© ICDP, the International Continental Scientific Drilling Program, 1996-2020

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Quaternary Tertiary Tropics - Colônia Sediment Archive Drilling Project QUE COISA

South America, Brazil, São Paulo, Colônia

revised workshop-proposal: ICDP-2014/17
for the funding-period starting 2014-01-15
by Marie Pierre Ledru, Wolf Uwe Reimold, Daniel Raul Ariztegui, Édouard Bard, Édouard Bard, Alvaro Penteado Crósta, Claudio Riccomini
Abstract
Although lowland Tropics are the richest in hydrological and biodiversity resources, the effects of tropical climate variability on these resources are still too poorly documented to predict the future of densely populated regions. The Colonia structure is located in southern Brazil, close to the city of Sao Paulo (23°52'8 46°42'20"W). It contains a bog deposited in a hilly circular structure of 3.6 km diameter with an outer rim elevated by up to 125 m. The structure is formed in Proterozoic crystalline rocks and 230 m of organic-rich, fine-grained sediments fill the Colonia basin. Drilling the Colonia sediments will provide a unique archive on Southem Hemisphere climate development as well as improve our knowledge about tropical rainforest evolution. Indeed, as it is located within the Atlantic rainforest domain, this site has become a reference site for tropical paleoecological research because the upper 8 m of sediments record 130 ka of paleoenvironmental history. Thus, assuming a continuous and relatively uniform sedimentation rate, the sediment fill could account for up to 2.5 Ma of sedimentation history. The second goal for the proposed drilling of the Colonia basin is to understand the process that led to its formation. Drilling into the basement of the Colonia structure could provide the necessary information to unravel its origin, complementing the main goal of the project regarding climate change and, thus, adding a valuable scientific bonus. Other similar possible impact structures recognized in Brazil entirely dried up and did not preserve any sediment infill, thus making the Colonia site unique. This proposal is aimed at holding an international workshop in Brazil, at the Institute of Geosciences of the University of Sao Paulo in 2014 to form an international and multidisciplinary team that defines detailed scientific and operational goals of a drilling campaign and the subsequent scientific evaluation of sedimentary strata recovered. The principal workshop outcome will be a draft of science and drilling operations plan for a full proposal submission to ICDP in January 2015.
Scientific Objectives
  • The bog sediment record in the Colonia structure located in the Atlantic rainforest domain of southem Brazil, close to the city of Sao Paulo (23°52'S; 46°42'20''W; 900 m asl) has strong potential to better understand climate forcing in the Southern Hemisphere and more particularly:
  • - to analyze millennial to orbital-scale climate dynamics in the southem Tropics and characterize Southem Hemisphere climatology;
  • - to characterize the link between Pliocene and Pleistocene tropical biodiversity;
  • - to explore continuously, at the Milankovitch scale and for the first time, the driving mechanisms and patterns for tropical forest diversity;
  • - to bring new information about changes in tropical hydrological cycles and transition between cold/warm climates at low latitudes; and - to establish the process that lead to the formation of the structure of Colonia
Keywords
Biodiversity, Brazil, COLONIA, ICDP-2014/17, Impact crater, Paleoclimatology, Rain forest, South america, Southern hemisphere, Tropics
Location
South America, Brazil, São Paulo, Colônia: -23.86667, -46.70556

© ICDP, the International Continental Scientific Drilling Program, 1996-2020

www.icdp-online.org