2012:Horizon annealing: a collection-based approach to automated sequencing of the fossil record. Lethaia, Vol. 45, A number of different approaches to quantitative biochronology have been proposed and used to construct high-resolution time-scales for a range of uses. We present a new approach, horizon annealing, which uses simulated annealing to optimize the sequencing of collection horizons. Temporal sequences of events produced by this method are compared with those produced by graphic correlation, CONOP and RASC for a series of previously studied exemplar data sets. Horizon annealing produces results similar to other methods, but it does have properties (the ordination of collections and the avoidance of some local minima) that make it useful for high-resolution studies, particularly those based on capture-mark-recapture methods requiring detailed presence-absence data for individual collections and taxa. h Chronostratigraphy, graphic correlation, graptolite, rate of evolution, CONOP9.H. David Sheets [sheets@canisius.edu], Zachary T. Izard [izard_z@yahoo.com] and John