Geological Society of America

T53 No Dates: No Rates—Utilizing Geochronometers to Quantify Rates of Geomorphic Processes or Archaeological Development over a Wide Range of Temporal and Spatial Scales

Sunday, 22 October 2017
1:30 PM - 5:30 PM
Room 3B

OPTICAL DATING SEDIMENTS FROM COASTAL BRITISH COLUMBIA: SUCCESSES, CHALLENGES, AND PLANS FOR THE FUTURE

Paper number: T53-8
Program: Technical Sessions
Time: 3:25 PM – 3:40 PM

Authors

Christina M. Neudorf Presenting Author
University of the Fraser Valley, Abbotsford, BC
Christina M. Neudorf Presenting Author
Hakai Institute, Pruth Harbour, Calvert Island, BC
Olav Lian
University of the Fraser Valley, Abbotsford, BC
Libby C.M. Biln
Simon Fraser University, Burnaby, BC
Libby C.M. Biln
Hakai Institute, Pruth Harbour, Calvert Island, BC
Jordan K. Bryce
Simon Fraser University, Burnaby, BC
Jordan K. Bryce
Hakai Institute, Pruth Harbour, Calvert Island, BC
Jordan B.R. Eamer
University of Calgary, Calgary, AB
Nicole Smith
Hakai Institute, Pruth Harbour, Calvert Island, BC
Dan H. Shugar
University of Washington Tacoma, Tacoma, WA
Ian J. Walker
Arizona State University, Tempe, AZ
John Clague
Simon Fraser University, Burnaby, BC

Abstract

We review geochronological data obtained from four localities on the coast of British Columbia (BC), Canada: Hunter and Calvert islands of the Central Coast, and Quadra and Savary islands of the Discovery Islands region further south. The luminescence characteristics of samples used for optical dating, including quartz and feldspar optical signals, their response to laboratory irradiation and heat treatments, and the fading rates of feldspar, are discussed. Where possible, ages obtained using both optical and radiocarbon dating methods at the same site are compared. At some sites, we observe apparent inconsistencies between optical and radiocarbon ages; some of these can be explained by site formation processes (e.g., mixing between old and young sediments, the re-working of organic material, bioturbation and pedogenesis). However, potential issues with our optical dating procedures, such as inadequate delay times during fading measurements, or non-reproducible fading measurements, cannot be ruled out. We discuss initial results of our ongoing investigation into the robustness of our optical dating procedures on coastal deposits in BC, and suggest future avenues of research.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-304332

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