MATLAB algorithm for grayscale analysis of carbonate cyclicity: example application to Demopolis chalk (Cretaceous, Alabama)

Cyclostratigraphic studies of rhythmically bedded pelagic/hemipelagic carbonate sequences, which are important for understanding paleo-oceanographic conditions and paleoclimatic controls, can be facilitated by computer-assisted grayscale analysis. Application of a simple yet flexible algorithm, “docore”, written for the MATLAB software package and its associated image processing toolbox, can be used to generate detailed grayscale curves or time series that closely approximate carbonate time series from rapidly scanned images. The potential of “docore”-derived grayscale data as proxies for carbonate is demonstrated through comparative analyses of carbonate, organic carbon and grayscale data from a core drilled within the Upper Cretaceous Demopolis Chalk of western Alabama.