Sand and Sandstone

Sand is loose unconsolidated material having particle size between silt and pebbles (1/16 to 2mm). When held together by chemical cement or by clay, they are called sandstone. Sandstone results from the breaking down or weathering of older rocks and from the transportation and sorting of rock fragments by water or by wind. Sand and sandstone is commonly used in making glass, as building materials (mainly concrete), as filters and for making molds in foundries. The sand/sandstone along the larger rivers is abundant, although some of the deposits have impurities.

Sand is abundantly found in Kansas. Most of it consists of grains of quartz and feldspar. Sand also contains traces of other materials such as igneous and metamorphic rocks formed outside of Kansas and carried in by stream & rivers. Sand occurs in most large stream valleys, in regions of old glacial outwash (Atchison County) or in deposits of wind-blown sand in dunes along the Arkansas River in Hamilton, Kearny, Finney, Gray, Ford, Kiowa, Edwards, Pratt, Pawnee, Stafford, Barton, Clark and Reno Counties. Sand Dunes are also found along I-70 in Dickinson and Saline counties. Loose sand is found in parts of the Ogallala Formation (Tertiary) along old river deposits in western Kansas.

Sandstones consist largely of quartz grains and are held together by some natural cement or matrix such as calcium carbonate, iron oxide, silica cement, or clay. Sandstone is classified according to the type of cement.

Sandstone occurs interbedded with shale and limestone in the eastern part of the state(Pennsylvanian & Permian) occurring as channel deposits cutting through limestone. Most of this sandstone is buff or brownish in color, and some is cemented by iron oxide. Sandstone of the Dakota Formation (Cretaceous) is present in the Smoky Hills region in north-central Kansas in a area extending from Rice and McPherson counties to Washington County. Much of it is cemented by dark-brown iron oxide and is so resistant to erosion that it caps steep hills. The Dakota sandstone also forms large concretions at Rock City near Minneapolis, Kansas and a Mushroom Rock State Park in Ellsworth County. Soft crumbly iron oxide cemented Cheyenne Sandstone (Cretaceous) form cliff and box canyons in small areas in Kiowa, Comanche and Clark counties. Colors includes yellow, reds, purple and brown. Red, fine grained Permian sandstones outcrop in picturesque canyons in south-central Kansas.

At the surface, calcium carbonate cemented sandstone is the most common rock in the Ogallala Formation (Tertiary) in western Kansas. This rock is porous and the particles are poorly sorted. It looks so much like concrete that it is popularly known as mortar beds. Good outcrops occur near the town of Cedar Bluffs in Decatur County.

Opaline Sandstone has an opal cement. (also called orthoquartzite, although it is not a metamorphic rock) Hard, dense gray-green opaline sandstones are found in some parts of the Ogallala Formation, especially in southern Phillips County and also occurs in Graham, Hodgeman, Ness, Norton, Rawlins, Rooks and Smith counties. It is occasionally used as a building material and good examples are present in a Hill City, Kansas park.

Table 2 - Particle Size
Sedimentary Rocks

Size

Fragment

Rounded, Subrounded, Subangular
Aggregate

Angular
Aggregate
> 256mm Boulder Boulder gravel, Boulder conglomerate

Rubble
256 - 64mm Cobble Cobble gravel, cobble conglomerate

  Breccia
64 - 4mm Pebble Pebble gravel, pebble conglomerate
4 - 2 mm Granule Granule gravel  
2 - 1/16 mm Sand Sand, Sandstone Grit (1/2 - 1 mm)
1/16 - 1/256mm Silt Silt, Siltstone  
< 1/256 mm Clay Clay, Shale