The dendrograph is proposed as a two-dimensional correlation diagram for epicting the mutual relationships among geologic variables. It is onsidered to be the next higher dimensional form of the dendrogram. The dendrograph has the advantage, in that both a within-group and a between-group correlation among variables can be displayed. This permits a more accurate interpretation of the existing data. A rule for ordering variables within the given hierarchical structure is described which imparts to the dendrograph a pyramid shape and preserves, where possible, the initial rank-order preference among the variables. Statistical tests are needed to ensure that a given dendrograph does not merely reflect a random pattern and that no more than the actual number of groupings of variables is considered significant. An example taken from the literature serves to illustrate how the dendrograph is effective in depicting the mutual correlations among a set of geologic variables.