EarthChem Portal Features You Should Know About

Once you’ve learned the basics of how to obtain sample and geochemistry data from the EarthChem Portal, here are six useful features that will enhance your EarthChem experience.

  1. Visualize Sample locations on Maps
  2. Visualize Geochemical data on TAS and Harker Diagrams
  3. View Data Download statistics in the Citation database
  4. Save your queries for future use
  5. Save and Share your queries in the Glossary
  6. Advanced Data Display Options - showing units and methods

1. Visualize Sample locations on Maps

The location of EarthChem samples can be visualized on a number of different maps, including static maps, dynamic maps, and Google Earth.

EarthChem's static maps are useful for inserting in reports or other visual projects. The files are .jpeg and can be saved to your computer.

EarthChem's dynamic map option allows you to view your query samples on a topographic map. The map can be zoomed in for closer views. Clicking on the colored dots - the sample locations - will link you to more detailed information for individual samples.

EarthChem sample location and information can be viewed in Google Earth in two ways. Once you get to your sample selection, you can download the results of your query in a KML file, then view it in Google Earth. You can also download a KML that contains the current information for all EarthChem samples (Download EarthChem.kml). In both cases, clicking on the sample icon brings up a window with more information about the sample.

(Note that the location precision for samples is different for different databases. Some samples may only be reported to one or two decimal places, but some may have up to six decimal places. Please be aware of this as you zoom in on samples.)

EarthChem Portal Map


2. Visualize Geochemical data on TAS and Harker Diagrams

Once you have obtained your sample selection, you can view a TAS (Total Alkali vs SiO2) or Harker (oxides of elements against SiO2) Diagrams. Simply click on the buttons under “Visualization Tools” after completing your query.

A Total Alkali Silica (TAS) Diagram might be useful to view your sample data if you are concerned with volcanic rocks. These diagrams plot the bulk total alkalis (sodium & potassium) versus the silica content of the rocks from your samples.

Harker diagrams, or variation diagrams, are useful for detecting geochemical and genetic trends in the petrology of your samples. After clicking on the "Plot Harker Diagrams" button you will be brought to a page with a number of Harker diagrams displaying your sample data. At the bottom of the page are various options for modifying the appearance of the diagrams. You can also select an option that allows you to link directly to each data sample point's information from the graphs.

tas Diagram


3. Save your queries for future use

Have you ever wanted to save a particular query so you can repeat it in the future? This is useful, for example, for repeating a query after EarthChem has loaded more data. You can save a complicated query with several constraints set. First, you must be logged in with a GeoPass account (more information). Then, after obtaining your query results, simply click the “Save Query” button in the lower right hand corner of the screen, and choose a name for your saved query.  The next time you want to repeat the query, log in with GeoPass and click the “Saved Queries” option in the left-hand Portal Menu to see a list of your saved queries. Simply click on the "View" button and you will arrive at your previous sample set.

EC Portal Saved Queries

4. Save and Share your queries in the Glossary

The EarthChem Glossary allows you to share your saved queries with other EarthChem users. Currently, there are many Glossary entries that have geographic areas and/or age predefined. For example, there is an entry for Coso Volcanic Field, sample age less than 6 Ma.

To create a Glossary entry, you must be a registered user with GeoPass. Navigate to the Glossary page by clicking “Glossary” in the left-hand Portal Menu, then click the button at the top “Add Glossary Entry.” You will see a page where you can set the name of the Glossary entry, the description, and edit the constraints of the query.

When you first create a Glossary entry, you will be the only user who can see it, and you can edit or delete the entry. Upon creation of an entry, an email notification is sent to the EarthChem Portal developers, and they review the Glossary entry for appropriateness and then publish the entry on the Glossary page.


Earth Portal Glossary

5. Advanced Data Display Options - showing units and methods

EarthChem Portal has several options for displaying geochemical output. Did you know that you have different options for displaying measurement units and analytical methods?

For example, because the data is compiled from different databases, you may want to see what Unit of measurement is being reported. You can achieve this by clicking on the  “Show Units” option in the “Advanced Output Options” screen. Another column will be added to the output table that lists the unit. The same can be done for Method.  The default is that the output table displays one row per method, which consolidates rows but does not allow for the unit or method display options.

Advanced Output

If you have any questions or comments, please email