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Acceptance Speech for the 1989 Alfred E. Treibs Award
The Geochemical Society Awards
I209
Acceptance Speech for the 1989 Alfred E. Treibs Award JAMES R. MAXWELL*
Mr. President,
Ladies and Gentlemen:
Let me say immediately that I feel both honoured and delighted by being selected by the Geochemical Society to be this year’s recipient of the Treibs Medal. I should also say, however, that in a sense I am acting here today only as a representative of several past and present Graduate Students and Postdoctoral Fellows. These collaborators, through their enthusiasm for research, and their diligence and perseverence, especially with a rather moody supervisor, have been mainly responsible for the Society’s recognition of the work of the Bristol Organic Geochemistry Unit. In other countries the current situation of our Graduate Students is perhaps not generally realised. As a result of various external pressures they probably have the lowest income of similar students in any of the Western countries, and for the shortest period of time. The fact that they choose at all to become Graduate Students in the UK is itself a tribute to them. I would also like to pay a special tribute to my mentor, colleague, and friend, Geoff. Eglinton, who was himself a recipient of this award in 198 1. Indeed, it was mainly as a result of his infectious enthusiasm, scientific flair, and obvious foresight, that I chose, in 1965, to become the first Graduate Student at the University of Glasgow in Scotland, in the then relatively new field that we now call molecular organic geochemistry. I was also particularly lucky then to have as a second supervisor another well-known organic geochemist, Archie Douglas. I remain grateful to him, not only for the unselfish help he gave me but also for the hours of stimulating discussions and arguments we had together in broad Scottish accents, often suitably lubricated with the national beverage! Around this time very little was known about the structures of the individual organic compounds present in sediments and petroleums, compounds that we now call biological markers. The few components which had been identified, for example, by pioneers such as Ted Whitehead at B.P., tended to be treated by organic chemists and by petroleum geologists as academic curiosities and not much else. They had an origin from precursors biosynthesised by ancient organisms, but so what? I particularly remember, for example, oils and sediments from the Niger Delta being described in conversation as “unique” because they contained particular triterpanes not then found in other oils or sediments. Nowadays, when such components are encountered, for example, in an oil, their presence can be taken as evidence for a source rock having a deltaic or lacustrine origin and a Late Cretaceous or younger age, because the functionalised precursor compounds were most likely biosynthesised by angiosperms. I choose this as a simple example to show how the presence
* School ofchemistry, Organic Geochemistry Unit, University of Bristol, Cantock’s Close, Bristol, England, BS8 ITS, UK.
James R. Maxwell
of particular biological markers and their distributions can nowadays be used to assist in providing information about depositional palaeoenvironments, by way of providing information about the types of organisms which contributed organic matter. Another aspect of the structures of biological markers which was considered curious was the predeliction of some of us to be concerned with determining the three-dimensional structures or stereochemistry of various biological markers such as acyclic isoprenoid compounds and steroidal compounds. To an organic chemist such considerations are, however, only natural because enzymes must have biosynthesised the precursors of these fossil compounds with highly specific stereochemistry. In this context it is gratifying, therefore, to hear petroleum geochemists, and even the occasional geologist, now mention routinely “molecular maturity parameters” and, for example, “20s to 20R ratios in ~OLCY steranes.” It is important, however, to emphasise that palaeoenvironment and maturity studies, and various other applications which have incorporated biological marker distributions with varying degrees of success, are in a sense the tip of an iceberg. This iceberg comprises a great deal of fundamental and
painstaking work to identify individual compounds, either by synthesis or by isolation and structure determination, as well as laboratory studies aimed at unravelling thr mechanisms of the diagenetic reactions which alter the various compounds and their precursors. With some types of compounds progress has been slow. Alfred Treibs himself first obtained “blood from a stone” by isolating red porphyrin pigments from sedimentary rocks and petroleum. In addition, he used their presence not only as evidence for the biological origin of petroleum but also to indicate a relatively low temperature for petroleum formation. It was only about 40 or 50 years later, however, in the late 1970s and in the 198Os, that we and others were able to obtain the precise structures of a number of the individual components of these complex mixtures and thereby link them to chlorophylls. Now that these structures have been established, hopefully the scene is set for organic geochemists to capitalise properly on this knowledge by way of applying the distributions to geological problems. One point about delivering a speech like this is that it gives one an opportunity to mull over the last twenty or so years. In doing so, 1 am immediately struck by the number of friendships I have made, not only with fellow scientists from other institutions, but also with former colleagues and collaborators from Bristol. A number of these friends are now actively pursuing research careers in organic geochemistry, not least of them today’s citationist, Simon Brassell. All I can say here is that I truly miss our many hours of stimulating discussions and our collaborations. Stanford’s gain is Bristol’s IOSS.
