Quaternary Dune Sands of Northeast Barton County

John Barker, Elizabeth Coffey, and Graham Markowitz

Fall 2009 ES546 Field Geomorphology
Dr. James S. Aber, Instructor

Table of Contents
Introduction
Methods
Site Characterization
Theories Behind Cheyenne Bottoms
Results/Conclusions
References

Inactive sand dunes in the study area near Camp Aldrich (Aber, 2009). October 28, 2009

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Introduction

Cheyenne Bottoms is a natural water filled depression located in central Kansas within Barton County. This basin offers an essential wetland for waterfowl during their central North American migration route. Cheyenne Bottoms encompasses 64 square miles (166km˛) and is in close proximity of Great Bend and Hoisington (Zimmerman, J.L. 1990). Present day Cheyenne Bottoms is managed by the Kansas Department of Wildlife and Parks and partially by the Nature Conservancy for its importance as a resting place for many rare and endangered species. Much funding for the upkeep and usage of the wetland has been in conjunction with mainly hunters as it continues to be designated as a premier hunting and bird watching location.

The lowland region comprised of primarily limestone and sandstone in which Cheyenne Bottoms is located was carved out and flattened by the Arkansas River. Throughout the Arkansas River floodplain, deposits of sand and other sediment have been passed to other points along its path. Sand dunes, such as the ones concentrated northeast of Cheyenne bottoms were created by wind and water erosion (Kansas Geological Survey). Two of the most generally accepted theories can be linked to warping and erosion during the tectonic forces of the Central Kansas Uplift. Stream capture is a common occurrence throughout the regional basins, making surficial wind and stream erosion a much more influential mechanism for the deposition of the adjacent sand dunes. These particular sand dunes where Camp Aldrich is located are presently not active with most covered by various vegetation. Many techniques such as small format aerial photography were utilized to determine which geomorphic processes were once active to produce this physiographic region.

Revised map of Kansas physiographic regions.
Taken from Aber and Aber (2009).

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Methodology: Small Format Aerial Photography

Aerial photography can present the characteristics of certain landforms with a completely different perspective. These photographs show geomorphic features that cannot usually be seen from ground views. This aerial perspective was not acquired by planes or satellites, but from small-format aerial photography. The low-height viewpoint is made possible by unmanned platforms such as blimp and kites, which can hold up a range of compact digital cameras (Warner et al., 1996). Kite and blimp aerial photography is achievable by a lifting mechanism, either wind for the kite or helium for the blimp to help elevate the camera apparatus.

Environmental factors are exceedingly pertinent in determining the model of kite and camera being used. If wind conditions are suitable, larger kites can support an improved model of camera, usually associated with a heavier piece of equipment. However, under low wind conditions, blimps can be utilized to help elevate equivalent cameras (Aber and Aber, 2007)

Helium filled blimp used to capture the landscape of Cheyenne Bottoms from five hundred feet in the air. Photo taken by author Elizabeth Coffey, 2009.

This style of small-format aerial photography was set up for kite aerial photography. The kite used throughout the Field Geomorphology course was the Rokkaku model. The camera rig was attached to the kite line following the increase in elevation of the kite from a controlled spool that is manned from the ground. This large wooden reel includes 1000 meters of line and a 1 meter handle that can be positioned for greater leverage.

The camera rig for kite and blimp aerial photography was controlled by a radio transmitter, which can be manipulated to provide all angles of the targeted landform. Our pictures were taken from up to 500 feet (150m) above the ground using radio controlled camera rigs that could be tilted vertical to horizontal and rotated 360 degrees (Aber and Aber, 2009).

Camera rig attached to the underside of the blimp. Photo taken by author Elizabeth Coffey, 2009.
The kite was used during our field work of the sand dunes at the study area near Camp Aldrich. Photo taken by Elizabeth Coffey, 2009.

Wind conditions were suitable in the Cheyenne Bottoms vicinity to participate in both kite and blimp aerial photography.

