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California State University, Sacramento Stratigraphic sections |
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California State University, Sacramento Stratigraphic sections |
| Examples of stratigraphic sections: |
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A stratigraphic section (also called a
stratigraphic column) is a visual representation of a field outcrop.
It often starts with field measurements of bed and unit thicknesses.
It may be a composite section that was produced by visiting several
exposures.
The purpose of the stratigraphic column is to give your reader a quick, visual representation of what you saw in the field. It includes the unit names,ages, thicknesses and descriptions. It also shows where samples or fossils were collected. There are many types of stratigraphic columns. To find out more read Compton's Field Geology, pp. 222- 241. There are two types of stratigraphic columns: 1) Weathering profiles: Some stratigraphic columns show a weathering profile, with more resistant units sticking out further and softer easily eroded units narrower in the column. This type of stratigraphic column is more artistic and parts should be drawn by hand because units do not have a consistent resistance to weathering. You can use computer graphics for the heading, scale and explanation if you draw a weathering profile for your stratigraphic column. Examples of a weathering profile: 2) Grain size: Many stratigraphic columns use grain size. Coarser units have wider spaces on the column, and finer units have narrow spaces. These stratigraphic columns are often used by stratigraphers and sedimentologists. Example of a stratigraphic column that uses grain size: Stratigraphic column with grain size From Riggs et al., Journal of Sedimentary Research, v. 67., no.1 Note that this stratigraphic column does not include a title! |
What to include in your stratigraphic section: 1) Title at the top, centered, all capital letters. Ex:
STRATIGRAPHIC SECTION OF THE MEHRTEN FORMATION NEAR NIMBUS DAM, CALIFORNIA
2) Include a scale along the left side of the column that shows series, stage, formation and meters (or feet) above base.
3) Label the lithologic column "Grain size" or "Weathering profile".
4) Use standard lithologic symbols. If you have several units, color the beds to match your map units.
5) Use symbols to represent scoured (erosional surfaces), faults or sedimentary structures.
4) Include a column that show where samples, data, fossils or photographs were collected.
5) Give brief lithologic descriptions:
Letter neatly or use computer graphics for the lithologic descriptions.
Each description must be across from the beds it is describing.
Align all descriptions (left-justify).
Phrases or common abbreviations are O.K.! You do not need completed sentences
6) Include "Drawn by" and the date in the bottom right corner or on the top right below the title.
| Template for stratigraphic sections: |
| You can do much of the labeling in powerpoint or similar graphics programs. Here is a template to get you started: |
