Palaeoenvironmental Reconstruction Research Articles

Web Mapping and Real–Virtual Itineraries to Promote Feasible Archaeological and Environmental Tourism in Versilia (Italy)

The Versilia plain (NW Italy) experiences forms of tourism that are mainly limited to the beach area and concentrated in the summer season. The area is rich in cultural and natural heritage, not yet adequately enhanced. The presence of four local archaeological museums and a natural park offers a great opportunity to favour feasible archaeological and environmental tourism. The aim of this study is to use a holistic methodology to improve a different type of tourism in the study area. We propose a consilient multidisciplinary approach based on geological, biological and archaeological data in order to enhance the cultural and natural heritage of the Versilia plain. We have based our study on the reconstruction of palaeoenvironment maps showing the evolution of the territory and used them as a leitmotiv to link the archaeological museums and the natural park. We define real and virtual itineraries to create a synergy between the most important archaeological and natural sites and museums. It is possible to promote a different type of tourism in the study area by decreasing human impact and creating a relationship between the fragmented natural and archaeological heritage. Palaeoenvironment maps and real and virtual itineraries can be consulted with the aid of a web application, more specifically web mapping, developed with free and open-source libraries. The web mapping also contains other geological, geomorphological and archaeological datasets, which allow to understand the evolution of the environment and the cultural and natural heritage of the study area. The dataset available on the web mapping is also downloadable.

A bird assemblage across the MIS 9/8 boundary: The Middle Pleistocene of Galería (Atapuerca)

Quaternary faunal remains are key for the understanding of the effect of climatic changes on both animal and human populations. Here we show for the first time in Atapuerca the analysis of an avian assemblage through the MIS9/8 boundary, a moment of climatic deterioration that coincides with the spread of Neanderthals and the adoption of Levallois technology. A total of 603 bird remains belonging to 17 taxa have been identified in the Middle Pleistocene units GIII and GIV (Galería site, Atapuerca, Spain). The assemblage is dominated by the extinct raven Corvus corax antecorax, followed by other cave-dwelling taxa. The palaeoenvironmental reconstruction points to the presence of open landscapes and water bodies in the lower units. Both the number of remains and the taxa diversity decreases dramatically towards the upper unit. This general decreasing concurs with the beginning of the MIS8 stage, and it is observed in other faunal groups in Atapuerca, pointing to a MIS8 glacial stage in the Iberian Peninsula stronger than previously described.

A 87Sr/86Sr, δ18O and δ13C record of Turonian-Santonian belemnites from lower Volga region of the East European Platform: Stratigraphic significance and palaeoenvironmental reconstructions

We present the first strontium, carbon and oxygen isotope data on belemnites from the Upper Cretaceous (Turonian-Santonian) strata of the Lower Volga region, located between Saratov and Volgograd. The Sr-isotope evidence confirms the regional biostratigraphic data, indicating a deep erosion at the Coniacian-Santonian boundary, which suggests that some belemnitellid rostra from the lower Santonian so-called “Sponge horizon” of the Ozerki, Pudovkino and Mizino-Lipshinovka sections were redeposited from middle and upper Coniacian deposits and that the first representatives of the genus Belemnitella are thought to be late Coniacian in age. This study provides the first evidence of the Cenomanian-Coniacian Sr-isotope minimum from the East European (Russian) Platform, likely related to underwater Caribbean basaltic volcanism. New data suggest that the initial phase of Caribbean volcanism coincided with the temperature maximum and development of oceanic anoxic conditions (OAE 2), but the peak of the assumed volcanic activity in the late Turonian (90.8 Ma) was probably accompanied by a decrease in temperature and phytoplankton productivity. The problem of the regional Coniacian-Santonian oceanic anoxic event 3 (OAE 3) and global end-Cretaceous cooling is also touched upon.

