Compositional and multivariate statistical analyses for grain-size characterisation of intertidal sedimentary facies in an estuarine environment

Abstract

This study presents the characterisation of grain size dynamics within an estuarine environment through statistical summarisation of grain size distribution and multivariate statistics. A total of 44 samples were taken from seven (7) main locations to the depth of ~15 cm at the intertidal depositional environment of Camel Estuary, Southwest England. A wide range of grain size statistical parameters explored here shows that outer estuarine sediment is composed of coarse sand population mixed with fine/medium sand while mid-estuarine sediment composition is of fine/medium sand population. The inner sediment deposition is a total deviation from other sections of the estuary, suggesting that the decrease in transportation energy caused the deposition of very fine sediments at this sedimentary facie. The summation of grain size distributions and multivariate statistics have shown that these methods can be used to determine sediments with similar parameters and, therefore, are a good proxy in recognising sedimentary facies within an inter-tidal depositional environment.

Keywords

• grain size distributions
• principal component analysis
• sediments
• camel estuary
• depositional environment
• sorting
• median