The last twenty or so years have also seen an enormous expansion of activity in the field of organic geochemistrl, which is a truly interdisciplinary one, as the name itseif implies. Because ofthis, I would like to reiterate a note ofcaution given by Pierre Albrecht in his speech of acceptance foul years ago. As research scientists in an interdisclplinap field, it is incumbent on us not to adopt a blinkered approach by becoming too specialised in our own little sub-fields. Kesearchers originally from backgrounds in geology. chemistry. microbiology, and so on must continue to communicate and collaborate with each other as the subject contmues to progress. However. despite this note of caution, I believe that exciting times lie ahead. In the area of molecular organic geochemistry, for example, we must continue to tr‘! to understand at a fundamental level the origins 01’various types of biological markers and the processes which alter them. We also need to take more of the mystique out of the insoluble organic materials we call kerogens. It seems to me that there is no a priori reason why there should be any magic about the structures of kerogens. We just have to be a littlc bit smarter here in determining these structures! Hopefully. we will then be in a position to take palaeoenvironment assessment through biological markers out of its current semi-empirical mode. Finally, ladies and gentlemen, let me once again. on behalf of myself and my co-workers both past and present, thank the Geochemical Society for the Alfred Treibs Award for 1989, particularly because the medal itself depicts a petroporphyrin whose structure we were able to assign a few years ago.
F. W. CLARKE AWARD The F. W. Clarke Award was not given in 1989.
ORGANIC GEOCHEMISTRY DIVISION OF THE GEOCHEMICAL BEST PAPER AWARD 1989 The Best Paper Award of the Organic Geochemistry Division for 1989 was presented to Dr. Jaap S. Sinninghe DamstC for his papers: J. S. SINNINGHE DAMSTB, W. I. C. BUPSTRA, J. W. DE LEEUW, and P. A. SCHENCK (1989) The occurrence and identification of series of organic compounds in oils and sediment extracts: II. Their presence in samples from hypersaline and non-hypersaline palaeoenvironments and possible application as
source,
palaeoenvironmental
SOCIETY
and maturity
indicator.
Geo-
chim. Cosmochim. Acta 53, 1323-l 34 1. J. S. SINNINGHE DAMST~, W. I. C. RIJPSTRA, A. C. KOCKVAN DALEN, J. W. DE LEEUW, and P. A. SCHENCK (1989) Quenching of labile functionaiized tips by inorganic sulphur species: Evidence for the formation of sedimentary organic sulphur compounds at the early stages of diagenesis. Geochim. Cosmochim. Acta 53, 1343-1355.
I209
Acceptance Speech for the 1989 Alfred E. Treibs Award JAMES R. MAXWELL*
Mr. President,
Ladies and Gentlemen:
Let me say immediately that I feel both honoured and delighted by being selected by the Geochemical Society to be this year’s recipient of the Treibs Medal. I should also say, however, that in a sense I am acting here today only as a representative of several past and present Graduate Students and Postdoctoral Fellows. These collaborators, through their enthusiasm for research, and their diligence and perseverence, especially with a rather moody supervisor, have been mainly responsible for the Society’s recognition of the work of the Bristol Organic Geochemistry Unit. In other countries the current situation of our Graduate Students is perhaps not generally realised. As a result of various external pressures they probably have the lowest income of similar students in any of the Western countries, and for the shortest period of time. The fact that they choose at all to become Graduate Students in the UK is itself a tribute to them. I would also like to pay a special tribute to my mentor, colleague, and friend, Geoff. Eglinton, who was himself a recipient of this award in 198 1. Indeed, it was mainly as a result of his infectious enthusiasm, scientific flair, and obvious foresight, that I chose, in 1965, to become the first Graduate Student at the University of Glasgow in Scotland, in the then relatively new field that we now call molecular organic geochemistry. I was also particularly lucky then to have as a second supervisor another well-known organic geochemist, Archie Douglas. I remain grateful to him, not only for the unselfish help he gave me but also for the hours of stimulating discussions and arguments we had together in broad Scottish accents, often suitably lubricated with the national beverage! Around this time very little was known about the structures of the individual organic compounds present in sediments and petroleums, compounds that we now call biological markers. The few components which had been identified, for example, by pioneers such as Ted Whitehead at B.P., tended to be treated by organic chemists and by petroleum geologists as academic curiosities and not much else. They had an origin from precursors biosynthesised by ancient organisms, but so what? I particularly remember, for example, oils and sediments from the Niger Delta being described in conversation as “unique” because they contained particular triterpanes not then found in other oils or sediments. Nowadays, when such components are encountered, for example, in an oil, their presence can be taken as evidence for a source rock having a deltaic or lacustrine origin and a Late Cretaceous or younger age, because the functionalised precursor compounds were most likely biosynthesised by angiosperms. I choose this as a simple example to show how the presence
* School ofchemistry, Organic Geochemistry Unit, University of Bristol, Cantock’s Close, Bristol, England, BS8 ITS, UK.
