Frequently Asked Questions

What is NAVDAT?
Why do I need to log into NAVDAT?
Benefits of NAVDAT
How do I submit data?
Complementary Database Efforts
Database Format
Current Status of the Database
Where can I find geospatial data for the western United States?
How can I make Total Alkali vs. Silica and other geochemical diagrams?
Information for teachers and students
Institution Numbers
How are Age Values Calculated?
What are Rock Type and Rock Class?
Navdat Glossary

What is NAVDAT?

The NAVDAT project is compiling existing age, chemical, and isotopic data from Late Cretaceous to Holocene extrusive and intrusive igneous rocks from the western United States, British Columbia, and northern Mexico into a web-accessible electronic database. NAVDAT will be integrated into a geographic information system (GIS) to allow visualization of complex age-compositional patterns in volcanism throughout the study region. The addition of necessary relational and graphical tools will allow users of the database to address a wide variety of issues concerning the geologic evolution and present volcanic state of western North America.

Why do I need to log into NAVDAT?

NAVDAT is free for everyone to use. The user name and password allow users to save datasets, queries, graphs and diagrams on the server. If you have any problems with the database, the user name allows the NAVDAT web master to track down and resolve your issue.

Benefits of NAVDAT

Studies of time-space-composition patterns of igneous rocks have contributed greatly to our understanding of the links between petrology and tectonics. However, most such studies have been performed on relatively restricted areas, on ad hoc datasets that are available only to the compiler and disappear when the project ends (some of us remember compiling data on punch cards). The goal of NAVDAT is to produce a web-accessible, comprehensive, continually updated database of a continent-sized area.

Specific benefits of the NAVDAT database will include:

Free to everyone
Universal access
Comprehensive coverage
Ability to visualize time-space-composition patterns of magmatism and how they relate to tectonic events and geologic hazards
Ability to use the database to add attributes to digital geologic maps (e.g., to assign ages to igneous polygons)

How to submit Data

The NAVDAT database helps the geochemical and geochronological community by allowing users to submit both published and unpublished data over the web. Data from a masters or Phd thesis is a welcome addition to the database. Data is submitted by uploading data through a web based interface. Only registered users can submit data, which aids in quality control of the data. To learn more about data submission Click Here. If you have any questions about data submission please contact Jason Ash at

Complementary Database Efforts

NAVDAT is one of several geoinformatics efforts that are underway. It is directly complementary to PetDB (a database of oceanic igneous rocks) and GEOROC (a global igneous geochemical database). Related efforts include the following:

CHRONOS - Interactive Chronostratigraphy and Stratigraphic Databases
GERM - Geochemical Earth Reference Model
DLESE - Digital Library for Earth System Education
EarthChem - Advanced Data Management in Igneous Geochemistry
ISES-CI - Workshop for identifying the cyberinfrastructure Needs and Opportunities for Petrology, Geochemistry and Tectonics.

Database Format

The NAVDAT database structure is a modification of the relational database structure set up by the PetDB project. The reason for the modifications was to allow the search and storage of samples collected by hand as opposed to samples collected on ocean bottoms by ship. In the future this will permit seamless searches across multiple databases. The data are fully attributed with critical meta data.

Current Status

Data entry for the western United States commenced in 2002 and there are now thousands of samples to search from. Visualization tools such as maps, total alkali vs. silica, and harker diagrams are available to aide with selection of data. Data is being added frequently to the data with help from contributors around the world who want their data available to the community. New search capability is always being added, if there is a function, feature, or diagram you would like added to the database, please contact Jason Ash. If you experience any problems with the site do you hesitate to contact Jason Ash and he will get back to you promptly. Click here to see current database coverage and number of samples to search from in the database.

Where can I find geospatial data for the western United States?

Two good sources for geospatial data for the western United States are the Keck Library at UNR and the USGS.
Earth Sciences & Mining Research Information Center

Seamless geographic data distribution system
Seamless Data Distribution System, National center for Earth Resources Observations and Science

How can I make Total Alkali vs. Silica and other geochemical diagrams?

Dr. I Wayan Warmada at Gadjah Mada University in Indonesia has created some wonderful gnuplot scripts for common diagrams like total alkali vs. silica plots that student and professors of geology and geochemistry will find useful.

What are Rock Type and Rock Class?

Rock Type and Rock Class seem confusing to everyone. The basic way that NAVDAT is set up is that there are 4 levels to naming a sample.
  • Level 1 - The highest level classification. This is usually assumed to be "igneous," but can be sedimentary or metamorphic.
  • Level 2 - Next level of breakdown. For igneous rocks, this is volcanic or plutonic. This level is equal to "Rock Type" in our data entry schema.
  • Level 3 - Basic chemical classification. Mafic, intermediate, felsic, etc.
  • Level 4 - The name you actually call a rock. This would be basalt, granite, etc. This level is equal to "Rock Class" which is short for Rock Classification in our data entry schema.

Information for Teachers and Students

The geochemical data in NAVDAT can be used by teachers and students for undergraduate and graduate petrology and geochemistry classes. The database has the ability to create total alkali vs. silica, alkali/iron/magnesium, and spider diagrams as well as maps with sample locations. We hope that students and teachers will find NAVDAT valuable for online experiments with geochemistry and petrology. NAVDAT is currently working with Dr. David Mogk on development of an "educational overlay" for geochemical databases. If you have and questions or concerns about using NAVDAT in the classroom, please contact Jason Ash or Dr. David Mogk.

Links for Teachers
Geoscience Education in the New Cyberinfrastructure: Some Examples for Teaching Petrology
Carleton College site for teaching petrology in the 21st century.

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