APPROACHES TO AUTOMATED INTEGRATED GEOCHRONOLOGY: MERGING GRAPHIC CORRELATION METHODS WITH SEQUENCE SLOTTING

In determining geological time scales and correlations, biostratigraphic, geochemical and geophysical data such as isotope excursions, paleomagnetic field orientation, magnetic susceptibility, dated events, ash beds, pollen counts and a range of other measures have been used to form composite sections and time lines. Biostratigraphic methods (graphic correlation, CONOP, RASC, UA-Graph, and Horizon Annealing) have been developed to establish the sequence of discrete unique events, whereas sequence slotting methods can match isotope curves and other types of continuous data. Efforts to combine these types of data in automated correlation have often incorporated them sequentially, typically using biostratigraphy to establish an initial framework, with other measures providing fine tuning. We have developed a small set of classes of different types of time-stratigraphic information, which allow an integrated approach to automated correlation using a wide range of types of data simultaneously to correlate multiple sections. A limited number of data classes and cost functions allows incorporation of a wide range of data types into the Horizon Annealing method of geochronological estimation.