| The top seal of the ''Glob alt'' reservoir is especially effective because it is thick and has a regional extent as a consequence of its position at a third-order turnaround from regression to transgression. This turnaround is from regressive cycles 3.4–3.5–3.6 to transgressive cycles 3.7–3.8 on the Haq et al.<ref name=ch04r43>Haq, B., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change: SEPM Special Publication 42, p. 71–108.</ref> cycle chart (see Figure 4-25). | | The top seal of the ''Glob alt'' reservoir is especially effective because it is thick and has a regional extent as a consequence of its position at a third-order turnaround from regression to transgression. This turnaround is from regressive cycles 3.4–3.5–3.6 to transgressive cycles 3.7–3.8 on the Haq et al.<ref name=ch04r43>Haq, B., Hardenbol, J., Vail, P., R., 1988, Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change: SEPM Special Publication 42, p. 71–108.</ref> cycle chart (see Figure 4-25). |