PETROG, AGSO's Petrography Database, is a relational computer database of petrographic data obtained from microscopic examination of thin sections of rock samples. The database is designed for petrographic descriptions of crystalline igneous and metamorphic rocks, and also for sedimentary petrography. A variety of attributes pertaining to thin sections can be recorded, as can the volume proportions of component minerals, clasts and matrix.
PETROG is one of a family of field and laboratory databases that include mineral deposits, regolith, rock chemistry, geochronology, stream-sediment geochemistry, geophysical rock properties and ground spectral properties for remote sensing. All these databases rely on a central Field Database for information on geographic location, outcrops and rock samples. PETROG depends, in particular, on the Field Database's SITES and ROCKS tables, as well as a number of lookup tables of standard terms. ROCKMINSITES, a flat view of PETROG's tables combined with the SITES and ROCKS tables, allows thin-section and mineral data to be accessed from geographic information systems and plotted on maps.
This guide presents an overview of PETROG's infrastructure and describes in detail the menus and screen forms used to input and view the data. In particular, the definitions of most fields in the database are given in some depth under descriptions of the screen forms - providing, in effect, a comprehensive data dictionary of the database. The database schema, with all definitions of tables, views and indexes is contained in an appendix to the guide.
