PeAt bog Records of Atmospheric Dust flux

Holocene palaeoenvironmental and paleoclimatic implications for Southern South America.

PARAD is an ANR-funded project having the main objectives to reconstruct Holocene dust cycles and trace dust sources in Tierra del Fuego using peat records. Although peat bogs have been abundantly used to monitor past atmospheric pollution, less attention has been given to pre-anthropogenic signals, especially in the Southern Hemisphere. Yet they are important to 1/ better understand the different particle sources during the Holocene, and 2/ to tackle the linkage between atmospheric dust loads and climate change. The main objectives of PARAD are therefore: 1) to provide high-resolution continuous records of natural atmospheric dust using the elemental and isotopic signature of peat cores in South America, and 2) to assess the linkage between dust inputs and climate.

State-of-the-art analytical technologies will allow us to explore the use of a broad range of trace elements as dust proxies (soil particles, volcanism, cosmogenic dusts, marine aerosols). Radiogenic isotopes (Pb, Nd, Hf) will be used as tracers for fingerprinting predominant sources. Coupling these findings with biological proxies (plant macrofossilsand detailed age-depth modeling, we expect not only to identify and interpret new links between atmospheric dust chemistry and climate change but also to significantly improve our understanding of peat bogs as archives of climate change, and the role of dust in both palaeoenvironmental and palaeoclimatic changes. Our investigations will help in assessing: 1/ the global vs. local character of each peat record; 2/ the spatio-temporal variation of pre-anthropogenic atmospheric dust geochemical pattern and fluxes during the Holocene at a centennial resolution and 3/ the possible link between dust load and source patterns with climatic fluctuations. Besides its main objectives, PARAD will bridge the gap between peat geochemists and paleoecologists and will feed three main topics: 1/ global change and adaptation of living organisms, 2/ land use and environmental changes (e.g. erosion), and 3/ human impact on biodiversity.

PARAD is an international project coordinated by F. De Vleeschouwer at EcoLab (CNRS), Toulouse, France. It will use, among others, the analytical platform of the Observatoire Midi Pyrénées (OMP-Toulouse), the radiocarbon platform of the GADAM Centre (Poland) and the growing scientific excellence of the PARAD Scientific Community to ensure ideal conditions to develop this project.

The intense web of reinforced and new collaborations within PARAD will provide the ideal condition for high quality and state of the art research. PARAD is gathering together leading laboratories in various fields. Each laboratory has a huge record of publication and projects, and will provide its own speciality. EcoLab, LEGOS and OMP will provide the state of the art analytical facilities needed for this proposal. RCMG and Stockholm participants will provide a crucial expertise in particle analysis. EPC will provide the palaeoenvironmental context (e.g. vegetation change). GADAM will provide the best available radiocarbon age modelling. Argentinean partners (CIGES and CADIC) will provide their precious expertise in Tierra del Fuego palaeoenvironment and dust cycles. Additional expert partners from USC, QUB, GADAM and UAlberta, will provide crucial support in interpreting the data.

To summarize, PARAD is a joint initiative grouping the top leading scientists in:

  1. dust and palaeodust in Tierra del Fuego
  2. peat geochemistry
  3. palaeoenvironmental changes in peat
  4. radiocarbon chronology
Stars: PI and co-I,
Circles: Partners.
  1. EcoLab (PARAD host institution, PI F. DE Vleeschouwer, Co-I G. Le Roux) and related labs in Toulouse (LEGOS – C. Jeandel)
  2. Co-I (RCMG-S. Bertrand)
  3. EPC (UK)
  4. CADIC (Argentina)
  5. CIGES (Argetina)
  6. GADAM (Poland)
  7. Geological Sciences (Sweden)
  8. IES (Germany)
  9. Univ. S. de Compostella (Spain)
  10. QUB (Ireland). Black plain arrows: existing collaboration between EcoLab and partner institutions (through ongoing research). Black dashed arrows: collaboration that will be initiated between EcoLab and partner institutions. Blue arrows: existing/future collaborations between 2 partner institutions. Green: regular partnering labs; yellow: laboratories from Southern countries; orange: expert labs, blue: labs form convergence regions (sensu E.U.).