Initial Publication Date: October 19, 2006
Useful Databases and Tools
Resources at EarthChem.org
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Focus
- compositions of igneous materials from convergent margins, oceanic islands, and large igneous provinces
Geographic coverage
- global (oceans and continents)
Tectonic settings
- oceanic islands
- seamounts
- oceanic plateaus
- submarine ridges
- ocean basin flood basalts
- continental flood basalts
- convergent margins (arcs)
Earth materials
- volcanic igneous rocks
- plutonic igneous rocks
- mantle xenoliths
- volcanic glasses
- metamorphic rocks (not emphasized)
- sedimentary rocks (not emphasized)
- minerals (from rocks and veins)
- inclusions (glass, mineral, and fluid)
Strengths
- data is easily searchable by tectonic setting, geographic region, igneous province, and in many cases volcanic field or igneous suite
- lots of precompiled datasets arranged by tectonic setting, geographic location, and rocktype
Limitations
- age data is only included if it is mentioned in the original reference, hence the number of samples with quantitiative age information is lacking
- the tabulated isotopic compositions are of limited use because of the lack of age information (e.g., initial isotopic ratios are not available)
Downloading options
- Excel-compatible comma-separated textfiles
- HTML files
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Focus
- compositions of igneous materials from the ocean floor
Geographic coverage
Tectonic settings
- abyssal hills
- aseismic ridges
- back-arc basins
- failed rifts
- forearc basins
- fossil ridges
- fracture zones
- incipient rifts
- oceanic plateaus
- oceanic islands
- off-axis spreading centers
- old oceanic crust
- seamounts
- spreading centers
- trenches
- triple junctions
Earth materials
- volcanic igneous rocks
- plutonic igneous rocks
- volcanic glasses
- mantle xenoliths
- metamorphic rocks (not emphasized)
- minerals
- glass inclusions
Strengths
- data is easily searchable by tectonic setting, geographic region, and in some cases igneous suite
- precompiled datasets include global rock data grouped by chemical element, and MORB data grouped by region
Limitations
- the database is mainly limited to samples of approximately zero age
Downloading options
- Excel-compatible comma-separated textfiles (.csv format)
- HTML files
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Focus
- ages and compositions of Cenozoic igneous rocks from western North America
Geographic coverage
- western U.S., western Mexico, and British Columbia
Earth materials
- volcanic igneous rocks
- plutonic igneous rocks
Strengths
- every sample is accompanied by quantitative age data. This makes it ideal for examining and plotting space-time-composition trends
- contains an automated feature that generates maps
Limitations
- not easily searchable by tectonic setting, geographic regions smaller than states or provinces, or by igneous province or suite
- no precompiled files other than those obtained from queries (not really a problem, though)
Downloading options
- Excel-compatible tab-delimited textfiles
- HTML tables
- maps of sample locations
- major element variation ("Harker") diagrams
- total alkali vs. silica (TAS) diagrams (used for rock classification)
- geology, elevation, gravity, and magnetic GIS coverages for western states
Other Resources
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