Figure 9: Section across the Chattian/Aquitanian boundary exposed in the road cutting along the east bank of the Swift River, south of its mouth, Hope Bay, Portland, with nannofossil occurrences and foraminifer samples (yellow boxes). The sample with Mio. tani comes from the upper part of the Chester Formation in the highest part of the Chattian. T, turbidite; B, bentonite; BP, bedding plane; F, flint. Partial details have been given by Robinson (2004) and Mitchell et al. (2024).