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Introduction of Paul W. Gast for the V. M. Goldschmidt medal of the Geochemical Society
Geochimica et Cosmochimica Acta, 1973, Vol. 37, pp. 1625 to 1633. Pergamon Press. Printedin Northern Ireland
Award of the V. M. Goldschmidt and F. W. Clarke Medals of the Geochemical Society November 13th, 1972, Minneapolis, Miiesota,
U.S.A.
The President-Elect of the Geochemical Society, Professor B. J. Skinner, Yale University, acting as Chairman, called upon President F. R. Boyd to present the awards to the medallists. The speeches of Introduction and Acceptance follow:
Introduction of Paul W. Gast for the V. M. Goldschmidt Medal of the Geochemical Society by WILLIAM C. PHINNEY* Mr. President,
members of the Geochemical Society, and guests: Anyone who knows of Paul Gast’s accomplishments should consider it an honor to introduce him. I consider it a special honor for not only am I introducing a highly respected and outstanding geochemist, whose attempts to develop models for the chemical evolution of the earth and, more recently, the moon have been always at the forefront of earth and planetary science; but I am also introducing a long-time friend whose family has been closely related to my family throughout the 13 years that we have known each other. My first meeting with Paul occurred in early 1959 when I visited the University of Minnesota to interview for a faculty position. The discussion with Paul was significantly different than I encountered in any other interview. Within 30 seconds of our introduction we were in the midst of the meanings of element distributions between minerals, rocks, and major units within the earth. As though this were not enough to cover in his 30 minute time slot of the interview schedule, we also discussed the importance of elemental ratios and the effects of multistage geologic events on the redistribution of isotopes and trace elements. Needless to say, the time scale for the remaining interviews required revision. The advantage of a fellow faculty member with whom discussions of this quality and content were possible was a major point in my choosing to join the University of Minnesota faculty. He did not disappoint me. Paul majored in chemistry at Wheaton College, Illinois, where he received a B.S. in 1952. Between his junior and senior years, he received a summer research scholarship at Columbia’s Lamont Geological Observatory where he spent 6 weeks on an oceanographic vessel. As a budding oceanographer, he planned to do Cl4 work on samples to be collected during this voyage. The sampling equipment failed to function properly and no samples could be collected, thus dooming his first major scientific experiment to failure. Although this may have caused the early demise of a brilliant career in oceanography, it is clear that the interest continued as demonstrated by his organizing a more limited oceanographic-type expedition on Lake Superior in 1961. * Chief, Geology Branch, Manned Spacecraft Administration, Houston, U.S.A. 1625
Center, National
Aeronautics
and Space
1626
Award of the V. K Goldsc~idt
and F. W. Clarke medals
This first brief and unsuccessful experience with earth science apparently acted more as a challenge than a deterrent. On returning for his senior year at Wheaton, he took several geology courses and applied to Lamont for graduate studies in geochemistry. Despite his problems of the previous year, he was admitted and given a second chance to accompiish a summer of research but this time in mass spectrometry. This second summer of research was apparentIy more successful than the first, as it was the beginning of a long and rewarding romance with mass spectrometry. VVithin a year he commenced Sr isotope studies at the Department of Terrestrial Magnetism as part of his graduate research. In 1957 he com.pleted his Ph.D. at Columbia and remained there for one more year as a research associate before joining the faculty of the Department of Geology at the University of Minnesota in 1958. As he accumulated data during his graduate research, he noted the relationships between various rock types and their isotopic or trace element compositions. In seeking reasons for these correlations, he began to develop chemical models req~7iring fractionation of elements between major units of the earth. However, geochemists at that time were not prone to considerations of the earth as a whole. Trace element roulette and dating games were fashionable in those days and Paul agreed to play the latter in his dissertation research. After arriving at Minnesota he further pursued his earlier ideas on chemical models of the earth. This work culminated in his now classic paper “Limitations on the Composition of the Upper Mantle,” published in the Journal of Geop~~~sic~l Research in early 1960. Utilizing ratios of alkali elements in various rock types and apportioning these in various major units of the crust and mantle he was able to suggest that the earth has a non-chondritic composition. This was the forerunner in a field of research which was to attract numerous investigators over the following several years. Various meteorite models of the earth, selective volatilization of components in the early stages of earth’s evolution, time and nature of major chemical fract,ionations in earth history, and effects of high pressure on fractionation of certain components are among the many research efforts spurred by his paper. Efforts to further quantify his ideas on large-scale chemical fractionatio~l included determinations of compositions of various rocks from old shield complexes and young volcanic areas. I recall several discussions involving mathematical models for simultaneous calculation of various component concentrations during multistage fractionation. Throughout these and other discussions, it was gratifying to a geologist like myself to note Paul’s strong desire to understand the geologic field relationships in all areas from which his samples were derived. His students at Knnesota spent many weeks studying the field areas from which they collected samples for chemical studies. His work with young basalts coupled with the exciting new ideas about the role of oceanic crust in the tectonic history of the earth suggested that study of oceanic In ridge basalts would be a key to chemical fractionation through earth’s history. 1965, this interest led him back to the old friends and familiar territory of Lamont where current oceanographic studies of the mid-oceanic ridges allowed ease of access to samples as well as a voice in planning the sampling. Study of this subject culminated in the discussion of mantle fractionation in a recent paper with Bob Hay ancl Norm Hubbard titled, “Ch emical Characteristics and Origin of Oceanic Ridge Volcanic Rocks” in the Journal of Geophysical Research, 1970. Another of his major
Award of the V. M. Goldschmidt and F. W. Clarke medals
1627
contributions during this period was the quantification of partial melting calculations based on distribution coefficients between melt and several crystalline phases simultaneously. Again this provided a further refinement of mantle composition in his fractionation models. It is not unexpected that lunar materials and their relation to the formation of terrestrial planets would be of interest to Paul, whose fractionation models require that compositional constraints be placed on the initial material from which earth formed. In 1965, he became a charter member of the geochemistry working group for initial planning of lunar exploration and sample study. The group set many of the basic policies required for collecting, processing, studying, and distributing lunar samples. By 1967, Paul was chairman of this group. During this time he was instrumental in urging NASA to appoint a formal team of scientists representing the total lunar science community for detailed planning of processing and distributing lunar samples for analyses. The result was the Lunar Sample Analysis and Planning Team for which Paul served as chairman in 1969 during the first lunar sample returns. As the early Apollo missions became reality, the complexity of processing, distribution, and study of lunar samples became more apparent. This was compounded by resignations of top science management at the Manned Spacecraft Center and it was clear that strong leadership as well as competent scientists were a necessity at MSC if the maximum scientific return were to be obtained from Apollo. In early 1970, Paul accepted the position of Chief of the Planetary and Earth Sciences Division at MSC. During the past 2$ years he has developed the most respected lunar science research organization in the world and has become the most influential lunar science advisor in NASA. His foresight in developing the science training of Apollo flight crews, organizing high quality preliminary examinations of lunar samples, assembling an outstanding group in lunar research, and constantly making suggestions or challenges to the numerous lunar science experiments has led to a high degree of excellence in the science return from Apollo missions. As might be expected, he could not be kept from developing chemical models of the moon. Again, studies of the nature of initial composition and ensuing fractionation have seen Paul at the forefront. It is with great pleasure that I present to you Dr. Paul Gast for the first GoldSchmidt award.
