Statistical analysis of turbidite bed thickness patterns from the Alpine fold and thrust belt of western and southeastern Greece

Abstract

A statistical evaluation of turbidite bed thickness was performed for 11 turbidite successions which constitute part of foreland basins formed along the Alpine fold and thrust belt of western and southeastern Greece. The purpose was to compare the results from this study with previously published investigations and discuss if and how statistical approaches could contribute to the environmental analysis of turbidite deposits in tectonically complex areas. Bed thickness datasets exhibit a clear non-normal signal in their distribution behavior. Statistical analysis was focused on: i) fitting of widely used non-normal theoretical distribution models using robust non-parametric goodness-of-fit statistical tests, and ii) detecting the possible presence of asymmetric bed thickness cycles and/or non-random bed thickness clustering. Results indicate that the studied bed thickness datasets are well characterized by a bimodal lognormal distribution model probably reflecting deposition from both high- and low-density turbidity currents. Several datasets exhibit distributions characterized by power law tails. Exponential distribution types were not observed. All datasets exhibit non-random thinning-upward bed thickness trends probably due to tectonically induced gravity flows. Proposed methods for identifying depositional sub-environments using turbidite bed thickness statistics were found to have limited applicability. Observations of the present study may prove useful for the environmental analysis of turbidite deposits in fold and thrust belt areas characterized by limited outcrop exposures.