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Estimating limiting age for pleistocene erosional surfaces in central Montana by uranium-series dating of associated travertines

✍ Scribed by Barney J. Szabo; David A. Lindsey


Book ID
102198077
Publisher
John Wiley and Sons
Year
1986
Tongue
English
Weight
426 KB
Volume
11
Category
Article
ISSN
0360-1269

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✦ Synopsis


Travertine deposits overlie the highest Number 2 surfaces in central Montana and clasts of travertine occur in gravels on lower Number 2 surfaces. Dating these travertine deposits may provide limits on the ages of surfaces that record intervals of extensive erosion during Pleistocene time. Analysis of three travertine samples from the southeast side ofThe Park yield an average uranium-thorium age of 73000+7000 years. Another sample from the west side of The Park is 320000 (+ 160 OOO, -70 OOO) years old. These results indicate that travertine deposits may have formed at several intervals. The surface beneath The Park travertine is older than about 320 OOO years. Number 2 pediment gravels that contain travertine downslope from the oldest dated sample may be younger than about 320000 years.