Preface: Canadian Continental Drilling Program Cretaceous-Tertiary (K-T) Boundary Project
The geochemistry paper by Lerbekmo, Sweet, and Davidson utilizes neutron activation analyses and laser ablation ‐ inductively coupled plasma ‐ mass spectrometry (LAICP-MS) to analyze the boundary claystone. The application of LA-ICP-MS to the boundary claystone is new and, although controversial, could potentially add substantially to the geochemistry of the interval by the precise positioning of analyses that permits detection of geochemical charges in closely spaced intervals. This application demonstrates the presence of four layers within the boundary claystone, contrasting to the two or three zones previously recognized. Braman and Sweet provide the terrestrial palynology of the core holes, identifying major floral zones, correlation with previous work, and unconformities within the sequence. These palynological zones are applicable elsewhere in Late Cretaceous ‐ Paleocene stratigraphic studies, not just the K‐ T boundary. McIntyre outlines the dinocyst stratigraphy of