• Particle Size Analysis Toolpack v2

    A zip file containing a suite of tools for analyzing continuous particle size curves from laser diffractometry.

    Includes:

    • export templates for Malvern software,
    • analysis template for recommended quality control procedure,
    • reporting templates for organized presentation of results with additional metrics, and
    • a data filter for removing the larger particle size peak from bimodal curves.

     

    Download the PSA Toolpack (4.7 MB)
  • Filtering Particle Size Distribution of Mixed Sediments (2012 INQUA Loess Conference)

    Most loess has unimodal textural curves, with a peak in the silt fraction. However, in thin loess areas, where loess overlies coarse-textured sediment, it often has a bimodal textural curve, due to pedoturbation. We present a method that can tease out these two textural signatures and thus, estimate the original particle size distribution of the loess. In this method the coarser sediment portion of such a “mixed” particle size distribution curve is removed, or “filtered out.” The end result is a curve (and data) that better reflect the original textural characteristics of the loess.

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  • USDA Soil Texture Class Macro

    An Excel spreadsheet containing a macro for calculating the USDA soil texture class. The macro can be used as a cell function, allowing you to automatically calculate the texture class from a series of cells with percentages of soil separates.

    Download spreadsheet containing the USDA Soil Texture Class Macro (22.3 KB)
  • Thin, pedoturbated, and locally sourced loess in the western Upper Peninsula of Michigan

    County soil surveys document thin loess deposits across large tracts of Michigan’s western Upper Peninsula (UP), which we informally call the Peshekee loess. Our study is the first to examine the distribution, thickness and textural characteristics of these loess deposits, and speculate as to their origins. We introduce and describe a method by which the mixed sand data are removed, or “filtered out,” of the original particle size data, to better reflect the original textural characteristics of the loess.

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  • Precision of soil particle size results using laser diffractometry

    Because laser diffractometry produces much more detailed data than does traditional pipette analysis, and because a much smaller sample is used in the analysis, precision or repeatability of laser-produced PSA data is a concern. The approach presented provides both a simple method for assessing the variation in PSA data sets and establishes a comparable standard for determining when additional measurements are needed to find a more precise result.

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