GSA Connects 2022 meeting in Denver, Colorado

Paper No. 190-13
Presentation Time: 5:05 PM

PROF. DAVID B. SCOTT’S LEGACY TO FORAMINIFERA RESEARCH OF SOUTH AMERICAN SALT MARSHES AND MANGROVES


BARBOSA, Catia, Department of Geochemistry, Universidade Federal Fluminense, Outeiro de Sao Joao Batista, s/no., Niteroi, 24020-141, Brazil and ESPINOSA, Marcela A., Instituto de Geología de Costas y del Cuaternario, Universidad Nacional de Mar del Plata, CONICET-UNMDP, CC 722 7600, Mar del Plata, Argentina

Foraminiferal studies in South America have gained a quantitative approach for the reconstruction of Quaternary sea levels, from fieldwork carried out by Prof. David Scott from December 1987 to February 1988. We sampled mangroves and salt marshes from Brazil to Argentina, considering vertical zonation of vascular plant communities and mean sea level, to test the hypothesis of foraminiferal zoning of salt marshes in comparable latitudes between northern and southern hemispheres. The adversities of the Patagonian Desert notwithstanding, we were able to sample different tidal marshes beyond 50oS latitudes in cooperation with Brazilian and Argentinian institutions. Publications and a book chapter describing the foraminiferal faunas were generated. The estimated altitude error quantified for the higher water level from the faunal zoning of benthic foraminifera in transects in Brazilian mangrove and marsh borders was first established at + or – 6cm, represented by the assemblage of Haplophragmoides wilberti, Arenoparella mexicana, Trochammina inflata.

Although at that time Argentina had active researchers, such as Prof. Esteban Boltovskoy and Silvia Watanabe, who hosted us at the Natural History Museum in Buenos Aires, Brazilian institutions were experiencing a gap in foraminifera staff training, with the retirement of the country’s important professors as Setembrino Petri, Ivan M. Tinoco, Walter Narchi among others. The visit of Prof. Scott strongly encouraged personnel to work with foraminifera at that critical moment.

Later, Prof. Scott tried to establish the faunal zonation also for Valdivia estuary in Chile, where local neotectonic lead to the occurrence of only two faunal zones of wide elevational range (over 0.5m), therefore restricting the reconstruction of sea-level histories. Nevertheless, this work much contributed to the elucidation of tsunami and neotectonics in Chile’s sedimentary record.

Undoubtedly, we can attribute to Prof. David Scott the quantitative observational deployment of foraminifera as a tool for understanding and monitoring of sea level in marsh environments. A scientific heritage was the training of personnel to work in these environments, which have continued to the present day, with improved methods and observations.