| Jochen J. Brocks
Junior Fellow of the Harvard Society of Fellows
Department of Earth and Planetary Sciences, Harvard University
Botanical Museum, Harvard University
26 Oxford St.
Cambridge, MA 02138
| full PDF version of CV
| The central theme of my research is the discovery and study of molecular and isotopic signals in ancient and modern sediments to obtain information about the interaction between life and its environment. My current research as a Junior Fellow at Harvard University focuses on the development of biomarker parameters that can yield new information about environmental conditions in ancient aquatic systems, particularly the redox structure of sediments and water columns. I apply these biomarkers to investigate redox conditions and life on a late Archean carbonate platform and to test the hypothesis of a globally euxinic ocean in the Mesoproterozoic. Two future projects are currently under review for funding. These include the investigation of environmental and biological changes across the Precambrian-Cambrian boundary and the study of diagenetic evolution of redox sensitive molecules in Recent sediments. The projects are outlined below.
- development of redox parameters based on biomarker patterns
In the past year, I developed a new fossil biomarker that recognizes euxinic and intensely stratified water bodies with a chemocline less than 20 meters below the water surface. The new marker was successfully applied to a Paleoproterozoic basin (see below), and might prove particularly significant in elucidating the intensity of Oceanic Anoxic Events. The continuation of the project over the next few years focuses on the development of a more universal biomarker redox parameter. The research involves the analysis of new biomarker patterns, compound specific carbon isotopes, sulfur isotopes, and redox sensitive elements in both Recent and ancient sediments.
- the biogeochemistry of a late Archean carbonate platform
As part of a project funded by the Agouron Institute, and in collaboration with Andrew Knoll, Nicolas Beukes, Woodward Fischer and Yanan Shen, I am studying the organic geochemistry of an exceptionally well preserved late Archean carbonate-iron formation complex in South Africa. This multidisciplinary project has just begun, but it promises to yield unusually detailed information about the redox structure of a late Archean basin, and the cycling of bioessential elements such as C, S, N, Fe and Mo. Biomarkers, if present, might yield the first ever glimpse of the organisms that inhabited stromatolitic reefs in the Archean.
- a mesoproterozoic euxinic ocean
A model proposed by Donald Canfield in 1998 envisages that the world oceans did not become ventilated and oxic at ~1.8 billion years ago, but remained anoxic (and additionally turned sulfidic) until possibly 800 million years ago. If confirmed, this hypothesis would rewrite almost one quarter of Earth history, with profound implications for our understanding of Proterozoic environmental and biological evolution. To find evidence for or against such an ocean, I am currently investigating biomarkers and compound specific isotopes of a late Paleoproterozoic basin from northern Australia. First results demonstrate that the analyzed sections of the basin were probably over extended periods of time stratified and euxinic just meters below the water/atmosphere interface. However, this extreme signal only carries information about the open ocean if it also occurs in contemporary basins of other continents. Therefore, future work will extend the search to Proterozoic basins across the world.
- oceanic anoxia and the Cambrian explosion
This project, planned for the coming years, is complementary to, and in cooperation with, Roger Summons' analysis of infracambrian oils from Oman. It tests the hypothesis that drastic changes in the redox conditions of the oceans might have triggered the explosive diversification of metazoans at the beginning of the Cambrian Period. It involves systematic collection of biomarker data, compound specific carbon isotopes, and inorganic geochemical redox parameters on exceptionally well preserved boundary sections.
- the future in paleobiogeochemistry
The field is young, and most paths and directions are still hidden. Biogeochemistry will play a crucial role in a multitude of disparate topics such as global element cycling, mineral precipitation, ore formation, water quality, eutrophication, oceanic anoxic events, global warming and mass extinctions. For all subjects, it will be important to build bridges between biogeochemical signals from the past and microbiological and diagenetic processes in the present. Here it will remain my philosophy to not only apply existing techniques and parameters to interesting current topics, but also to develop new methodologies and principles. This is best achieved in a research environment that has the critical mass of analytical facilities, and that promotes the collaboration between scientists of different fields.
| In my dissertation, I developed high resolution techniques to study trace amounts of molecular fossils (biomarkers) and was able to discover what are by far the oldest known biomarker molecules in late Archean rocks of the Hamersley Basin, Australia. Interpretation of these molecules demonstrated that biological oxygen production evolved more than 2.7 billion years ago, and that ancestral eukaryotic organisms must have existed ~800 million years before microfossil evidence indicates that the lineage arose. This work was honored by the American Association for the Advancement of Science, publishers of the journal Science, as one of the ten most significant breakthroughs of the year across all disciplines.
