WALTER B. DALLWITZ 1914-1992 Walter (Wally) Dallwitz was born on 5 December 1914 at St Peters in South Australia, the first child of Benjamin and Dorothea Dallwitz and a descendant of German and Austrian families who had settled around Adelaide in 1845 and 1851. His early years were spent on his parents' farm at Modbury, South Australia, but at the age of twelve he went to board at Emmanuel College in Adelaide, where he completed his secondary education. His initial tertiary education was not in geology. He obtained a Diploma of Education from Adelaide Teachers College and taught for a year, before graduating BA in Latin and German from the University of Adelaide in 1940. He was a gifted athlete and ran at State Championship level at all distances between 100 yards and mile. The physique which he developed in pursuing this interest enabled him to supplement his income by working as an artists' model. In his BA course, Wally also studied some science, including geology, which became his abiding and overwhelming intellectual passion, although he retained his love of language throughout his life. Wally continued his studies at the University of Adelaide and received a l st Class BSc Honours degree in geology in 1942. He completed his MSc in 1943 and was awarded the Tate Memorial Medal for best original work in geology. Whilst studying for his geology degrees he was employed in the Geology Department as research assistant to Professor Sir Douglas Mawson. Two other noted and well-liked geologists, Drs C.T. Madigan and AR. Alderman, were also on the staff at this time. Wally's close friendship with all three persisted until their deaths. Wally's employment obligations at the University included demonstrating, and in this capacity, he met his future wife, Vera, who was taking Geology l as part of her BA course. They were married on 18 July 1942. In March 1944, Wally joined the Electrolytic Zinc Company at Rosebery, Tasmania, where he was engaged in surface and underground mapping and logging of diamond drill cores. In a report to the company, he presented a completely new interpretation of the geology of the area. He also suggested a method of enhancing the penetration of diamond drilling, which was widely adopted in the industry. Senior staff at EZ still remember Wally's name as one whose ideas helped formulate company concepts of the deposit there, and Dallwitz Street in Rosebery bears his name today. In December 1946, Wally was appointed to the Geological Branch of the Bureau of Mineral Resources (BMR) in Canberra. For a number of years, he headed the BMR laboratory and concerned himself entirely with science, although eventually he found it necessary to take on more administrative work. He nevertheless maintained an active role in BMR's scientific programs and spent some time in the field almost every year, and as much time as possible on the description and interpretation of field material. Wally regularly visited field parties of the Geological Branch's Metalliferous Section in remote areas of Australia, despite the debilitating arthritis which had slowly crippled him since his mid-twenties, and which necessitated numerous surgical operations over the years. He was a good companion in the field and bore the discomfort of his chronically painful condition with fortitude and, of course, good humour. He remained with BMR until his retirement as assistant Chief Geologist. Wally Dallwitz was a master petrographer in the 55 classical sense, with a special interest in igneous and metamorphic rocks. Optical mineralogy was his strength and he was a wizard with
his monocular petrographic microscope. His interests in other aspects of geology seemed to be secondary to his love of minerals and how they looked in thin section. He was the first to identify clinoenstatite (previously known only in a certain type of meteorite) in a terrestrial rock - a volcanic collected by J.E. Thompson from Cape Vogel, Papua New Guinea described in a benchmark paper published in Journal of Petrology (Dallwitz, Green and Thompson, 1966). The study included a detailed description of the rock, which was characterised by both high SiO2 (greater than 53 per cent) and high MgO (greater than 8 per cent). The paper was a major stimulus to subsequent international studies of the important suite of volcanic rocks now known as boninites. When Wally visited the Cape Vogel area in 1966 to obtain more material, one of the rocks collected at that time was found to contain as much as 70 per cent clinoenstatite in crystals up to 25 mm long. He published a discussion paper on these rocks in the Proceedings of the International Geological Congress for 1968. Unfortunately, his attendance at the congress in Prague was disrupted by the Soviet invasion. Wally appears to have been the first to identify primary anhydrite in andesite - in the 1951 and older lavas of Mount Lamington, also in Papua New Guinea. The observation was made shortly after the 1951 Lamington eruption but did not attract much attention at the time; today its significance is hard to overlook. Anhydrite bearing magmas currently are of international volcanological interest because of the 1991 Pinatubo eruption in the Philippines, which also produced lavas containing anhydrite, and because of the potential effect such sulphur-rich eruptions have on changing climate. In 1968, Bas Hensen, then a PhD student with David Green at ANU, produced coexisting sapphirine and quartz in high-temperature, high-pressure experiments on mixtures with medium to high alumina contents. In presenting these experimental studies to an international symposium at the ANU that year Hensen mentioned that sapphirine and quartz in stable equilibrium had not been found in terrestrial rocks. This immediately prompted Wally to recall having seen, not long before, these minerals in granulite collected by Ian McLeod of BMR from a small nunatak in Enderby Land, Antarctica, and his report on this occurrence was published as a letter to Nature in 1968. Wally subsequently helped recognise osumilite (also is a high temperature indicator) on a regional scale in Enderby Land's Napier Complex. A discussion of the significance of these discoveries (D.J. Ellis, J.W. Sheraton, R.N. England and W.B. Dallwitz, 1980, Contributions to Mineralogy and Petrology) stimulated metamorphic petrologists worldwide to re-examine granulite facies rocks for similar assemblages. Since then, much more emphasis has been given to defining the pressure-temperature-time evolution of high-grade metamorphic rocks. The Antarctic locality where the sapphirine-quartz association was first found has been officially named Dallwitz Nunatak. Wally was renowned also for his scientific editorial skills. He set high standards of consistency and integrity for the reports compiled by his staff in BMR. He was the bane of woolly thinkers and loose writers and spent hours with wayward authors, drilling them on the principles of the English language - where to start a paragraph, how to construct a sentence, and where to place a comma. He was a determined promoter of the very best scientific English. There were occasions when senior officers and others objected to his corrections and remarks, and some senior toes were trodden on in the process of Wally proving his point. In some of his flippant moments, Wally would post on the notice board edited versions of pages of the Financial Review.
He is remembered as a great personality and individualist. Wally remained a regular attender of the GSA meetings even after his retirement in 1979. His custom was to sit in the front row in order to gain an uninterrupted view of the speaker and slides, and he would stir discussion, asking, in a good-natured manner, questions that were penetrating, thought-provoking, and commonly the very ones that others in the audience were too embarrassed to ask! They reflected Wally's genuine desire to improve his knowledge and were not designed to score points off the speaker, although some of the more direct ones could set even the most confident of speakers back on their heels, floundering for a respectable answer. He also had a seemingly inexhaustible supply of anecdotes with which to enliven the discussions. Wally was a great admirer of the works of Rabelais, and the exuberant type of Rabelaisian humour came through in his own wit; and at times could shock the more gentile audience. Few who heard Wally tell one of his favourite ribald jokes will forget his honest and refreshing sense of fun. He proudly regarded himself as something of an iconoclast and scorned any form of pomposity. Unfortunately, some of the idols he attempted to break with his biting sarcasm, not unexpectedly, took umbrage to the treatment, and this did not help Wally's professional advancement. However, those who knew him well understood that his cynical and at times somewhat hard-nosed utterances belied a gentle, caring nature. Wally was a loving and devoted family man and a proud grandfather of six, the youngest of whom, Emily (pictured with him above), shared his birthday. Walter (Wally) Dallwitz died on 30 November 1992. Jan Hodgson