Abstract Cyclothems are stratigraphic sequences deposited during glacial-eustatic transgressive–regressive inundations of land. Major cyclothems are most complete on lower shelves and become separated by exposure surfaces higher on the shelf. Minor cyclothems extend only onto lower shelves or are parasequences reflecting a reversal of sea level during general phases of transgression or regression. In Midcontinent North America, highstand condensed intervals of major cyclothems are conodont-rich black shales correlated eastwards into the Illinois and Appalachian basins. The number of cyclothems decreased by loss of lesser cyclothems across these basins, signifying an eastwards increase in their depositional elevations. Generalized palaeogeographical maps show that facies successions developed across these basins during a single major interglacial transgression and regression. The control of glacial eustasy by the interaction of Earth's orbital parameters, along with radiometric dating, allows subdivision of the cyclothem succession into c. 400 kyr groupings, which reflect the longest eccentricity cycle and facilitates global correlation. Delineation of the basinward extents of regression from the disappearance of exposure surfaces elucidates the history of basin-margin development. Major cyclothems that underwent reversals of general sea-level trend display ‘splays’ of lesser cycles onto the higher shelf. Geochemical cycles ‘nested’ within deepest-water shales on low shelves appear as thin nearshore facies between exposure surfaces at their high-shelf shorelines.

Abstract Quaternary glacio-eustasy has traditionally been determined in part by the examination of fossil coral reefs on carbonate islands and coasts uplifted by tectonics. These studies do not properly account for dissolutional denudation, which is cumulative, making higher and therefore older terraces exist at elevations far below their assumed depositional elevation. Karst pedestals (karrentische) on Guam reveal the extent of the denudation ( c. 50 mm ka −1 ) and demonstrate that theoretical denudation models can be accurately applied to eogenetic carbonates in tropical settings. Aeolian calcarenite islands such as the Bahamas have been used as tectonically stable sea-level calibrations for other islands, which may not be correct. Flank margin caves, forming in the distal margin of the freshwater lens within a carbonate island, are excellent sea-level indicators. Analysis of flank margin cave elevations indicates that the Bahamas have had past sea-level highstands >6 m, perhaps up to 15 m or more, for which no fossil coral data exist. Denudational removal of these older corals has biased the record to younger events and only flank margin caves remain as viable terrestrial signatures of these older sea-level highstands.