The Hampole Discontinuity and Hampole Beds (Cadeby Formation, Upper Permian): deposition on the Zechstein English Shelf, South Yorkshire, UK, with data from new exposures

A review of the exposures in the Cadeby Formation, Upper Permian (Lopingian Series) in South Yorkshire by the Sheffield Area Geology Trust revealed groups of previously undescribed sites near the base of the Sprotborough Member, at, and just above, the Hampole Discontinuity. These sites indicate: a wider degree of palaeoenvironmental variation along the Hampole Discontinuity surface than was previously evident; that the discontinuity surface is not laterally continuous; and imply some caution is needed when using these exposures as marker horizons. The field data is used to inform a palaeoenvironmental reconstruction for the period of the Hampole regression. A complex of near-offshore pools and islands, an area of partly exposed shoal and lagoon, and an embayment are identified.

Palaeocene to Miocene southern Tethyan carbonate factories: A meta‐analysis of the successions of South‐western and Western Central Asia

AbstractOne hundred and forty‐four published successions of shallow‐water carbonates, deposited between the Palaeocene and the Miocene, from the Levant to the Himalayas, have been re‐analysed using a standardised approach to investigate the distribution of carbonate facies and carbonate‐producing organisms. Large benthic foraminifera were found to be the volumetrically most important group of carbonate producers during the whole period, with a peak in abundance during the Eocene. Colonial corals are relatively abundant during the Palaeocene and Miocene, their abundance peaks during the Oligocene and has a minimum during the Eocene. Red calcareous algae have a similar pattern although their peak in abundance covers both the Oligocene and Miocene. Green calcareous algae decrease from the Palaeocene onward. Facies related to very shallow and/or restricted marine conditions peak during the Miocene and in particular during the Aquitanian. Both the pattern of large benthic foraminifera and of colonial corals seems to be related to temperature, with warm periods favouring the former group and cool periods the latter group. Red calcareous algae display a pattern similar to that of colonial corals suggesting that the periods favourable for one group are, on a large scale, also favourable for the other. The progressive decrease of green calcareous alga could be tentatively related to a preservation bias connected to the transition from Palaeogene assemblages that included presumably calcitic taxa of green algae to Neogene assemblages entirely constituted by aragonitic taxa with limited preservation potential. The Aquitanian peak in facies related to very shallow and/or restricted marine conditions is most likely connected to the progressive narrowing of the Tethys related to the collision between Arabia and Eurasia. These results denote an overall agreement between the abundance of the various types of shallow‐water carbonate facies and large‐scale environmental and geological processes, highlighting the potential for palaeoenvironmental reconstruction locked in the shallow‐water record.

A Critical Assessment of the Congruency between Environmental DNA and Palaeoecology for the Biodiversity Monitoring and Palaeoenvironmental Reconstruction.

The present study suggests that standardized methodology, careful site selection, and stratigraphy are essential for investigating ancient ecosystems in order to evaluate biodiversity and DNA-based time series. Based on specific keywords, this investigation reviewed 146 publications using the SCOPUS, Web of Science (WoS), PUBMED, and Google Scholar databases. Results indicate that environmental deoxyribose nucleic acid (eDNA) can be pivotal for assessing and conserving ecosystems. Our review revealed that in the last 12 years (January 2008–July 2021), 63% of the studies based on eDNA have been reported from aquatic ecosystems, 25% from marine habitats, and 12% from terrestrial environments. Out of studies conducted in aquatic systems using the environmental DNA (eDNA) technique, 63% of the investigations have been reported from freshwater ecosystems, with an utmost focus on fish diversity (40%). Further analysis of the literature reveals that during the same period, 24% of the investigations using the environmental DNA technique were carried out on invertebrates, 8% on mammals, 7% on plants, 6% on reptiles, and 5% on birds. The results obtained clearly indicate that the environmental DNA technique has a clear-cut edge over other biodiversity monitoring methods. Furthermore, we also found that eDNA, in conjunction with different dating techniques, can provide better insight into deciphering eco-evolutionary feedback. Therefore, an attempt has been made to offer extensive information on the application of dating methods for different taxa present in diverse ecosystems. Last, we provide suggestions and elucidations on how to overcome the caveats and delineate some of the research avenues that will likely shape this field in the near future. This paper aims to identify the gaps in environmental DNA (eDNA) investigations to help researchers, ecologists, and decision-makers to develop a holistic understanding of environmental DNA (eDNA) and its utility as a palaeoenvironmental contrivance.

