sloping ridges.

Alluvial plain

An alluvial plain is a largely flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the smaller area over which the rivers flood at a particular period of time, whereas the alluvial plain is the larger area representing the region over which the floodplains have shifted over geological time.

Mississippi embayment Low-lying basin filled with Cretaceous to recent sediments

The Mississippi Embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its confluence with the Ohio River at Cairo, Illinois. The current sedimentary area was formed in the Cretaceous and early Cenozoic by the filling with sediment of a pre-existing basin. An explanation for the embayment's formation was put forward by Van Arsdale and Cox in 2007: movement of the earth's crust brought this region over a volcanic "hotspot" in the Earth's mantle causing an upthrust of magma which formed the Appalachian-Ouachita range. Subsequent erosion caused a deep trough that was flooded by the Gulf of Mexico and eventually filled with sediment from the Mississippi River.

Gulf Coastal Plain plain around the Gulf of Mexico in the Southern United States and eastern Mexico

The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico.

Mississippi Delta (disambiguation) Disambiguation page providing links to topics that could be referred to by the same search term

Mississippi Delta may refer to:

Loess Hills

The Loess Hills are a formation of wind-deposited loess soil in the westernmost parts of Iowa and Missouri, and the easternmost parts of Nebraska and Kansas, along the Missouri River.

Chickasaw Bluff human settlement in United States of America

The Chickasaw Bluff is the high ground rising about 50 to 200 feet (20–60 m) above the Mississippi River flood plain between Fulton in Lauderdale County, Tennessee and Memphis in Shelby County, Tennessee.

Arkansas Scenic Byways highway system

The Arkansas Scenic Byways Program is a list of highways, mainly state highways, that have been designated by the Arkansas State Highway and Transportation Department (AHTD) as scenic highways. The Arkansas General Assembly designates routes for scenic byway status upon successful nomination. For a highway to be declared scenic, a group interested in preserving the scenic, cultural, recreational, and historic qualities of the route must be created. Mayors of all communities along the route and county judges from each affected county must be included in the organization. Scenic highways are marked with a circular shield in addition to regular route markers.

Crowleys Ridge Parkway highway in Arkansas and Missouri

Crowley's Ridge Parkway is a 212.0-mile-long (341.2 km) National Scenic Byway in northeast Arkansas and the Missouri Bootheel along Crowley's Ridge in the United States. Motorists can access the parkway from US Route 49 (US 49) at its southern terminus near the Helena Bridge over the Mississippi River outside Helena-West Helena, Arkansas, or from Missouri Route 25 (Route 25) near Kennett, Missouri. The parkway runs along Crowley's Ridge, a unique geological formation, and also parts of the St. Francis National Forest, the Mississippi River and the Mississippi Alluvial Plain. Along the route are many National Register of Historic Places properties, Civil War battlefields, parks, and other archeological and culturally significant points.

Arkansas Delta

The Arkansas Delta is one of the six natural regions of the state of Arkansas. Willard B. Gatewood Jr., author of The Arkansas Delta: Land of Paradox, says that rich cotton lands of the Arkansas Delta make that area "The Deepest of the Deep South."

Geography of Arkansas

The geography of Arkansas varies widely. The state is covered by mountains, river valleys, forests, lakes, and bayous in addition to the cities of Arkansas. Hot Springs National Park features bubbling springs of hot water, formerly sought across the country for their healing properties. Crowley's Ridge is a geological anomaly rising above the surrounding lowlands of the Mississippi embayment.

Ozark Highlands (ecoregion)

The Ozark Highlands is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in four U.S. states. Most of the region is within Missouri, with a part in Arkansas and small sections in Oklahoma and Kansas. It is the largest subdivision of the region known as the Ozark Mountains, flatter in comparison to the Boston Mountains in Arkansas, the steepest part of the Ozarks.

Lake Frierson State Park

Lake Frierson State Park is a 114-acre (46 ha) Arkansas state park on Crowley's Ridge in Greene County, eastern Arkansas.

Mississippi Alluvial Plain (ecoregion)

The Mississippi Alluvial Plain is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Arkansas, Louisiana, and Mississippi. It parallels the Mississippi River from the Midwestern United States to the Gulf of Mexico.

The geology of Arkansas includes deep 1.4 billion year old igneous crystalline basement rock from the Proterozoic known only from boreholes, overlain by extensive sedimentary rocks and even some volcanic rocks. The region was a shallow marine, riverine and coastal environment for much of the early Paleozoic as multi-cellular life became commonplace. At the end of the Paleozoic in the Permian the region experienced coal formation and extensive faulting and uplift related to the Ouachita orogeny mountain building event. Extensive erosion of new highlands created a mixture of continental and marine sediments and much of the state remained flooded even into the last 66 million years of the Cenozoic. In recent Pleistocene and Holocene time, glacial sediments poured into the region from the north, down major rivers, forming dunes and sedimentary ridges. Today, Arkansas has an active oil and gas industry, although hydraulic fracturing related earthquake swarms have limited extraction and the state also has mining of brines, sand, gravel and other industrial minerals.

Highway 334 is a designation for two state highways in the Arkansas Delta. One segment begins at Highway 1 Business (AR 1B) in Forrest City and runs southeast to Tuni. A second route begins at US Highway 79 (US 79) at Bledsoe and runs east. Both routes were created in the mid-1960s, and have remained along the same alignment since. Both routes are maintained by the Arkansas Department of Transportation (ArDOT).

References

  1. "National Scenic Byways - Scenic Byways and Highways - Arkansas Scenic Routes". Archived from the original on 2013-09-12. Retrieved 2013-06-19.
  2. 1 2 Roy B. Van Arsdale, Robert A. Williams, Eugene S. Schweig, Kaye M. Shedlock, Jack K. Odum and Kenneth W.King, "The origin of Crowley's Ridge, northeastern Arkansas: Erosional remnant or tectonic uplift?" Bulletin of the Seismological Society of America; August 1995; v. 85; no. 4; p. 963-985. Abstract
  3. Bettis, E. Arthur; Muhs, Daniel R.; Roberts, Helen M.; Wintle, Ann G. (2003). "Last Glacial loess in the conterminous USA". Quaternary Science Reviews. 22 (18–19): 1907–1946. doi:10.1016/s0277-3791(03)00169-0.
  4. Muhs, Daniel R.; Bettis, E. Arthur (2003). "Quaternary loess-Paleosol sequences as examples of climate-driven sedimentary extremes" (PDF). Geological Society of America Special Paper. 370: 53–74. doi:10.1130/0-8137-2370-1.53. Archived from the original (PDF) on 10 February 2012.
  5. Crowley's Ridge Parkway National Scenic Byway Archived 2004-03-13 at the Wayback Machine
  6. Crowley's Ridge Parkway
  7. 1 2 Crowley's Ridge Archived March 12, 2003, at the Wayback Machine
  8. "Crowley's Ridge Natue Center". Arkansas Fish and Game Commission. Retrieved 6 November 2017.
  9. "Forrest L. Wood Crowley's Ridge Nature Center". Encyclopedia of Arkansas. Retrieved 6 November 2017.

Coordinates: 36°08′31″N90°34′30″W / 36.142°N 90.575°W / 36.142; -90.575