Creating a Personal
Geodatabase
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Download
base image
- Open ArcCatalog
- Create a new workspace folder
- Right-click on the new folder and
select new Personal Geodatabase – name it Geology
- Right-click the new Personal
Geodatabase and choose new Feature Dataset – name it GeoFeatures
- Select Import and use the base image
for the coordinate system
- Select the defaults until finished
i.
Right-click
on the new Feature Dataset and choose new FeatureClass – name it
Lithology use
Polygon geometry
ii.
Add
two new text fields called “Description” and “Abbrev”
iii.
Finish
Finish the Personal
Geodatabase by
adding a “Faults” Feature Class (line geometry) with one new field
named
“FaultType”
- Right-click the Feature Dataset and
create new Topology (enter a cluster tolerance of 1 when prompted and
add “Must Not Overlap” and “Must Not Have Gaps” when prompted to add
rules.
Geology Map
- Open ArcGIS and add the base image
(flv_geo.tif) first followed by the Lithology and Faults feature
classes.
- Digitize polygons as shown in class –
add the abbreviation for each polygon to the “Abbrev” field as you
digitize – the abbreviations can be used after polygon digitizing is
completed to calculate the “Description” field values. Use the
following descriptions:
Qa = Quaternary alluvium
Qoa = Quaternary alluvium, older
QTc = Quaternary and Tertiary alluvium
Ts = Tertiary densely welded tuff
Trat = Tertiary non-welded tuff
- Now digitize the faults using the
varying symbology on the base image as a guide to segmentation
- Add attributes as follows for each
fault segment:
Solid lines = Normal
fault
– definitely located
Dashed lines = Normal
fault
- approximately located
Dotted Lines = Normal
fault
= concealed
Now make a map that is cartographically correct.
Use the
lithologic abbreviations in the Lithology feature class table to
annotate the
polygons and then give each rock type a color fill. Give faults an
appropriate
symbol and finally add a grid (labels only), a north arrow, a scale
bar, and a
legend.