Foraminifera indicate Neogene evolution of Yongle Atoll from Xisha Islands in the South China Sea

The study presents a detailed record of foraminiferal faunas from CK2 core, a 928.75 m long core drilled in the center of Xisha Islands, South China Sea, for biostratigraphy and palaeoenvironmental reconstruction of the study area. Coupling foraminiferal biostratigraphy and bulk-sediment strontium-isotope chronologic age revealed that carbonate deposition occurred from Early Miocene (~19.6 Ma) to present. Examination of 281 petrologic thin sections and 246 unconsolidated sediment samples revealed 141 foraminiferal taxa, among which the foraminiferal abundance and simple diversity peaked in the Middle Miocene and Pliocene to early Pleistocene strata. Nine foraminiferal assemblages (FAs) were distinguished, documenting eight distinct facies that indicated five intervals in the development of Xisha Islands. At the initial interval (19.6–17 Ma), a coral, coralline algal and shallow-water larger foraminifers (FA1 and FA2) association colonized the shallow platform facies, forming an aggrading sequence in response to tectonic subsidence and sea-level rise. Platform development slowed from 17 to 10.19 Ma, dominated by the miliolids and small benthic foraminifers as well as larger benthic foraminifers (FA3 and FA4) representing lagoonal to reef-flat facies with agradation to progradation (backreef infilling) associated with sea-level fall. At 10.19–4.35 Ma, a deepening sequence was indicated by the change from shallow-water benthic foraminifers (FA5) upward to deeper dwelling species (FA6), as a result of climatic cooling and abrupt sea-level fluctuation. As sea level rose, the platform was drowned from 4.35 to 2.18 Ma, as indicated by abundant planktic foraminifers and large, flat benthic foraminifers (FA7 and FA8). At 2.18–0.089 Ma, the platform aggraded rapidly with sea level fall indicated by the appearance of thick benthic foraminifers (FA9) and increased coral. The close association between the biofacies and regional paleobathymetry, which was in phase with the long-term global sea-level change, suggest that foraminiferal morphology and assemblage composition are ideal parameters for paleobathymetric and paleo-depositional environmental interpretations.

Ecology of testate amoebae along an environmental gradient from bogs to calcareous fens in East-Central Europe: development of transfer functions for palaeoenvironmental reconstructions

Testate amoebae play an important role in biomonitoring and the understanding of peatland (palaeo)ecology. However, their application has been mainly limited to Sphagnum-dominated peatlands, especially ombrotrophic bogs. To facilitate wider use of these microorganisms, we explored their ecology along a gradient from mineral-poor acidic bogs to mineral-rich calcareous fens with tufa formation using a new calibration dataset of over 250 samples from East-Central Europe. Specifically, we examined environmental controls on testate amoebae along the complete gradient and separately in the minerotrophic (pH >5.5) and ombrotrophic (pH <5) parts. Based on these findings, we developed and statistically evaluated transfer function models for the dominant factors controlling the community composition of these protists. Multivariate statistical analysis showed that groundwater pH was the main driver of species composition in the full and minerotrophic datasets. In contrast, testate amoeba communities in the ombrotrophic dataset were primarily structured by depth to water table (DWT). Under leave-one-out cross-validation (LOO), the best-performing model for DWT gave a prediction error (RMSEP) of 5.43 cm. The most robust models for groundwater mineral richness yielded RMSEPLOO of 0.45 and 0.27 pH units, for the full and the minerotrophic dataset respectively. This is the first study to present a complete set of testate amoeba-based transfer functions that allow reconstructions of Holocene hydrochemical and hydrological (hydroclimatic) variability in different mire types within one region. The new models open up the possibility for testate amoebae to become a valuable tool in palaeoecological research, although further work is needed to fully assess their performance and usefulness in practice.

