Gastrochaenolites as Palaeoenvironmental Information Traps: The Case of the Tholos of La Pastora (Valencina de la Concepción, SW Spain)

ABSTRACTIn the Mio-Pliocene calcareous sandstone slabs used as capstones at La Pastora tholos in the Copper Age megasite of Valencina de la Concepción-Castilleja de Guzmán (SW Spain), marine bioerosion structures produced in the 3rd millennium BCE were recognised. In this work, we focus on the perforations made by the lithophage bivalve Petricola lithophaga, called Gastrochaenolites, specifically on its functionality as a ‘trap’ of sediment of the environment where they were produced and of which there are no observable outcrops. The microfaunal content consisting of planktonic and benthic foraminifera as well as ostracods was studied. It was possible to infer the palaeoenvironmental conditions of the place where the slabs were quarried, c. 4700–4600 years ago, which correspond to a wide marine bay. The presence of benthic foraminifera like Astrononium stelligerum, Elphidum crispum, Ammonia beccarii and ostracods like Loxoconcha elliptica and Cytherois fischeri implies that the sector of the bay had a water temperature of no more than 20°C, a bathymetry between 0 and 25 m of depth. Also, episodes of fluvial influence caused a variation in water salinity between 30 and 35‰, attested by the presence of euryhaline species of ostracods from low energy environments and clay substrates, thus confirming estuarine conditions.KEYWORDS: GastrochaenolitespalaeoenvironmentforaminiferaLa Pastora tholosbioerosion AcknowledgementsSpecial mention is made to Dr. Kamal Bradeshany of Durham University for his invaluable help and supervision in the materials laboratory of the Archaeology Department. The authors thank Salvador Ciaurriz and Francisco Sánchez Díaz for the illustrations.Disclosure StatementNo potential conflict of interest was reported by the author(s).Data Availability StatementThe data that support the findings of this study are available from the corresponding author upon reasonable request.Additional informationNotes on contributorsSamuel Ramírez-Cruzado Aguilar-GalindoSamuel Ramírez-Cruzado Aguilar-Galindo is a PhD student at the University of Sevilla. His thesis is about Geoarchaeology focusing on prehistoric sites. he try to study archaeological sites from the point of view of geology. he did him Geology degree at the University of Huelva and then my Archaeology masters in the University of Sevilla.Fernando Muñiz GuineaFernando Muñiz Guinea is a lecturer in Geology at the University of Sevilla (Spain). his current research centres in Ichnology, Taphonomy and Invertebrate paleontology.Francisco Ruiz MuñozFrancisco Ruiz Muñoz is a Full Professor in Paleontology at the University of Huelva (Spain). His current research focuses on Tsunami, Environment, Heavy Metal Pollution and Ostracoda.Maria Luz González-RegaladoMaría Luz González-Regalado is a professor in Paleontology at the University of Huelva (Spain). He is currently work at the Departamento de Ciencias de la Tierra, Universidad de Huelva. He do research in Paleontology. Their current project is 'Geoarchaeology of Huelva Estuary, SW Spain: Morphosedimentary evolution and peopling'. My interests are Micropaleontology, Palaeoecology and Estuaries.Juan Manuel Vargas JímenezJuan Manuel Vargas Jiménez held the post of Municipal Archaelogist of Valencina de la Concepción (Seville) and Director-Curator of the Museum of Valencina de la Concepción.Doctor of the Prehistory program of the University of Seville with which I obtained the Excellent Cum Laude qualification unanimously with mention of Industrial Doctorate for the applied research project with direct knowledge transfer to the heritage protection, conservation and difussion. he have a wide experience in archaelogical heritage management, having carried out analysis and planning work related to protección, land distribution and town planning. he directed more than thirty archaelogical interventions, covering the cronological arc from the Modern Age to Prehistory. In terms of research, it collaborates with different institutions and professionals, in projects that concern the archaeological site of Valencina, in the case of the Universities of Seville, Huelva or the German Archaeological Institute.Marta Díaz-GuardaminoMarta Díaz-Guardamino is Assistant Professor in Archaeology, the Digital Visualization Lab Manager, and the Visual and Material Culture RIG lead. Before joining Durham in 2018, she was Lecturer in Archaeology at Cardiff University, where she convened and taught modules on the European and British Neolithic, archaeological theory and Geographical Information Systems. Here at Durham, she teach mainly on British, Iberian, European and World prehistory (Neolithic to Bronze Age), and digital visualization techniques. My research specialism focuses on late prehistoric connectivity, social relations, monuments and art in Atlantic Europe (5th-1st millennia BC.Leonardo García SanjuánLeonardo García Sanjuán is a Full Professor in Prehistory at the University of Sevilla (Spain). he started my academic career as a pre-doctoral research fellow at that same university (1991-1996) and then he worked as a European Commission Marie Curie Program post-doctoral research fellow at the University of Southampton, UK (1997-1998), and as a Lecturer in Archaeology at the University of Bradford, UK (1999-2000). Since 2000 he work at the University of Sevilla, where he coordinate the ATLAS Research Group (HUM-694). his current research centres on a number of themes, including early social complexity, burial practices, megalithic monuments and prehistoric landscapes, with a focus on Late Neolithic, Copper Age and Bronze Age Iberia. Over the years he have also become interested in other topics such as rare rocks, exotic materials, radiocarbon dating and stelae.Teodosio Donaire RomeroTeodosio Donaire Romero is a Lecturer in Geology at the University of Huelva (Spain). His research focuses on Petrology, Geochemistry, Geochemical Modeling and Petrography among others.Joaquin Rodríguez-VidalJoaquín Rodríguez Vidal is a Full Professor in Geology at the University of Huelva (Spain). he teach Geodynamics and Geomorphology. My research centres on a number of themes, including Paleoclimatology, Sedimentology, Quaternary Geology, Coastal Geomorphology, Pleistocene, Neanderthals, Geoarchaeology, Micromorphology, Speleology.Luis Miguel Cáceres PuroLuis Miguel Cáceres Puro is a Full Professor in Geology at the University of Huelva (Spain). His main interest are Coastal Geomorphology, Geomorphology, Quaternary Geology and Coastal Processes.