Thought experiments imply that stratigraphic cycles controlled directly by eustasy include keep-up, catch-up, catch-down (foreshortened or truncated), and give-up variants, different patterns of thick ness and facies being governed by the interplay of sedimentation rate and accommodation space. Most examples of these types are, in addition, base-cutout cycles, wherever lowstands of sea level dropped below the top of the underlying cycle. Overall thicknesses of multiple cycles at any locale are controlled ultimately by net subsidence rate. Accordingly, even keep-up and catch-up cycles can faithfully record full accommodation only where tectonic subsidence during cycle formation paced eustatic fluctuation. Paradoxically, however, only condensed cycles that fortuitously compensate for syncycle tectonic subsidence can accurately record the eustatic amplitude, as adjusted for water loading.
- Geological Society of America