Participant of COCARDE Network


University of Johannesburg

Field geology, stratigraphy and sedimentology, and geobiology of African Paleozoic and Pre-Paleozoic hydrocarbon-seep dominate carbonate environments, and their application for planetary field analogues (remote sensing and planetary geology).
Investigation sites: northern and southern Africa.


Hydrocarbon, cold seep deposits are characterized by authigenic, microbially-induced carbonates with 13C-depleted values, commonly cementing shelled biota. The characteristics and evolution of recent and fossil seep settings are well defined, as well as the criteria for their recognition in the geologic record. However, if hydrocarbon seeps are well known in geologic setting, they are rarely recorded in Palaeozoic and Precambrian strata and the reasons remain unclear. The focus of our research is to localize and investigate potential fossil seep systems and related signatures and biosignatures in the Palaeozoic and Precambrian record in Africa using a comparative analyses and geomicrobiological approaches.
This research aims also at comparing geological features, morphologies and processes linked to methane-bearing fluid flow at multiple scales on Mars and Earth. The value of hydrocarbon deposits and mounds as a Mars analogue is highlighted by convincing (microscopic) evidence of life to fluid escape features that can guide exploration for life on Mars.



  • Dr. Angelo P. Rossi, sedimentologist and planetary geologist, Jacobs University Bremen, Germany
  • Dr. Monica Pondrelli, sedimentologist and Planetary geologist, IRSPS, Università G. D'Annunzio, Pescara, Italy
  • Dr. Silvia Danise, palaeoecologist, University of Plymouth, United Kingdom



Recent and on-going projects

  • Geobiology of African Precambrian seeps (NRF-South Africa, 2011-12)



We benefits from the facilities of the Geology Department and Spectrau-The Central Analytical Facility of the Faculty of Science at the University of Johannesburg:


  • Light Microscopy: Zeiss Axioplan 2 Compound Microscope; Zeiss Discovery Stereo Microscope; Olympus BX51 TRF.
  • Raman Microscopy: WITec alpha300R (532nm).
  • Electron Microscopy: Jeol 5600 Scanning Electron Microscope with EDS and a Centaurus backscatter/cathodoluminesence system; FEI XL40 ESEM with two EDAX Sapphire Si(Li) EDS.
  • Mass spectroscopy:ThermoFisher X-SeriesII ICP-MS’s; SHIMADZU QP2010 Gas Chromatography Mass Spectrometer; MAP 215-50 Noble Gas Mass Spectrometer.
  • Nuclear Magnetic Resonance: Varian Unity Inova 300MHz Nuclear Magnetic Resonance Spectrometer.
  • Optical spectroscopy: Spectro ARCOS Inductively Coupled Plasma Optical Emission Spectrometer.
  • Thermal analysis:Mettler Toledo DSC822e Differential Scanning Calorimeter.
  • X-ray analysis: Cameca SX-100 Microprobe; Jeol 733 Superprobe; Panalytical X-PertPro X-Ray Diffractometer; Panalytical MagiX PRO X-Ray Fluorescent Spectrometer.


More detailed infos:




Barbara Cavalazzi


Prof. Dr.
N.J. Beukes


Related publications


Cavalazzi B, Barbieri R, Cady SL, George A.D., Gennaro S Lui A, Westall F, Rossi AP, Ori GG, TajHeddine K, IN PRESS. Iron-framboids in the hydrocarbon-related Middle Devonian Hollard Mound of the Anti-Atlas mountain range in Morocco: Evidence of potential microbial biosignatures. Sedimentary Geology. Online since 16 September 2011.

Danise S, Cavalazzi B, Dominici S, Westall F, Monechi S, Giuoli S, IN PRESS. Evidence of microbial activity in a Miocene whale carcass from shallow water sediments (Voghera, Northern Italy). Palaeogeography, Palaeoclimatology, Palaeoecology. Online since 9 December 2011.


Barbieri R, Cavalazzi B, 2008. Fossil microorganisms at methane seeps: an astrobiological perspective. In Seckbach, J. and Walsh, M. (Eds), From Fossils to Astrobiology. Records of Life on Earth and the Search for Extraterrestrial Biosignatures, Springer, New York, pp. 297-317.


Cavalazzi B, 2007. Chemotrophic filamentous microfossils from the Hollard Mound (Devonian, Morocco) as investigated by focused ion beam. Astrobiology 7, 402-415.

Cavalazzi B, Barbieri R, Ori GG, 2007. Chemosynthetic microbialites in the Devonian carbonate mounds of the Hamar Laghdad (Anti-Atlas, Morocco). Sedimentary Geology 200, 73-88.

Cavalazzi B, 2007. Fossil microbial evidences from Miocene Roccapalumba (Central Sicily, Italy) methane-seep carbonates. Grzybowski Foundation 12, 7-13.


Cavalazzi B, Barbieri R, 2006. Fossil prokaryotes of cold-seep carbonates. CIESMMonograph 29, 123-132.


Barbieri R, Cavalazzi B, 2005. Microbial fabrics from Neogene cold seep carbonates, Northern Apennine, Italy. Palaeogeography, Palaeoclimatology, Palaeoecology, 227, 143-155.


Barbieri R, Ori GG, Cavalazzi B, 2004. A Silurian cold seep ecosystem from Middle Atlas, Morocco. Palaios, 19, 527-542.

Barbieri R, Cavalazzi B, 2004. Astrobiological implications of microbial morphologies in cold fluid-generated carbonates. Advancefs in Space Research, 33, 1262-1267.