|education and professional experience
awards and fellowships
- Diplom Chemie (~MSc Chemistry): University of Freiburg (Germany), Department of Organic Chemistry and Biochemistry 1997
- Ph.D., Organic Geochemistry : University of Sydney (Australia), Department of Geology and Geophysics, 2001
- Election into the Harvard Society of Fellows as Junior Fellow (2001)
- Invited key note speaker and Award for Best Presentation, Australian Organic Geochemistry Conference (2000)
- Top ten, Scientific break-throughs of the year 1999, Science, 286, 2239. (1999)
- Personal Grant from the American Chemical Society Petroleum Research Fund (1998)
- Overseas Fellow of the Studienstiftung des Deutschen Volkes (1997)
- Fellow of the Studienstiftung des Deutschen Volkes (1994-97)
- MIT, Visiting lectures in organic geochemistry, 2003
- University of Sydney, Teaching Assistant, Field Geology, 2000
- University of Freiburg, Teaching Assistant, Organic Chemistry, 1997
- University of Freiburg, Laboratory Instructor, Organic Chemistry, 1996
| born 21 september 1970, Germany year (note: password required to access this information)
Originally, I studied chemistry at the Albert Ludwigs University of Freiburg and received a Masters in Organic Chemistry in the group of Professor Christoph Ruchardt. However, during my undergraduate time, I also visited courses in the nearby Geology department and participated in field excursions and fossil excavations. To combine my two fields of interest, I started a dissertation in organic geochemistry and received a PhD from the Department of Geology and Geophysics at the University of Sydney under the supervision of Professor Roger Buick. During my dissertation, I worked with Dr. Simon George in the Organic Geochemistry laboratory of CSIRO Petroleum in Sydney, and with Professor Roger Summons at the Organic Geochemistry and Stable Isotope Laboratory of the Australian Geological Survey Organization (now Geosciences Australia), whose website you are now on, and who is now an MIT professor.
| Brocks J. J., Logan G. A., Buick R., and Summons R. E. (1999) Archean molecular fossils and the early rise of eukaryotes. Science 285, 1033-1036.
Brocks J. J., Welle F. M., Beckhaus H.-D., and Ruchardt C. (1997) Are centered peptide radicals stabilized by a capto-dative effect? Tetrahedron Letters 38, 7721-7724.
Brocks J. J., Beckhaus H.-D., Beckwith A. L. J., and Rcuhardt C. (1998) Estimation of bond dissociation energies and radical stabilization energies by ESR spectroscopy. Journal of Organic Chemistry 63, 1935-1943.
Brocks J. J. (2001) Molecular fossils. In McGraw-Hill Yearbook of Science & Technology 2001, pp. 252-255. McGraw Hill.
Brocks J. J., Love G. D., Snape C. E., Logan G. A., Summons R. E., and Buick R. (2003) Release of bound aromatic hydrocarbons from late Archean and Mesoproterozoic kerogens via hydropyrolysis. Geochimica et Cosmochimica Acta 67(8), 1521-1530.
Brocks J. J., Summons R. E., Buick R., and Logan G. A. (2003) Origin and significance of aromatic hydrocarbons in giant iron ore deposits of the late Archean Hamersley Basin in Western Australia. Organic Geochemistry 34(8), 1161-1175.
Bowden S. A., Love G. D., Snape C. E., Brocks J. J., Logan G. A., and Summons R. E. (2003) Detection and significance of molecular fossils of Chlorobiaceae in Paleoproterozoic sediments. Astrobiologie 3(4), 612-613.
Pearson A., Budin M., and Brocks J. J. (2003) Phylogenetic and biochemical evidence for sterol synthesis in the bacterium Gemmata obscuriglobus. Proceedings of the National Academy of Sciences, in press.
Brocks J. J., Buick R., Logan G. A., and Summons R. E. (2003) Composition and syngeneity of molecular fossils from the 2.78 - 2.45 billion year old Mount Bruce Supergroup, Pilbara Craton, Western Australia. Geochimica et Cosmochimica Acta 67(22), 4289-4319.
Brocks J. J., Buick R., Summons R. E., and Logan G. A. (2003) A reconstruction of Archean biological diversity based on molecular fossils from the 2.78 - 2.45 billion year old Mount Bruce Supergroup, Hamersley Basin, Western Australia. Geochimica et Cosmochimica Acta 67(22), 4321-4335.
Brocks J. J. and Summons R. E. (2003) Sedimentary hydrocarbons, biomarkers for early life. In Treatise in Geochemistry, Vol. 8 (ed. H. D. Holland), 53pp. in press. Elsevier.