Cretaceous (Campanian) depositional sequences in the Mesaverde escarpment of the southern Big Horn Basin (Wyoming) appear to have been deposited at 100,000 year intervals. Studies of several sections suggest that despite their high frequency nature, the sequences contain elements of sequence architecture, including transgressive surfaces (ravinements), flooding surfaces, thin onlapping (transgressive) deposits, and downlapping (regressive) deposits. This hypothesis will be investigated by 1) collecting field data, 2) constraining numerical simulations against the field data, and 3) returning to the field to check model predictions against the field evidence. In step 1, strata thicknesses and grain sizes in these sequences will be measured along a series of 30 meter sections along shore-normal and shore-parallel transects. In step 2, the data will be used to modify and extend existing numerical models for facies and sequence formation. Existing techniques for 1-D forward modeling of stratal successions will be extended. Depositional systems (lithofacies assemblages) will be simulated in 2 dimensions by "chaining" 1-D synthetic stratigraphic columns. Cyclic sedimentation ("parasequence stacking") will be simulated by varying basin parameters such as water depth and sedimentation rate. In step 3, predictions of the models will be compared against further field studies.
