Petrological Database of the Ocean Floor
Encyclopedia
The Petrological Database of the Ocean Floor (PetDB) is a relational database
and repository for global geochemical data on igneous and metamorphic
rocks generated at mid-ocean ridges including back-arc basins, young seamounts, and old oceanic crust. These data are obtained by analyses of whole rock powders, volcanic glasses, and minerals by a wide range of techniques including mass spectrometry
, atomic emission spectrometry, x-ray fluorescence
spectrometry, and wet chemical analyses. Data are compiled from the scientific literature by PetDB data managers, as well as being provided by members of the scientific community. PetDB is supported by the U.S. National Science Foundation
.
The initial funding phase of PetDB (1996–2001) supported the development of the database structure and population with data values. Renewed funding (2002–2007) permitted the migration of the database into an ORACLE-based environment administered by the Center for International Earth Science Information Network (CIESIN) of Columbia University , continued data entry, and enhancement of the web-interface with a more user-friendly design.
The relational database structure of PetDB is a sample-based implementation and designed to accommodate chemical and petrological data for any type of rock sample, along with essential metadata
that provide information about the sample (e.g. location and time of collection, taxonomy, petrographic description) and the data quality (e.g. analytical procedure, reference standard measurements) (Lehnert et al. 2000). Initially developed for PetDB and its subareal counterpart GEOROC , this relational data model has demonstrated utility and flexibility by its application in subsequent geochemical database projects including NAVDAT , MetPetDB
, EarthChem Deep Lithosphere and SedDB
v.0.1 .
Since its inception, PetDB has supported a wide array of scientific endeavors, providing easy access to a comprehensive global dataset of geochemical data for mid-ocean ridge
basalts and abyssal peridotites. PetDB has been cited in more than 147 peer-reviewed scientific articles as the source of data used to develop and test new hypotheses which range from the chemical and mineralogical composition of Earth’s mantle (e.g. Salters & Stracke 2004, Thirlwall et al. 2004), to the generation and evolution of continental and oceanic crust (e.g. Weyer et al. 2003, Cipriani et al. 2004), melt transport phenomena (Braun & Kelemen 2002, Spiegelman & Kelemen 2003), to global geochemical seawater budgets (e.g. van der Flierdt et al. 2004).
PetDB is administered by the group at LDEO-CIESIN headed by K. Lehnert and is a member of the
NSF
supported EarthChem project along with complementary database efforts GEOROC and .
on analytical methods and publication information.
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
and repository for global geochemical data on igneous and metamorphic
Metamorphic rock
Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...
rocks generated at mid-ocean ridges including back-arc basins, young seamounts, and old oceanic crust. These data are obtained by analyses of whole rock powders, volcanic glasses, and minerals by a wide range of techniques including mass spectrometry
Mass spectrometry
Mass spectrometry is an analytical technique that measures the mass-to-charge ratio of charged particles.It is used for determining masses of particles, for determining the elemental composition of a sample or molecule, and for elucidating the chemical structures of molecules, such as peptides and...
, atomic emission spectrometry, x-ray fluorescence
X-ray fluorescence
X-ray fluorescence is the emission of characteristic "secondary" X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays...
spectrometry, and wet chemical analyses. Data are compiled from the scientific literature by PetDB data managers, as well as being provided by members of the scientific community. PetDB is supported by the U.S. National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
.
History
Development of PetDB began in 1995 when scientists from the Lamont-Doherty Earth Observatory (LDEO) C. Langmuir (now at Harvard University), W. Ryan, and A. Boulanger saw the potential impact of new information technologies such as the World Wide Web and relational databases on the use of scientific data in research and in the classroom.The initial funding phase of PetDB (1996–2001) supported the development of the database structure and population with data values. Renewed funding (2002–2007) permitted the migration of the database into an ORACLE-based environment administered by the Center for International Earth Science Information Network (CIESIN) of Columbia University , continued data entry, and enhancement of the web-interface with a more user-friendly design.
The relational database structure of PetDB is a sample-based implementation and designed to accommodate chemical and petrological data for any type of rock sample, along with essential metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
that provide information about the sample (e.g. location and time of collection, taxonomy, petrographic description) and the data quality (e.g. analytical procedure, reference standard measurements) (Lehnert et al. 2000). Initially developed for PetDB and its subareal counterpart GEOROC , this relational data model has demonstrated utility and flexibility by its application in subsequent geochemical database projects including NAVDAT , MetPetDB
MetPetDB
MetPetDB is a relational database and repository for global geochemical data on and images collected from metamorphic rocks from the earth's crust...
