The Mt Buller igneous suite in the southeastern Lachlan Fold Belt encompasses a large variety of rock types, from gabbros through diorites to granites. Mafic rocks and enclaves have primitive, mantle‐like initial ⁸⁷ Sr/ ⁸⁶ Sr values, 0.7037–0.7045, and ϵ _Nd values +5.6 to +4.1. The granites do not show distinctively more radiogenic initial ⁸⁷ Sr/ ⁸⁶ Sr values, suggesting they are derived from the same parent as the gabbros. Most of the Mt Buller rocks do not show a positive correlation between silica and initial ⁸⁷ Sr/ ⁸⁶ Sr, or between silica and ¹⁴³ Nd/ ¹⁴⁴ Nd values, indicating that neither crustal contamination nor mixing between mantle‐ and crustal derived melts has been important and that these rock types are likely to have formed by fractional crystallization from a common mantle‐derived parent. Some scatter in compatible trace elements, particularly in granites and diorites, may be explained by mixing. Geochemical modelling confirms a comagmatic origin of the suite. Magma generation probably took place in the subduction‐modified upper mantle. This mechanism may play an important role in I‐type granite petrogenesis in particular tectonic settings such as during an efficient slab roll‐back or sinking of oceanic crust in divergent subduction conditions.

In spite of several studies attempting to relate the chemical composition of clinopyroxenes to the nature of their host rock or depth of crystallisation, there is no empirical background to enable compilation of both pressure and temperature conditions of CPX crystallisation. On the basis of experimental data and employing multivariate statistics, the empirical PT‐space was developed. This PT‐space allows distinction of CPXs crystallising from basaltic magmas over a large range of temperature (1100–1300°C) and pressure (0‐>20 kbar). In low‐pressure crystallisation (P<2 kbar), the Ti/Mg ratio in magma can be related to the clinopyroxene composition enabling primitive and evolved basaltic magmas to be distinguished in spite of coincidence in the En‐Wo‐Fs values of clinopyroxenes. These diagrams are particularly useful in studies of rocks and xenoliths in the oceanic floor environment, since the stratigraphical sequence of samples and crystallisation parameters, including a nature of possible parental magmas, are difficult to establish directly. Soesoo, A., 1997: A multivariate statistical analysis of clinopyroxene composition: empirical coordinates for the crystallisation PT‐estimations. GFF, Vol. 119 (Pt. 1, March), pp. 55–60. Stockholm. ISSN 1103–5897.