Search

The La Janda wetland record allows to expand the knowledge of the evolution of a restricted estuary since the Last Glacial Maximum. Multiproxy analysis of the sediments (facies, geochemistry, pollen, fossils) reveals that this system exhibits a classic incised valley sequence but differences with the adjacent estuaries can be established. The La Janda sedimentary infill can be split in four main sequences: (1) the Falling Stage Systems Tract (>20.6 ka BP) and (2) the Lowstand Systems Tract (16.7–20.6 ka BP) deposits record fluvial sedimentation in a narrow and incised valley, here seminally identified in the Gulf of Cádiz estuarine system; and (3) the Transgressive Systems Tract (7–16.7 ka BP), ending with the Holocene marine flooding surface at 7 ka BP, is composed of estuarine and marine basin deposits infilling a still steep and narrow topography coupled with the fast retreat of the river mouths. The (4) Highstand Systems Tract (0–7 ka BP) is composed of estuarine basin deposits with fluvial and tidal currents deposits in a wide a gentle sloped estuarine valley and it records the transformation of the basin into a terrestrial one. Comparison to other areas in the Gulf of Cádiz allows to correlate the different estuaries and to distinguish between open and restricted ones by the development of spit systems during the Highstand Systems Tract. But further work is needed to clarify the stratigraphy of the present eustatic cycle in the Gulf of Cádiz as the scarcity of data does not allow to determine the evolution of its estuaries during the last fall and rise of sea level. Such knowledge is crucial to disentangle the role of climate and tectonics in the future evolution of our coasts and design measures to adapt to sea level rise.

Over the past decades, substantial progress has been made in tsunami research. Be that as it may, little is still known about tsunami deposits and their related depositional mechanisms in coastal areas in historical and archaeological contexts. In particular, the Phoenician, Greek and Roman trade and military networks along the Mediterranean and Atlantic coasts, with their cities, harbours and additional facilities, are susceptible to serving as archives for extreme wave events. The ruins of the Roman city of Baelo Claudia, located on the Bay of Bolonia Bay (southern Spain), offer a unique environment for studying historical tsunamis in the Gulf of Cadiz. Baelo Claudia suffered at least two earthquakes in Roman times, namely, in the first and fourth centuries CE. The latter, associated with a tsunami, led to the city’s destruction and subsequent decline. Accordingly, three tsunami deposits in Baelo Claudia, dated to ca. 4000 cal BP (2000 BCE), ca. 400 CE and 1755 CE, the last corresponding to the Lisbon tsunami, are described here. The multi-disciplinary research conducted on the sedimentary, archaeological and palaeontological records has revealed event deposits, together with major landscape changes in the environs of the bay after tsunami landfall. Furthermore, the significant archaeoseismic damage detected in recently excavated buildings has been dated to the end of the fourth-century CE. The results presented here serve to supplement the earthquake and tsunami record of coastal Iberia., The authors are grateful to German Science Foundation (DFG grant, RE 1361/28-1) and the MINECO-FEDER Spanish Research Project CGL2015-67169-P (QTECSPAIN-USAL) for their support.

Palynological record is affected by several factors, such as taphonomic processes, which could cause a bias of the pollen spectra. The study of these processes occurring on archaeological deposits could provide insight into formation and sedimentation conditions, but also into anthropogenic activities. Based on these hypotheses, we have analyzed the taphonomic features of the pollen record on sediments collected from the layer M of the Abric Romani archaeological site (40–110 ka BP), which is characterized by a high temporal resolution. Four kinds of taphonomic alterations were identified in pollen and spores: thermal alteration, fracturing, compaction, and corrosion. Palynological concentrations and the presence of microcharcoal particles have been also registered. Regarding the different origins and spatial location of the samples, we intend to establish a connection between the pollen preservation degree and the diversity of processes occurring at the site. In light of the sedimentological history of the archaeological site and the fact that layer M has been considered a palimpsest of great complexity, palynological results seem to show the existence of different depositional events. Considering the relationship between the identified alterations, it seems that thermal alteration would be linked to biostratinomic processes, while fracturing, corrosion, and compaction damages could derive from the fossil-diagenetic phase.

