Discusses the need to take into account the effects of arrested fractional crystallization in the petrographic classification of volcanic rocks containing plagioclase phenocrysts. Describes the development and use of a computer program to accomplish this task graphically. (TW)

Describes a computer-assisted oil exploration and production game for students involved in a short course in petroleum geology. Outlines the game and its procedures, and provides sample structure maps generated by the computer in the course of playing the game. (TW)

Provides directions for interfacing the Lehman seismograph through an analog/digital converter. Discusses potential modifications and applications of this approach. (ML)

Describes a deterministic computer model that incorporates: (1) initial framework composition; (2) abrasion factors for quartz, feldspar, and rock fragments; and (3) a fragmentation ratio for rock fragments to simulate the recycling of coastal sands by rivers and beaches. (TW)

Describes a microcomputer program that simulates the pattern of evolution and produces clade diagrams and summary statistics. Allows users to vary the odds affecting the fate of a species. (TW)

Describes a computer program written in Microsoft BASIC for use on personal computers to calculate travel times of refracted waves in layered structures with arbitrary dipping interfaces. Exercises for student use are given to illustrate some of the basic properties of reversed refraction travel time graphs. (TW)

Describes how the graphics capabilities of the Apple Macintosh computer can be used in geological teaching by customizing fill patterns with lithologic symbols. Presents two methods for doing this: creating a dummy document, or by changing the pattern resource resident in the operating system. Special symbols can also replace fonts. (TW)

Describes how microcomputer spreadsheets are easily adapted for use in groundwater modeling. Presents spreadsheet set-ups and the results of five groundwater models. Suggests that this approach can provide a basis for demonstrations, laboratory exercises, and student projects. (ML)

Advocates a computer-controlled x-ray diffractometer as an inexpensive analytical tool that is easy to use and applicable to a wide range of geological problems. Both qualitative and quantitative experiments are possible. Exercises can easily be customized to local geology. Ideal for small departments with limited resources for providing hands-on…

Discusses the use of interactive computer-assisted lab exercises that combine text, graphics, and simple animation. Students use these self-paced applications to test their level of comprehension, identify their misconceptions, and seek explanatory information. Benefits include consistency in teaching and evaluation, and the ability to link with…

Discussed is a program created to serve as an instructional tool for teaching basin analysis. Described is the use of the program for interpreting plots resulting from backstripping methods. Included in the discussion are implementation, applications and availability of the "Subside!" program. (CW)

Described is a software package, "Trapeze," within which a routine called LinDis can be used. Discussed are teaching methods, the linear discriminant model and equations, the LinDis worksheet, and an example. The set up for this routine is included. (CW)

Discusses a computer database which includes optical properties of 142 minerals. Uses fuzzy logic to identify minerals from incomplete and imprecise information. Written in Turbo PASCAL for MS-DOS with 128K. (MVL)

Describes a computer program which represents the first merger of an expert system and imaging technology into a tool to assist in learning mineral identification. Presents a discussion of the system's development, evaluation of effectiveness, and future modifications. (RT)

Spreadsheets are well suited to many geochemical calculations, especially those that are highly repetitive. Some of the kinds of problems that can be conveniently solved with spreadsheets include elemental abundance calculations, equilibrium abundances in nuclear decay chains, and isochron calculations. (Author/PR)