Welcome to litholog’s documentation!

litholog is focused on providing a framework to digitize, store, plot, and analyze sedimentary graphic logs (example log shown below).

Graphic logs are the most common way geologists characterize and communicate the composition and variability of clastic sedimentary successions; through a simple drawing, a graphic log imparts complex geological concepts (e.g., the Bouma turbidite sequence or a shoreface parasequence). The term ‘graphic log’ originates from a geologist graphically drawing (i.e., ‘logging’) an outcrop or core; other synonymous terms include measured section and stratigraphic column.

litholog is a package-level extension of agile-geoscience/striplog, with additional features that focus on lithology, and an API that is geared toward facilitating machine learning and quantitative analysis.

The package provides two primary data structures:

• Bed, which stores data from one lithologic bed or unit (e.g., top, base, lithology, thickness, grain size, etc). Bed is equivalent to a striplog.Interval

• BedSequence, which stores a collection of Beds in stratigraphic order (either elevation or depth order). BedSequence is equivalent to a striplog.Striplog

Utilities

Several utilities for working with graphic logs are included with litholog:

• default lithology colors for Beds that can be easily modified

• transformations for grain-size data from millimeter (mm) to log2 (a.k.a. psi) units, which are far easier to work with than mm.

• calculation of the following metrics at the BedSequence level:

  • net-to-gross

  • amalgamation ratio

  • psuedo gamma ray log

  • Hurst statistics (for determining facies clustering)

Data

The data provided with this demo come from two papers, and all logs were digitized using the Matlab digitizer included with this release.

• 7 logs from Jobe et al. 2012 (html, pdf).

• 6 logs from Jobe et al. 2010 (html, pdf).

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Tutorials:

• litholog basics
  • Default Colors and Legend
  • Make a Bed and a BedSequence from scratch
  • Plotting a BedSequence
    • Simple plotting
    • Adding intra-Bed grain-size data to a plot
    • Other plotting methods
• Demo of litholog functionality using the included demo data
  • Load the demo data from a csv using pandas
    • Use wentworth to make log2 grain size data
  • Convert dataframe to BedSequences
  • Basic data retrieval from a BedSequence and its Beds
    • BedSequence
    • Bed
  • Plotting
    • Basic plotting
    • Including intra-Bed grain-size data in a plot
      • Extracting fining-upwards profiles from a Bed
    • Flipping the order of a BedSequence
    • Plot mulitple logs at the same scale (i.e., a correlation panel)
  • Save out images
  • Statistics for BedSequences
  • Pseudo gamma-ray log
  • Other methods not demonstrated here
• litholog
  • litholog package
    • Subpackages
      • litholog.sequence package
    • Submodules
    • litholog.bed module
    • litholog.defaults module
    • litholog.utils module
    • litholog.wentworth module
    • Module contents

Indices and tables

• Index

• Module Index

• Search Page