IDEAN   23403
INSTITUTO DE ESTUDIOS ANDINOS "DON PABLO GROEBER"
Unidad Ejecutora - UE
artículos
Título:
Mid-Pleistocene benthic foraminifera of Southwestern South Atlantic: driven by primary productivity or water masses properties?
Autor/es:
GARCÍA CHAPORI, N., LAPRIDA, C., VIOLANTE, R., WATANABE, S. AND TOTAH, V.
Revista:
MICROPALEONTOLOGY
Editorial:
MICROPALEONTOLOGY PRESS
Referencias:
Lugar: New York; Año: 2014 vol. 60 p. 195 - 210
ISSN:
0026-2803
Resumen:
Benthic foraminifera have been used as proxies of both deep water mass properties and exported productivity to the sea floor. In the Atlantic sector of the Southern Ocean, it has been shown that the water mass signal is overprinted by the productivity signal as benthic foraminiferal assemblages depend almost exclusively on primary productivity. According to our results, the assemblages of core SP1251 do not indicate the dominance of any specific deep-water mass. Conversely, productivity-related markers do present a coherent signal, as factor analysis revealed that the productivity signal has been the main factor in determining the structure of benthic communities. The more relevant assemblages were composed of high organic matter-associated species such as A. weddellensis, I. inflata, E. exigua, U. peregrina among other uvigerinids. Additionally, our results show that the glacial primary productivity regime was not uniform. While SSTs were 4-6°C lower than modern values and subantarctic planktonic foraminifera dominated the assemblage, primary productivity was moderate, and the flow of organic matter to the sea floor was pulsive, generating an oligo-mesotrophic benthic environment. Otherwise, when SSTs and transitional planktonic foraminifera abundance increased, primary productivity was high and constant leading to a meso-eutrophic environment. These variations in the exported productivity would be related to variations in the shelf break upwelling of Patagonia as a consequence of variations in the Antarctic upwelling, which played a fundamental role in the surface nutrient availability of the Southern Ocean between glacial and interglacial cycles.