Coastal Archaeological Sites Research Articles

The potentials and limitations of two taxa of terrestrial snails (polygyra spp. And euglandina rosea) as a source material for the radiocarbon dating of indigenous shell mounds and middens in florida, usa

Preferred materials for radiocarbon dating are often rare on coastal archaeological sites, leading many archaeologists to date more common and abundant marine shells. But marine shell is often difficult to reliably radiocarbon date owing to the effects of the marine reservoir effect, especially where local environmental factors such as hardwater and limestone substrates complicate corrections. Terrestrial gastropods provide a potential alternative material for radiocarbon dating, although they are variably impacted by the same environmental factors and thus require testing to determine their reliability for dating archaeological deposits. We compare radiocarbon dating results from paired archaeological samples of wood charcoal and Odocoileus virginianus (white-tailed deer) bone with the shells of two terrestrial snail taxa—Polygyra spp. (flat coil snails) and Euglandina rosea (rosy wolf snails)—from the Cockroach Key archaeological site, in Tampa Bay, an open-water estuary on the western coast of the Florida Peninsula, USA. In one-third of the total 12 pairings, we found no statistically significant difference at the 95% probability level. For the other pairings, differences between snail shell dates and the reference dates ranged from decades to several centuries. Overall, our results suggest that both taxa have the potential to yield reliable radiocarbon dates, although not without complications.

Early Stages of Metal Corrosion in Coastal Archaeological Sites: Effects of Chemical Composition in Silver and Copper Alloys.

In this study, metal disks with different chemical composition (two Ag-based alloys and three Cu-based alloys) were buried in the soil of coastal archaeological sites for a period of 15 years. The aim was to naturally induce the growth of corrosion patinas to obtain a deeper insight into the role of alloying elements in the formation of the patinas and into the degradation mechanisms occurring in the very early stages of burial. To reach the aim, the morphological, compositional and structural features of the patinas grown over 15 years were extensively characterized by optical microscopy, field emission scanning electron microscopy coupled with energy dispersive spectrometry, X-ray diffraction and micro-Raman spectroscopy. Results showed that the Cu amount in Ag-based alloys strongly affected the final appearance, as well as the composition and structure of the patinas. Corrosion mechanisms typical of archaeological finds, such as the selective dissolution of Cu, Pb and Zn and internal oxidation of Sn, occurred in the Cu-based alloys, even if areas enriched in Zn and Pb compounds were also detected and attributed to an early stage of degradation. In addition, some unusual and rare compounds were detected in the patinas developed on the Cu-based disks.

Holocene Crab Consumption at Watinglo, Papua New Guinea

Malacostraca are commonly found in coastal archaeological sites in the Indo-Pacific; both swimming and terrestrial crabs. This archaeological evidence as well as ethnographic studies indicate that they formed an important component of the human diet in the past as they still do in many regions today. However, they often go unidentified and largely unanalysed in archaeological research due to the highly fragmentary state of the remains and the associated difficulties posed for identification and quantification. Here we discuss these issues and provide an example of crab remains recovered from a coastal archaeological site in Papua New Guinea, Watinglo shelter, with an occupation record spanning from the Terminal Pleistocene to historic times. We also briefly compare these finding to crab remains from archaeological sites of similar antiquity in Indonesia and the Philippines.

Coastal archaeological site visibility problems and underwater prospects in the Northern Lake Superior Basin

