A metadata scheme for a rock-magnetic data base - considerations and applications

The diverse nature of magnetic property data of rocks slows down the development of a proper data base. This diversity concerns not only the set of parameters determined but also the various types of techniques and instrumentation used, the types of samples, their magnetic and thermal history, and last but not least the diversity of potential users including rock-, paleo- and environmental magnetists, magnetic anomaly modelers, researchers interested in magnetic properties of 'standard' magnetic minerals. Needless to say, these aspects impose special constraints on the data base structure. The metadata scheme proposed begins with the same sample information structure as that of the envisaged paleomagnetic data base, thus optimizing flexibility in interfacing or integrating the databases. For fundamental rock magnetism, various additional fields are required for material properties (including mineralogy, grain size, stoichiometry, defect density, etc.) and experimental conditions (including pretreatments and initial state). The proposed data structure aims to strictly separate the actually measured data and the set of derived parameters. The integrated nature of many magnetic studies will require linking to geochemical and chronostratigraphic data bases in the somewhat further future.