EXTRACTING WATER DEPTH CHANGE FROM CARBONATE STRATIGRAPHY WITH HIDDEN MARKOV MODELS

Carbonate facies are often used to reconstruct paleo water depth and define parasequence (or high-frequency sequence) structure in ancient sedimentary basins. We are interested in the uncertainty associated with the assumptions that underpin these inferences. Here, we present a method that uses modern maps of bathymetry and the geographic distribution of facies atop the modern Great Bahama Bank to extract a signal of water depth change from facies transitions in vertically stacked carbonate strata. This probabilistic approach incorporates the observed complexity in the water depth distribution of immediately adjacent modern carbonate environments, and results in an impartial interpretation of stratigraphic data with quantified uncertainties. Moreover, this analytical tool can be used to improve correlation of stratigraphic sections based on the aggregate transitions between facies or other qualitative discrete data and provides insight into the variability of water depth change associated with stacked carbonate parasequences.