Ordovician and Silurian strata of northeastern British Columbia: stratigraphic sections and synthesis of biostratigraphy

Thirty-six stratigraphic sections document the Ordovician and Silurian strata of northeastern British Columbia. The sections were measured through outcropping strata deposited on the MacDonald and Cassiar platforms, in the adjoining Kechika Trough of the Selwyn Basin, the Nasina Basin, and within transitional zones between these regions. Synthesis of published and unpublished data from studies of microfossils and of invertebrate and vertebrate macrofossils constrains the ages of the formations and assists in the interpretation of the stratigraphic history of the region. Several regional unconformities are recognized within the successions. From the platformal rocks and the transitional rocks, hiatuses can be documented during the earliest Caradoc, mid to late Caradoc, late Ashgill to very early Llandovery, mid Llandovery and within the interval Wenlock to Ludlow. Within the basinal rocks, only the Llandovery hiatuses have been recognized.