Hostname: page-component-5c6d5d7d68-xq9c7 Total loading time: 0 Render date: 2024-08-22T22:25:34.121Z Has data issue: false hasContentIssue false

Late Quaternary Floodplain Sedimentation along the Pomme de Terre River, Southern Missouri

Published online by Cambridge University Press:  20 January 2017

G. Robert Brakenridge*
Affiliation:
Department of Geosciences, University of Arizona, Tucson, Arizona 85721

Abstract

New cross sections and dates from along the Pomme de Terre River clarify the complex local history of valley development and floodplain sedimentation. The observed history begins with a series of ancient bedrock strath terraces that record past bedrock valley positions at 15.5 to more than 58 m above the modern bedrock floor. Each strath is capped by 1–2 m of channel gravel and sand permeated by red clay. Sometime previous to ca. 140,000 yr B.P., a much lower bedrock valley only about 5–6 m above the modern level was excavated. By 140,000 yr B.P., accumulation of red and gray mottled silty clay had commenced, and had reached to 8.5 m above the modern floodplain before 48,900 ± 900 14C yr B.P. Sometime between ca. 49,000 and 45,000 14C yr B.P., erosion caused abandonment of an oxbow meander, and lowered the bedrock valley to about its present depth. Younger yellowish-red and gray mottled silty clay alluvium then began accumulating. This mid-Wisconsinan fill reached to 2.5 m above the modern floodplain sometime before 31,800 ± 1340 14C yr B.P., at which time another erosional phase was in progress. A late Wisconsinan olive clay accumulated between 27,480 ± 1950 and ca. 23,000 14C yr B.P., followed by approximate stability until 13,550 ± 400 14C yr B.P. After stability, an erosional episode began, but by 10,200 ± 330 14C yr B.P., deposition of a distinctive brown clayey silt was underway. This early Holocene fill reached to about the same level as the mid-Wisconsinan fill by 8100 ± 140 14C yr B.P. Erosion occurred between this date and 7490 ± 170 14C yr B.P., but the former floodplain level was rapidly reattained, and was apparently stable until ca. 5000 14C yr B.P. Finally, erosional unconformities and 17 dates from the brown clayey silt, and from younger grayish-brown silty sand underlying the modern floodplain, record subsequent episodes of floodplain erosion at ca. 5000, 2900, 1500 and 350 14C yr B.P. The timing of Pomme de Terre floodplain sedimentary regimes, characterized by net aggradation, erosion, or stability, may have been controlled by climate. In particular, both periods of stability appear to have been coeval to times of strongly zonal upper atmospheric circulation. Intensified zonal circulation would have resulted in less frequent large floods and an increased dominance by floods of small to moderate size. In contrast, there are no obvious parallels to be drawn between this local alluvial history and sea level or glacial outwash induced baselevel changes.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ahler, S.A. Sedimentary processes at Rodgers Shelter Wood, W.R. McMillan, R.B. (1976). Prehistoric Man and His Environments Academic Press New York 123-139 Google Scholar
Brakenridge, G.R. (1978). Quaternary deposits and soils in southern Missouri and their paleoclimatic significance Tenth International Congress on Sedimentology Abstracts Vol. 1, International Association of Sedimentologists 82-83 Google Scholar
Brakenridge, G.R. (1979). The impact of climatic change on floodplain sedimentation, soil formation, and eolian activity in southern Missouri Geological Society of America Abstracts with Programs 11, 7 393 Google Scholar
Brakenridge, G.R. (1980).Widespread episodes of stream erosion and their climatic cause Nature (London) 283, 655-656 CrossRefGoogle Scholar
Bull, W.B. (1979).Threshold of critical power in streams Geological Society of America Bulletin Part I 90, 453-464 Google Scholar
