Leslie Hsu edited data integration.md  over 9 years ago

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Topical synthesis databases provide integrated geochemical data for a specific topic of interest. Integration of geochemical data means that measurements, standards, and preparation are documented in a standard way, and delivered to the user in a single table from up to hundreds of original publications. Tabulation of such data by hand may take years, but synthesis databases have the benefit of years of operation. Examples of specific topics include ocean floor geochemistry [PetDB](http://www.earthchem.org/petdb), geochemistry of sediments [SedDB](http://www.earthchem.org/seddb), hydrothermal vent systems [VentDB](http://www.earthchem.org/ventdb), xenoliths (Deep Lithosphere Data Set - now part of [PetDB](http://www.earthchem.org/petdb)), Ar-Ar geochronology ([Geochron](http://www.geochron.org)), and North American volcanic rocks (NAVDAT) (Table 1).    Integrated data are used in compilations to examine larger scale geochemical trends. Examples of such compilations that have used PetDB include “Origin of a 'Southern Hemisphere' geochemical signature in the Arctic upper mantle” (Goldstein, 2008), \citep{http://dx.doi.org/10.1038/nature06919},  and Composition of the depleted mantle (Salters and Stracke, 2004). \citep{http://dx.doi.org/10.1029/2003GC000597}.  Each EarthChem topical database arose from a user community that determined standards, features, and scope of the desired data. Different data have different parameters that are important to the investigators when selecting and viewing the data. For example, in SedDB there is depth in core and the ability to accommodate different materials that are sampled such as wood and paleosol. In VentDB for vent fluids, there are vent flow types and end-member and raw data used to calculate the derived values. In Geochron, the system works directly with data reduction programs and data from the instruments that produce geochronology and thermochronology data.