Late Holocene interaction of natural processes and human activity at two archaeological sites in the Ten Thousand Islands area of southwest Florida, USA

AbstractPalaeoenvironmental analysis of Late Holocene stratigraphic sequences recovered from two southwest Florida archaeological sites reveal a synchronous evolution of events caused by natural processes (e.g. sea‐level rise) and human activity (e.g. construction of shell works). Basal mangrove peats indicate that a transition from a terrestrial to coastal landscape started ~4000 cal bp in conjunction with the Late Holocene sea‐level rise. Continued sea‐level rise ultimately submerged the area to create estuarine conditions. Commensurate with submergence was the construction of relatively large (0.5 to 1.0 km2) shell mounds from 1500 to 1050 cal bp. These activities started in the estuarine environment and over time produced emergent landscape features with significant local relief (&gt;7 m). The overlap in radiocarbon ages of oysters collected from the estuarine interval and the overlying shell mounds suggests construction material was locally harvested. About 1120 cal bp and during the waning of an indigenous presence in the area, red mangrove forests re‐emerged along the margins of each site and within the adjacent estuary to create an expansive mangrove‐dominated landscape within which both shell works are now embedded. This palaeoenvironmental reconstruction contradicts the prevailing notion that the two sites were purposely constructed on the mainland and adjacent to tidally influenced rivulets.

A new 87Sr/86Sr record of Cretaceous marine invertebrates from the palaeo-Pacific and its implication for stratigraphical and palaeoenvironmental reconstructions

We present the first strontium isotope data of Cretaceous marine invertebrates from north-eastern Russia and the Magellan Seamounts. These provide evidence of a late Turonian age (91.2–90.4 Ma) for the upper part of the Penzhinskaya Formation (Koryak Upland) and a late Coniacian date (90.4–86.4 Ma) for the cephalopod-bearing deposits of the Magellan Seamounts. In addition, they yield information on seasonal variations in the 87Sr/86Sr ratio in marginal marine environments during the late Turonian. These data raise doubts about a previously postulated hiatus spanning the Turonian–Santonian interval. Our results reveal a close temporal correlation between Sr-isotope excursions and the major Oceanic Anoxic Events (OAEs), which suggests a causal link. However, the link between the late Santonian–early Campanian Sr-isotope minimum and Oceanic Anoxic Event 3 (OAE-3) has yet to be fully resolved and requires additional evidence.

Identifying relict periglacial features in watershed landscape and deposits of Borisoglebsk Upland, Central European Russia

Watershed landscapes of the Central Russian Plain, which were subjected to the Late Pleistocene permafrost, bear witness to widespread cryogenic structuring. It is reflected both in semi-regular spots, blocks and polygons in soil and vegetation cover on arable fields and as vertically oriented wedge casts in surficial deposits. This study aimed to identify relict periglacial features in both the landscape and sedimentary sequence of the Borisoglebsk Upland to determine if there is a correspondence of these cast networks to the distribution of landforms and regular patterns of soil and vegetation cover. Combined interpretation of aerial and satellite multi-temporal imagery and detailed investigation of vertical cross-sections in gradually expanding geotechnical trenches including apparent magnetic susceptibility measurements allowed us to reveal and spatially correlate three generations of wedge casts, each buried by well-pronounced sedimentary units, and a specific bulbous type of cast. The type of cryogenesis, erosion and slope mass-movements changed from the Late Pleniglacial to Late Glacial, representing a good proxy in the watershed sedimentary cover for palaeoenvironmental reconstructions. However, regular polygonal patterns caused by these casts are almost erased in the modern topography whereas shallow dry gullies mostly inherit pre-Holocene wider linear depressions with no clear relationship to the buried cryogenic polygons.