Curray, J.R. Sediments and history of Holocene transgression, Continental Shelf, northwest Gulf of Mexico Shepard, F.P. et al. (1960). Recent Sediments, N.W. Gulf of Mexico American Association of Petroleum Geologists Tulsa, Okla 221-266 Google Scholar
Delcourt, P.A. Delcourt, H.R. (1978). Reply to comments by Ervin G. Otvos, Jr. Quaternary Research 9, 253-259 Google Scholar
Dreimanis, A. (1977). Late Wisconsin glacial retreat in the Great Lakes region, North America Annals of the New York Academy of Sciences 288, 70-89 Google Scholar
Fisk, H.N. (1951).Loess and Quaternary geology of the lower Mississippi valley Journal of Geology 59, 333-356 CrossRefGoogle Scholar
Haynes, C.V. Late Quaternary geology of the lower Pomme de Terre valley Wood, W.R. McMillan, R.B. (1976).Prehistoric Man and His Environments Academic Press New York 47-61 Google Scholar
Haynes, C.V. (1977). Report on geochronological investigations in the Harry S Truman Reservoir area, Benton and Hickory counties, Missouri Cultural Resources Survey, Harry S Truman Dam and Reservoir Project Vol. 10, Department of Anthropology, University of Missouri Columbia 23-32 Google Scholar
Haynes, C.V. (1978). Late Quaternary geochronology of the lower Pomme de Terre River, Missouri Meeting of the Society of American Archeologists (abstract) Google Scholar
Johnson, D.L. (1977). Soils and soil-geomorphic investigations in the lower Pomme de Terre valley Cultural Resources Survey, Harry S Truman Dam and Reservoir Project Vol. 10, Department of Anthropology, University of Missouri Columbia 59-139 Google Scholar
King, F.B. (1977). Spatial and temporal distribution of plant resources in the Harry S Truman Reservoir Cultural Resources Survey, Harry S Truman Dam and Reservoir Project Vol. 10, Department of Anthropology, University of Missouri Columbia 33-58 Google Scholar
King, J.E. (1973). Late Pleistocene palynology and biogeography of the western Missouri Ozarks Ecological Monographs 43, 539-565 Google Scholar
Knox, J.C. Concept of the graded stream Melhorn, W.N. Flemal, R.C. (1976). Theories of Landform Development State University of New York Publications in Geomorphology 169-198 Binghamton, N.Y. Google Scholar
Knox, J.C. Bartlein, P.J. Hirschboeck, K.K. Muckenhirn, R.J.(1975). The response of floods and sediment yields to climate variation and land use in the upper Mississippi Valley University of Wisconsin Institute for Environmental Studies Report No. 52 Madison Google Scholar
Kraus, E.B. (1973). Comparison between ice age and present circulation Nature (London) 245, 129-132 Google Scholar
Leighton, M.M. (1960). The classification of the Wisconsin glacial stage of the north central U.S. Journal of Geology 68, 529-552 Google Scholar
McKinney, C.R. (1979). Implications of high U234 for dating early man Geological Society of America Abstracts with Programs 11, 7 477 Google Scholar
Otvos, E.G. (1978).Comment on “The Tunica Hills, Louisiana-Mississippi: Late glacial locality for spruce and deciduous forest species” by P. A. and H. R. Delcourt Quaternary Research 9, 250-252 CrossRefGoogle Scholar
Saucier, R.F. Fleetwood, A.R. (1970). Origin and chronologic significance of late Quaternary terraces, Ouachita River, Arkansas and Louisiana Geological Society of America Bulletin 81, 869-890 Google Scholar
Saunders, J.J. (1977). Late Pleistocene Vertebrates of the Western Ozark Highlands, Missouri Illinois State Museum Reports of Investigations, No. 331, Springfield Google Scholar
U.S. Department of Commerce (1964). Decennial Census of the U.S. Climate Supplement, 1951–1960, Missouri U.S. Department of Commerce Google Scholar
U.S. Geological Survey (1961).Surface Water Supply of the U.S. to 1960. Part 6-B: Missouri River Basin below Sioux City, Iowa United States Geological Survey, Water-Supply Paper 2119 Google Scholar
Williams, J. (1978). A brief comparison of model simulations of glacial period maximum atmospheric circulation Palaeogeography, Palaeoclimatology, Palaeoecology 25, 191-198 CrossRefGoogle Scholar
Wood, W.R. McMillan, R.B. 1976). Prehistoric Man and His Environments (Academic Press New York Google Scholar