AbstractThe early to middle Holocene was marked by considerable variability in lake levels in the Lake Superior Basin due to a combination of meltwater runoff, isostatic adjustment, shifting glacial margins, and climate change. These processes likely had a large impact on the preservation and visibility of coastal archaeological sites dating from the Early Period (Paleoindian) to the Middle Period (Shield Archaic). Of particular interest is the brief interval after 9300 cal. B.P. when ancestral Lake Superior dropped to its lowest level (Houghton) and human populations may have made incursions deeper into the basin. Elsewhere in the Upper Great Lakes, this period is associated with offshore archaeological sites submerged by rising water levels later in the Holocene. New geological data from the Thunder Bay, ON, region yield exceptional insight into the paleohydrology of the Houghton phase and, hence, the underwater archaeological prospects of this low water phase in the northern Lake Superior Basin. These data indicate that the lake reached its lowest level by at least ~9100 cal. B.P. but was highly unstable, at least initially, due to a combination of climate and meltwater runoff. Early underwater sites may be confined to two short, hydrologically closed, lowstands between ~9100 and 8700 cal. B.P. and would have been impacted by at least one lake transgression. Such sites, however, may still hold better potential for organic preservation and the visibility of large cultural features compared to their terrestrial counterparts. Coastal sites occupied when the lake was hydrologically closed may be especially well‐preserved due to rapid inundation before the gradual, and generally erosional, Nipissing transgression occurred.

Archaeology of Australia’s coastline: The role of geomorphology in the visibility and preservation of archaeological deposits on sandy shores, with a Gippsland case study

In Australia as elsewhere in the world, coastal archaeological sites are increasingly threatened by rising seas and changing storm patterns, along with encroaching human activities. Understanding the geomorphological context is key to understanding the positioning of archaeological deposits in or on coastal landforms, their vulnerability to erosion and their resilience and capacity for longer-term management and preservation. Here we review the dynamics of beach-barrier systems to contextualise the potential of archaeological deposits to survive erosional processes, especially those associated with current and anticipated impacts of climate change. In doing so, we outline a practical logic for zoning coastal landforms and processes by their proclivity to either erode or preserve archaeological deposits, to assist in the planning of management agendas. It is the sediment budgets and how they change in relation to variation in sea level that fundamentally determine the potential preservation of archaeological deposits in coastal beach-barrier environments. We advocate close transdisciplinary collaboration between archaeology, geomorphology and site managers (i.e. Traditional Owners and land-and-sea management agencies) to better understand the wider landscape dynamics of coastal archaeological sites and landscapes.

Risks and destruction of coastal archaeological sites in Algeria – the case of the coast of El Hamdania

Abstract The Algerian coast is rich in cultural heritage. Many major historical cities and archaeological remains are scattered along its coastline. This cultural heritage is increasingly threatened by the rapid urbanisation that Algeria has experienced in recent years. In 2018 the area of El Hamdania (Cherchell region) was selected as the site of a new commercial mega port. This large construction project will affect a number of archaeological sites located in this region. This paper aims to highlight the archaeological importance of the El Hamdania region and assesses the risks of such a construction to the heritage of the region. The archaeological evidence discussed is based on survey work carried out by members of the Laboratoire d’Études Historiques et Archéologiques (LEHA), an institution that carries out research projects on coastal and maritime archaeology in Algeria.

Inundation risk assessment of Eastern Mediterranean Coastal archaeological and historical sites of Türkiye and Greece.

Archaeological and historical sites, including World Heritage Sites, archaeological sites, castles, fortresses, towers, bridges, necropolises, and ruins, which are a shared legacy of humanity, are at risk of inundation due to sea level rise resulting from global climate change and increased carbon emissions, much like settlements, transportation systems, agricultural areas, and animal habitats. These locations are significant hot spots for connecting the past to the present regarding human history. Throughout history, settlements have been established around wetlands and shorelines. For this reason, the most significant danger threatening coastal archaeological and historical sites is the risk of inundation due to sea level rise. Creating an inundation risk map could be beneficial for planning and conservation studies due to reasons such as the long duration of archaeological studies, lack of a qualified workforce, and budget constraints. To this end, inundation risk maps were created for five different scenarios with risk classes varying from very high to very low, considering global and local sea level rise predictions. The study evaluated 464 historic areas located on the Eastern Mediterranean coasts of Türkiye and Greece. The findings indicate that a significant number of archaeological and historical sites, such as Knidos and Delos, will be inundated even in the lowest sea level rise scenarios. According to the inundation risk map, 34 sites are at very high risk, 21 at high risk, 25 at medium risk, 26 at low risk, and 41 at very low risk of inundation.

