Geologic Maps in Arcview

Geologic maps in ArcView

This exercise is optional, but will allow you to gain more confidence using ArcView

Use the designated PCs or field laptops for this exercise.

1. Open ArcView, New View, Add Theme; navigate to the OC/Hamilton/Geology folder and select Image; Hamilton 7.5’ Quad. Select View; Properties and enter meters in the distance and map units bars.

2. Select View, Add Theme, Feature, navigate to the OC/Hamilton/Geology and select the finger lakes bedrock geology shapefile.

3. Arrange the themes so that the bedrock geology overlies the topographic map coverage.

4. Double-click on the colored box (legend) next to the finger lakes theme label. Edit the legend by assigning a unique value to the material field. Return to View.

5. Use the ID Tool to determine the bedrock material type. The key for the bedrock shapefile can be viewed in Word by opening the text file “Bedrock Key” in then OC/Hamilton/Geology folder. What rock units are found on the Hamilton 7.5’ quad? Note that there are inaccuracies on this coverage.

6. Clip the bedrock coverage by making a new theme, polygon at the size of the Hamilton 7.5’. Name this ‘clipping’. Check under File; Extensions and select (check) Geoprocessing. With both themes highlighted in the View, select View; Geoprocessing Wizard. Make sure the clipping theme and bedrock theme are appropriately placed. Give the new theme a name (e.g. Hambedrock) and save. Delete the finger lakes geology theme.

7. Highlight the new Hamilton bedrock coverage and select Theme; Start Editing. Use the editing tools to move the boundaries of polygons, etc. Stop editing to save changes (make sure your are editing your new clipped coverage if you want really save changes.)

8. Load the MrSid images and overlay the bedrock coverage on these.

9. Use the legend editor to assign transparent lined symbols to the materials fields. Select View; Layout to prepare a map for printing.

10. In Layout view, highlight the legend and use Graphics; Simplify to edit the legend and enter the appropriate stratigraphic units.

OC 2002