Paleomagnetic Study of the mid-Cretaceous Mount McIntyre pluton, Whitehorse map area (105D), southern Yukon Territory

The paleomagnetic signature of the mid-Cretaceous Mount McIntyre Pluton, west of Whitehorse, was evaluated to develop a better understanding of the motion history of Cordilleran terranes through time. Excluding an anomalous result from the Carmacks Group, all previous tectonic estimates for terranes in the Yukon have been extrapolated from Alaska, British Columbia or the northwestern United States. The Mount McIntyre Pluton (109 Ma) and the adjacent Whitehorse Pluton (112 Ma), are granitic bodies that intrude Triassic and Jurassic sedimentary strata of the Stikine Terrane. Paleomagnetic measurements on samples from 20 granitic sites yielded three clusters of ChRM directions. Each cluster is specific to a geographical area of the Mount McIntyre pluton. The two most northeasterly sites are from a region of mixed igneous rocks between the Mount McIntyre and Whitehorse Plutons and thus are not considered. The other 11 northern sites give a well-defined mean ChRM direction that is steeply down and northeast. Seven sites in the southern part of the pluton gave a well-defined ChRM direction that is directed steeply down and to the northwest. The mean paleopole for the southern sites…

Publisher

Government of Yukon

Resources

3

Catalogue metadata updated

2026-08-26