ters record a few swarm-like sequences. Interestingly, LASL researchers recently noted a major relative subsidence northwest of Espanola associated spatially with the earthquake belt. Geodetic releveling analysis reveals a maximum subsidence of about 5 centimeters between surveys performed in 1934 and 1939. Researchers suggest that the sinking and the associated earthquakes originate in deflation of a shallow magma body. Continued studies will help to identify the processes responsible for regional extension in the Southwest. Plate movements not only create earthquakes and produce volcanism; they also determine where mineral deposits form. In addition, most geothermal energy resources originate as a result of plate interaction. The LASL hot dry rock experiment on Fenton Hill is successful partly because of its location on the edge of the Rio Grande rift. Plate travels determine whether diamonds form in Arkansas or gold appears in California. Many ore bodies, for example, occur at present or past boundaries of crustal plates. Geology is a young discipline with a rapidly increasing pace of surprising discoveries. Only astronomy shares with it the complexities of scale and time. In 20 A.D. Seneca wrote, "It is useful to be assured that the heavings of the Earth are not the work of angry deities. These phenomena have causes all their own." Two millennia later we are just beginning to understand what those causes are. Moreover, we are just beginning to exploit our understanding through improved exploration for mineral and energy resources. Few theories have made such an impact on their disciplines, and few disciplines, stimulated by new theories, have had such an impact on energy technologies as has plate. tectonics on the geosciences. The Rio Grande Rift. The crosshatched areas indicate the Rift itself and the stippled areas indicate surface volcanics. P Professor (Fredrik) Born February 5, 1906, Langesund, Norway by Robert A. Penneman rof. Zachariasen, one of the outstanding scientists of the 20th Century, is gone. "Willie" leaves to his countless friends the warm remembrance of his gracious manner, his great good humor, and his generous friendship. His rich and varied scientific contributions engaged him to the last. He was one of the giants in x-ray crystallography and was involved in every major advance in that field. Linus Pauling wrote of him: I have known Professor Zachariasen for nearly fifty years. His principal field of work has been the determination of the structure of crystals of inorganic substances by use of the xray diffraction technique. This is a field in which I also have done a large amount of work, and I believe that I am in a position to form a sound opinion about his ability and his contributions. It is my opinion that he has been and is the world leader in this field. I feel that he is to be classed among the outstanding scientists of the twentieth century, and at the top in the field of inorganic crystal structures. The Formative Years Zachariasen began his career, unknowingly, with his youthful exploration of the islands in Langesundfjord near his home, islands rich in well-crystallized rare earth minerals. He was to return to those islands later as a student at the University of Oslo under the great geochemist Prof. Goldschmidt, who had purchased one of the islands for his studies. "Willie" rowed him out on occasion, a short journey for the son of a sea captain. The trips to the islands combined work with pleasure. Mrs. Zachariasen supplied a photograph of a picnic on one of the islands; in it Prof. Goldschmidt is seen talking to guest Albert Einstein. The vivid memory of those days never left Zachariasen; some dozens of years later he correctly identified (on sight) one of the crystal specimens from the Langesundfjord islands-a specimen that had been mislabeled by a commercial firm. Zachariasen spent his student days (1923-1928) in the midst of that exciting period when Goldschmidt and his collaborators worked out general laws governing distribution of chemical elements in minerals; they were the first to apply x-ray diffraction to the study of geochemistry. During those years Zachariasen read hundreds of x-ray films, an activity that he continued throughout his life. Where the results were of particular significance, as in the recent controversy involving the a' and a" phases of cerium, he would read each film several times. Zachariasen published his first paper at age 19, after presenting it before the Norwegian Academy of Science the year before. It was on x-ray diffraction studies of oxides. With its publication in 1925 he began a period of contributions to the scientific literature, most of them singly authored, which would span 55 years. At age 22, he received his Ph.D., the youngest person ever to receive it in Norway. In 1928-29, he was a Postdoctoral Fellow at the laboratory of Sir Lawrence Bragg, where he began his study of silicate structures, a study that would later culminate in the first real understanding of the structure of glass. He returned to the University of Oslo, but within a year accepted a call from Nobel Laureate Arthur Compton to join the faculty of Physics at the University of Chicago. He was 24. Before leaving Norway in 1930, he married Ragni DurbanHansen, the striking granddaughter of the pioneer Norwegian geochemist, W. C. Brøgger, who discovered and first described the extensive mineral deposits of the Langesund area. Willie and his bride spent their honeymoon on the ship that brought them to the United States to fulfill his commitment to the University of Chicago. There he spent the next 44 years. The Zachariasens had two children, Fredrik Zachariasen (at the California Institute of Technology, Pasadena) and Ellen Z. Erickson of Santa Monica. Zachariasen The University of Chicago Many honors came to him during the 44 years at the University of Chicago, He advanced to full Professor, then to Department Head (during the critical post-war years when the department was rebuilt), and finally to Dean of the Physical Sciences. He was a kindly administrator and solicited advice, but always maintained a policy that one had to "select the few from the many." He was a member of the Norwegian Academy of Science, the U.S. National Academy of Science, the American Academy of Arts and Sciences, the American Physical Society, the American Crystallographic Association, and the Executive Committee of the International Union of Crystallography. He was presented with the honorary degree of Doctor of Science by the New York Polytechnic Institute. The 1930s were years of financial hardship. Travel funds were nonexistent and Zach would sit up on a night train to New York, give his paper at a scientific meeting the next day, and return that night to save the cost of a hotel room. During that same period x-ray work was shut down for six months for lack of a $75 tube. But those were also years of high scientific productivity. Following his work with silicates and other oxy-anions, Zachariasen began to think about how the glass structures were built. In 1932 he published his landmark paper on the structure of glass. Referring to this paper in 1961, Charles H. Green wrote: "The present day understanding of glass rests heavily on a singly lucid paper, only 12 pages long, written in 1932 by W. H. Zachariasen." Zachariasen continued through 1941 to study complex oxy-anions and to develop his work on the diffuse scattering of x rays caused by thermal motion. In 1941 he became an American citizen. He was then in his mid-30s and already a world figure, having published 80 experimental and theoretical papers, including major papers on diffuse scattering, oxide structures, and the structure of glass. A significant change was soon to occur following the onset of World War II. The War Years In parallel with his academic career, Zachariasen began in 1943 to immerse himself in a then-secret activity, doing all the x-ray identification work for a new project on the Chicago campus. As part of a major wartime effort, scientists had gathered at the Metallurgical Laboratory to work with new elements that had not yet been seen, new elements whose chemistry was largely a mystery. Recall the situation-Enrico Fermi had just demonstrated the existence of the chain reaction at Chicago in December 1942, using uranium.* Plans were being rushed for the pilot plant at Oak Ridge, Tennessee, and the production reactors at Hanford, Washington. This meant that the new element, plutonium, would be made in large quantity using neutrons from a nuclear reactor. Before this, plutonium could be made only in microgram quantities by tedious cyclotron irradiation. *During the Fall of 1942 I was in Massachusetts as part of the Chicago team aiding in the production of sufficiently pure uranium metal. |