Human observations of late Quaternary coastal change: Examples from Australia, Europe and the Pacific Islands

In the aftermath of the last ice age, when sea level rose along most of the world's coastline, the activities of coastal peoples were impacted by coastal submergence, land loss and sometimes isolation as offshore islands formed. In some parts of the world, there is clear evidence that people encoded their observations of postglacial sea-level rise into oral traditions that were communicated across hundreds of generations to reach us today in an intelligible form. In other contexts, people's observations of rising sea level are likely to have formed the foundations of ‘legends’ about undersea places and the peoples inhabiting them.For a selection of coastal sites in Australia and northwest Europe, this study discusses a range of contrasting situations in which culturally-grounded stories about coastal submergence, land loss and isolation plausibly recollect the nature and effects of postglacial sea-level rise. Using science-based histories of postglacial sea-level change, minimum ages are determined for each group of site-specific stories; in the case of Australia, these range from 7000–11,500 BP, for northwest Europe from 5500 to 9500 BP. For selected sites in the Pacific Islands, where human settlement about 3000 years BP post-dated the end of postglacial sea-level rise, localized submergence is recalled in traditional stories of local people.It is argued that studies of late Quaternary coastal evolution can often be filled out by adding details from stories preserved in local cultures, something which leads to a clearer picture of the human-societal impacts of coastal submergence and land loss than can be obtained from palaeoenvironmental reconstructions and geological evidence alone.

Microstratigraphy and palaeoenvironmental implications of a Late Quaternary high‐altitude lacustrine record in the subtropical Andes

AbstractHigh‐mountain lake records in semiarid foreland settings, such as the central Andes of North‐western Argentina, are highly restricted and often deprived of well‐preserved microstratigraphic information to analyze palaeoenvironmental changes and their causes, particularly for periods prior to the Last Glacial Maximum. Laguna La Salada Grande (23°S/65°W, 4063 metres above sea‐level) is a closed shallow lake located at Cordillera Oriental, North‐western Argentina with a unique depositional record, including geomorphic and stratigraphic evidence of palaeoenvironmental changes since the Late Pleistocene. In order to understand the depositional dynamics of this mountain lacustrine system at different timescales, limnogeological multiproxy analyses together with a radiocarbon and 210Pb‐based chronology were applied on massive and laminated sediments from La Salada Grande. Laminated deposits were further analyzed using novel sub‐centimetric mineralogical, textural and geochemical automated methods (including a combination of micro‐X‐ray fluorescence and quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN®). Thick laminated microfacies at the beginning of the sequence record a deep and organic matter productive palaeolake prior to ca 34 ka (1 ka = 1000 years before 1950), that changed into a highly fluctuating shallower‐palaeolake with frequent detrital influxes after ca 34 ka. Microstratigraphy of the coarser‐grained detrital laminae between 31 ka and 25 ka reveals irregular and probably sub‐centennial high‐energy discharge events, pointing to convective atmospheric activity as the main trigger. After ca 21 ka the lake evolved to deeper water‐level conditions resulting in fine‐grained deposits with limited delivery of coarse‐grained sediments, followed by an abrupt lake level drop and incision. The multi‐millennial palaeoenvironmental reconstruction of La Salada Grande, and its correlation with other palaeoclimate records, shows a close link between the lacustrine depositional processes and palaeoclimate changes associated with the South American summer monsoon dynamics. This multifocal research in such an understudied environment provides key knowledge about lacustrine functioning and discharge events−climate interactions of mountain lakes of semi‐arid climates.