Acceptance Speech V. M. Goldschmidt Medal PAUL W. GAST* I would like to thank all of those who are responsible for this occasion for bringing me back to this cold climate. I am very honored to be the first recipient of the V. M. Goldschmidt Medal. Those of you who know me know that I am not usually at a loss for words. The appropriate words for this occasion, however, seem to have escaped me. A scientific lecture is clearly not the proper response. A humorous * Chief, Planetary and Earth Sciences Division, Manned Spacecraft Center, National Aeronautics and Space Administration,
Houston,
U.S.A.
1628
Award of the V. M. Goldschmidt and F. W. Clarke medals
before-lunch speech is quite beyond my abilities. Thus, somewhat out of desperation, I have chosen this occasion to share with you some thoughts that arise out of experiences I have had in the last few years. They may be entitled “a view from the bridge”. Some of you may know that in the last three years I have had the privilege of occupying a very interesting and somewhat unique position in which I have served as a bridge between a vocal and highly talented scientific community and a very large and very complex Government agency. These three years have been an education that may rival the five years I spent in graduate school in their total impact. They have provided a perspective on both the scientific community and on the Government bureaucracy which has reoriented much of my thinking about both of these facets of our society. Whether we like it or not, we must recognize that we are tied together by symbiotic bonds that are often stretched to the point where they are almost severed. Early during my scientific adventures, I lived with the idea that the best atmosphere in which to do science was, indeed, the proverbial ivory tower; that is, I had the notion that we scientists somehow deserved a sheltered or cloistered env~onment largely protected from the storms of the society which surround us. I now seriously doubt that this is, in fact, the ultimate ideal towards which we should strive or that we should suggest to our students that the ivory tower is the most prestigious goal toward which they can strive. For me, the past three years have been a learning experience and an adventure that I treasure very highly. I hope that all of those who have been involved in the ‘nonscientific’ aspects of lunar exploration are able to look back on this time with similar feelings. We seem to have entered a time when the success of many of our efforts depends on the success of enterprises that involve hundreds to thousands of people, many of whom have no understanding of the major objectives of these projects. The Apollo and Viking projects are certainly examples of this type of science. The JOIDES project may be another example. The experiences of the last three years have shown that we can closely interweave scientific, management, and technical personnel in order to accomplish major goals. They have shown that within large organized efforts we may be able to preserve ‘islands’ where research is carried on with relative independence. Rowever, if there ever was an ivory tower, many of us had to leave it in order to work in a very different world. The knowledge that a ‘city of refuge’ could be found if one had to is somewhat reassuring, but our perspective of the world is changed from that seen within the ivory tower; and I suspect it is healthier and more realistic. I also suggest that projects like Apollo and JOIDES may not be unique endeavors in our science ; rather, they may represent important patterns for the future management of science. The application of rational scientific thinking to en~onmental problems will probably require similar efforts in which pure science, engineering, and complex management need to be integrated into one organization before solutions to these problems are at hand. Thus, it may serve us well to look at what we are doing and at what we have done to see if the past has any lessons for the future. I would like to suggest one. In my opinion, one of the better-defined and darker shadows cast over the Apollo science program has been the often acrimonious
Awtwd of
the V. M. ~oldsc~dt
and F. W. Clarkemedals
1629
differences of opinion that have surfaced during the planning phases of this program. Some of my administrative colleagues find it difficult to understand how science can accomplish its ends from a position of such disarray. It is very clear to me that the participation of science with other segments of our society in a search for the solution of some of these problems that face us will require much more than a demonstration or claim of relevance. The ability to address complex issues and decisions incisively will be essential. We live in a very pragmatic and empirical society. The managers and administrators of this society do not always plaoe the same value on the heritage of open and free scholarship that we do. They place a high value on the ability to identify and solve problems. A major ingredient in these solutions consists of decisions. We may find ourselves in a position to affect these decisions by means of technical and expert advice. Only too often our advice is so transparently self-serving or contradictory that we forfeit our role in the decision-making. I can only hope that the upcoming generations of geoche~nists, geologists, and geophysicists have enough intellectual common ground to avoid the appearance of working at cross purposes. It is not hard to imagine that the success of future efforts in the geosciences may depend not only on the cooperation of different subdisciplines in this part of the intellectual arena, but on cooperation between such diverse disciplines as medicine and geoscience. Hopefully, the evolution of the scientific disciplines has not progressed to the point where fertile crossbreeding between diverse areas of science is no longer possible. Clearly, I have no answers to the problems I have raised here. I can only suggest that less specialized education might be helpful. Otherwise, the best I can do this morning is to point to the problem. I hope that those in decision-making positions take note and that those who are deciding their own future will consider some career goals that have not been held in high esteem by most of their intellectual peers.
