Entry Category: Geography

Soils

Arkansas has a diversity of rich soils that developed in a favorable environment for growing plants. The soils of Arkansas are the foundation of the number-one industry in the state—agriculture. Arkansas soils are natural, dynamic bodies of broken-down and weathered mineral and organic matter, in some places altered by human activity, capable of growing plants. Soils are unique and exist as a creation of five soil-forming factors: parent material, climate, topography, organisms, and time. Soil parent material is the geological source of the mineral component, defined as particles less than two millimeters in diameter. Arkansas soils developed from residium, loess, alluvium, and old marine sediment parent materials. Residium is weathered rock, and Arkansas’s residium is mostly soil derived from sandstone, …

Spring River

Flowing through northeastern Arkansas for approximately seventy-five miles in a southeastern direction, the Spring River empties into the Black River near Black Rock (Lawrence County). Mammoth Spring (Fulton County), adjacent to the Arkansas-Missouri state line, serves as the headwater for the Spring River. It expels more than nine million gallons of water each hour through a vent located eighty feet below the surface of Spring Lake, a low-turbidity body of water created by a dam downstream from the spring in what is now Mammoth Spring State Park. Although the water from the spring flows into the lake with great force, the vent’s depth prevents viewers on the surface from seeing the characteristic bubbling that springs typically produce. The consistent discharge …

Springs

Springs are naturally occurring geologic features that transport emerging groundwater to the land surface. They also represent a transition from groundwater to surface water. This water can be released through one opening, multiple openings, or numerous seeps in the rock strata or soil. Springs have unique properties such as discrete habitats with relatively constant conditions like temperature, dissolved oxygen concentration, and flow. The underground reservoirs from which springs arise may be cavernicolous limestone, gravel, sand, sediment, soil, or other permeable formations. A spring’s presence depends on the nature and relationship of permeable and impermeable units, the position of the water table, and the land topography. Faults often play an important role in the location of springs by damming up an …

St. Francis River

The St. Francis River originates in the northeast corner of Iron County, Missouri, and flows for twenty-five miles through the St. Francois Mountains, where it is a clear, fast-flowing whitewater stream until it reaches the Mississippi Alluvial Plain north of Poplar Bluff, Missouri, at which point the river becomes a sluggish, silt-laden stream. The river there turns south and travels 207 miles, forming the boundary between the Missouri bootheel and northeast Arkansas and then coursing between Crowley’s Ridge and the Mississippi River. The mouth of the St. Francis where it flows into the Mississippi is in the St. Francis National Forest just north of Helena-West Helena (Phillips County). The St. Francis River valley has been the site of human habitation …

Strawberry River

The Strawberry River rises southwest of Salem (Fulton County) and flows southeast from there for approximately ninety miles before emptying into the Black River in northeastern Independence County. The town of Strawberry (Lawrence County) takes its name from the river. Forty-three miles of the river have been have been designated part of the Arkansas Natural and Scenic Rivers System. The Strawberry River is a popular stream for canoeists and fishers. In addition to the smallmouth bass, the river is home to thirty-nine species of freshwater mussel, many of them rare, as well as the Strawberry River orangethroat darter (Etheostoma fragi), which lives only in this river system. The area around the Strawberry River has been the site of human habitation …

Sunken Lands

The term “sunken lands” (also called “sunk lands” or “sunk country”) refers to parts of Craighead, Mississippi, and Poinsett counties that shifted and sank during the New Madrid earthquakes which took place between 1811 and 1812. Because the land was submerged under water, claims to property based on riparian rights by large landowners generated controversy which lasted decades and ultimately reached the U.S. Supreme Court. When the New Madrid earthquakes began in December 1811, the territory which is today northeastern Arkansas was sparsely populated. An early chronicler described the earthquakes’ effect as the ground moving like waves on the land, when suddenly the earth would burst, sending up huge volumes of water and sand, leaving chasms where the earth had …

Table Rock Dam and Lake

Although Table Rock Lake lies mostly in the Ozark Mountains of Missouri, it plays an important role in water resource development for the White River basin, most of which lies in Arkansas. Its dam and reservoir are part of a flood-control system designed to reduce flooding in Arkansas’s Delta and the Mississippi drainage. Its hydroelectric power supplies electricity that the Southwest Power Administration sells to municipalities and rural cooperatives across northern Arkansas, southern Missouri, and several adjoining states. Recreational development resulting from the lake contributes to the economies of both Missouri and Arkansas. Table Rock Dam is located at river mile 528.8 on the White River about eight miles southwest of Branson, Missouri. The lake extends westerly from the dam …

Tyronza River

The Tyronza River rises in Mississippi County and flows primarily southwest until it empties into the St. Francis River just north of Parkin (Cross County). It no longer resembles the stream that it was up until the early twentieth century, as it has been channelized, ditched, and had its meander loops cut-off. Before the formation of the levee and drainage districts in the late nineteenth century that rerouted and channelized existing streams, the Tyronza River arose out of a body of water called Carson Lake located southwest of Osceola (Mississippi County). From there, it flowed across low swampy land, a region the locals referred to as the “scatters of Tyronza,” into Tyronza Lake before narrowing down into the regular path …

Waterfalls

Waterfalls often form as a stream flows over different bands of rock, with the soft rock eroding more quickly to undercut the hard rock. Unsupported, the overhanging rock eventually collapses. This fallen rock crashes down into a pool of water where the water’s swirling action results in more erosion. Over time, this process is repeated, resulting in a series of stair-step waterfalls retreating up a hillside. Nature creates an array of different types of vertical water runoffs. Experts have different ideas about what constitutes a waterfall. Although there are no definitive criteria, two methods have been developed to categorize waterfalls. Geometrical Classification categorizes waterfalls based on shapes and physical features. This method is helpful to identify falls for their visual …

West Gulf Coastal Plain

aka: Gulf Coastal Plain
aka: Coastal Plain
The Gulf Coastal Plain is an area of relatively gently sloping terrain extending across the southern portion of the United States from Texas to Georgia. It was covered by the waters of the Gulf of Mexico until about 50 million years ago. The land rose during periods of tectonic uplift, and water in the Gulf of Mexico retreated to near its present position. Because it was covered by the waters of the Gulf of Mexico for much of its history, the geologic terrain of the Coastal Plain is flat to rolling. Its bedrock is deeply covered with sediment, and the surface has extensive deposits of sand and gravel. The western portion of the Gulf Coastal Plain—the West Gulf Coastal Plain—extends …

White River

The 722-mile-long White River flowing through northern Arkansas and southern Missouri is a major tributary of the Mississippi River. The river begins in northwestern Arkansas in the Boston Mountains and flows east toward the Fayetteville (Washington County) area, where it then turns north. Near Eureka Springs (Carroll County), the river enters Missouri. It then flows southeast back into Arkansas past Bull Shoals (Marion County), Mountain Home (Baxter County), and Calico Rock (Izard County). At Batesville (Independence County) begins the second section of the river, known as the lower White. From Batesville, the White River flows south for 295 miles through Arkansas’s Delta region, past Augusta (Woodruff County), Des Arc (Prairie County), Clarendon (Monroe County), and St. Charles (Arkansas County), before …