BRIDGE RIVER ASH AND SOME OTHER RECENT ASH BEDS IN BRITISH COLUMBIA

Canadian Journal of Earth Sciences - Tập 4 Số 1 - Trang 163-170 - 1967
H. W. Nasmith, W. H. Mathews, Glenn E. Rouse

Tóm tắt

The character, distribution, and age of the Bridge River ash from postglacial sites in British Columbia and Alberta are discussed. The ash consists of dust-sized shards with ellipsoidal fragments of pumice. With a source in the region of the upper Lillooet River, the ash both, thins and fans out east-northeasterly as far as westernmost Alberta in the vicinity of the North Saskatchewan River. Peat immediately below the ash in a bog near Jesmond, British Columbia, was dated by radiocarbon at 2 440 ± 140 years before present (B.P.). The track of the Bridge River ash overlaps that of the Mazama ash of about 6 600 years, but lies north of the presently known distribution of St. Helens Y ash of approximately 3 200 years B.P. It is suggested that with a distinctive character and limited distribution, the Bridge River ash is potentially valuable as a postglacial marker horizon in southcentral British Columbia.

Từ khóa


Tài liệu tham khảo

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WESTGATE J. A., 1967, Can. J. Earth Sci., 4, 155, 10.1139/e67-006

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Thông tin xuất bản

Canadian Journal of Earth Sciences

Tập 4 Số 1

163-170

Thông tin tác giả