"Gradistat v 9.1" is a widely used software program for calculating grain size statistics from sedimentological data, typically running as a macro-enabled Microsoft Excel spreadsheet
. It was originally developed by Simon J. Blott and Kenneth Pye at Royal Holloway, University of London.
likely refers to the software's active use in analyzing "hot" or high-energy event deposits, such as those from storms, floods, or volcanic activities, which require rapid and precise statistical profiling. The Story of Gradistat: From Sieve to Spreadsheet
In the late 1990s, sedimentologists faced a "laborious process" when analyzing large sets of grain size data. Traditional methods involved manual calculations or cumbersome early computer programs that offered little flexibility.
GRADISTAT is a widely utilized software package integrated into Microsoft Excel, designed for the rapid calculation and statistical analysis of particle size distributions in unconsolidated sediments. Originally developed by Dr. Simon J. Blott and published in 2001, the program streamlines the laborious process of manual grain size classification for geologists, geomorphologists, and sedimentologists. Core Functionality and Statistical Methods
The primary utility of GRADISTAT lies in its ability to process data from various measurement techniques, including sieve analysis and laser granulometry. It provides comprehensive outputs by automating several standard geological calculations:
Statistical Measures: It calculates mean, mode, sorting, skewness, and kurtosis.
Calculation Modes: Parameters are derived using both the Folk and Ward (1957) graphical method and the method of moments.
Unit Scales: Statistics are provided in metric units (microns/mm) arithmetically and geometrically, as well as logarithmically using the phi scale.
Textural Classification: The software automatically assigns physical descriptive terms (e.g., "very coarse sand," "moderately sorted") and sediment names based on the Folk (1954) nomenclature. Software Versions and Evolution
While the original 2001 release was designed for Excel 97 and 2000, the software has seen several updates to maintain compatibility with modern operating systems and spreadsheet versions:
I notice you're asking about "Gradistat v 9.1" (I assume "v 91 hot" refers to version 9.1, possibly a typo or shorthand). GradiStat is a granulometry (grain size analysis) program, commonly used for sedimentology and geomorphology. gradistat v 91 hot
Below is a proper report structure assuming you have run a grain-size analysis using Gradistat v9.1 and need to present the results professionally. I'll include sections, key outputs from Gradistat, and interpretation guidance.
Grain size analysis characterizes sediment texture, informing depositional environment, transport processes, and porosity. This report presents statistical parameters derived from [method: sieve / laser diffraction / hydrometer] data processed via GradiStat v9.1, which calculates graphical and moment measures following Folk & Ward (1957) and others.
Gradistat has since been replaced by R packages (G2Sd, sedistats) and web apps. But ask any coastal geomorphologist over 40 about “v.91 Hot,” and you’ll see a flicker of recognition — maybe a suppressed smile.
One retired professor admitted, “I still have it on a Zip disk. Somewhere. It’s probably the only copy left. And no, you can’t have it.”
Whether Gradistat v.91 Hot was a genuine advance, a happy accident, or a shared hallucination matters little. It represents a brief moment in science when one person’s hacked spreadsheet macro felt like magic — fast, dangerous, and just unstable enough to make every result feel earned.
In the end, “v.91 Hot” isn’t just software. It’s a ghost in the machine of Earth science history: the version that wasn’t supposed to exist, but did — running hot somewhere, for someone, one last time.
Would you like a fictional “user manual” snippet for Gradistat v.91 Hot, or a comparison table of its rumored features vs. the official version?
is a widely used software package designed for the rapid calculation of grain size statistics, specifically tailored for researchers in geomorphology and sedimentology. It operates as an integrated program within Microsoft Excel, making it highly accessible for analyzing unconsolidated sediments. Core Functionality
GRADISTAT simplifies the laborious process of calculating statistics for large sample sets, processing approximately 50 samples per hour. Data Compatibility
: The program accepts data from various standard measuring techniques, including dry/wet sieving laser granulometry Statistical Methods
: It calculates key metrics—such as mean, mode, sorting (standard deviation), and skewness—using both the Folk and Ward (1957) graphical method method of moments "Gradistat v 9
: Statistics are calculated in metric units (arithmetically and geometrically) and logarithmic phi units. Key Features Versatile Input
: It handles both standard and non-standard sieve sizes, allowing users to input weight or percentage retained in various size fractions. Graphical Output
: The software generates a range of visual reports, including frequency plots
, cumulative distribution curves, and ternary diagrams (e.g., Gravel-Sand-Mud or Sand-Silt-Clay). Summary Reports
: Users can generate comprehensive summary sheets for individual samples or multiple sample comparisons. Software Versions
While the original version was developed for early Excel releases (1997/2000), Version 8.0
is the most common legacy update compatible with newer Excel versions. A fully revised version, known as GRADISTAT-PRO
, has also been under development to provide even greater functionality for professional sediment analysis.
For more information and to access the software, you can visit Kenneth Pye Associates Ltd GRADISTAT software - Kenneth Pye Associates Ltd
Feature: Real-Time Thermal Pre-Treatment Correction (Hot-Drying Module)
This feature would directly address research showing that "hot-plate drying" (drying samples at high temperatures or on a hot plate) can introduce variability in grain size distributions, especially in the coarser (>10 μm) range. 4. Graphical Plots (Include if available)
Integrated Correction Factors: Automatically applies statistical weights to samples flagged as "hot-dried" to correct for the potential loss of fine particles or contamination that occurs during high-heat pre-treatments.
Thermal Impact Visualization: A new graph overlay that compares raw data against expected distributions for oven-dried vs. hot-plate-dried samples to highlight any "drying-induced" outliers.
One-Click "Hot" Metadata Tagging: Allows users to tag specific samples as "hot" in the Excel input sheet to automatically adjust the calculation of sorting, skewness, and kurtosis based on known thermal impacts.
Automated Method Comparison: Rapidly toggles between Folk and Ward and Moment methods to see which statistical approach best minimizes the noise introduced by the hot-drying process. GRADISTAT software - Kenneth Pye Associates Ltd
GRADISTAT is a widely used Microsoft Excel-based software program designed for the rapid analysis of grain size statistics
in sedimentology. Developed by Simon Blott and Kenneth Pye, it streamlines the complex calculations required to classify unconsolidated sediments like sand, silt, and gravel. Kenneth Pye Associates Ltd 🛠️ Key Technical Features Rapid Processing : Capable of analyzing approximately 50 samples per hour. Statistical Methods : Calculations include Folk and Ward (1957) graphical measures and the Method of Moments Output Metrics
: Provides results for mean, mode, sorting (standard deviation), skewness, and kurtosis. Multiple Scales : Computes data in both metric units (micrometers) and Versatile Inputs
: Accepts data from various standard measuring techniques, including dry/wet sieving and laser granulometry. Michigan Technological University 📊 Graphical Outputs
The program is highly valued for its ability to transform raw data into visual research tools: Frequency Plots : Displays the distribution of grain sizes within a sample. Cumulative Distribution Curves
: Shows the total percentage of material coarser or finer than a specific size. Ternary Diagrams : Generates triangular diagrams
(e.g., Folk or Shepard triangles) to show relative proportions of gravel, sand, and mud. 💻 Version History & Compatibility Release Date Compatibility Details Early 2000s The original published version for Excel 97/2000. Updated for use with Excel 2007 through 2010. v9.1 / PRO In Development
Modern updates aimed at improving functionality and compatibility with newer Excel versions. 🔍 How to Use GRADISTAT GRADISTAT v 4.0
