Jochen Brocks

Jochen Brocks is a paleobiogeochemist at the Research School of Earth Sciences at ANU.

Home Page: http://shrimp.anu.edu.au/people/jjb/jjb.html

Jochen is particularly interested in the early evolution of life on Earth, microbial ecosystems and environments in the Precambrian (the time before 542 million years ago), and major environmental cataclysms and biological innovations that caused major mass extinctions or spawned the emergence of complex forms of life.

To find clues to major events of the past, Jochen studies biomarkers. Biomarkers are the molecular fossils of biological lipids. After the death of an organism, lipids can be preserved for hundreds of millions of years entombed in sedimentary rocks. We extract these traces of lipids from ancient rocks and analyze the structures using mass spectroscopy. Many molecular fossils are diagnostic for certain groups of organisms, and they can be used to reconstruct ancient microbial ecosystems that otherwise disappear without traces.

I am also interested in unusual living microbial ecosystems in Australia such as sulphidic lakes and water reservoirs, and extremely salty inland environments such as Lake Tyrell.

Current research projects:

- The evolution of microbial ecosystems across the Precambrian/Cambrian boundary (see also web page of PhD student Richard Schinteie)
- The chemical and biological evolution of the oceans in the Proterozoic (2500 to 542 million years ago)
- Microorganisms and fossil lipids in a hypersaline lake in outback Victoria (Lake Tyrrell). When did the lake become so salty?
- Biomarkers in dust storms and desert crusts
- The application of culture independent genomic and proteomic techniques for the study of lipids and biomarkers

Research Group and Regular Visitors

- Janet Hope (Laboratory Manager)
- Richard Schinteie (PhD student)
- Claudia Jones (PhD student, UC Berkeley)
- Marlene Bausch (Masters student, U. Bremen)
- Amber Green (Honours student)
- Carina Lee (summer scholar)

Relevant Publications

A full publication list and downloadable PDFs can be found at http://shrimp.anu.edu.au/people/jjb/JJB%20CV_frame.html

  • Brocks J. J., and Schaeffer P. (2008) Okenane, a biomarker for purple sulfur bacteria (Chromatiaceae), and other new carotenoid derivatives from the 1,640 Ma Barney Creek Formation. Geochim. Cosmochim. Acta , in press.
  • Brocks J. J. , Love G. D., Summons R. E., Knoll A. H., Logan G. A., and Bowden S. A. (2005) Biomarker evidence for green and purple sulfur bacteria in an intensely stratified Paleoproterozoic sea. Nature, 437, 866-870.
  • Brocks J. J. , Pearson A. (2005) Building the biomarker tree of life. Reviews in Mineralogy and Geochemistry, Vol. 59 (eds. J. Banfield et al.), pp. 233-258. The Mineralogical Society of America, Chantilly.
  • 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 100(26) , 15352-15357.
  • Brocks J. J. and Summons R. E. (2003) Sedimentary hydrocarbons, biomarkers for early life. In Treatise on Geochemistry , Vol. 8 - Biogeochemistry (ed. H. D. Holland and K. K. Turekian), pp. 63-115. Elsevier.
  • 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.