Skip to main content
Department of Geography, Geology, and the Environment

Stratigraphic Column

Purpose and Introduction

The purpose of this project is to introduce you to the stratigraphy of the western Powder River Basin and instruct you in the methods of measuring and presenting stratigraphic columns. You will spend three days measuring and describing the stratigraphic units along the eastern flank of the Big Horn Mountains. You will first measure and describe the Archean and Cambrian rocks along US 14 west of Dayton, WY near Steamboat Mountain. Next you will measure and describe Ordovician through Pennsylvanian strata exposed along Crazy Woman Canyon. Lastly, you will measure and describe Permian through Cretaceous units in the Bud Love Big Game Winter Refuge northwest of Buffalo. Base maps of these areas will be provided daily.

Each day you will record this stratigraphic information in your field notebook. Once completed, you will be required to submit three individual stratigraphic columns, one for each day's work, for grading. It would be wise to work on each day’s column that evening. Here are the guidelines for the formal drafts of the columns:

Helpful Hints

  • use 1” : 50’ as the vertical scale in your notebook.
  • try to capture the variability of units on the scale of 20-40’
  • use the evening of each day to work on that day's column
  • calculate the maximum thickness of your three sections before you cut your paper; you don't want to end up with a piece that is too small to fit your largest section!
  • use the standard lithologic symbols found at the back of the guidebook when filling in your sections
  • the right side of each of your sections should be a weathering profile that reflects each units’ relative resistance to erosion.
  • use the reference section for the Big Horn Basin as a template for the construction of your sections

Project Components, Guidelines and Layout

  • Your final stratigraphic columns should be drafted at a scale of 1 inch to 100 feet.
  • They should be drafted as neatly as possible on the provided graph paper.
  • They should be in appropriate detail that reflects the variability of each formation.
  • The following information should be included in each of the columns:
    • a descriptive title of each section including the location where it was measured,
    • the lithostratigraphic and chronostratigraphic nomenclature,
    • the thickness that you measured,
    • appropriate patterns and symbols,
    • a weathering profile,
    • brief lithologic descriptions.

At the end of this project you will turn in:

  • Three graphical stratigraphic columns, all on one sheet of paper
  • Brief written descriptions of each formation, including thicknesses, all written adjacent to the part of the stratigraphic column to which they pertain (i.e. on the same large sheet of paper as your graphical stratigraphic columns)
  • Your field notebook