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The Guandacol Formation, in the homonymous area, consists of an alternation between proglacial and postglacial marine strata, including deltaic and turbidite sandstones, black shales, and resedimented diamictites. In order to characterize the palynology at Cerro Guandacol, a systematic sampling was undertaken through the entire succession in the south of Sierra de Maz, La Rioja Province (Fig.1). Twenty one samples were taken and processed following standard palynological methods; just four associations were obtained with rather good preservation of palynomorphs. Another seven barely productive samples present only poor palynological remains, fungal hyphae and phytoclasts of terrestrial origin, with or without fine particles of amorphous organic matter. A sample from an ice-rafted debris unit taken from the base of the Guandacol Fm. yielded the first palynoassemblage (CICYTTP-Pl 513) of scarce palynomorphs composed of spores and Botryococcus. Among the spores, Cordylosporites sp. cf. C. absimilis is mostly recognized in the Tournaisian (Strunian?) of Brazil, Densosporites regalis is known from the Malimán Fm. (Tournaisian-early Visean of Precordillera (Amenábar et al. 2007) to the late Visean (Mag Zone) in Brazil (Melo and Playford 2012), Densosporites pseudoannulatus is Strunian-Visean up to Mag Zone of Brazil (Melo and Playford 2012, Playford et al. 2012), Cristatisporites sp. cf. C. mattheusii, recorded from the Malimán, El Ratón and Cortaderas formations (Amenábar et al. 2007, Pérez Loinaze 2007, Amenábar and di Pasquo 2008), Cristatisporites peruvianus is documented from the Tournaisian-Visean in the Malimán Fm. (Amenábar et al. 2007) and Brazil (Playford et al. 2012; Melo and Playford 2012), and in the late Visean of Perú and Bolivia (Azcuy and di Pasquo 2005), Vallatisporites ciliaris , and Cristatisporites rollerii Ottone and Cristatisporites stellatus are recorded in the Cortaderas and Guandacol formations and the latter in the El Ratón Fm. as well. A second assemblage (CICYTTP-Pl 477) is recovered from a confined turbidite deposit at the top of the lower of two mass transport deposits at Sierra de Maz. Few species were confidently identified such as, Apiculiretusispora tuberculata, A. variornata, Cristatisporites scabiosus, C. inordinatus, C. matthewsii, C. chacoparanensis, C. stellatus , Cyclogranisporites microgranus, C. rinconadensis, ?Schopfipollenites sp. Most of these species are known from the Malanzán and Guandacol formations (Raistrickia densa-Convolutisporta muriornata SubZone a- (DMa SZ) (Fig.2). The remaining two assemblages (MP-P 8931 and 8926) are taken from a thin unit of shales with dropstones immediately overlying the upper of the two mass transport deposits at Sierra de Maz. Identified spores are Calamospora sp., Cristatisporites stellatus, C. menendezii, Cristatisporites sp., Verrucosisporites sp. Considering this information and previous palynologic data from the Cerro Bola area (Césari and Limarino 2002, Valdez et al. 2013) and the well-established lithostratigraphic correlation between the successions at Cerro Bola and Sierra de Maz (Valdez et al. in rev.), we interpret that the first assemblage is the oldest for the Guandacol Fm., probably akin to the Tournaisian-Visean, and a younger Serpukhovian ? ?Bashkirian age is suggested for the second one, correlated with the lower DMa SZ. The other two assemblages are also assigned to the DMa SZ. This conclusion endorses our previous interpretations made from lithostratigraphical analysis (Valdez et al. in rev.), that Guandacol Fm. at its type section started accumulation well before the rest of Paganzo Basin areas. Thus, this finding supports the definition of a Guandacol-La Peña sub basin that started evolving before the widespread intracratonic Paganzo basin and probably under a particular tectonic regime making possible to preserve older glacial events than in the rest of the basin. [Projeto BG-01] REFERENCES Amenábar, C.R., di Pasquo, M.M., 2008. Nuevos aportes a la palinología, cronología y paleoambiente de la Precordillera Occidental de Argentina: formaciones El Planchón, Codo (Devónico) y El Ratón (Mississippiano). Lilloa (Fundación Miguel Lillo), 21(1), 3-20. Amenábar, C.R, di Pasquo, M.M., Carrizo, H., Azcuy, C.L., 2007. Palynology of the Chigua and Malimán Formations in the Sierra del Volcán, San Juan province, Argentina. Part 2. Cavate, pseudosaccate and cingulizonate spores. Ameghiniana 44, 547-564. Azcuy, C.L., di Pasquo, M.M., 2005. Early Carboniferous palynoflora from the Ambo Formation, Pongo de Mainique, Peru. Review of Palaeobotany and Palynology 134, 153-184. Césari, S.N. & Limarino, C.O., 2002. Palynology of glacial sediments from the Guandacol Formation (Carboniferous) in the Cerro Bola area, Paganzo Basin, Argentina. Alcheringa 26, 159-176. di Pasquo, M.M. 2007. Update and importance of the Carboniferous and Permian paleontological records of the Tarija Basin. En: E. Díaz-Martínez, I. Rábano (eds.), 4º European Meeting on Paleontology and Stratigraphy of Latin American (Madrid, http://www.igme.es/4empsla), Instituto Geológico y Minero de España, Serie Cuadernos del Museo Geominero No. 8, 107-112. di Pasquo, M.M., 2009. The Pennsylvannian palynoflora from the Pando X-1 Borehole, northern Bolivia. Review of Paleobotany and Palynology 157, 266?284. Melo, J.H.G., Playford, G., 2012. Miospore palynology and biostratigraphy of Mississippian strata of the Amazonas Basin, northern Brazil. Part Two. American Association of Stratigraphic Palynologists, Contributions Series 47, 93-208. Pérez Loinaze, V., 2007. A Mississippian miospore biozone for Southern Gondwana. Palynology 31, 101-117. Playford, G., Borghi, L., Lobato, G., Melo, J.H.G., 2012. Palynological dating and correlation of Early Mississippian (Tournaisian) diamictite sections, Parnaíba Basin, northeastern Brazil. Revista Española de Micropaleontología 44, 1-22. Valdez, V., di Pasquo, M.M., Kneller, B. 2013. Palinoasociaciones carboníferas en la Formación Guandacol en el área de Cerro Bola, La Rioja, Argentina. XXIII Congresso Brasileiro de Paleontologia (Gramado 13-18/10), Abstracts: 40. Valdez, V., Milana, J.P., Kneller, B., in rev. Mega deslizamientos gravitacionales de la Formación Guandacol en Cerro Bola y Sierra de Maz, Provincia de La Rioja." Revista de la Asociación Geológica Argentina. (Enviado en Abril de 2014)