1. What kinds of data can I obtain through PetDB?

PetDB provides access to major oxide, trace element, isotopes, age, and modal data from igneous and metamorphic rocks, xenolith samples from the Earth's mantle and lower crust and ophiolites. The analytical data are complemented by associated metadata which provide information on how the data was obtained, including information about the sample, analytical method, rock texture, literature reference, and geographic location.

2. I am a first-time user and do not have specialized geochemistry knowledge. How do I begin?

PetDB search facets are meant to be intuitive, but please see our tutorial for tips on how to get started.

3. How do I suggest a reference for entry into PetDB? 

If you would like to suggest a reference that is missing from PetDB, please email us at

4. How do I know these data are reliable?

EarthChem databases contain data that have appeared in the public record. This includes journal articles, monographs, ODP briefs, masters and doctoral theses. EarthChem cannot guarantee the accuracy of reported data beyond peer review at the publication and committee level. We strongly urge users to use the same level of critical judgment as they would with any other kind of published data.

5. What are “precompiled” datasets and how are they useful?

Precompiled datasets group together analyses for samples, even if published in different papers. Datasets that are not precompiled are listed in individual rows and require much more post-download manipulation prior to analysis.

Precompiled datasets undergo a database script that selects data according to data quality. For example, if potassium in a sample has been analyzed by both x-ray fluorescence (XRF) and wet chemistry (WET) the precompiled routine will choose the XRF data for its higher quality. These sets are particularly useful to educators and researchers who want to analyze data quickly without extensive processing of the downloaded spreadsheet. For more information on precompiled datasets please see our tutorial

6. Are there other databases out there similar to PetDB?

Yes. PetDB is a member of the EarthChem federation of geochemistry databases and is part of a larger community of cyberinfrastructure projects that provide open access to geoscience data.

EarthChem Portal: Integrated geochemistry data from PetDB, SedDB, MetPetDB, GEROC, NAvDat, USGS, and GANSEKI
EarthChem Library: open-access repository for geochemical datasets (analytical data, experimental data, synthesis databases) and other digital resources relevant to the field of geochemistry
NAVDAT: Geochemistry of volcanic rocks from the western United States
GEOROC: Geochemistry of rocks from the continents and oceans
MGDS: Marine Geoscience Data System – MARGINS data portal
Geochron: Geochronology and quantitative chronostratigraphy
SedDB: Geochemistry of marine sediments from across the globe
SESAR: Sample Registry for IGSN (International GeoSample Numbers), cataloguing and preserving sample information
LEPR: Library of Experimental Phase Relations

7. How can I visualize my dataset on a map if I don’t own GIS software?

You can download GeoMapApp free of charge from the Marine Geoscience Data System website  ( GeoMapApp is software that allows the user to visualize data in a number of different ways. Instructions on how to install and use the tool are available on the website.