James R. Maxwell
of particular biological markers and their distributions can nowadays be used to assist in providing information about depositional palaeoenvironments, by way of providing information about the types of organisms which contributed organic matter. Another aspect of the structures of biological markers which was considered curious was the predeliction of some of us to be concerned with determining the three-dimensional structures or stereochemistry of various biological markers such as acyclic isoprenoid compounds and steroidal compounds. To an organic chemist such considerations are, however, only natural because enzymes must have biosynthesised the precursors of these fossil compounds with highly specific stereochemistry. In this context it is gratifying, therefore, to hear petroleum geochemists, and even the occasional geologist, now mention routinely “molecular maturity parameters” and, for example, “20s to 20R ratios in ~OLCY steranes.” It is important, however, to emphasise that palaeoenvironment and maturity studies, and various other applications which have incorporated biological marker distributions with varying degrees of success, are in a sense the tip of an iceberg. This iceberg comprises a great deal of fundamental and
painstaking work to identify individual compounds, either by synthesis or by isolation and structure determination, as well as laboratory studies aimed at unravelling thr mechanisms of the diagenetic reactions which alter the various compounds and their precursors. With some types of compounds progress has been slow. Alfred Treibs himself first obtained “blood from a stone” by isolating red porphyrin pigments from sedimentary rocks and petroleum. In addition, he used their presence not only as evidence for the biological origin of petroleum but also to indicate a relatively low temperature for petroleum formation. It was only about 40 or 50 years later, however, in the late 1970s and in the 198Os, that we and others were able to obtain the precise structures of a number of the individual components of these complex mixtures and thereby link them to chlorophylls. Now that these structures have been established, hopefully the scene is set for organic geochemists to capitalise properly on this knowledge by way of applying the distributions to geological problems. One point about delivering a speech like this is that it gives one an opportunity to mull over the last twenty or so years. In doing so, 1 am immediately struck by the number of friendships I have made, not only with fellow scientists from other institutions, but also with former colleagues and collaborators from Bristol. A number of these friends are now actively pursuing research careers in organic geochemistry, not least of them today’s citationist, Simon Brassell. All I can say here is that I truly miss our many hours of stimulating discussions and our collaborations. Stanford’s gain is Bristol’s IOSS.
The last twenty or so years have also seen an enormous expansion of activity in the field of organic geochemistrl, which is a truly interdisciplinary one, as the name itseif implies. Because ofthis, I would like to reiterate a note ofcaution given by Pierre Albrecht in his speech of acceptance foul years ago. As research scientists in an interdisclplinap field, it is incumbent on us not to adopt a blinkered approach by becoming too specialised in our own little sub-fields. Kesearchers originally from backgrounds in geology. chemistry. microbiology, and so on must continue to communicate and collaborate with each other as the subject contmues to progress. However. despite this note of caution, I believe that exciting times lie ahead. In the area of molecular organic geochemistry, for example, we must continue to tr‘! to understand at a fundamental level the origins 01’various types of biological markers and the processes which alter them. We also need to take more of the mystique out of the insoluble organic materials we call kerogens. It seems to me that there is no a priori reason why there should be any magic about the structures of kerogens. We just have to be a littlc bit smarter here in determining these structures! Hopefully. we will then be in a position to take palaeoenvironment assessment through biological markers out of its current semi-empirical mode. Finally, ladies and gentlemen, let me once again. on behalf of myself and my co-workers both past and present, thank the Geochemical Society for the Alfred Treibs Award for 1989, particularly because the medal itself depicts a petroporphyrin whose structure we were able to assign a few years ago.
F. W. CLARKE AWARD The F. W. Clarke Award was not given in 1989.
ORGANIC GEOCHEMISTRY DIVISION OF THE GEOCHEMICAL BEST PAPER AWARD 1989 The Best Paper Award of the Organic Geochemistry Division for 1989 was presented to Dr. Jaap S. Sinninghe DamstC for his papers: J. S. SINNINGHE DAMSTB, W. I. C. BUPSTRA, J. W. DE LEEUW, and P. A. SCHENCK (1989) The occurrence and identification of series of organic compounds in oils and sediment extracts: II. Their presence in samples from hypersaline and non-hypersaline palaeoenvironments and possible application as
source,
palaeoenvironmental
SOCIETY
and maturity
indicator.
Geo-
chim. Cosmochim. Acta 53, 1323-l 34 1. J. S. SINNINGHE DAMST~, W. I. C. RIJPSTRA, A. C. KOCKVAN DALEN, J. W. DE LEEUW, and P. A. SCHENCK (1989) Quenching of labile functionaiized tips by inorganic sulphur species: Evidence for the formation of sedimentary organic sulphur compounds at the early stages of diagenesis. Geochim. Cosmochim. Acta 53, 1343-1355.