The default tool is the "Zoom In" tool, so you can immediately start using the map just by using your mouse to draw a box around the area of the map you want to view or by clicking once on a spot on the map. If you change the Theme, Basemap, or Overlays options, click on the "Update Map" button in the Setup tab to redraw the map.

To display legend or location information for the area you are viewing, click on the Key tab for a legend or Location tab at the bottom left corner of the map. If you have the "Info Query" tool (on the Tools tab) selected, you can click on any spot on the map to display Query Results for that spot.

Read the rest of this Help page to learn more about how to interact with the map.

Use the Setup tab options to select the map theme and any additional layers you want to display on the map.

SELECT MAP THEME:

• Stratigraphy (default) displays a map showing merged interpretational stratigraphic units (see background - compilation process). Information displayed when you use the Info Query tool with this theme is Terrane Group, Formation, Member, Unit, and Reference ID. If you have selected the Faults overlay and you click on a fault, information for the fault is also shown.
• Rock Properties displays a map showing rock properties, as described by the original author, for lithology rock types found in a particular area. Information displayed when you use the Info Query tool with this theme is Lithology General Unit, Lithology Rock Type, Crystal/Grain Size, Layering characteristics, Geotechnical Properties, and Reference ID. If you have selected the Faults overlay and you click on a fault, information for the fault is also shown.
• Basic Rock Type displays a map showing the most generalized rock type, such as sedimentary or metamorphic. Information displayed when you use the Info Query tool with this theme is General Lithology Type, Geology Rock Type, Geology General Unit, and Reference ID. If you have selected the Faults overlay and you click on a fault, information for the fault is also shown.
  
  
• None displays a map showing only the basemap information, if you have selected an "Add Basemaps" option in the Setup tab. Use this theme to display shaded relief and/or the USGS topographic basemap of the area. If you have selected the Faults overlay and you click on a fault, information for the fault is also shown.

ADD OVERLAYS:

Optionally, you can display formation level polygons boundaries, faults, highways, major cities, and U.S. Geological Survey 7.5 minute topographic quadrangle outlines on the map.

• Formation Boundaries. To distinguish the boundaries of the original author's formations within each interpretive Terrane Group, select this option. Formation boundaries do not appear until you zoom in to at least 1:50,000 scale.

(above) Full map extent with Theme set to None and Faults overlay on.

• Faults. To display fault traces, zoom to at least 1:500,000 (if you select "None" for the theme, you can see the fault traces at any scale). Fault certainty symbols are shown on the map itself. Display other fault information -- fault name (if known), fault type, dip direction, and Reference ID -- by clicking the InfoQuery tool on or very close to a fault trace. Fault certainty symbols are:
  • Certain (solid line)
  • Approximate (long dashed line)
  • Inferred (short dashed line)
  • Concealed (dotted)

Click on the popup links in the Key tab to learn more about fault types (normal, oblique-slip, reverse, strike-slip, thrust; right and left-lateral; lineaments) and to see an illustration of each type.

• Highways. The highway overlay layer displays major highways and is visible until you zoom in to 1:100,000 scale. At that scale the highway layer automatically turns off. The topographic basemap (on by default) shows roads and highways when you zoom in to at least 1:100,000.
  
  
• Cities/Towns. The cities/towns overlay layer is visible at all scales. Uncheck the box hide this layer.
  
  
• USGS 7.5' quad outlines. Turn on this layer to see the entire U.S. Geological Survey 7.5 minute topographic quadrangle series coverage for Oregon. When you zoom in far enough, the names of the quadrangles appear.

ADD BASEMAPS:

You can view the map with shaded relief and/or with a topographic basemap. The shaded relief (also known as hill shading) is from 30-m DEMs - U.S. Geological Survey [USGS] digital elevation model data. The topographic map is a DRG - digital raster graphic - a scanned image of a 1:100,000 scale USGS standard topographic map series map). Contours on the topographic map are meters. Both base maps are ON by default. The example below shows the same map area with the base maps ON and OFF.

Click on the Tools tab NAVIGATION tools to move around the map by zooming in and out, panning,and zooming to specific scales. Use the INFORMATION tools to see information about specific points in the map and to download a map or legend image. When you click on a tool, text appears below to tool to tell you how to use the tool and to remind you which tool is active. You will save yourself lots of frustration if you keep in mind which tool is currently selected before you click on the map.