Tsunamis and other extreme wave events draw a severe threat to coastal populations today and in historic times. The ancient settlement of Cerro del Villar located in present-day Málaga, southern Spain, was built by Phoenicians around the second quarter of the 8th century BCE on a small sand bar (island) in the wide estuary of the Guadalhorce River. Later, the sand bar connected to the southern river bank and alluvial plane. Due to the low height above mean sea level, the site has been prone to river floodings, as well as extreme wave events of the Mediterranean Sea. In order to understand the palaeoenvironmental evolution and settlement history, as well as its vulnerability, it is important to analyse the nature of the events by dating and interpretation of the sedimentary record.Here, we present first results of a short field campaign carried out in October 2019 at the western end of the Guadalhorce River palaeo-estuary, outside the boundaries of the archaeological zone. Two sediment cores (MAL-CV-1; ca. 3.70 m length and MAL-CV-2, ca. 4.69 m) were drilled southwest of the Phoenician site. A total of eight non-invasive ground-penetrating radar (GPR) profiles were carried out in the surroundings of the cores, and additional GPR profiles close to the beach were taken to understand the changes in the depositional environment along the coast. The cores cover a stratigraphy of three different sediment units: a basal sand unit representing a palaeo-beach, followed by a large silt and clay unit developed in a lagoon environment, and topped by another silt and clay unit representing floodplain conditions. At MAL-CV-1 two possible high-energy event units (Ey and Ez) interrupt the low-energy silt and clay units. At MAL-CV-2 event unit Ey is preserved as well, the other event unit Ez is concealed by an anthropogenic unit rich in ceramic, brick and glass fragments. GPR profiles show the same stratigraphy and allow a lateral continuation of the different units and event deposits. With the help of these GPR profiles, event unit Ez can be traced in-between the anthropogenic unit of MAL-CV-2. In terms of chronology, two radiocarbon dates establish the transition between the basal palaeo-beach and the lagoon at 4352-4325 cal. BC (6274-6301 cal. BP) and the anthropogenic layer to be younger than 2201-2126 cal. BC (4075-4150 cal. BP). The establishment of coastal freshwater lagoons with plentiful Hydrobia gastropods and ostracods resembles the last stage of post-glacial sea level rise in the Mediterranean. In the future, these promising first results will be extended by additional radiocarbon dates and a palynological study to better understand the climate and palaeoenvironmental evolution.

12th International Symposium on Knappable Materials, ISKM 12, Budapest, Hungary, 20 Nov 2019 - 24 Nov 2019; Journal of Lithic studies 8(2), (2021). doi:10.2218/jls.6546 special issue: "Proceedings of the 12th International Symposium on Knappable Materials, Budapest", Published by University of Edinburgh, Edinburgh

Climate change and sea level variation during the Quaternary shaped the southernmost Santa Catarina's Coastal Plain and its landscape, promoting vegetation changes and different geomorphological features that resulted in the formation of sand barriers, relocation of fluvial channels, lagoons and rivers. In this context, prehistoric occupation of the territory took place through different migratory events over the Holocene. This study presents a palaeoenvironmental reconstruction of the last 8000 years BP, based on pollen analysis from the core collected in Campo Mãe Luzia natural deposit (Araranguá municipality, SC, Brazil). The palynological, sedimentary, chronological and altimetric records were integrated with a revision of the archaeological data, allowing for the contextualization of the different groups within each environmental phase. Three distinct palaeoenvironmental phases are suggested for the last 8000 years BP: Phase I, characterized as an estuarine-lagoon environment, with no reports of human occupation; Phase II, a transition between the lagoon environment and the gradual formation of a coastal swamp, followed by an expansion of the sandy coastal barrier; Phase III, characterized by Atlantic rain forest development and their colonization. Human occupation was registered in the last two phases, with settlements of hunter-gatherer groups, sambaquis builders, and Meridional Jê and Guarani groups. This research is linked to the research project “Arqueologia Entre Rios do Urussanga ao Mampituba”, it was developed by the Research Group in Archeology and Integrated Management of Territory of the Universidade do Extremo Sul Catarinense (UNESC). It was supported by the Universidade do Extremo Sul Catarinense (UNESC) through the projects 01510.001172/2011-74 (IPHAN) and 455865/2014-2 (CNPq), and by the Instituto de Geociências of the Universidade Federal de Rio Grande do Sul (UFRGS), through the project 454804/2014-8 (CNPq). We thank to the Laboratório de Palinologia Marleni Marques Toigo (UFRGS) and to the Laboratório de Interação Animal-Planta (UNESC) for their collaboration in different steps of the research. This paper profited from helpful comments by Paulo DeBlasis and Jedson Cerezer. info:eu-repo/semantics/publishedVersion

