Comparing Late Middle to Early Late Devonian Western North American Paleo Sea-Level Curves using Carbonate Stratigraphy

High resolution quantitative modeling of paleoeustasy within the Devonian has yet to be accomplished due to the complexity of the available carbonate records and the significant assumptions and interpretations necessary to calculate changes in sea-level. This study utilizes stratigraphic data from Brady (2012), which include four cores from Iowa, U.S.A., within the continental interior and four stratigraphic sections from the continental margin of Nevada, U.S.A. A model for calculating eustatic sea-level developed by Hillgärtner and Strasser (2003) was applied to develop a quantitative eustatic sea-level curve for the late middle to early late Devonian. Sea-level curves derived from the Nevada sections modeled an overall change in sea level approximately two times greater than that of Iowa, alluding to the varying completeness of the record in each locality and the difficulty of comparing the two basins. The magnitudes of cycle to cycle sea level changes were similar enough between localities to allow for comparison and correlation at resolutions of fourth to fifth order sea-level change. This study demonstrated that when the limitations of the geologic record are considered and accounted for, a high resolution quantitative mean sea-level curve can be constructed using data from multiple sections from two distinct localities. Comparing the same temporal records in Iowa and Nevada provided insight into what was preserved and what may be missing in the stratigraphy from two areas that experienced the same rate of sea level change under distinct sediment supply and accommodation space schemes.