The Holocene palaeoenvironmental evolution of Vitória Bay, Espírito Santo, Brazil

Abstract

Micropalaeontological analyses of two sediment cores (T_A and T_D) collected from a tropical bay in Brazil were conducted. Continental palynomorphs and carbonised particle data were associated with stable isotopes (C and N) assessed using 14C dating. The main objective was to integrate these data with the results of isotopic analyses in order to establish the palaeoenvironmental dynamics of the area during the Holocene. The samples were sub-sampled every 10 cm and then submitted for standard methodological processing for each analysis. The T_A sediment core was dated at three depths, and the oldest depth, 150 cm, had an age between 7241–7339 cal yr BP. The T_D sediment core had an age between 6778 and6948 cal yr BP at its deepest depth, 370 cm. Using radiocarbon dating and micropalaeontological analyses, the integrated assessment of the two sediment cores indicated that the core with a coarser granulometry core was a continuation of the core with the finest granulometry. Consequently, both the lithological change and the preservation of the microfossils could be directly related to periods of sea level variations observed in the coastal region of Brazil.