Late Roman–Early Byzantine Leukos settlement, Karpathos, Greece: Geoarchaeology, archeoseismology, and paleogeography

AbstractThis archeoseismologic study focuses on the Leukos settlement that thrived on the west coast of the forearc island of Karpathos in the 4th−6th centuries CE. The onshore site occupies the eastern rim of the offshore Karpathos Basin, the deepest Aegean basin, in a sector of the Hellenic forearc typically regarded as seismically insignificant. Investigations of faulting, sedimentary processes, and secondary earthquake effects (hydraulic fracturing, liquefaction, tilting, landslides) are integrated with observations of previously surveyed and newly discovered archeological remains to appraise syn‐ to post‐Early Byzantine seismicity and establish a sequence of faulting. Calibrated radiocarbon dates, the first from Karpathos, indicate intermittent faulting and seismicity spanning the 4th−10th centuries CE, likely contributing to the early 7th‐century CE abandonment of Leukos. The coseismic rupture of competent cobbles whose fractures are filled with fluidized sediment is an established paleoseismologic tool for recognizing earthquakes of magnitude Mw ≥ 6; this study extends that criterion to archeoseismology. This study underscores the need to evaluate land movements, sea‐level fluctuations, and shoreline migration for coastal archeological sites. A plausible Late Roman paleogeography emerges in which Leukos occupied a contiguous peninsula rather than surrounding three modern harbors. This study encourages re‐evaluation of seismic and tsunami hazards in the sector of the Hellenic forearc surrounding ancient Leukos and the Karpathos Basin.

Tracking the effects of the long‐term changes on the coastal archaeological sites of the Mediterranean using remote sensing data: The case study from the northern shoreline of Nile Delta of Egypt

AbstractClimate change effects along with anthropogenic activities present the main factors that threaten the existence of heritage sites across the north Nile Delta of Egypt close to the coastline of the Mediterranean Sea. Observing the changes in the landscape close to the archaeological sites is an important issue for decision‐makers in terms of reducing the negative impact of natural events and human activities. The coastal heritage sites are becoming strongly threatened by the rising sea level phenomena that will happen due to global warming. Focusing on the distribution of the archaeological sites, this study aims to detect the areas at risk of shoreline erosion or accretion in the northern shoreline of the Nile Delta. In this study, the changes in the northern shoreline of the Nile Delta were observed and calculated during the last hundred years based on the integration between the old topographic maps from surveys in 1900, 1925 and 1945, optical satellite images captured by Landsat in 1972, 1986 and 2000; Sentinel2 2021; and the Radar SRTM data. The results of this study showed that the changes were enormous with a great shoreline erosion process over the last 121 years recorded along the shoreline in the periods between 1900–1925, 1925–1945, 1945–1972, 1972–1986, 1986–2000 and 2000–2021. The areas eroded were about 5.3, 4.7, 5.6, 8.9, 2.5 and 5.4 km2, respectively. Such negative movements caused the loss of two heritage sites, and the expected changes will lead to the loss of additional heritage sites in the next 500 years. Furthermore, a model was suggested for protecting the coastal heritage sites threatened by the risk of submergence. This study can help the decision‐makers to detect the coastal archaeological sites at risk and create innovative solutions for protecting these irreplaceable heritage sites.

Ornament, Weapon, or Tool? Microwear Analysis of Shark Teeth from the Rio Do Meio Site in Florianópolis, Brazil

AbstractShark remains are common in coastal archaeological sites in southern Brazil. Here we present an analysis of microwear visible on shark teeth found at the Rio do Meio site in Florianópolis, Brazil. It demonstrates that hafted shark teeth were used to work soft materials such as leather, as well as semihard materials such as wood and bone, whereas others probably functioned as arrowheads. The results also show a possible preference for tiger shark teeth use for woodworking. The identified technical motions include piercing, cutting, and scraping, as well as scaling and sawing. These findings allow us to question the common interpretation of shark teeth use as ornaments and as having symbolic value. Instead, shark teeth seem to have been used as tools and weapons in daily life.