Zoom In - With this tool selected, you can click on the map to zoom in and reset the map on the spot where you clicked. To more precisely define the area you want, click and drag (press down the mouse button and hold it down while you drag the mouse) to create an outline of the area you want to see. You can zoom anywhere between 1:2,500,000 and 1:24,000 scale.

Zoom Out - With this tool selected, click a spot on the map to zoom out. The map will automatically recenter on the spot you clicked.

Pan - Allows you to move around the entire map. Press down the mouse button and hold it down while you move the cursor up, down, right, or left. A red square on the location map in the upper left corner of the map area shows the current extent of the large map.

Zoom to Scale - Click on a number button to zoom to a preset scale:

Info Query - With this tool selected, click anywhere on the map to display, by means of the Query Results tab, geologic or lithologic information specific to that spot. The information changes depending on the selected map theme. To close the tab, click at the top of the tab title area.

Download Map Image - Click on "Download Map Image" tool to save a Portable Networks Graphic (.png) formatted file of the current map display or theme key (legend) that you can print if you have a printer. You can open the file and print it from your browser window or from other applications that can open .png files.

To download a file and print an image:

1. Click on the "Download Map Image" tool. Another browser window opens.
2. From the new window, choose to download a .png file of the key for the currently selected theme ("Download Current Theme Legend Image) or a .png file of the current map extent ("Download Current Map Image").
3. If you chose the "Download Current Map Image" option, select the image size and resolution that best meet your needs. The default settings are 640 x 480 pixel image size and 72 dpi resolution.
4. Click on the "Create Printable Image File" button. Another window, similar to the one below, opens.

5. Choose the application you want to use to open the .png file immediately or choose to save the .png file to your default location for downloaded files.
6. To print the image, open the .png file your preferred image viewing application, and select print from the application's menu options.

The red box on the small outline map of Oregon in the upper left corner of the map area shows the extent and location of the currently displayed large map. For very small areas the red box changes to a crosshair. You cannot click in the location map to change the large map.

The scalebar in the upper right corner of the map area provides an approximate scale in miles for the map. To see the exact map scale and other basic location information, click on the "Location Info" tab at the bottom left of the map area.

Key - Click on the Key tab in the bottom left of the map area to see a key or legend for the map units for colors displayed on the map. Each map theme has a different key. To close this tab, click on the tab title area.

For each theme you can click on the different unit names to display a popup descriptions of the units. The popup windows remain open until you close them. View all the keys.

Popup that displays when you click on "Dallas Group" link in Stratigraphic Key:

Location Info - Click on the Location Info tab in the bottom left of the map area to display the map projection system, the coordinates of the displayed map, and the current scale. To close the tab, click on the tab title area.

Info Query - With the Info Query tool selected, you can click anywhere on the map to view information specific to that spot. The information changes depending on the selected map theme and whether the faults overlay is on. If there is a lot of information for the point you clicked on, you may need to use the scroll bar on the right side of the Query Results tab window to see all the theme and faults data. The "Reference ID" refers to the original source data. To close the Query Results tab, click on the tab title area.

Stratigraphy theme:
Terrane Group
Formation
Member
Unit
Reference ID

Rock Properties theme:
Lithology General Unit
Lithology Rock Type
Crystal/Grain Size
Layering
Geotech Properties
Reference ID

Basic Rock Type theme:
General Lithology Type
Geology Rock Type
Geology General Unit
Reference ID

Faults overlay:
Fault Name
Fault Type
Certainty
Direction
Reference ID

"The map doesn't display"
If the map doesn't display, make sure your browser is JavaScript enabled. If you are using Internet Explorer, make sure the ActiveX control plugin is enabled.

"Edge faults"
In some areas the compilation map shows very abrupt boundaries between parts within the map (see illustration below). Geologists whimsically refer to these as "edge" faults. They occur where two source maps abut (see the location reference map to the right below for the illustrated source map boundaries). The reason may be that the authors mapped adjoining areas at different scales and therefore the maps are more or less detailed or that the authors differed in their interpretations or in their naming of rock units. You can use the Info Query tool on either side of the line to see the Reference IDs of the source maps and to learn how each author described the rocks on either side of the "edge fault."