Introduction of Dimitri A. Papanastassiou for the F. W. Clarke Medal G. J. ~ASSERB~R~~
There are, to me, three truly exciting personal experiences in science. The first of these is the experience of oneself, privately, observing and understanding something that is new and that is important. The second excitement is the act of precipitating understanding of some natural phenomenon in someone else. The third is to be honored to participate in the formal bestowal of professional recognition of a respected colleague, a student and a friend. I am greatly privileged to stand before two colleagues and friends of different scientific generations that are being recognized by this society today. The early pioneer work on Rb-Sr dating which was to play a role in Dimitri’s thesis was first carried out by Tom Aldrich at the Department of Terrestrial Magnetism under the stimulus of Louis Ahrens and later by G. W. Wetherill and G. R. Tilton of the Carnegie Institute of Washington. When Dimitri Anastassios Papanastassiou (DAP) was entering Athens College in Greece, Paul W. Gast was measuring Sr isotopes. Paul was a rather bumptious * Charles Arms Laboratory, Division Instituteof Technology, Pasadena, U.S.A.
of Geological
and Plamtary
Sciences,
California
1630
Award of the V. M. Goldschmidt and F. W. Clarke medals
young man, who as a high school student would announce to his father and brother at t*he supper table that he, P. W. Gast, was personally going to go to the moon regardless of either technologic or theologic di~culties. Gast had just establisl~ed that the change in *7Sr/@%r over the history of geologic time was very small ( 1955). The work that Dimitri was to do some ten years later was a direct out-growth of this fact. Dimitri was a student at Athens College, an American-sponsored high school for Greek boys. Through the enthusiasm and pedagogical skills of Andreas Remboulis, Dimitri became interested in science and as a result of his outstanding performance he was recommended to Cal Tech. In the forms sent out by Cal Tech, question three asks, “for what type of career is the applicant particularly suited?” Mr. Eliascos, the Assistant Principal of Athens College responded, “The type of career he wishes to This information, in conjunction with his detailed academic record was follow.” transmitted to our admissions officer, who promptly put this data into a universal formula which has as much control over predicting the future of a student as a recently t,outed universal phase rule which purported to describe the interrelationship of all known geologic processes. After processing all of this information, the computer output showed t*hat Dimitri would get a grade-point average of 1.96015 whereas the lowest passing grade-point average was 1+90000, so that this man’s future was not essentially encouraging. However, with the perseverance of Mr. Peter Richardson, the student counselor at Athens College, Dimitri was admitted to Cal Tech. Well, the GPA formula was pretty good, at least it got the sign right, because Dimitri passed and did so with honors for four years, and graduated in physics in the top IO per cent of his class with a GPA of 350037. I tell this story because it is true and because I hate the incompetent, inhibiting, predictive testing of students. In his undergradute years, Dimitri worked in the Kellogg Radiation Laboratory under Tommy Lauritsen, Tom Tombrello and Ward Whaling. He was then interested in low energy nuclear physics. This represented an exciting endeavor and one which kept him in touch with a variety of fields of modern physics and astrophysics. As a member of the Division of Geological Sciences and also a member of the Kellogg staff I had attempted since 1955 to attract bright young physicists to work jointly in problems of importance in earth and planetary sciences. The importance of continually interdigitating the concepts and developments of physics with our science seemed overwhelming to me, although some physicists considered it too ‘classical’ (that is, old fashioned) an area. Since Dimitri was thinking of returning to Greece, this area of the physical sciences seemed of sufficient vigor and small enough in scale that it might reasonably be In any event, he was considered an appropriate candidate and Tommy transported. Lauritsen literally took Dimitri under his wing and guided him ~~w~~ from Kellogg to Arms. I think he mumbled something about DAP being a sacri~cial lamb. In any event, DAP began to work with me when we had just started the design of a new generation of computer-interfaced isotope ratio mass-spectrometers with digital output, which I hoped would permit routine measurements at the level of a few parts in ten thousand. The spectrometer grew from conception through ion optical calculations to a hardware reality which in fact can produce data with a precision of five
Award of the V. M. Goldschmidt and F. W. Clarlre medads
1631
parts in one hundred thousand. This permitted a look at minute isotopic differences which were previously invisible. Small or negligible effects became real and measurable quantities with deep petrogenetic and chronologic meaning. The change in sSr/s%r in chondrites is about O-01per cent in 10 million years. With development of these techniques coupled with great attention to mineralogic properties, DAP showed that it was possible to date the basaltic achondrites and that there were resolvable variations in the initial strontium in meteorites which represented five million years in early solar system history. This has given us acronyms such as BABI and ADOR in the literature (1969, 1970). Since then he hasspent his timeestablishing a lunar chronology using the 8%b-*7Sr decay scheme. (1971, 1972a, 1972b). It is this endeavor by a young man which is the subject of this award. DAP is a true Athenian-he is a multilingual and versatile perfectionist who has made a temporary peace with the demigods who run the world imperfectly. He has learned to mispronounce Greek words and to scrawl Greek symbols in the vulgar fashion used by the large uneducated world. As a true Athenian he is a snob. During a late session when we were writing a paper, I referred to Alexander the Great as a Greek, to which Dimitri retorted, “Oh that Macedonian!” When, during a lecture on the cosmic time scale, he heard me recite part of the book of Genesis in Hebrew, he commented that it sounded peculiar since he was used to hearing it in the original Greek. I don’t know if DAP will fulfil his youthful hope of moving some of his science back to Greece. His infatuation with the United States is in great part due to a very intelligent and gracious young woman, his wife Teri. I expect he will stay and enrich our environment. When Dimitri filled out his admission form twelve years ago he was obliged to write a short statement about his long term future. He wrote: “Indeed, what I think will play the decisive role in my choosing a career will be my love for science. Whether it is a place in industry or in the government, it will be the same to me as I long as it won’t be a routine work. . . . I guess all this sounds a little pompous. remember [a] teacher telling me that, when you are young, you want to hecomc a pioneer in science, and then, when you grow older, you find yourself engaged in an ordinary job, not caring any more for original research work. Still he [the teacher] loved to hear of boys having such hopes for the future.” Mr. President, may I present the Clarke Medalist, D. A. Papanastassiou, a young man who has been on the cutting edge of original research and will as he grows older undoubtedly stay there for a long time. REFERENCES CAST P. W. (1955) Abundance of SF during geologic time. Bull. Geol.Soc. Amer. 66, 1449-1&X PAPANASTASSIOU D. A. (1970) The determination of small time differences in the formation of planetary objects. Ph.D. Thesis, California Institute of Technology. PAPANASTASSIOUD. A. and WASSERBURC G. J. (1969) Initial strontium isotopic abundances and the resolution of small time differences in the formation of planetary objects. Earth Planet. Sci. Lett. 5, 335. PAPANASTASSIOU D. A. and WASSERBURG G. J. (1971) Lunar chronology and evolution from Rb-Sr studies of Apollo 11 and 12 samples. Earth Planet. Sci. Lett. 11,37. PAPANASTASSIOUD. A. and WASSERBURU G. J. (1972) The Rb-Sr age of a crystalline rock from Apollo 16. Earth Planet. Sci. Lett. 16, 289.