When the Land Sings: Reconstructing Prehistoric Environments Using Evidence from Quaternary Geology and Geomorphology, with Examples Drawn from Fluvial Environments in the Nile and Son Valleys

Geomorphic evidence from rivers and lakes can help explain past changes in the locations of archaeological sites as well as environmental and climatic changes in their catchment areas. Examples drawn from the Blue and White Nile valleys in northeast Africa and from the Son and Belan valleys in north-central India reveal how Quaternary climatic fluctuations in the headwaters of these rivers are reflected in changes in river channel patterns downstream as well as in the type of sediment transported. Soils and sediments that contain prehistoric and historic artefacts can be analysed to show the type of environment in which the artefacts accumulated. Beds of volcanic ash may preserve former landscapes and their fossil remains and can provide a synchronous time marker against which to assess changes in the archaeological record. The pattern and tempo of past sea level fluctuations has controlled the distribution of coastal archaeological sites and helps to explain the absence of certain Holocene Neolithic sites in southeast Asia. Disturbance of archaeological sites by plants and animals, especially termites in tropical regions, can affect the stratigraphic and chronological integrity of the site.

The tempest: Geoarchaeological examinations of tropical cycle/hurricane signatures in a submerged, formerly coastal shell midden site, Econfina Channel, Florida, U.S.A.

The nature of preservation potential for submerged cultural landscapes on continental shelves remains varied and not easily defined. This is due to two factors: First, relatively few sites have been discovered offshore, creating a small sample size. Second, excavation and analysis of such submerged sites have only begun to mature during the past few decades. We present here results from an exploratory study of one such site that examines impacts from two tropical cyclone systems in successive years. The main feature of this site is a specific type of archaeological feature: a shell midden. These sites are excellent indicators for coastal occupations globally and can retain evidence for major developments in cultural evolution, including reactions to climate change and sea-level rise from the Pleistocene into the Holocene. Further, they are found worldwide. The degree to which middens have been impacted by past and present marine forces, including tropical cyclones, is a key factor in their potential to preserve such evidence. We used a geoarchaeological methodology that quantifies particle size fractions from sediments taken from various zones within the site to compare them before and after each storm. Results have significant implications for preservation of submerged, formerly coastal archaeological sites globally.

A palaeothermometer of ancient Indigenous fisheries reveals increases in mean temperature of the catch over five millennia

Climate change is altering the distribution and composition of marine fish populations globally, which presents substantial risks to the social and economic well-being of humanity. While deriving long-term climatic baselines is an essential step for detecting and attributing the magnitude of climate change and its impacts, these baselines tend to be limited to historical datasets and palaeoecological sediment records. Here, we develop a method for estimating the ‘ancient Mean Temperature of the Catch’ (aMTC) using Indigenous fisheries catch records from two archaeological sites in the northeast Pacific. Despite different catch compositions, we observe an increase in aMTC over a 5,000-year period at two contemporaneously occupied archaeological sites in southwestern British Columbia, Canada. We document cooler catches from 5,000 to 3,000 cal yr BP and comparatively warmer catches from 1,800 to 250 cal yr BP. These warmer temperatures are broadly consistent with palaeoceanographic sea surface temperature proxies from British Columbia and Alaska. Because this method requires converting measures of fish bones into estimates of fish size structure, abundance, biomass, and finally aMTC, opportunities exist to account for both variation and uncertainty at every step. Nevertheless, given that preindustrial fisheries data are ubiquitous in coastal archaeological sites, this method has the potential to be applied globally to broaden the temporal and geographic scale of ocean temperature baselines.

