Measurements of the Cretaceous Paleolatitude of Vancouver Island: Consistent with the Baja-British Columbia Hypothesis

摘要

A previously unsampled outcrop of gently dipping or flat-lying Upper Cretaceous sedimentary strata in the Vancouver Island region, which contains unaltered aragonitic mollusk fossils, yielded a stable remanent magnetization that is biostratigraphically consistent with Cretaceous magnetochrons 33R, 33N, and 32R. These results, characterized by shallow inclinations, indicate an Upper Cretaceous paleolatitude of about 25 ± 3 degrees north, which is equivalent to that of modern-day Baja California. These findings are consistent with the Baja-British Columbia hypothesis, which puts the Insular Superterrane well south of the Oregon-California border in the Late Cretaceous.