ESPINOSA Marcela Alcira
congresos y reuniones científicas
PROF. DAVID B. SCOTTS LEGACY TO FORAMINIFERA RESEARCH OF SOUTH AMERICAN SALT MARSHES AND MANGROVES
CATIA BARBOSA; MARCELA ESPINOSA
Congreso; GSA Connects 2022 meeting; 2022
The Geological Society of America (GSA)
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 countrys 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 Chiles 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.