O EOL GIC G A D D A E D C E I H C I L E O S F u n 2 d 6 la serena octubre 2015 ada en 19 U-Pb ages of detrital zircons and Palynology of the Silurian Cancañiri Formation from the Bolivian Altiplano Udo Zimmermann1, Shirley Lopez2, Mercedes di Pasquo3, Tom Andersen4, Sveinung Hatløy1, Trine Mehus1, Caroline Ruud1, Siri L. Simonsen4 1Department of Petroleum Engineering, University of Stavanger, 4036 Stavanger, Norway;
[email protected]; 2Universidad Mayor de San Andrés, PO box 9087,
[email protected] 3Laboratorio de Palinoestratigrafía y Paleobotánica, CICYTTP-CONICET. Matteri y España s/n, E3105BWA Diamante, Entre Ríos, Argentina;
[email protected] 4Department of Geosciences, University of Oslo, N-0316 Oslo, Norway;
[email protected] Eupoikilofusa striatifera, Fractoricornula sp., 1 Introduction Helosphaeridium citrinipeltatum, Leiofusa cucumis, Leiofusa thomissa, Leiofusa parvitatis, Leiofusa cf. Samples from the Lower Paleozoic Cancañiri Formation estrecha, Neoveryhachium carminae, Onondagaella sp., at la Cumbre, La Paz-Bolivia (Andes Centrales), were Veryhachium strangulatum, chitinozoans Cyathochitina analysed for petrography, geochemistry, dating of detrital sp. B sensu Paris, Cyathochitina campanulaeformis, zircons and palynology. This unit was interpreted as Conochitina elongata, Conochitina cf. armillata, recycled from previous glacigenic deposits (Díaz- Desmochitina acollare, Sphaerochitina sp. C Grahn et Martínez, 1997, 2005) probably from the latest Ashgilian al.), others from the Ordovician (Acanthodiacrodium to the early Llandoverian. The aim of our study is to crassus, Orthosphaeridium spp., Vulcanisphaera reveal more information about the depositional setting of tuberata, Focusphaera elongata, Lagenochitina the succession often interpreted as one of the most cilindrica, Lagenochitina baltica, Lagenochitina significant rock section containing lithological obeligis), and a third one with long stratigraphic range constraints for the Hirnantian ice age in western South from Ordovician to younger ages (Leiofusa tumida, America.