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Site Characterization

Climate/Vegetation:

In analysis of sediment and pollen record of Cheyenne Bottoms, evidence shows a regional vegetation and climate change during the late Quaternary. “Two major litho- and biostratigraphic units, a Farmdalian zone and a Holocene zone are separated by a major unconformity spanning the Woodfordian zone.” (Fredlund, 2002) There is evidence of a basin-wide drying preceding the unconformity. The lack of accumulation of sediment suggests a region-wide aridity and strengthened surface winds that would have caused active sand dunes. Before this aridity in the early Woodfordian, 24,000 to 11,000 years ago, a persistent shallow water marshland dominated the Cheyenne Bottoms vegetation. The dominant vegetation was an open grassland-sage steppe throughout the Farmdalian zone, 30,000 to 24,000 years ago, with limited populations of spruce, juniper, aspen, birch, and boxelder. Water levels have fluctuated throughout the Holocene, 11,000 to present.

View of Cheyenne Bottoms vegetation. Photo taken by author Elizabeth Coffey, 2009.
View of Camp Aldrich study area, displaying the active vegatation atop the inactive sand dunes (Aber, 2009).

Geomorphology:

The surface of the study area northeast of Cheyenne Bottoms consists of Quaternary dune sand. Ranging in thickness from 0 to 50 feet, the wind-blown sand is fine to medium grained containing small amounts of silt, clay, and coarse sand. The dune sand is believed to have originated locally from the Cheyenne Bottoms basin as a result of eolian deposits of a drier climate during the middle Holocene. The middle Holocene was a time of warmer temperatures, also known as the Medieval Warm Period.

The source of the sand is believed to be from the local, surficial bedrock of the Dakota Formation which consists of white, gray, red, brown, and tan kaolinitic claystone, mudstone, shale, siltstone and sandstone (Zeller et al., 1968). The origin of this sediment is the result of stream action on the Dakota Formation during the Pleistocene. The sandstone was eroded and deposited throughout the area which includes the natural basin of Cheyenne Bottoms. The consequent erosion at this time was due to the incising of streams because of lower sea-levels (Frye & Leonard, 1952). The feature possibly responsible for the erosion of the sandstone bedrock and transport of the sediment is the Galatia Channel, a channel from the early Pleistocene. Throughout the Pleistocene there were approximately three other drainage patterns that shaped the area which eventually evolved into the drainage pattern of today (Frye & Leonard, 1952).

As the climate in the area shifted during the middle Holocene to a much warmer, drier, semi-arid climate, the finer alluvial deposits of Cheyenne Bottoms gave way to the elements, predominantly strong southwesterly winds. The direction of the predominant wind patterns in the area correlates the position of the basin of Cheyenne Bottoms to the position of the sand dunes. As you move to northeast from Cheyenne Bottoms the texture of the eolian deposits grade from larger sands to finer sands, silts and clays. Presently the sand dunes are inactive because of the present humid climate in the region, it has enabled vegetation to take over stabilizing the top of the dunes and the water table has risen securing the sand below.

Geologic map of Barton County. The Quaternary dune sand (Qds) is located to the northeast of Cheyenne Bottoms (Kansas Geological Survey, 2009).

Nebraskan age drainage patterns during the Pleistocene. The Galatia channel is a proposed cause of erosion of bedrock, transport and deposition of sediment into Cheyenne Bottoms, eventually supplying the source for the dune sands to the northeast (Frye and Leonard, 1952).

Human Land Use:

Cheyenne Bottoms and the surrounding sand dunes have been used in many fashions for humans’ use that have affected land, water, and wind. For decades Cheyenne Bottoms has been used primarily for waterfowl hunting grounds. The upkeep of the wetlands provides an ideal migratory stop for many species of waterfowl. This has altered the water and vegetation with the diversion of water in a dike and canal system for the Cheyenne Bottoms National Wildlife Refuge. Intricate water diversion systems have raised the water table in comparison to the surrounding area.

Use of land for agricultural purposes has been taxing on the top sediments, creating an erosional environment that disrupts the natural vegetation and sediments. The sand dunes have become non-active since their original wind and water depositional period because of the lowering water table and the growth of vegetation. With the disturbance of the sand for use in concrete and country roads, the sediments have been disheveled and natural processes altered. Structures such as residential and commercial buildings have disrupted the wind that sweeps across Kansas. Wind would only increase in intensity while going around these structures which could upset the surrounding loose sediments. Lastly, the raising of the water table of Cheyenne Bottoms could result in the lowering of the water of the sand dunes area. Sand dunes could essentially become active again if conditions become favorable. Humans’ use of the land has already disturbed the natural processes of the land and potential consequences lie in the future.

