Figure F9. The Cretaceous/Paleocene boundary from Walvis Ridge Holes 1262B, 1262C, 1267A, and 1267B. Strong changes in magnetic susceptibility and color reflectance indicate the Fe oxide–bearing, nonbioturbated foraminifer nannofossil boundary layer. The interpolated bases of planktonic foraminifer zones are indicated by arrows, sample density by black squares. Records all at the same scale.