Palynostratigraphy of the Zorritas Formation, Antofagasta region, Chile: Insights on the Devonian/Carboniferous boundary in western Gondwana

Abstract

a b s t r a c tThe Middle Member of the Zorritas Formation in the Antofagasta Region of northern Chile, yielded terrestrial and marine palynomorph assemblages which span the Devonian/Carboniferous boundary. The assemblages show a clear predominance of terrestrial palynomorphs with 70 miospore species, 18 marine phytoplankton species, two non-marine algae and one chitinozoan species, all coming from 15 productive levels. Palynomorphs are poorly preserved and most of them are reworked. Three palynological associations are recognized based on miospores. These are assigned to the TournaisianeVisean, Tournaisian and probable latest Famennian. Age assignments are discussed in the frame of the spore zonal schemes established for Euramerica and western Gondwana. The stratigraphical distribution of spores allows the identification of the probable position of the Devonian/Carboniferous boundary within the Zorritas Formation. This system boundary is proposed for the first time in Palaeozoic sedimentary rocks of northern Chile. The presence of Gondwanan typical miospore species indicates affinities with this palaeocontinent even though the Tournaisian and TournaisianeVisean miospore associations support the cosmopolitanism already suggested for the early Carboniferous flora. The significant number of reworked palynomorphs together with the sedimentological analysis of the studied sections, suggest that these deposits were severely impacted by the climatic change and major sea level fluctuations. Similar conditions were recorded in coeval western Gondwana basins.Ó 2016, China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

First record of late Devonian-early Carboniferous palynoflora from the Lipak Formation, Spiti Basin, Tethyan Himalaya, India, and their biostratigraphic implications

“…The recovered palynomorphs of the Lipak Formation can be correlated with Devonian and Carboniferous palynocompositions of the Zorritas Formation, Argentina. This Formation is characterised by occurrences of both terrestrial and marine palynomorphs (Rubinstein et al, 2017). The terrestrial palynoassemblage of the Zorritas Formation shows a limited resemblance with present palynoassemblage in having common palynotaxa, namely Rugospora, Verrucosisporites , Lophozonotriletes and Knoxisporites .…”

“…Several number of palynological studies have been carried out from Devonian-Carboniferous strata of the world and is continuously being updated for high-resolution palynostratigraphy and correlation of contemporary strata across the globe, especially from South America (Brazil: Loboziak et al, 2000;Melo & Loboziak, 2003;Muro et al, 2020;Playford et al, 2012;Souza et al, 2003Souza et al, , 2015; and references therein), Argentina (Césari & Perez Loinaze, 2021;Gutiérrez & Balarino, 2018;Loinaze, 2005;Loinaze et al, 2014;Noetinger & Di Pasquo, 2011;Pineda et al, 2021;Rubinstein et al, 2017;and references therein), South Africa (Streel & Theron, 1999), Europe (Avchimovitch, 1992;Avchimovitch et al, 1988Avchimovitch et al, , 1993Clayton et al, 1977Clayton et al, , 1978Filipiak, 2004;Higgs et al, 2000;Maziane et al, 1999;Streel et al, 1987;and references therein), Australia (Playford & Satterthwait, 1986), Turkey (Higgs et al, 2002) and China (Guo et al, 2022;Liu et al, 2019;Peng et al, 2022;Wellman et al, 2012;Xu et al, 2022;and references therein).…”