Generalities

Authors of manuscripts submitted to Geochimica et Cosmochimica Acta are requested to submit their Primary Data Tables as electronic files which will accompany the manuscript as electronic annexes, in a standard comma-delimited ASCII format. The purpose of doing this is to provide the data in a computer-friendly format, i.e. to provide an electronic file which can be read into a computer, and used by various data manipulation programs, without the need for tedious and error-prone manual entry by a human operator reading a hardcopy table. This in turn will make the data more readily useful to individual users who may wish to display or manipulate the data and also facilitate incorporation into the major geochemical databases.

As used in this context a Primary Data Table is any tabulation of chemical (including isotopic) analyses of natural materials - rocks, sediments, water samples, meteorites, and so on.

Authors are requested to provide the comma-delimited ASCII files for posting as electronic annexes even when the same data are tabulated in the main hardcopy print version of the paper. In such case, the data are presented twice: Once as a printed version for visual inspection, once as an electronic file suitable for reading by computer.

In some cases authors will choose to provide, or be asked to provide, data tables only as electronic annex files, i.e. without a corresponding hardcopy-printer table. In this case the annex files should be in comma-delimited ASCII format. At their discretion, authors will be invited to also provide additional annex files reporting the same data in a form more suited to visual inspection, e.g. a pdf file for a formatted data table.

File Format

Authors are requested to provide data files in comma-delimited ASCII text format. This is a standard ASCII text (i.e. containing only the 256 standard ASCII characters) file, which can be considered a two dimensional matrix, with rows delimited by the carriage-return character and, within rows, fields corresponding to columns delimited by commas.

Data should be organized so that the various data for a given sample are arrayed in the various columns (rather than vice versa). The initial rows should contain various introductory information, such as title, column headers, etc.

Various data manipulation programs can produce files of the appropriate format. In particular, if the data can be loaded into the widely used program Excel, a file of the appropriate format can be produced easily by using the "Save As ...." facility, and in the Save As dialog box, in the "Save As Type ..." listbox, selecting "CSV (Comma delimited) (*.csv)" format.

Metadata

Experience with geochemical databases suggests that one of the principal factors limiting the utility of archived geochemical data is the lack of sufficient supplemental data, or metadata (colloquially called data about data). An oft-cited form of metadata that is often omitted from reports of geochemical data is the location (latitude and longitude) of the sample; another is a sufficiently detailed sample name. Other forms of metadata that are often not sufficiently well provided are column-header designations for the units in which the data are reported (e.g. ppm or ppb), analytical errors, values for interlaboratory standards, and so on. GCA authors are encouraged to consider what metadata are most appropriate and necessary for their own data, and to report metadata as well as feasible, as a means of helping to make their own data as useful and as widely accessible to the geosciences community as possible.

A more detailed examination of the subject of electronic data reports, the issue of metadata, and specific suggestions for improvements is provided by Staudigel et al (2003) G3 4-3 (click here for a copy in pdf format).