Benefits of hindsight
In 1937, Phillips concluded that the regional-scale pattern of lineation which he had observed at both micro- and macroscales in the Moine metasediments, trending broadly NW-SE and plunging to the SE, was attributable to ‘movements along southwest to north-east lines, earlier than the post-Cambrian displacements’ (Phillips 1937b, p. 597). It appeared to post-date the intrusion of the Cam Chuinneag igneous complex (Phillips 1937b, p. 595, 1945, p. 210), to pre-date the isoclinal folding (Phillips 1945, p. 211), and the associated fabric was broken down by the ‘dislocation-metamorphism’ of the Moine Thrust Zone (Phillips 1945, p. 212).297 Furthermore, Phillips agreed with Read's interpretation that although the pervasive NW-SE ‘stretching lineation’ (Read et al. 1926, p. 121) pre-dated the Moine Thrust itself, ‘it is the lineation parallel to the b-axis of the fabric which has provided the direction of yield during the later thrust-movements’ (Phillips 1937b, p. 597). As Flinn put it (pers. comm. 1998), Phillips’ interpretation was ‘right (to some extent) for the wrong reasons.’
Although the style of Phillips’ (1945) composite petrofabric diagrams (e.g. Figs 6.8-6.10) has recently been found by Richard D. Law to be particularly helpful as an aid to kinematic interpretation,298 much of the controversy which dogged Phillips’ petrofabric research was attributable to the fact that in his own work Phillips followed Sander's usual kinematic interpretation of the ‘ b-axis ‘ as being orthogonal to the principal compressive stress and, hence, to the ‘direction of transport’, a view which, as has been seen, unfortunately became increasingly controversial.
Figures & Tables
The Life of Frank Coles Phillips (1902–1982) and the Structural Geology of the Moine Petrofabric Controversy
Frank Coles Phillips was a photographer mineralogists and structural petrologists working in themiddle of the twentieth century. He was very influential, both in the UK and abroad and was responsible for encouraging the development of structural geology as a discipline in Australia and for the adoption of the stereogram as a fundamental interpretational tool in structural geology in the UK. He was a superb teacher, perhaps best known amongst mineralogist and geologist of today for his classic textbooks, An Introduction to Crystallography and The Use Steographic Projection in Structural Geology.
Phillips was the first to apply the methods of structural petrology (the study of the microscopic fabric of deformed rocks) in an attempt to unravel the complex structural history of the Moine rocks of northwestern Scotland. his findings were at odds with those of his contemporaries and resulted in the Moine petrofabrics becoming embroiled in a long-running controversy, only completely resolved since the mid-1980s.
This geological biography of an important twentieth century mineralogist and petrolohist takes a critical look at Philips' research in the context of contemporaneous developments in structural and Moine geology. It reviews his work in relation to both past problems and present solutions. It will be of interest to all gelogist, especially structural and microstructural geologist, historians of science and the general leader with an interest in science.