1632
Award of the V. M. Goldschmidt and F. W. Clarke medals
PAPANASTASSIOU D. A. and WASSERBTJ~~ G. J. (1972) Rb-Sr systematics of Luna 20 and Apollo 16 samples. Earth Planet. Sci. Lett. 17, 52.
Acceptance Speech F. W. Clarke Medal D. A. PAPANASTASSIOU* Not so long ago, Professor Wasserburg and I were involved in an erudite search for an eclectic name for our first six digit isotopic ratio. The final acronym for “basaltic achrondite best initial”, BABI, has now become a recognizable entity found even in a subject index. It marks in a possibly more succinct manner than I may have appreciated originally the beginnings of a new chapter in what might be considered isotope archaeology for the sun, as opposed to the well-documented application of isotopes to the origins of Hellenic marbles. A few years before that instant, several eager and egocentric Greeks, freshly out of high school, landed on a New York pier. We were very surprised at the absence of a red carpet which we expected for our arrival as new Fulbright scholars. ,4s it turned out we were greeted instead by the insatiable open hand of a baggage handler. The obvious moral in this land of opportunity was that persistence beyond the norm I received slightly more pertinent advice as a fledgling must be commonplace. undergraduate from a physicist, close to four o’clock one morning. We were both waiting for some particularly slow ion counts to accumulate to a preset value, when he volunteered that physics is 95 per cent grind and 5 per cent fun. This has always seemed a fair proposition although it must be clear that occasions similar to the one this morning constitute a serious attempt to upset this delicate balance. My first formal contact with science involved nuclear physics. I spent several summers as an undergraduate plotting cross-sections from a multichannel analyzer and Nilsson states from a computer output. While most probably still dizzy, I took Professor Lauritsen’s advice to walk to the next building and talk to Wasserburg. He promptly concluded that my education would best be furthered by reading massspectrometer charts with a magnifying lens. That task was later changed to picking individual grains with a micro-manipulator under a microscope. At least chart reading must have been primarily a diversion, since he had already designed the next generation mass-spectrometer with automatic disgorging of digital data. The building of that machine proceeded while he toured Europe. It was possibly appropriate that the first preliminary statement of the capabilities of the new instrumentation was included in a review of the age of meteorites. This review was also notable for its emphasis on the strong similarities between the structure of a planet with a core and that of a hard-boiled egg. I have of course been privileged to participate in the development of the new instrumentation. A slightly less appreciated but intimately connected advance has been the development of micro-techniques for handling very small samples. This approach may be described as the whole crystal method as opposed to whole rock analyses. The application of high precision mass-spectrometry and of clean microtechniques for sample handling has been rather crucial for lunar samples. For * Charles Arms Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, U.S.A.
1632
Award of the V. M. Goldschmidt and F. W. Clarke medals
1633
example, these methods have allowed an Rb-Sr age determination on the only rock available from the core obtained at the Luna 16 site. This was a fine-grained, 60 mg boulder and with a modest enrichment in 87Sr/86Srof one per mil. These methods are singularly applicable to the study of inherent isotopic heterogeneity in any rock system, including lunar breccias and terrestrial sedimentary rocks. Recently the word ‘errorchron’ has been coined to emphasize the possibility of increased dispersion in experimental data determining an apparent isochron due to geological disturbances. With the increased sensitivity as applied to lunar samples it is likely that errorchrons will become obsolete and that disturbed phases will be clearly identified. This will allow a better understanding of open systems and the extent of metamorphic reactions. In lunar work, experiments with individual crystals and with neighboring, centimeter-sized, rock fragments have resolved some rather complex, partially equilibrated rock systems and have allowed the identification of ancient lunal crustal material. It is now possible to apply these methods to the investigations of single chondrules or small identifiable inclusions in meteorites. Single inclusions in iron meteorites have been analyzed for some time now and have yielded important isotopic and age information. On a different front the same methods as applied to meteorites and the moon are now beginning to show some temporal structure and chronological order, so that we may soon be able to establish the primitive nature of solar materials based on isotopic as well as on possibly more debatable elemental relations. The BABI value has been established as a marker in time. However, almost before the BABI value was published, we obtained a lower value for the meteorite Angra dos Reis. Therefore one must consider that there exist even wider possible variations in the values of ~7Sr/86Sr with which planets condensed. This is an exciting prospect. The duration of the game now clearly involves tens of millions of years of tantalizing events as we It has are allowed a look at the eve of the very early stages of planetary evolution. always been a surprise that a planet as active as the moon has preserved some extremely primitive isotopic samples. One must also face the problem that meteorites may in fact be open and complex systems. This has been established for some iron meteorites although it is important to understand the nature of the disturbances and in particular whether they are inherent to some meteorites. It would be less interesting if they result only from terrestrial weathering; alternatively open systems may represent early solar system processes or recent events just prior to the meteorite’s impact with the earth. On the earth, of course, we do not have the luxury of working with 4.6 AE rocks. However, these methods can be applied directly on the other end of the scale to very young rocks in the range of tens of thousands of years. One of these days it is conceivable that one could measure the change in 87Sr/86Sr of a solution of a Rb mineral, during a year, thereby allowing another determination of the 87Rb half-life. It is a great honor and pleasure to be in the position of accepting the first F. W. Clarke medal of the Geochemical Society. I find it especially important that this medal is instituted at a time when the first data and theories about the lunar crust occupy so much scientific effort and imagination. The person most responsible for my presence here exposed himself earlier by recounting knowledge which characteristically would not escape the thoughtfulness of a direct scientific progenitor.
