Semester

Fall

Date of Graduation

2019

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Geology and Geography

Committee Chair

J. Steven Kite

Committee Co-Chair

James A. Thompson

Committee Member

Amy Hessl

Committee Member

Kathleen Benison

Committee Member

Katherine Heckman

Abstract

Canaan Valley in West Virginia contains a greater area of peatlands than any other locality in the mid-Atlantic Highlands. Extensive fieldwork focused on peat stratigraphy and pedology, combined with high-resolution radiocarbon dating, was used to evaluate five peatlands within Canaan Valley National Wildlife Refuge (CVNWR) in the central Appalachian Mountains. One hundred soil cores were profiled and described, 30 with laboratory data, including 52 radiocarbon dates. Calibrated basal peat dates among the five mapped peatlands indicate a late Pleistocene timeframe for the onset of peat genesis, ranging from ~18,600 to ~15,200 cal yr BP. The dates for peat initiation are older than those published previously from other central Appalachian Mountain peatlands. Peat accumulation rates varied from 0.02 mm/yr to 1.34 mm/yr with a mean of 0.14 mm/yr. Results of age-depth profiles show similar trends in peat accumulation: moderately high peat accumulation during the late Pleistocene, below average peat accumulation in the early Holocene, the slowest peat accumulation (if any) during the mid-Holocene, and rapid peat accumulation in the early late Holocene. Very few samples were collected correlating to the last 2,000 years; however, those few suggest a possible decrease in peat accumulation.

CVNWR peatlands hold pedomemory of latest Pleistocene and Holocene climatic fluctuations in the central Appalachian Mountains. The field investigation revealed a distinct pattern of organic soil horizons throughout five study peatlands. The anaerobic lower portion of the peat soil profile consists of varied thicknesses of a combination of hemic and sapric soil materials, characteristically layered as a hemic horizon, underlain by a sapric horizon, underlain by another hemic horizon, these also correlate with general trends in the age-depth plots. Late Pleistocene peat initiation and accumulation form the lower hemic horizon, correlating with general warming after the Last Glacial Maximum. Between 10,000 and 4,200 cal yr BP, low peat accumulation and decomposition of previously deposited peat prevailed, forming the sapric, or most decomposed, horizon in the anaerobic portion of the soil profile. This early to mid-Holocene interval of minimal accumulation and significant decomposition indicates a climatic change to a dryer environment. The upper hemic horizon within the anaerobic portion of the soil profile formed during the wetter early late Holocene. A sapric horizon at the water table is overlain by an aerobic fibric surface horizon in uppermost portion of the soil profile

Soil profiles were classified according to Soil Taxonomy, and soil cores were mapped using the Soil Survey Manual. CVNWR Histosols were classified as Dysic, frigid Sapric Haplohemists and given an official series description and new soil series name of Canaan Valley peat. The five CVNWR peatland landforms are now mapped with a new map unit, Canaan Valley peat, moist, 0 to 3 percent slopes (map symbol CavA), totaling 246 hectares. These rare soils support unique ecosystems of high conservation value and ecological significance.

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