A BASIC program for in-field entry of lithologic descriptions in borehole logs to a hand-held portable computer system

Abstract

A series of BASIC programs is described to allow entry, after validation and checking, of coded lithologic descriptions of sedimentary strata in drill cores to an electronic database using a battery-powered, hand-held computer at the drill site. The programs make use of a simple method for systematic description of the sediments derived from the combinations of lithologic features in a representative suite of samples from the coal-bearing strata of the Sydney Basin. New South Wales, Australia. Rock type, texture, and composition or color, in addition to significant minor constituents, sedimentary and mechanical structures, are recorded by selecting the appropriate alpha-numeric codes from a relatively small list. These are validated against a built-in dictionary, and a complete translation of the log entry displayed for immediate checking. Further information can be added, if required, as an addendum in prose form, after which thickness or depth data are entered. The data for each lithological unit are stored in the nonvolatile memory of the portable computer. However, they can be transferred to cassette tape or disk if required, or electronically downloaded to the main database for the project. A translated copy of the log can be obtained on site if necessary using a battery-powered printer. A comprehensive graphic log also may be obtained using a simple, compact pen plotter.