ANÁLISIS PALINOFACIAL DE LA ALOFORMACIÓN PLAYA DEL ZORRO (MIOCENO TARDÍO/PLIOCENO), VALLE DEL CAJÓN, CATAMARCA, ARGENTINA

HORN, M.Y.; MARTÍNEZ, MARCELO A.; ANZÓTEGUI, M.L.

REVISTA BRASILEIRA DE PALEONTOLOGIA

SOC BRASILEIRA PALEONTOLOGIA

Lugar: Porto Alegre; Año: 2016 vol. 19 p. 85 - 94

1519-7530

PALYNOFACIES ANALYSIS OF PLAYA DEL ZORRO ALLOFORMATION (LATE MIOCENE/PLIOCENE)CAJON VALLEY, CATAMARCA, ARGENTINA. This paper presents the palynofacies analysis results from La Cascaditalocality of Playa del Zorro Alloformation (late Miocene-Pliocene), being the fi rst palynological study of the Neogene outcropsof the Cajon Valley, northwestern Argentina. Eleven palynological and organic matter samples were analyzed, only three ofthem containing palynomorphs (spores of Glomus sp. and Lycoperdon sp., Chlorophyta algae colonies, spores Zygnemataceaeand few angiosperm pollen grains). Four types of organic matter were identifi ed: phytoclasts (translucent and opaque),palynomorphs, amorphous organic matter and zooclasts. Given the overall frequency of these types and relative frequenciesof the particles that constitute them, two palynofacies can be distinguished. The Palynofacies Type I is characterized by therelatively high frequency semi-opaque and equidimensional opaque phytoclasts, reduced organic amorphous matter andlow representativeness of palynomorphs; suggesting oxidizing environments, poor transport and high-energy environment.The Palynofacies Type II is characterized by high relative frequency of palynomorphs and amorphous organic, and have thelower values of phytoclasts, which suggests an environment with more reducing conditions than those of the PalynofaciesI, temporarily anoxic and shallow. The climate regime would have been warm, semi-arid with a marked dry seasonality.