Presentation Type

Poster

Faculty Mentor’s Full Name

George Furniss

Faculty Mentor’s Department

Geology

Abstract

The Bitterroot Valley, located south of Missoula, Montana along US Hwy 93, has a diverse geological history including significant glacial carved canyons and evidence of Glacial Lake Missoula. Just a couple miles south of Hamilton (46-9-36 N, 114-11-29 W) is a peatland field about three hundred acres in size. In the Bitterroot we are interested in dating the oldest lower portion of this deposit out of curiosity to better understanding the geology of the valley. Core samples were obtained in early February 2018. This particular area has a history of peat mining, and we know the top two to three feet of material was removed in the 1970s. Using a hand soil auger, we removed and saved three samples at: 1.8 ft., 2.5 ft., and 3.5 ft. depth. The total thickness of the peat deposit may have been originally five feet or more where the sample was taken. From the surface we drilled through continuous peat to the lowest depth, where we recovered one-inch diameter smooth stones, mixed with smaller pebbles and sand, indicating the bottom of the peat layer. The samples were dried and the sample from the 2.5 ft. depth was sent to Beta Analytic, Inc. in Miami, FL, for radiocarbon dating. Our goal was to determine whether the peat deposit is old enough to be considered ice age or whether it dates to the post ice age Holocene. Either way this information will improve our knowledge of the geological history of the Bitterroot Valley.

Category

Physical Sciences

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Apr 27th, 11:00 AM Apr 27th, 12:00 PM

Establishing Peatland Geologic Dating and Formation in Ravalli County

UC South Ballroom

The Bitterroot Valley, located south of Missoula, Montana along US Hwy 93, has a diverse geological history including significant glacial carved canyons and evidence of Glacial Lake Missoula. Just a couple miles south of Hamilton (46-9-36 N, 114-11-29 W) is a peatland field about three hundred acres in size. In the Bitterroot we are interested in dating the oldest lower portion of this deposit out of curiosity to better understanding the geology of the valley. Core samples were obtained in early February 2018. This particular area has a history of peat mining, and we know the top two to three feet of material was removed in the 1970s. Using a hand soil auger, we removed and saved three samples at: 1.8 ft., 2.5 ft., and 3.5 ft. depth. The total thickness of the peat deposit may have been originally five feet or more where the sample was taken. From the surface we drilled through continuous peat to the lowest depth, where we recovered one-inch diameter smooth stones, mixed with smaller pebbles and sand, indicating the bottom of the peat layer. The samples were dried and the sample from the 2.5 ft. depth was sent to Beta Analytic, Inc. in Miami, FL, for radiocarbon dating. Our goal was to determine whether the peat deposit is old enough to be considered ice age or whether it dates to the post ice age Holocene. Either way this information will improve our knowledge of the geological history of the Bitterroot Valley.