Award of the V. M. Goldschmidt and F. W. Clarke Medals of the Geochemical Society November 13th, 1972, Minneapolis, Miiesota,
U.S.A.
The President-Elect of the Geochemical Society, Professor B. J. Skinner, Yale University, acting as Chairman, called upon President F. R. Boyd to present the awards to the medallists. The speeches of Introduction and Acceptance follow:
Introduction of Paul W. Gast for the V. M. Goldschmidt Medal of the Geochemical Society by WILLIAM C. PHINNEY* Mr. President,
members of the Geochemical Society, and guests: Anyone who knows of Paul Gast’s accomplishments should consider it an honor to introduce him. I consider it a special honor for not only am I introducing a highly respected and outstanding geochemist, whose attempts to develop models for the chemical evolution of the earth and, more recently, the moon have been always at the forefront of earth and planetary science; but I am also introducing a long-time friend whose family has been closely related to my family throughout the 13 years that we have known each other. My first meeting with Paul occurred in early 1959 when I visited the University of Minnesota to interview for a faculty position. The discussion with Paul was significantly different than I encountered in any other interview. Within 30 seconds of our introduction we were in the midst of the meanings of element distributions between minerals, rocks, and major units within the earth. As though this were not enough to cover in his 30 minute time slot of the interview schedule, we also discussed the importance of elemental ratios and the effects of multistage geologic events on the redistribution of isotopes and trace elements. Needless to say, the time scale for the remaining interviews required revision. The advantage of a fellow faculty member with whom discussions of this quality and content were possible was a major point in my choosing to join the University of Minnesota faculty. He did not disappoint me. Paul majored in chemistry at Wheaton College, Illinois, where he received a B.S. in 1952. Between his junior and senior years, he received a summer research scholarship at Columbia’s Lamont Geological Observatory where he spent 6 weeks on an oceanographic vessel. As a budding oceanographer, he planned to do Cl4 work on samples to be collected during this voyage. The sampling equipment failed to function properly and no samples could be collected, thus dooming his first major scientific experiment to failure. Although this may have caused the early demise of a brilliant career in oceanography, it is clear that the interest continued as demonstrated by his organizing a more limited oceanographic-type expedition on Lake Superior in 1961. * Chief, Geology Branch, Manned Spacecraft Administration, Houston, U.S.A. 1625
Center, National
Aeronautics
and Space
1626
Award of the V. K Goldsc~idt
and F. W. Clarke medals
This first brief and unsuccessful experience with earth science apparently acted more as a challenge than a deterrent. On returning for his senior year at Wheaton, he took several geology courses and applied to Lamont for graduate studies in geochemistry. Despite his problems of the previous year, he was admitted and given a second chance to accompiish a summer of research but this time in mass spectrometry. This second summer of research was apparentIy more successful than the first, as it was the beginning of a long and rewarding romance with mass spectrometry. VVithin a year he commenced Sr isotope studies at the Department of Terrestrial Magnetism as part of his graduate research. In 1957 he com.pleted his Ph.D. at Columbia and remained there for one more year as a research associate before joining the faculty of the Department of Geology at the University of Minnesota in 1958. As he accumulated data during his graduate research, he noted the relationships between various rock types and their isotopic or trace element compositions. In seeking reasons for these correlations, he began to develop chemical models req~7iring fractionation of elements between major units of the earth. However, geochemists at that time were not prone to considerations of the earth as a whole. Trace element roulette and dating games were fashionable in those days and Paul agreed to play the latter in his dissertation research. After arriving at Minnesota he further pursued his earlier ideas on chemical models of the earth. This work culminated in his now classic paper “Limitations on the Composition of the Upper Mantle,” published in the Journal of Geop~~~sic~l Research in early 1960. Utilizing ratios of alkali elements in various rock types and apportioning these in various major units of the crust and mantle he was able to suggest that the earth has a non-chondritic composition. This was the forerunner in a field of research which was to attract numerous investigators over the following several years. Various meteorite models of the earth, selective volatilization of components in the early stages of earth’s evolution, time and nature of major chemical fract,ionations in earth history, and effects of high pressure on fractionation of certain components are among the many research efforts spurred by his paper. Efforts to further quantify his ideas on large-scale chemical fractionatio~l included determinations of compositions of various rocks from old shield complexes and young volcanic areas. I recall several discussions involving mathematical models for simultaneous calculation of various component concentrations during multistage fractionation. Throughout these and other discussions, it was gratifying to a geologist like myself to note Paul’s strong desire to understand the geologic field relationships in all areas from which his samples were derived. His students at Knnesota spent many weeks studying the field areas from which they collected samples for chemical studies. His work with young basalts coupled with the exciting new ideas about the role of oceanic crust in the tectonic history of the earth suggested that study of oceanic In ridge basalts would be a key to chemical fractionation through earth’s history. 1965, this interest led him back to the old friends and familiar territory of Lamont where current oceanographic studies of the mid-oceanic ridges allowed ease of access to samples as well as a voice in planning the sampling. Study of this subject culminated in the discussion of mantle fractionation in a recent paper with Bob Hay ancl Norm Hubbard titled, “Ch emical Characteristics and Origin of Oceanic Ridge Volcanic Rocks” in the Journal of Geophysical Research, 1970. Another of his major
Award of the V. M. Goldschmidt and F. W. Clarke medals
1627
contributions during this period was the quantification of partial melting calculations based on distribution coefficients between melt and several crystalline phases simultaneously. Again this provided a further refinement of mantle composition in his fractionation models. It is not unexpected that lunar materials and their relation to the formation of terrestrial planets would be of interest to Paul, whose fractionation models require that compositional constraints be placed on the initial material from which earth formed. In 1965, he became a charter member of the geochemistry working group for initial planning of lunar exploration and sample study. The group set many of the basic policies required for collecting, processing, studying, and distributing lunar samples. By 1967, Paul was chairman of this group. During this time he was instrumental in urging NASA to appoint a formal team of scientists representing the total lunar science community for detailed planning of processing and distributing lunar samples for analyses. The result was the Lunar Sample Analysis and Planning Team for which Paul served as chairman in 1969 during the first lunar sample returns. As the early Apollo missions became reality, the complexity of processing, distribution, and study of lunar samples became more apparent. This was compounded by resignations of top science management at the Manned Spacecraft Center and it was clear that strong leadership as well as competent scientists were a necessity at MSC if the maximum scientific return were to be obtained from Apollo. In early 1970, Paul accepted the position of Chief of the Planetary and Earth Sciences Division at MSC. During the past 2$ years he has developed the most respected lunar science research organization in the world and has become the most influential lunar science advisor in NASA. His foresight in developing the science training of Apollo flight crews, organizing high quality preliminary examinations of lunar samples, assembling an outstanding group in lunar research, and constantly making suggestions or challenges to the numerous lunar science experiments has led to a high degree of excellence in the science return from Apollo missions. As might be expected, he could not be kept from developing chemical models of the moon. Again, studies of the nature of initial composition and ensuing fractionation have seen Paul at the forefront. It is with great pleasure that I present to you Dr. Paul Gast for the first GoldSchmidt award.
