The cyclic waxing and waning of continental ice sheets during global icehouse periods is a major driver of sea-level rise and fall. Globally exposed late Paleozoic cyclic strata are interpreted to record sea-level fluctuations driven by orbitally forced glacial-interglacial cycles. However, the maximum relative sea-level (RSL) change is controversial, with estimates ranging from 0 m to 120 m. Previous estimates of, and long-distance stratigraphic correlations based on, late Paleozoic sea level assumed a “bathtub” approach that does not account for the complex spatiotemporal patterns of sea-level change that develop during cycles of ice-sheet retreat and growth due to glacial isostatic adjustment (GIA). Here, we explore the extent to which GIA contributed to the observed spatial variations in the maximum RSL change during the late Paleozoic. Our model predictions show that location relative to initial (glacial) marine shoreline controls ∼30% of local ice-age maximum RSL in far-field (relative to ice sheets) locations, and stratigraphic estimates show similar trends. This pattern is due to continental levering processes in which ocean loading leads to proximal continental upwarping. Additionally, we show that except for ice-sheet-proximal areas, sea-level cycles are in phase such that transgression-regression cycles should correlate across large distances.
Coulson et al. (Tue,) studied this question.