Rocks that reveal stories: the origin and evolution of the Amazon and climate change

• Grant number: 23/03229-0
• Support Opportunities: Scholarships in Brazil - Scientific Journalism
• Start date: June 01, 2023
• End date: May 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: André Oliveira Sawakuchi
• Grantee: Adriana de Farias
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Instituto De Matemática E Estatística, Brazil
• Associated research grant: 18/23899-2 - Trans-Amazon Drilling Project: origin and evolution of the forests, climate, and hydrology of the South American tropics, AP.PFPMCG.TEM

Abstract

The Amazon biome is home to the greatest diversity of species on Earth and is an important element of the carbon cycle, with the capacity to influence the global climate. The Amazon rainforest is crucial for the production and distribution of atmospheric humidity in South America, in addition to sustaining the largest hydrographic basin in the world, which connects the Andean mountains with the equatorial Atlantic Ocean. The geological, climatic and biological evolution of the Amazon represents one of the great themes of contemporary Science, as it is fundamental to understand the origin of tropical biodiversity and the effects of climate change and the evolution of the physical landscape on the biota, both in relation to the changes that have occurred in the past and those projected for the future. It is also noteworthy that during the Mesozoic, the Amazon region was part of the Central Atlantic Magmatic Province (PMAC), one of the largest magmatic events ever to occur on Earth, which would have impacted the composition of the atmosphere and induced the biotic mass extinction of the boundary Triassic/Jurassic. The history of the Amazon and its global relevance motivate the "Trans-Amazon Drilling Project" (TADP, Projeto de Drilling Transamzônica), an international research initiative that aims to answer the following questions: (1) How did the climatic and geological history of the Cenozoic, including Did the uplift of the Andes, the formation of the Amazon River and the expansion of the Atlantic Ocean influence the origin of the Amazon rainforest and its incomparable biodiversity? (2) What is the origin of the PMAC sils complex in Amazonia and how did this affect the composition of the atmosphere and the processes that led to the mass extinction of the Triassic/Jurassic boundary? These questions can only be answered by drilling to access the Cenozoic history of the Amazon recorded in sediments from continental and oceanic areas, as well as the PMAC sils and their host sedimentary rocks. TADP represents the broadest research program ever organized to study the origin and evolution of the Amazon. The TADP is planned and executed within the scope of the International Continental Scientific Drilling Program (ICDP), encompasses researchers from 12 countries and aims to carry out drilling to collect sediment and rock cores in locations along a profile between the Andean foreland and the Atlantic margin, which will represent about 10% of the equatorial terrestrial circumference. Along this equatorial section, the following will be sampled in an unprecedented and systematic way: (1) the Cenozoic stratigraphic record, comprising sedimentary successions from 370 to 2000 m thick in the locations selected for drilling (Acre, Solimões, Amazonas and Marajó basins) , and (2) the PMAC magmatic rocks and host sedimentary rocks, underlying Cenozoic sequences in much of the Brazilian Amazon. This will be the first time that the Cenozoic sedimentary strata of the Amazon will be continuously drilled and sampled through cores for scientific purposes. This project will make it possible to carry out systematic analyzes of the geological and climatic history of the Amazon since the beginning of the Cenozoic, a period considered key to understanding the initiation and consolidation of the Neotropical forest and the Amazon watershed. Thus, this project will bring scientific advances of great relevance, as it will make it possible to understand the origin and transformations of the Amazon forest and the Amazon river basin, fundamental elements of the global climate system.The general objective of this journalistic research project is to communicate, inform and disseminate the scientific knowledge acquired through the thematic project in question, including the history of research development, motivations, scientific contributions and expected results in terms of the global context.