A frequently encountered problem in structural geology is the analysis and interpretation of directional data with a geographical distribution. Such data may arise, for example, as samples of fracture strikes collected at a number of locations (rocky outcrops, road cuttings, etc.), trends of geological structures mapped in underground mines where they are exposed in the tunnel roof, or as lineaments annotated on aerial or satellite photographs. From such data, it is of interest to determine the structural domains in the area, that is, to partition the area into subareas of homogeneous structural pattern. This paper presents a method for performing such an analysis, and applies it to a data set collected from an underground coal mine.

Several tests of discordancy for an outlying value in a sample of data from Fisher's distribution are investigated, and recommendations made about their use. One of the tests is modified for application to testing discordancy of several outliers in a single Fisher sample. The various tests are applied to some samples of artificial data and palaeomagnetic data.

ABSTRACTInaccuracies in the Formula method for thermal process evaluation–which could lead to overestimates of the lethal value and reduce the margin of safety of processes‐were found. Revised tables for C:g and fh/U:g systems are presented as well as revised coefficients for polynomials fitted to the tables for use in programmable calculators.