Impacts of climate change on coastal archaeological sites in County Kerry, Ireland

This paper deals with the effects of climate change on coastal heritage sites located on the south west coast of Ireland. The three case studies discussed below are National Monument sites in State care. The Office of Public Works (OPW) is responsible for their day-to-day maintenance and conservation. The sites used as case studies are Dunbeg Promontory Fort, Skellig Michael and Ballinskelligs Priory. Climate change has been affecting these sites and causing damage to their historic fabric. The OPW has taken mitigating measures to reduce the impact of climate change on these sites and protect their architectural, archaeological and natural features.

The potential impact of rising sea levels on China's coastal cultural heritage: a GIS risk assessment

Without rapid international action to curb greenhouse gas emissions, climate scientists have predicted catastrophic sea-level rise by 2100. Globally, archaeologists are documenting the effects of sea-level rise on coastal cultural heritage. Here, the authors model the impact of 1m, 2m and 5m sea-level rise on China's coastal archaeological sites using data from the Atlas of Chinese Cultural Relics and Shanghai City's Third National Survey of Cultural Relics. Although the resulting number of endangered sites is large, the authors argue that these represent only a fraction of those actually at risk, and they issue a call to mitigate the direct and indirect effects of rising sea levels.

Volcanic ash, victims, and tsunami debris from the Late Bronze Age Thera eruption discovered at Çeşme-Bağlararası (Turkey)

The Late Bronze Age Thera eruption was one of the largest natural disasters witnessed in human history. Its impact, consequences, and timing have dominated the discourse of ancient Mediterranean studies for nearly a century. Despite the eruption's high intensity (Volcanic Explosivity Index 7; Dense Rock Equivalent of 78 to 86 km) [T. H. Druitt, F. W. McCoy, G. E. Vougioukalakis, Elements 15, 185-190 (2019)] and tsunami-generating capabilities [K. Minoura etal., Geology 28, 59-62 (2000)], few tsunami deposits are reported. In contrast, descriptions of pumice, ash, and tephra deposits are widely published. This mismatch may be an artifact of interpretive capabilities, given how rapidly tsunami sedimentology has advanced in recent years. A well-preserved volcanic ash layer and chaotic destruction horizon were identified in stratified deposits at Çeşme-Bağlararası, a western Anatolian/Aegean coastal archaeological site. To interpret these deposits, archaeological and sedimentological analysis (X-ray fluorescence spectroscopy instrumental neutron activation analysis, granulometry, micropaleontology, and radiocarbon dating) were performed. According to the results, the archaeological site was hit by a series of strong tsunamis that caused damage and erosion, leaving behind a thick layer of debris, distinguishable by its physical, biological, and chemical signature. An articulated human and dog skeleton discovered within the tsunami debris are in situ victims related to the Late Bronze Age Thera eruption event. Calibrated radiocarbon ages from well-constrained, short-lived organics from within the tsunami deposit constrain the event to no earlier than 1612 BCE. The deposit provides a time capsule that demonstrates the nature, enormity, and expansive geographic extent of this catastrophic event.

Holocene climate dynamics on the European scale: Insights from a coastal archaeological record from the temperate Bay of Biscay (SW France)

The main drivers of Europe's climate during the Holocene result from the coupling and interplay of external and internal radiative processes with the shifting patterns of many dynamic components (e.g. glaciers, ocean currents, wind fields, vegetation cover). Those driving forces were expressed across a range of geographical scales, from local to global, in a diverse set of records forming a patchwork of evidence as to the fundamental pacing effect of climate on past ecosystems. Various sedimentary deposits resulting from those complex forcing contexts bear climatic signatures that it is not always easy to disentangle especially with respect to local factors.The present paper focuses on a coastal archaeological site on the Medoc peninsula (the Lède du Gurp site in south-western France) that records Holocene palaeoenvironmental changes, decoded here century after century and integrated with ongoing events on a pan-North-Atlantic scale. Based on updated geoarchaeological approaches, thanks to new applications of proxies, especially X-ray fluorescence (XRF) core scanning methods for this article, continuous sedimentary records have been analysed in order to reconstruct a regional framework for past ecosystem events, including events potentially related to human activity. Our work identifies signals on various scales in the record under study, with both long- and short-term trends and local and global imprints, but all closely bound up with proximal North Atlantic Ocean dynamics. It highlights how western European environments (and so populations) were dependent upon the linearity of climate evolution at the key Northgrippian/Meghalayan transition.