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Theories Behind Cheyenne Bottoms

Many theories and hypothesis concerning the formation of wetlands at Cheyenne Bottoms include salt or evaporite dissolution, tectonic and structural movement, stream capture, meteor impact, and wind erosion. Because of few publications and limited research regarding the structural geology, the creation of the wetlands is still unclear. Some theories have been disproved but many are considered plausible. One hypothesis associated to a meteor impact is no longer accepted as the foundation of the wetlands because no remains of a meteorite around the impact area have been discovered.

Other active theories include subsidence due to dissolution of rock salt or other evaporites found within the area. The dissolution of the local Hutchinson Salt Member of the Wellington Formation was said to be the only sequence thick enough to support the amount of subsidence associated with the Cheyenne Bottoms depression (Bayne 1977). Although there are many sinkholes associated with the dissolution of the Wellington Formation in the area, the Hill Hole type topography can usually be related to a saline water body. This does not seem to be the case with the wetlands at Cheyenne Bottoms.


Results/Conclusions

The relationship between the Quaternary dune sand and the basin at Cheyenne Bottoms has been the result of geomorphic processes, while presently human influence has played a larger part in the identification of these areas.

A series of processes have acted upon the region to produce the sand dunes near Camp Aldrich and shape the area. The processes include glacial drainage, extensive erosion of the bedrock, alluvial deposition, and eolian erosion and deposition. This activity is the result of a humid to arid climate cycle since the middle of the Holocene. Climate change throughout the Holocene has allowed the subsurface to influence the surface especially in the case of keeping the sand dunes inactive or active. Although the origin of the Cheyenne Bottoms remains unclear the geomorphic processes responsible for the sand dunes have played some part in enhancing the basin feature through alluvial and wind erosion.

Through the implementation of canals to keep water supplied to the basin and the construction of elevated objects in the basin that have diminished the effects of wind. The effects of human influence have kept the area of study geomorphically stable.

The ability to view the landscape using the methods of small format aerial photography has given the opportunity to capture landforms from a different perspective which gives the scientist an alternate avenue in interpolating the land and its relationships.

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References

Aber, J.S., Aber, S. 2009. Kansas Physiographic Regions-Bird’s-eye Views. Educational Series 17, 2009. Lawrence, Kansas. The University of Kansas. Kansas Geological Survey. p 3,4.

Aber, J.S., Aber, S. 2007. Kite Aerial Photography Cameras and Rigs. www.geospectra.net/kite/equip/camera_rigs.htm. Accessed October 27, 2009.

Aber, J.S., Aber, S. 2004. Kite Aerial Photography Equipment. www.geospectra.net/kite/equip/equip.htm. Accessed October 27, 2009.

Bayne, Charles K. Geology and Structure of Cheyenne Bottoms, Barton County, Kansas. 1977. Kansas Geological Survey. Bulletin State Geological Survey of Kansas; 211 pt. 2. University of Kansas Publications, Lawrence Kansas. www.kgs.ku.edu/Publications/Bulletins/211_2/index.html. Accessed October 3, 2009.

Fredlund, G.G. 1992. Analysis of Quaternary pollen from Cheyenne Bottoms, Kansas: evidence for late Quaternary vegetation and climates in the Central Great Plains. Dissertation. University of Kansas, Lawrence, Kansas, USA.

Frye, J. C. & A. B. Leonard, 1952. Pleistocene geology of Kansas: Summary of Pleistocene drainage changes. KGS Bulletin, no. 99. www.kgs.ku.edu/Publications/Bulletins/99/07_drain.html. Accessed Oct. 20, 2009.

Kansas Geological Survey, 2009. Barton county geologic map. www.kgs.ku.edu/General/Geology/County/abc/barton.html. Accessed Oct. 20, 2009.

Latta, B. F. 1950. Geology and groundwater resources of Barton County, Kansas. KGS Bulletin, no. 88. www.kgs.ku.edu/General/Geology/Barton/05_geol.html. Accessed Oct. 20, 2009.

Warner, W.S., Graham, R. W. and Read, R. E., 1996, Small format aerial photography: Bethesda, Maryland, American Society for Photogrammetry and Remote Sensing, 348 p.

Zeller, D. E., J.M. Jewett, C.K. Bayne, E. D. Goebel, H. G., O’Connor, and A. Swineford, 1968. Stratigraphic succession in Kansas. Mesozoic Era: Cretaceous system. KGS Bulletin, no. 189. www.kgs.ku.edu/Publications/Bulletins/189/09_meso.html#CRET. Accessed Oct. 20, 2009.

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