Upper Ordovician graptolites and conodonts are recorded from the Yerba Loca Formation in two sections, in the El Toro and Las Viudas creeks, from the El Tigre Range in the Western Precordillera of San Juan Province, Argentina. A collection of graptolites from the late Sandbian Climacograptus bicornis Zone and conodonts on bedding plane surfaces corresponding to the Amorphognathus tvaerensis Zone are presented. Graptolites apparently corresponding to the early Sandbian Nemagraptus gracilis Zone have also been recorded. The fossils determined allow for regional and global correlations, revealing sections suitable for future integrated studies on deep marine environments that are poorly known in the Argentine Precordillera.
Albanesi, G. L., Banchig, A. L., Zeballo, F. J. and Lopez, F. E. 2022. Bioestratigrafía de conodontes ordovícicos en la sección Agua de los Caballos en la comarca de Ancaucha, Precordillera Occidental de San Juan, Argentina (Biostratigraphy of Ordovician conodonts at the Agua de los Caballos section of the Ancaucha locality, Western Precordillera of San Juan, Argentina). In XXI Congreso Geológico Argentino (XXI Argentinean Geological Congress), Puerto Madryn, Chubut (Foix, N., ed.), ST VI-12, 261–262.
Blasco, G. and Ramos, V. A. 1976. Graptolitos caradocianos de la Formacion Yerba Loca y del cerro La Chilca, Departamento Jáchal, Provincia de San Juan (Caradocian graptolites from the Yerba Loca Formation and La Chilca Hill, Jáchal Department, San Juan Province). Ameghiniana, 13(3–4), 312–329.
Brussa, E. D. 1995. Upper Middle Ordovician–Lower Upper Ordovician graptolites from the Western Precordillera, Argentina. In 5th International Graptolite Conference (Mitchell, C. E., ed.). Graptolite News, 8, 15–16.
Caballé, M., Cuerda, A. J., Alfaro, M. and Furque, G. 1993. Nuevos hallazgos de graptolitos en el Ordovícico de la sierra del Tigre, Precordillera de San Juan (New finds of graptolites in the Ordovician of El Tigre Range, Precordillera of San Juan). In XII Congreso Geológico Argentino y II Congreso de Exploración de Hidrocarburos (XII Argentinean Geological Congress and II Hydrocarbon Exploration Congress) (Spalletti, L. A., ed.), 2, 268–280.
Cuerda, A. J. and Cingolani, C. A. 1998. El Ordovícico de la región del cerro Bola en el Bloque de San Rafael, Mendoza: sus faunas graptolíticas (The Ordovician of the Bola Hill region of the San Rafael Block, Mendoza: its graptolite faunas). Ameghiniana, 35(4), 427–448.
Lopez, F. E., Ortega, G., Banchig, A. L. and Conde, O. A. 2022. La Zona de Climacograptus bicornis (Sandbiano tardío) en la sierra del Tigre, Precordillera Occidental de San Juan (The Climacograptus bicornis Zone (Late Sandbian) in El Tigre Range, Western Precordillera of San Juan). In XXI Congreso Geológico Argentino (XXI Argentinean Geological Congress), Puerto Madryn, Chubut (Foix, N., ed.), ST VI-12, 280–281.
Ortega, G. and Brussa, E. 1990. La subzona de Climacograptus bicornis (Caradociano temprano) en la Formación Las Plantas en su localidad tipo, Precordillera de San Juan, Argentina (The Climacograptus bicornis Subzone (Early Caradocian) in the Las Plantas Formation at its type locality, Precordillera of San Juan, Argentina). Ameghiniana, 27(3–4), 281–288.
Ortega, G. O., Brussa, E. D. and Astini, R. A. 1991. Nuevos hallazgos de graptolitos en la Formación Yerba Loca y su implicancia estratigráfica, Precordillera de San Juan, Argentina (New graptolite finds in the Yerba Loca Formation and their stratigraphic im- plications, Precordillera of San Juan, Argentina). Ameghiniana, 28, 163–178.
Ortega, G., Albanesi, G. L. and Frigerio, S. E. 2007a. Graptolite–conodont biostratigraphy and biofacies of the Middle Ordovician Cerro Viejo succession, San Juan Precordillera, Argentina. Palaeogeography, Palaeoclimatology, Palaeoecology, 245(1–2), 245–263.
https://doi.org/10.1016/j.palaeo.2006.02.023
Ortega, G., Albanesi, G. L., Heredia, S. E. and Beresi, M. S. 2007b. Nuevos registros de graptolitos y conodontes ordovícicos de las formaciones Estancia San Isidro y Empozada, quebrada San Isidro, Precordillera de Mendoza, Argentina (New records of Ordovician graptolites and conodonts from the Estancia San Isidro and Empozada formations, San Isidro Creek, Precordillera of Mendoza, Argentina). Ameghiniana, 44(4), 697–718.
Ortega, G., Albanesi, G. L., Banchig, A. L. and Peralta, G. L. 2008. High resolution conodont-graptolite biostratigraphy in the Middle-Upper Ordovician of the Sierra de la Invernada Formation (Central Precordillera, Argentina). Geologica Acta, 6(2), 161–180.
Peralta, S. H., Finney, S. C. and Basilici, G. 2003. Portezuelo del Tontal Formation (Lower Caradoc), Western Precordillera, San Juan Province: its biostratigraphic and paleogeographic significance. In Ordovician from the Andes, Short Papers of the 9th International Symposium on the Ordovician System, INSUGEO(Albanesi, G. L., Beresi, M. S. and Peralta, S. H., eds). Serie Correlación Geológica, 17, 119–123.
Tickyj, H., Rodríguez, M., Cingolani, C. A., Alfaro, M. and Uriz, N. 2009. Graptolitos ordovícicos en el Sur de la Cordillera Frontal de Mendoza (Ordovician graptolites in the southern Cordillera Frontal of Mendoza). Revista de la Asociación Geológica Argentina, 64(2), 295–302.
