INVESTIGADORES
PONCE Juan Jose
artículos
Título:
Trace fossils as tools to unravel oxygen conditions: A case study from Los Molles Formation (Toarcian-lower Callovian)
Autor/es:
CAMPETELLA M.D. ; CARMONA, N.B.; PONCE JUAN JOSE; WETZEL, A.; RODRIGUEZ M.; PARADA, M.N.
Revista:
Revista de la Asociación Geológica Argentina
Editorial:
Asociación Geológica Argentina
Referencias:
Lugar: Buenos Aires; Año: 2020 vol. 77 p. 463 - 477
ISSN:
1853-7138
Resumen:
The Toarcian - lower Callovian Los Molles Formation in the Chacay Melehue section (southern limb of Cordillera del Viento - NeuquénBasin) comprises offshore-shelf deposits and subordinately, channel-levee and lobe deposits produced by density currents. Thesedeposits are characterized by two distinctive trace fossil suites: (1) Chondrites and Trichichnus in the offshore-shelf mud, and (2)Chondrites, Trichichnus, and Phycosiphon occurring in distal levee deposits. The generally low diversity and abundance of the tracefossils suggest severe environmental conditions. In particular, in the intervals containing Chondrites and Trichichnus, pyrite framboidsare abundant and most likely indicate low oxygen availability within the sediment. The presence of Phycosiphon in the levee depositsimplies short periods of improved oxygenation caused by the density currents originating in shallow water.