Acceptance Speech V. M. Goldschmidt Medal PAUL W. GAST* I would like to thank all of those who are responsible for this occasion for bringing me back to this cold climate. I am very honored to be the first recipient of the V. M. Goldschmidt Medal. Those of you who know me know that I am not usually at a loss for words. The appropriate words for this occasion, however, seem to have escaped me. A scientific lecture is clearly not the proper response. A humorous * Chief, Planetary and Earth Sciences Division, Manned Spacecraft Center, National Aeronautics and Space Administration,
Houston,
U.S.A.
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Award of the V. M. Goldschmidt and F. W. Clarke medals
before-lunch speech is quite beyond my abilities. Thus, somewhat out of desperation, I have chosen this occasion to share with you some thoughts that arise out of experiences I have had in the last few years. They may be entitled “a view from the bridge”. Some of you may know that in the last three years I have had the privilege of occupying a very interesting and somewhat unique position in which I have served as a bridge between a vocal and highly talented scientific community and a very large and very complex Government agency. These three years have been an education that may rival the five years I spent in graduate school in their total impact. They have provided a perspective on both the scientific community and on the Government bureaucracy which has reoriented much of my thinking about both of these facets of our society. Whether we like it or not, we must recognize that we are tied together by symbiotic bonds that are often stretched to the point where they are almost severed. Early during my scientific adventures, I lived with the idea that the best atmosphere in which to do science was, indeed, the proverbial ivory tower; that is, I had the notion that we scientists somehow deserved a sheltered or cloistered env~onment largely protected from the storms of the society which surround us. I now seriously doubt that this is, in fact, the ultimate ideal towards which we should strive or that we should suggest to our students that the ivory tower is the most prestigious goal toward which they can strive. For me, the past three years have been a learning experience and an adventure that I treasure very highly. I hope that all of those who have been involved in the ‘nonscientific’ aspects of lunar exploration are able to look back on this time with similar feelings. We seem to have entered a time when the success of many of our efforts depends on the success of enterprises that involve hundreds to thousands of people, many of whom have no understanding of the major objectives of these projects. The Apollo and Viking projects are certainly examples of this type of science. The JOIDES project may be another example. The experiences of the last three years have shown that we can closely interweave scientific, management, and technical personnel in order to accomplish major goals. They have shown that within large organized efforts we may be able to preserve ‘islands’ where research is carried on with relative independence. Rowever, if there ever was an ivory tower, many of us had to leave it in order to work in a very different world. The knowledge that a ‘city of refuge’ could be found if one had to is somewhat reassuring, but our perspective of the world is changed from that seen within the ivory tower; and I suspect it is healthier and more realistic. I also suggest that projects like Apollo and JOIDES may not be unique endeavors in our science ; rather, they may represent important patterns for the future management of science. The application of rational scientific thinking to en~onmental problems will probably require similar efforts in which pure science, engineering, and complex management need to be integrated into one organization before solutions to these problems are at hand. Thus, it may serve us well to look at what we are doing and at what we have done to see if the past has any lessons for the future. I would like to suggest one. In my opinion, one of the better-defined and darker shadows cast over the Apollo science program has been the often acrimonious
Awtwd of
the V. M. ~oldsc~dt
and F. W. Clarkemedals
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differences of opinion that have surfaced during the planning phases of this program. Some of my administrative colleagues find it difficult to understand how science can accomplish its ends from a position of such disarray. It is very clear to me that the participation of science with other segments of our society in a search for the solution of some of these problems that face us will require much more than a demonstration or claim of relevance. The ability to address complex issues and decisions incisively will be essential. We live in a very pragmatic and empirical society. The managers and administrators of this society do not always plaoe the same value on the heritage of open and free scholarship that we do. They place a high value on the ability to identify and solve problems. A major ingredient in these solutions consists of decisions. We may find ourselves in a position to affect these decisions by means of technical and expert advice. Only too often our advice is so transparently self-serving or contradictory that we forfeit our role in the decision-making. I can only hope that the upcoming generations of geoche~nists, geologists, and geophysicists have enough intellectual common ground to avoid the appearance of working at cross purposes. It is not hard to imagine that the success of future efforts in the geosciences may depend not only on the cooperation of different subdisciplines in this part of the intellectual arena, but on cooperation between such diverse disciplines as medicine and geoscience. Hopefully, the evolution of the scientific disciplines has not progressed to the point where fertile crossbreeding between diverse areas of science is no longer possible. Clearly, I have no answers to the problems I have raised here. I can only suggest that less specialized education might be helpful. Otherwise, the best I can do this morning is to point to the problem. I hope that those in decision-making positions take note and that those who are deciding their own future will consider some career goals that have not been held in high esteem by most of their intellectual peers.
