INVESTIGADORES
BOND mariano
capítulos de libros
Título:
New Miocene mammal assemblages from Neogene Manantiales basin, Cordillera Frontal, San Juan, Argentina
Autor/es:
LÓPEZ, G.M., VUCETICH, M.G, CARLINI, A.A., BOND, M., PÉREZ, M.E., CIANCIO, M.R., PÉREZ, D.J., ARNAL, M., AND A. ITATÍ OLIVARES
Libro:
Cenozoic Geology of the Central Andes of Argentina
Editorial:
SCS Publisher
Referencias:
Lugar: Salta; Año: 2011; p. 211 - 226
Resumen:
ABSTRACTThe discovery of abundant fossil mammals from two different levels of the lowest third of the Chinches Formation(Manantiales basin) located in Cordillera Frontal of San Juan, between 32°30? and 33°S, is reported. These synorogenic Miocenedeposits were deposited by the structural evolution of Cordón de La Ramada fold and thrust belt. Two diverse fossil mammalassemblages have been recognized, one from the lowest bearing horizon, informally named «Chinches bearing level» (CBL), andother, stratrigraphically higher, informally named «Las Hornillas bearing level» (LHBL). Marsupials, Xenarthra (Cingulata andTardigrada), Notoungulates (four families), Litopterns and six groups of rodents are represented in both mammal assemblages.The presence of Eocardia montana, E. excavata and Nesodon conspurcatus strongly suggests that the bearing levels may be referredto the Santacrucian SALMA (South American Land Mammal Age), late early Miocene in age. The morphology of Stenotatus sp.,Hapalops sp., Protypotherium sp., Neoreomys cf N. australis, and the mesotheriines is comparable to that of Santacrucian species.Although both assemblages are referred to the Santacrucian SALMA, differences in composition among them suggest slightdifferences in age. This temporal reference matches with studies of fission-track and magnetostratigraphy, and sedimentologicaldata of this sequence. The latitudinal intermediate location together with the particular taxonomic composition of these assemblagesmay provide the clue to understand the differences between Miocene faunas from Patagonia and the Altiplano (Chile andBolivia). As well, these assemblages are a new important source of information for the comprehension of the phyletic andgeographic relationships of several taxa, and the paleoenvironmental changes associated with the uplift of the Andes.