In AD 1755 a strong earthquake-generated tsunami destroyed large parts of the southwest Iberian coastline. Data for the study of the sedimentological characteristics and palaeo-ecological effects of the backwash of this well-known AD 1755 Lisbon tsunami and possible preceding events on the continental shelf was obtained during RV METEOR cruise M152 in November 2018, since the hydrodynamics of tsunami backwash currents are as yet poorly understood. Furthermore, the suitability of the shelf as a reliable sedimentary archive for tsunami deposits was investigated.Along the Algarve coast, prominent AD 1755 Lisbon tsunami deposits have been detected onshore for quite some time. Cruise M152 conducted a geophysical survey on the corresponding shelf area to obtain bathymetry and sub-bottom profiles for the recognition of depositional basins. Subsequently, 19 sediment cores were retrieved from the most suitable depositional basins by vibracoring at water depths from 65 to 114 m. The cores were analysed in a multiproxy approach (granulometry, magnetic susceptibility, P-wave velocities, organic and inorganic geochemistry, micropalaeontology). Deposits of the AD 1755 Lisbon tsunami were identified in most of the cores as a thin layer at ca. 20 cm depth.More surprisingly, a second event deposit dating to ca. 3700 years cal. BP was detected at core depths of 122 to 155 cm. It is even traceable in the sub-bottom profiles and consists of a distinctive ca. 30 cm thick well sorted medium-sized siliciclastic sand. Due to the thickness of the deposit an in-depth study of its characteristics was possible. It displays an erosive basal contact followed by a thin matrix-poor shell hash layer, a reversely graded fine sand layer and ultimately a massive, quite homogeneous medium sand resembling the Ta division of the Bouma sequence or the S1, S2 and S3 divisions of the Lowe sequence. The deposit is distinguishable from the silt to silty sand-dominated background sedimentation not only due to the textural and compositional features, but also due to contrasting geophysical and geochemical properties. Terrestrial provenance for (at least parts of) the sediment is revealed by biomarker analysis. Based on these characteristics, the deposit is interpreted as the result of a high density hyperpycnal flow from the coast towards the offshore caused by tsunami backwash. This event layer may be correlated to onshore observations of tsunami deposits along the southwest coast of Spain but has never been identified in Portugal where the onshore record of tsunami deposits only covers the last three millennia.The results of this multiproxy analysis strongly suggest the shallow offshore area below storm wave base to host reliable sedimentary archives for tsunami backwash deposits, which allow the discovery of as yet unknown events. Palaeotsunami research can benefit from the investigation of offshore archives, especially where onshore records are incomplete or sparse.

The southwest of the Iberian peninsula is, due to its border position between Africa and Europe, a key territory of major geoarchaeological interest, as well as a reservoir of biodiversity and a wildlife refuge area during the Holocene. Bioclimatic conditions have been significantly unstable during this period in the Western Mediterranean. Therefore, further studies are still required to understand how abrupt climate changes such as the 8.2 and 4.2 ka cal BP events impacted societies and environment. In November 2018 the RV Meteor cruise M-152 retrieved 19 vibracores and 4 gravity cores along the Algarve coast after mapping the bathymetry. One of these cores, GeoB23519-01, was taken 65 m below present sea level and recovered 365 cm of sediment. Four potential event layers were identified over the last 11 ka cal BP and, at least two of them, are related to tsunami deposits (ca. 4370 cal BP and AD 1755). This sedimentary archive was analysed in a multi-proxy approach, including palynological and micropalaeontological analyses, which allow characterizing palaeoenvironmental changes along the core. However, considering the characteristics of these deposits, we raise questions about how complex this palynological record is and how it mirrors some short-term events, climate dynamics, and cultural disruptions.