Silurian microplankton from the Cachipunco formation (santa bárbara range; andina central basin), Jujuy, Argentina

Abstract

The palynological content of Cachipunco Formation is described in this contribution. This formation lies in the Santa Barbara Range, Jujuy Province, and outcrops at two localities: Angosto Los Pereyras and Cumbre los Pereyras. The more complete succession is the one from Angosto Los Pereyras, where the formation comprises 273 m of dark siltstones interstratified with thin sandstones and without visible base or top. The microfloristic associations are characterized by the presence of: Ammonidium ludloviense (Lister) Dorning, Barbestiastra barbata (Downie) Sarjeant & Stancliffe, Domasia quadrispinosa Hill, Leiofusa exilata Dorning, L. parvitatis Loeblich, Multiplicisphaeridium arbusculum Dorning, M. eoplancktonicum (Eisenack) Lister, Neoveryhachium carminae Cramer, Proteolobus cylindricus Al-Ruwaili, Tylotopalla maraca Díez & Cramer, T. robustispinosa (Downie) Eisenack et al., Veryhachium trisphaeridium Downie, and Ambitisporites avitus Hoffmeister. According to the stratigraphic distribution of the theses species, the age of the Cachipunco Formation can be constrained to a Wenlockian-Ludlovian range. A new species is proposed Multiplicisphaeridium baldisii sp. nov.