Reconstruction of past storminess: Evaluation of an indicator approach using aeolian mineral grains buried in peat deposits, Estonia

Application of image analysis technique for measurement of sand grains in sediments

“…The aeolian sand influx (ASI) obtained from peat deposits of coastal bogs has been used to reconstruct changes in the past storminess [ [1] , [2] , [3] , 6 ], and Vandel et al. [11] proves ASI to be effective in detecting major trends in the recent storm activities. When concentrations of sands are high in samples, a wide range of methods are readily available from sieving to laser diffractometry [5] .…”

“…This paper describes the protocol and methods Vandel et al. [11] used for counting and measuring shape characteristics of mineral grains (i.e., diameter, area, perimeter, width and height of the bounding rectangle, Feret's diameter, circularity, aspect ratio, roundness and solidity) extracted from peat deposits in Estonia, using ImageJ – an open source program for image analysis. The following sections focus on the pretreatment of samples, useful tips for preparation of microscope slides to make image capture and analysis easier, and instructions and protocols in various steps of the image analysis and parameter settings with this semi-automated technique.…”

“…For example, Vandel et al. [11] show that it took up to seven slides to complete analysis of one sample and counted more than 1400 sand grains in total, when mineral matter content was high.…”

“…Vandel et al. [11] used a syringe with a cut off tip to measure sample volume of sediment. To make the ImageJ -based analysis efficient and less time-consuming, remove organic matter from samples by the LOI process at 550 °C [4] .…”

“…The residue of LOI 550 is treated on a 63 µm mesh (or similar, Vandel et al. [11] used 65 µm mesh) with HCl to remove carbonates and with KOH to remove diatoms and clean the sample. Also, the redundant silt and clay fractions are removed from the sample during the pretreatment, leaving only the sand fraction (>63 µm) that is needed for the image analysis.…”