Markov Chain and Substitutability Analysis of a Turbidite Succession, Cloridorme Formation (Middle Ordovician), Gaspé, Quebec

Abstract

Numerical analyses were made of the sequential ordering of divisions within the turbidite succession of the β1 Member, Cloridorme Formation, logged at the type section at Grand Étang in the Gaspé Peninsula, Quebec. The sequence is satisfactorily described by a first order Markov chain model, whose transition structure includes and corresponds in part to a Bouma model of sedimentation. Additional second order Markov modifications differentiate two types of parallel-laminated division associated with high (a minority) and ?low flow regimes (the majority). Substitutability analysis reinforces many of the genetic interpretations based on the Markov model. The results of autocorrelation and correlation of logarithmically transformed division thicknesses suggest the deposition of successive turbidites as essentially discrete events and the operation of two different depositional mechanisms within the history of at least two types of turbidite unit. However, there appears to be a positive association between successive basal clastic division thicknesses, possibly indicating a longer term control in the budgeting of coarse sediment available for deposition. The succession is characterized by three types of unit with distinctive internal division thickness relationships, lithology and associated bedforms.