The leucite-bearing rocks of the West Kimberley area, Western Australia

Abstract

Introduction The presence of leucite-bearing rocks in the West Kimberley area of Western Australia is first mentioned by Farquharson (1920, p. 42, and 1922, p. 56). They appear to have been noted first in the basin of the Fitzroy River by Blatchford and Talbot and in the proximity of the Lennard River by Wells (Simpson 1925, p. 59). Wade (1924, p. 9 and map) refers to these occurrences and shows their position on a geological map of the northern parts of Australia. Simpson (1925, pp. 58–9) describes specimens collected by Blatchford and Talbot and by Wells from “Barjar” (referred to in this paper as “Dadja”) Hill and Mt. North, gives an analysis of the Barjar Hill rock and draws attention to the peculiarities of mineral and chemical composition of these rocks. A report by one of the research committees of the Australasian Association for the Advancement of Science embodies extracts from Simpson's paper and a preliminary description by Skeats (1928, pp. 42–6) of specimens collected by Wade from P Hill and Bruton's Hill (described as “Hill C48,” 20 chains north from Brunton's Bend). An analysis of the rock from P Hill and of a silicified type from Bruton's Hill are included. The report states that eleven separate vents have been recorded from this area, and the occurrences are linked with the leucitic rocks of Sumbawa, Java, Celebes and Borneo. Blatchford (1927, pp. 20–1) gives a list of the nine occurrences known to him, but does not mention Mt. North, previously