Multi-proxy analysis of relative sea-level and paleoshoreline changes during the last 2300 years in the Campi Flegrei caldera, Southern Italy

This study aims to present new additional data regarding the relative sea-level (RSL) changes and the vertical ground movements (VGM) occurred in Campi Flegrei caldera since the Early Roman period (3rd century BC), commenting also on the accompanying changes of the coastal landscape and its implications in terms of human adaptation.The study area is located along the western sector of the Campi Flegrei caldera, one of the active volcanic systems of the Mediterranean region that started its activity more than 60 ka BP. Despite the human occupation of Campi Flegrei started not later than the Early Bronze Age (about 3.5 ka BP) and the earliest coastal settlements date back to the first Greek colonization of Southern Italy (ca. 800 BC), nowadays, the numerous coastal archaeological sites that are scattered in the studied area belong to the Roman period. The geoarchaeological interpretation of these remains allows detecting and dating of ancient positions of relative sea levels (RSLs), reconstructing of past coastal conformations, and measuring ancient VGM.The coastal sector between the modern Baia and Miseno was surveyed with a transdisciplinary and multi-proxy approach by means of direct and indirect methods, including, among others, paleo-environmental and archaeo-stratigraphic well logs analysis, geo-acoustic maps interpretation, and measurements of archaeological indicators of ancient sea levels.By comparing our measurement of RSL with the eustatic models of Peltier (2004) and Lambeck et al. (2011), the VGMs history of the coastal sector in the last 2300 years was reconstructed. Even if several volcano-tectonic oscillations were recorded, the obtained multi-proxy indications allow reconstructing two different behaviours in terms of vertical displacements: an overall subsiding trend affecting the area between the Early Roman period and the Middle Age, and a prevailing uplift after that period. The main coastal changes that occurred in the same period can be summarized in a coastal retreat ranging between 40 and 300 m, mainly due to the submersion of the pre-existing coastal area and leading to the submersion of villas, thermae, and other structures built on it. However, based on our measurements, the time span covered by the high-resolution data obtained from the three fish tanks here studied (60 BC – 12 AD) appears to be a period of volcano-tectonic stability, without significant VGMs.

Tracking turtles in the past: zooarchaeological evidence for human-turtle interactions in the ancient Eastern Mediterranean

Abstract

Relative sea‐level changes along the Fethiye coast (SW Turkey) based on recent archaeological data

AbstractWe investigated three coastal archaeological sites along the coast of Fethiye (south‐western Turkey, eastern Mediterranean) to reveal relative sea‐level changes that have occurred since early Byzantine times. Focusing on this little known period, the most recent archaeological data are presented here, providing new data for the history of sea‐level changes. Current elevations of submerged archaeological remains relative to present sea level were measured, and relative sea‐level change was determined, based on an approximation of the original elevation. The contemporary archaeological structures revealed three different sea levels in adjacent areas. Taking into account the time of the last use of the structures, instead of their time of construction, we suggest a relative sea‐level rise at a minimum rate of 1.6 ± 0.3 mm/year for Şövalye Island, 2.1 ± 0.3 mm/year for Gemiler Island, and 2.2 ± 0.6 mm/year for Ölüdeniz Lagoon for the last 1400 years. A comparison of the study results and geoarchaeological data from nearby sites on the western coasts of Fethiye Gulf revealed the degree of sea‐level change impact upon coastal archaeological sites. Results demonstrate that the seismically active Fethiye coast has been strongly influenced by the vertical tectonic movement since early Byzantine times.