Abstract
The impact of Holocene climate on vegetation and the alluvial landscape of the prairie peninsula's southern margin
Abstracts with programs - Geological Society of America, Vol.37(5), p.69
Geological Society of America, North-Central Section, 39th annual meeting
05/2005
Abstract
Continuing stratigraphic and geochemical investigation of Bear Creek, a fourth order tributary to the Sac River along the western margin of the Ozark Plateau, southwestern Missouri, offers a detailed picture of landscape response to Holocene climate and vegetation changes in the southern portion of the prairie-forest ecotone. The chronology, lithology, and distribution of valley fill sequences reconstructed from outcrops and coring transects provide a framework for stable carbon isotope (delta (super 13) C values) that yield a history of vegetation changes within the valley. Episodes of aggradation, stability, and erosion similar to those previously documented in larger valleys in the western Ozarks are present within the Bear Creek valley fill. A record of Holocene storm activity recorded in the speleothem record of Crevice Cave, located on the eastern margin of the Ozark Plateau, shows a shift in cave flood frequency around 4500 years BP to a state of more frequent and intense flooding (Lepley, 2004). Leply found the timing of the shift similar to a shift in state of El Nino events to one of increased frequency and intensity. At Bear Creek a period of increased channel activity and removal of floodplain sediment at approximately 4400 years BP corresponds with the increase in storm activity as recorded at Crevice Cave. Floodplain aggradation occurred from 4400 years BP until the late Holocene. During this period the vegetation record (soil delta (super 13) C values) suggests a landscape of lowland forests and upland prairie. In the late Holocene, approximately 1400 years BP, channel activity increased and forests emerged from the lowlands to dominate the uplands. The climate record at Crevice Cave indicates that major changes in the Bear Creek stream system are driven by increased precipitation and vegetation change brought about by a shift in the climate state to one where El Nino events are more frequent and intense.
Details
- Title: Subtitle
- The impact of Holocene climate on vegetation and the alluvial landscape of the prairie peninsula's southern margin
- Creators
- Adel E Haj - University of Iowa, Department of Geosciences Iowa City, IA USA United StatesA BettisJeffrey A DoraleScott J Carpenter
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.37(5), p.69
- Conference
- Geological Society of America, North-Central Section, 39th annual meeting
- Publisher
- Geological Society of America (GSA)
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, North-Central Section, 39th annual meeting
- Language
- English
- Date published
- 05/2005
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240919802771
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