Tropical South America is a key region on Earth, and the Amazon-Andean rainforest hosts over half of all terrestrial plant species. How this great biodiversity arose remains one of the foundational problems in modern science, and the question has spurred scientific research and debate since the pioneering work of Darwin and other naturalists of the 19th century. This project will obtain drill cores from the ancient sedimentary basins of the equatorial Amazon region of Brazil, an area that extends from the Andes to the Atlantic Ocean margin. This "Trans-Amazon Drilling Project" will span most of the width of continental South America and its offshore shelf. Each drill hole is planned to reach about 2 km deep, recovering the approximately 70-million-year history of the region. A large international team of scientists will apply an array of methodologies to study these cores in order to document the changes in plant species across the Amazon basin throughout its geological history and to determine how the evolution of the physical environment (including climate variation, uplift of the Andes, and development of the Amazon River) shaped the generation and distribution of plant and animal diversity. Collaborations with Brazilian partners will provide relevant educational material on Amazon geologic and biotic history, including ongoing educational programs for primary and secondary students, museum exhibits on unraveling long-term history via drilling, and outreach to enhance public appreciation of how geologic history influenced the forest and its species, thereby stimulating greater interest in conservation of this invaluable resource.
The forests and associated biota of the Amazon-Andean rainforest have evolved together with the physical landscape, closely linking processes in Earth's interior with climate, surface landscapes, ecosystems, and biodiversity. This project will investigate the geologic and climatic evolution of the entire near-equatorial Amazon region of Brazil, from the Andean foreland to the Atlantic Ocean margin, and the impact of that history on biotic evolution at regional to global scales. Drilling will occur in ancient sedimentary basins aligned along the modern Amazon River in a transect of sites that span the entire near-equatorial Amazon region of Brazil, from the Andean foreland to the Atlantic Ocean. This transect will span 40 to 73 degrees W longitude, thus encircling nearly 10% of Earth's equatorial circumference. This project will address fundamental linkages between the geology and biology of the Amazon region, including: (1) the changes in plant diversity across the Amazon Basin throughout the Cenozoic history of the angiosperm-dominated megathermal forests; (2) the evolution of the physical environment, including climate, tectonism, and landscape change, and how this has shaped the distribution of neotropical plant diversity and the origins of its species; and (3) the origins of the Triassic-Jurassic Amazonian diabase sills and the global environmental impact of the Central Atlantic Magmatic Province (CAMP) intrusions, one of the most significant igneous events in Earth history. Drill cores from this project will be archived at a NSF-supported facility for future access by researchers.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
