General Notes and Comments on Homework
1. Contacts should be drawn with a thin mechanical pencil (grey) then colored in. We should not draw contacts with the colored pencil (lines too thick).
2. Draw in the sides and bottom of the cross-section with a normal pencil… or perhaps a slightly heavier line
3. Note the orientation of the section at the ends in addition to A and B. This helps the reader orient themselves.
4. All maps and/or cross-sections need an explanation box. In the box, the stratigraphic column is presented (with boxes for the colors) from oldest at bottom to youngest at top. Also include all map symbols (contacts, strike and dip symbols etc...). In general, there is only one explanation box for the map and section.
5. Everything needs a title... the map and the section...
6. Include contacts above and below the ground surface, drawn exactly the same way.
7. The contacts on the map should be solid unless otherwise noted (i.e. unless we know that it is inferred). For most exercises (unless otherwise noted) you can assume that the units are very well exposed so that the contacts are constrained. For now, cross sections should have solid contacts whether above or below the ground.
From Herman map/cross section:
1. Coloring. Try to color as light and even as you can. Be careful about the surface under your map. It can impose lines in the coloring. Try to make it like a light even tint.
2. Contacts, and all lines should be drawn with pencil (as narrow as possible), Then, color in.
3. Please use the back of graph paper for cross-sections and constructions.
4. The topographic profile line should be as thin as possible with the dots used to construct the profile nearly invisible… no thicker than the line itself.
5. The left and right ends of the cross section should have a clean vertical line, and only the left side needs to be labeled with elevations. Label this end “Elevation (m)”. We never include labels or scale marks on the bottom of a section. It is always at map scale.
6. For structural geology and anything else where bedrock geology is shown, we never use vertical exaggeration of the vertical scale.
7. Try not to overcrowd the tick marks on the vertical of cross-sections. And make sure they are drawn with a ruler or very neatly.
8. A horizontal scale bar should be included if the cross section is not on the same page as the map.
9. When projecting the geology onto your cross section, make sure that the markings you use are virtually unnoticeable -- this is for neatness.
10. Don’t color too dark!
11. Be careful not to show something that we really don’t know, such as the thickness of units above or below what the map indicates.
12. Simple coloring is best on maps and sections. Adding symbols or ornament just clutters things and may be mistaken for structural data.
13. May people had errors associated with the orientation, location, or thickness of the dike. Please check this. On the section, the dike should not go higher or lower than the other units.