Introduction of Dimitri A. Papanastassiou for the F. W. Clarke Medal G. J. ~ASSERB~R~~
There are, to me, three truly exciting personal experiences in science. The first of these is the experience of oneself, privately, observing and understanding something that is new and that is important. The second excitement is the act of precipitating understanding of some natural phenomenon in someone else. The third is to be honored to participate in the formal bestowal of professional recognition of a respected colleague, a student and a friend. I am greatly privileged to stand before two colleagues and friends of different scientific generations that are being recognized by this society today. The early pioneer work on Rb-Sr dating which was to play a role in Dimitri’s thesis was first carried out by Tom Aldrich at the Department of Terrestrial Magnetism under the stimulus of Louis Ahrens and later by G. W. Wetherill and G. R. Tilton of the Carnegie Institute of Washington. When Dimitri Anastassios Papanastassiou (DAP) was entering Athens College in Greece, Paul W. Gast was measuring Sr isotopes. Paul was a rather bumptious * Charles Arms Laboratory, Division Instituteof Technology, Pasadena, U.S.A.
of Geological
and Plamtary
Sciences,
California
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Award of the V. M. Goldschmidt and F. W. Clarke medals
young man, who as a high school student would announce to his father and brother at t*he supper table that he, P. W. Gast, was personally going to go to the moon regardless of either technologic or theologic di~culties. Gast had just establisl~ed that the change in *7Sr/@%r over the history of geologic time was very small ( 1955). The work that Dimitri was to do some ten years later was a direct out-growth of this fact. Dimitri was a student at Athens College, an American-sponsored high school for Greek boys. Through the enthusiasm and pedagogical skills of Andreas Remboulis, Dimitri became interested in science and as a result of his outstanding performance he was recommended to Cal Tech. In the forms sent out by Cal Tech, question three asks, “for what type of career is the applicant particularly suited?” Mr. Eliascos, the Assistant Principal of Athens College responded, “The type of career he wishes to This information, in conjunction with his detailed academic record was follow.” transmitted to our admissions officer, who promptly put this data into a universal formula which has as much control over predicting the future of a student as a recently t,outed universal phase rule which purported to describe the interrelationship of all known geologic processes. After processing all of this information, the computer output showed t*hat Dimitri would get a grade-point average of 1.96015 whereas the lowest passing grade-point average was 1+90000, so that this man’s future was not essentially encouraging. However, with the perseverance of Mr. Peter Richardson, the student counselor at Athens College, Dimitri was admitted to Cal Tech. Well, the GPA formula was pretty good, at least it got the sign right, because Dimitri passed and did so with honors for four years, and graduated in physics in the top IO per cent of his class with a GPA of 350037. I tell this story because it is true and because I hate the incompetent, inhibiting, predictive testing of students. In his undergradute years, Dimitri worked in the Kellogg Radiation Laboratory under Tommy Lauritsen, Tom Tombrello and Ward Whaling. He was then interested in low energy nuclear physics. This represented an exciting endeavor and one which kept him in touch with a variety of fields of modern physics and astrophysics. As a member of the Division of Geological Sciences and also a member of the Kellogg staff I had attempted since 1955 to attract bright young physicists to work jointly in problems of importance in earth and planetary sciences. The importance of continually interdigitating the concepts and developments of physics with our science seemed overwhelming to me, although some physicists considered it too ‘classical’ (that is, old fashioned) an area. Since Dimitri was thinking of returning to Greece, this area of the physical sciences seemed of sufficient vigor and small enough in scale that it might reasonably be In any event, he was considered an appropriate candidate and Tommy transported. Lauritsen literally took Dimitri under his wing and guided him ~~w~~ from Kellogg to Arms. I think he mumbled something about DAP being a sacri~cial lamb. In any event, DAP began to work with me when we had just started the design of a new generation of computer-interfaced isotope ratio mass-spectrometers with digital output, which I hoped would permit routine measurements at the level of a few parts in ten thousand. The spectrometer grew from conception through ion optical calculations to a hardware reality which in fact can produce data with a precision of five
Award of the V. M. Goldschmidt and F. W. Clarlre medads
1631
parts in one hundred thousand. This permitted a look at minute isotopic differences which were previously invisible. Small or negligible effects became real and measurable quantities with deep petrogenetic and chronologic meaning. The change in sSr/s%r in chondrites is about O-01per cent in 10 million years. With development of these techniques coupled with great attention to mineralogic properties, DAP showed that it was possible to date the basaltic achondrites and that there were resolvable variations in the initial strontium in meteorites which represented five million years in early solar system history. This has given us acronyms such as BABI and ADOR in the literature (1969, 1970). Since then he hasspent his timeestablishing a lunar chronology using the 8%b-*7Sr decay scheme. (1971, 1972a, 1972b). It is this endeavor by a young man which is the subject of this award. DAP is a true Athenian-he is a multilingual and versatile perfectionist who has made a temporary peace with the demigods who run the world imperfectly. He has learned to mispronounce Greek words and to scrawl Greek symbols in the vulgar fashion used by the large uneducated world. As a true Athenian he is a snob. During a late session when we were writing a paper, I referred to Alexander the Great as a Greek, to which Dimitri retorted, “Oh that Macedonian!” When, during a lecture on the cosmic time scale, he heard me recite part of the book of Genesis in Hebrew, he commented that it sounded peculiar since he was used to hearing it in the original Greek. I don’t know if DAP will fulfil his youthful hope of moving some of his science back to Greece. His infatuation with the United States is in great part due to a very intelligent and gracious young woman, his wife Teri. I expect he will stay and enrich our environment. When Dimitri filled out his admission form twelve years ago he was obliged to write a short statement about his long term future. He wrote: “Indeed, what I think will play the decisive role in my choosing a career will be my love for science. Whether it is a place in industry or in the government, it will be the same to me as I long as it won’t be a routine work. . . . I guess all this sounds a little pompous. remember [a] teacher telling me that, when you are young, you want to hecomc a pioneer in science, and then, when you grow older, you find yourself engaged in an ordinary job, not caring any more for original research work. Still he [the teacher] loved to hear of boys having such hopes for the future.” Mr. President, may I present the Clarke Medalist, D. A. Papanastassiou, a young man who has been on the cutting edge of original research and will as he grows older undoubtedly stay there for a long time. REFERENCES CAST P. W. (1955) Abundance of SF during geologic time. Bull. Geol.Soc. Amer. 66, 1449-1&X PAPANASTASSIOU D. A. (1970) The determination of small time differences in the formation of planetary objects. Ph.D. Thesis, California Institute of Technology. PAPANASTASSIOUD. A. and WASSERBURC G. J. (1969) Initial strontium isotopic abundances and the resolution of small time differences in the formation of planetary objects. Earth Planet. Sci. Lett. 5, 335. PAPANASTASSIOU D. A. and WASSERBURG G. J. (1971) Lunar chronology and evolution from Rb-Sr studies of Apollo 11 and 12 samples. Earth Planet. Sci. Lett. 11,37. PAPANASTASSIOUD. A. and WASSERBURU G. J. (1972) The Rb-Sr age of a crystalline rock from Apollo 16. Earth Planet. Sci. Lett. 16, 289.
