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World Data Service for Geophysics

Marine Geology Data

PETROS Igneous Petrology Databank version 6.1


image of hard rock thin section under a petrographic microscope.

How to Cite:

Mutschler, F.E., Rougon, D.J., Lavin, O.P., and R.D. Hughes (1981): PETROS version 6.1 Worldwide Databank of Major Element Chemical Analyses of Igneous Rocks. National Geophysical Data Center, NOAA. doi:10.7289/V5QN64NM


data, codes files, and programs
README (format info)
tar icon.tar.gz file containing all of the above


PETROS is a worldwide data bank of major element chemical analyses of igneous rocks compiled for research and teaching purposes by Dr. Felix Mutschler and staff at Eastern Washington University. PETROS version 6.1 includes 37,300 major element chemical analyses divided into 307 major groups representing geographic areas or petrologic provinces. Also included are 468 average igneous rock compositions calculated by various authors, a bibliography of information sources, and complete format/operating instructions for PETROS.

In compiling PETROS, as few analyses as possible were rejected, allowing data bank users to exercise their own judgement on data values. Sources include published works, theses, and in a few cases, unpublished analytical data, all of which are referenced in the bibliography. Generally, only those analyses which included determinations of at least eight major oxides were accepted. Some quality control was exercised, and duplicate analyses, where possible were eliminated. Latitude/longitude information for samples is to the nearest one degree.

An accompanying program listing in FORTRAN for searching PETROS is included with the data file, along with complete format documentation.

Related Data:

NGDC archives a wide variety of digital marine geology data collections, paper reports, microfilm, etc. containing sediment and hardrock data. Many of the digital files are available for direct download. Sample-by-sample inventory information for all data, regardless of format available from NGDC are fully searchable through the marine geology inventory (GEOLIN).

More Igneous Petrology/Geochemistry Resources:

Geochemical Earth Reference Model (GERM)