Date of Award
2009
Degree Type
Thesis
Degree Name
Master of Science
Program
Geology
Supervisor
Dr. Desmond Moser
Second Advisor
Dr. Guy Plint
Abstract
The Western Canada foreland basin contains a rich record of Upper Cretaceous marine
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| and tectonic change, yet is sparse in biostratigraphically useful fauna that permit
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| continental and global correlation. However, numerous extensive bentonites have been
1 mapped in Cenomanian strata and traced into the U.S. portion of the basin where
relationships to globally correlated ammonite zones can be determined. The X, A-X and Bighorn River bentonites provide important calibration points for the Cenomanian Stage. Single zircon crystals from these bentonites were chemically-abraded and dated using high-precision U-Pb ID-TIMS geochronology techniques. The Pb/ U weighted-mean ages are: 95.87±0.10 Ma for the X-bentonite, 95.67±0.15 Ma for the A-X bentonite, and 94.29±0.13 Ma for the Bighorn River Bentonite (2a confidence level). These new ages establish a more precise maximum age for the Cenomanian/Turonian boundary and allow for more accurate measurements of the timing and rates of Cenomanian tectonic and eustatic activity in western North America.
Recommended Citation
Barker, Ivan R., "High-Precision ID-TIMS U-Pb Zircon Geochronology of Three Cenomanian Bentonites from the Western Canada Foreland Basin" (2009). Digitized Theses. 4171.
https://ir.lib.uwo.ca/digitizedtheses/4171