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Award of the V. M. Goldschmidt and F. W. Clarke medals
PAPANASTASSIOU D. A. and WASSERBTJ~~ G. J. (1972) Rb-Sr systematics of Luna 20 and Apollo 16 samples. Earth Planet. Sci. Lett. 17, 52.
Acceptance Speech F. W. Clarke Medal D. A. PAPANASTASSIOU* Not so long ago, Professor Wasserburg and I were involved in an erudite search for an eclectic name for our first six digit isotopic ratio. The final acronym for “basaltic achrondite best initial”, BABI, has now become a recognizable entity found even in a subject index. It marks in a possibly more succinct manner than I may have appreciated originally the beginnings of a new chapter in what might be considered isotope archaeology for the sun, as opposed to the well-documented application of isotopes to the origins of Hellenic marbles. A few years before that instant, several eager and egocentric Greeks, freshly out of high school, landed on a New York pier. We were very surprised at the absence of a red carpet which we expected for our arrival as new Fulbright scholars. ,4s it turned out we were greeted instead by the insatiable open hand of a baggage handler. The obvious moral in this land of opportunity was that persistence beyond the norm I received slightly more pertinent advice as a fledgling must be commonplace. undergraduate from a physicist, close to four o’clock one morning. We were both waiting for some particularly slow ion counts to accumulate to a preset value, when he volunteered that physics is 95 per cent grind and 5 per cent fun. This has always seemed a fair proposition although it must be clear that occasions similar to the one this morning constitute a serious attempt to upset this delicate balance. My first formal contact with science involved nuclear physics. I spent several summers as an undergraduate plotting cross-sections from a multichannel analyzer and Nilsson states from a computer output. While most probably still dizzy, I took Professor Lauritsen’s advice to walk to the next building and talk to Wasserburg. He promptly concluded that my education would best be furthered by reading massspectrometer charts with a magnifying lens. That task was later changed to picking individual grains with a micro-manipulator under a microscope. At least chart reading must have been primarily a diversion, since he had already designed the next generation mass-spectrometer with automatic disgorging of digital data. The building of that machine proceeded while he toured Europe. It was possibly appropriate that the first preliminary statement of the capabilities of the new instrumentation was included in a review of the age of meteorites. This review was also notable for its emphasis on the strong similarities between the structure of a planet with a core and that of a hard-boiled egg. I have of course been privileged to participate in the development of the new instrumentation. A slightly less appreciated but intimately connected advance has been the development of micro-techniques for handling very small samples. This approach may be described as the whole crystal method as opposed to whole rock analyses. The application of high precision mass-spectrometry and of clean microtechniques for sample handling has been rather crucial for lunar samples. For * Charles Arms Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, U.S.A.
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Award of the V. M. Goldschmidt and F. W. Clarke medals
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example, these methods have allowed an Rb-Sr age determination on the only rock available from the core obtained at the Luna 16 site. This was a fine-grained, 60 mg boulder and with a modest enrichment in 87Sr/86Srof one per mil. These methods are singularly applicable to the study of inherent isotopic heterogeneity in any rock system, including lunar breccias and terrestrial sedimentary rocks. Recently the word ‘errorchron’ has been coined to emphasize the possibility of increased dispersion in experimental data determining an apparent isochron due to geological disturbances. With the increased sensitivity as applied to lunar samples it is likely that errorchrons will become obsolete and that disturbed phases will be clearly identified. This will allow a better understanding of open systems and the extent of metamorphic reactions. In lunar work, experiments with individual crystals and with neighboring, centimeter-sized, rock fragments have resolved some rather complex, partially equilibrated rock systems and have allowed the identification of ancient lunal crustal material. It is now possible to apply these methods to the investigations of single chondrules or small identifiable inclusions in meteorites. Single inclusions in iron meteorites have been analyzed for some time now and have yielded important isotopic and age information. On a different front the same methods as applied to meteorites and the moon are now beginning to show some temporal structure and chronological order, so that we may soon be able to establish the primitive nature of solar materials based on isotopic as well as on possibly more debatable elemental relations. The BABI value has been established as a marker in time. However, almost before the BABI value was published, we obtained a lower value for the meteorite Angra dos Reis. Therefore one must consider that there exist even wider possible variations in the values of ~7Sr/86Sr with which planets condensed. This is an exciting prospect. The duration of the game now clearly involves tens of millions of years of tantalizing events as we It has are allowed a look at the eve of the very early stages of planetary evolution. always been a surprise that a planet as active as the moon has preserved some extremely primitive isotopic samples. One must also face the problem that meteorites may in fact be open and complex systems. This has been established for some iron meteorites although it is important to understand the nature of the disturbances and in particular whether they are inherent to some meteorites. It would be less interesting if they result only from terrestrial weathering; alternatively open systems may represent early solar system processes or recent events just prior to the meteorite’s impact with the earth. On the earth, of course, we do not have the luxury of working with 4.6 AE rocks. However, these methods can be applied directly on the other end of the scale to very young rocks in the range of tens of thousands of years. One of these days it is conceivable that one could measure the change in 87Sr/86Sr of a solution of a Rb mineral, during a year, thereby allowing another determination of the 87Rb half-life. It is a great honor and pleasure to be in the position of accepting the first F. W. Clarke medal of the Geochemical Society. I find it especially important that this medal is instituted at a time when the first data and theories about the lunar crust occupy so much scientific effort and imagination. The person most responsible for my presence here exposed himself earlier by recounting knowledge which characteristically would not escape the thoughtfulness of a direct scientific progenitor.