Accumulation rate of terrigenous and pelagic sediments during the last glacial cycle along the equatorial margin of South America

• Grant number: 23/17694-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: February 28, 2025
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Geological Oceanography
• Principal Investigator: Thiago Pereira dos Santos
• Grantee: Maysa Almeida Leonetti
• Host Institution: Escola de Artes, Ciências e Humanidades (EACH). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 18/15123-4 - Past perspectives on tipping elements of the climate system: the Amazon Rainforest and the Atlantic Meridional Overturning Circulation (PPTEAM), AP.PFPMCG.JP2

Abstract

The dynamics inherent to sediment production and transport in a sedimentary basin are closely related to the prevailing climatic conditions. These conditions can respond to processes on different scales, from regional to global. The sedimentation rate is one of the most traditional indicators for inferring the volume of sediment accumulated in a given time interval. Variations in sediment accumulation may reflect processes conditioned by the region's climate variability. This undergraduate research project aims to determine the sedimentation rate between the Last Glacial Maximum (23,000 - 19,000 years ago) and the mid-Holocene (6,000 years ago) on the northeastern continental margin of South America from French Guiana to the Northeast of Brazil. The material used in this project corresponds to a collection of 10 sedimentary cores recently collected in this region during a scientific expedition aboard the French research vessel R/V Marion Dufresne as part of the AMARYLLIS expedition (From Amazon deep-sea sediments to natural climate variability and slope instability processes). For this, 20 samples will be dated using the radiocarbon method using carbonate material from marine microfossils (planktonic foraminifera). In addition to this, previously published radiocarbon dates will be compiled to compose this new sample set. This project, therefore, will improve understanding of sedimentary dynamics in a vast area off South America, connecting these dynamics to current climate patterns of precipitation and ocean circulation in the Atlantic.