Guía de campo pre-congreso, 17-18 de Octubre de 2019: Ediacárico, Paleozoico Inferior y panorámicas en el Geoparque de la UNESCO Villuercas-Ibores-Jara

Abstract

Several stratigraphic units characteristic of the Ediacaran-Cambrian transition between Guadalupe and Castañar de Ibor, north of the Villuercas-Ibores-Jara Geopark (Cáceres), are described and illustrated here. The outcrops of (i) the Castañar and Villarta formations (Ibor Group, terminal Ediacaran and Terreneuvian), together with their content in vendotaenids, sabelliditids and microbial reefs with Cloudina; and (ii) the San Lorenzo Formation (Terreneuvian) and its palaeoichnological content, are detailed. Finally, the palaeoichnological record of the Armorican Quartzite (Lower Ordovician), mainly of Cruziana and Daedalus, which characterize some sites of geological interest (geosites) in the Geopark, are highlighted.

Were the First Trace Fossils Really Burrows or Could They Have Been Made by Sediment-Displacive Chemosymbiotic Organisms?

“…The record of the end of the Ediacaran and the Cambrian explosion of animal life include examples of Ediacaran survivors in Cambrian rocks (e.g. Swarpuntia Jensen et al 1998;Hagadorn & Waggoner 2000), and also evidence of putative Cambrian type trace fossils below the recognized Ediacaran Cambrian boundary (Gehling et al 2001;Högström et al 2013;Jensen et al 2019;Jensen et al 2000). It is to this latter transition, from the matground dominated Ediacaran to the macroscopically bioturbated Cambrian (McIlroy & Logan 1999;, that our attention is drawn herein.…”