, EarthChem Deep Lithosphere and SedDB
SedDB
SedDB is an online data management and information system for sediment geochemistry.SedDB is based on a relational database that contains the full range of analytical values for sediment samples, primarily from marine sediment cores, including major and trace element concentrations, radiogenic and...
v.0.1 .
Since its inception, PetDB has supported a wide array of scientific endeavors, providing easy access to a comprehensive global dataset of geochemical data for mid-ocean ridge
Mid-ocean ridge
A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges , typically having a valley known as a rift running along its spine, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading...
basalts and abyssal peridotites. PetDB has been cited in more than 147 peer-reviewed scientific articles as the source of data used to develop and test new hypotheses which range from the chemical and mineralogical composition of Earth’s mantle (e.g. Salters & Stracke 2004, Thirlwall et al. 2004), to the generation and evolution of continental and oceanic crust (e.g. Weyer et al. 2003, Cipriani et al. 2004), melt transport phenomena (Braun & Kelemen 2002, Spiegelman & Kelemen 2003), to global geochemical seawater budgets (e.g. van der Flierdt et al. 2004).
PetDB is administered by the group at LDEO-CIESIN headed by K. Lehnert and is a member of the
NSF
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
supported EarthChem project along with complementary database efforts GEOROC and .
Contents
In its current application, PetDB contains and provides on-line access to a complete set of chemical parameters (currently a total of 254 elements, oxides, isotopes and isotope ratios), as well as petrographic (mode) data through a sophisticated query interface. New data are continuously being added to the database as it is published and submitted to PetDB by authors. Data for a specific sample that is generated by different labs or published by various authors are linked and integrated through the use of a unique sample identifier generated by the database application.Statistics
As of April 2007, PetDB holdings consist of:- Samples: 35016
- Rock values (unspecified): 17034
- Whole rock values: 356549
- Glass values: 305472
- Mineral values: 157667
- Melt Inclusion values: 12232
- Total values: 848998
Data Output
Data from PetDB can be viewed in HTML tables and downloaded in spreadsheets in XLS format. During selection of chemical parameters a user can choose to retrieve data as individual values (each row in the data table contains values measured on the same samle with the same method and linked to the same reference) or in precompiled format. The precompiled format arranges all data associated with a sample in a single row, even when data is sourced from multiple publications. In cases where there is more than one data value for a particular chemical item, the precompilation algorithm selects the most recent analysis and the most precise method available. Links in the HTML table permit the user to access more detailed information about the sample, reference or data value (analytical procedure). The final spreadsheet output contains two worksheets. The first contains queried chemical data, geospatial coordinates, and abridged methods and references, while the second contains metadataMetadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
on analytical methods and publication information.
Further reading
- Braun, M. G. and P. B. Kelemen (2002). "Dunite distribution in the Oman Ophiolite: Implications for melt flux through porous dunite conduits" G-CUBED 3(11): 8603. doi:10.1029/2001GC000289
- Cipriani, A., H. K. Brueckner, et al. (2004). "Oceanic crust generated by elusive parents: Sr and Nd isotopes in basalt-peridotite pairs from the Mid-Atlantic Ridge." GEOLOGY 32: 657-660. doi:10.1130/G20560.1
- Lehnert, K.A., Su, Y., Langmuir, C.H., Sarbas, B., Nohl, U., "A global geochemical database structure for rocks", G-CUBED, Volume 1, 2000.doi:10.1029/1999GC000026
- Salters, V. J. M. and A. Stracke (2004). "Composition of the depleted mantle." G-CUBED 5(5). doi:10.1029/2003GC000597
- Spiegelman, M. and P. B. Kelemen (2003). "Extreme chemical variability as a consequence of channelized melt transport " G-CUBED 4. doi:10.1029/2002GC000336
- Thirlwall, M. F., M. A. M. Gee, et al. (2004). "Mantle components in Iceland and adjacent ridges investigated using double-spike Pb isotope ratios." GEOCHIM COSMOCHIM ACTA 68: 361-386. doi:10.1016/S0016-7037(03)00424-1
- van de Flierdt, T., M. Frank, et al. (2004). "Tracing the history of submarine hydrothermal inputs and the significance of hydrothermal hafnium for the seawater budget -- a combined Pb-Hf-Nd isotope approach." EARTH PLANET SCI LETT 222: 259-273. doi:10.1016/j.epsl.2004.02.025
- Weyer, S., C. Muenker, et al. (2003). "Nb/Ta, Zr/Hf and REE in the depleted mantle: implications for the differentiation history of the crust-mantle system." EARTH PLANET SCI LETT 205: 309-324. doi:10.1016/S0012-821X(02)01059-2