The 852/3 CE Mount Churchill eruption: examining the potential climatic and societal impacts and the timing of the Medieval Climate Anomaly in the North Atlantic region

Abstract. The 852/3 CE eruption of Mount Churchill, Alaska, was one of the largest first-millennium volcanic events, with a magnitude of 6.7 (VEI 6) and a tephra volume of 39.4–61.9 km3 (95 % confidence). The spatial extent of the ash fallout from this event is considerable and the cryptotephra (White River Ash east; WRAe) extends as far as Finland and Poland. Proximal ecosystem and societal disturbances have been linked with this eruption; however, wider eruption impacts on climate and society are unknown. Greenland ice core records show that the eruption occurred in winter 852/3 ± 1 CE and that the eruption is associated with a relatively moderate sulfate aerosol loading but large abundances of volcanic ash and chlorine. Here we assess the potential broader impact of this eruption using palaeoenvironmental reconstructions, historical records and climate model simulations. We also use the fortuitous timing of the 852/3 CE Churchill eruption and its extensively widespread tephra deposition of the White River Ash (east) (WRAe) to examine the climatic expression of the warm Medieval Climate Anomaly period (MCA; ca. 950–1250 CE) from precisely linked peatlands in the North Atlantic region. The reconstructed climate forcing potential of the 852/3 CE Churchill eruption is moderate compared with the eruption magnitude, but tree-ring-inferred temperatures report a significant atmospheric cooling of 0.8 ∘C in summer 853 CE. Modelled climate scenarios also show a cooling in 853 CE, although the average magnitude of cooling is smaller (0.3 ∘C). The simulated spatial patterns of cooling are generally similar to those generated using the tree-ring-inferred temperature reconstructions. Tree-ring-inferred cooling begins prior to the date of the eruption suggesting that natural internal climate variability may have increased the climate system's susceptibility to further cooling. The magnitude of the reconstructed cooling could also suggest that the climate forcing potential of this eruption may be underestimated, thereby highlighting the need for greater insight into, and consideration of, the role of halogens and volcanic ash when estimating eruption climate forcing potential. Precise comparisons of palaeoenvironmental records from peatlands across North America and Europe, facilitated by the presence of the WRAe isochron, reveal no consistent MCA signal. These findings contribute to the growing body of evidence that characterises the MCA hydroclimate as time-transgressive and heterogeneous rather than a well-defined climatic period. The presence of the WRAe isochron also demonstrates that no long-term (multidecadal) climatic or societal impacts from the 852/3 CE Churchill eruption were identified beyond areas proximal to the eruption. Historical evidence in Europe for subsistence crises demonstrate a degree of temporal correspondence on interannual timescales, but similar events were reported outside of the eruption period and were common in the 9th century. The 852/3 CE Churchill eruption exemplifies the difficulties of identifying and confirming volcanic impacts for a single eruption, even when the eruption has a small age uncertainty.

Back to Combe-Grèze (La Cresse, Aveyron): New data on the Neolithisation of the Grands Causses region, Southwestern France–abridged version

The small shelter of Combe-Grèze, located in a dolina of the Causse Noir plateau about ten kilometres northeast of Millau in Southwestern France, was first excavated in the second half of the 20th century, and more recently has been subject to new investigations by the authors of this contribution. The site was repeatedly occupied during the Holocene and has been widely referred to in neolithisation scenarios regarding the Mediterranean hinterlands. However, fieldwork carried out over the last few years in the area outside the shelter and the reevaluation of ancient collections stemming from the site have largely modified previous interpretations and evidenced that the site reveals a palimpsest of occupations. We therefore propose here an updating of the available data concerning the site, more particularly with regard to the nature of its occupational stages, its chronology, and the material production associated with the different occupations, the exploited resources, and the palaeoenvironmental reconstructions.

Carbon (δ13C) isotope variations indicate climate shifts and reflect plant habitats in the Middle Triassic (Anisian, Pelsonian) succession at Kühwiesenkopf/Monte Prà della Vacca (Dolomites, Northeast Italy)

We report carbon (δ13C) isotope records from the Middle Triassic (Anisian, Pelsonian) Kühwiesenkopf/Monte Prà della Vacca succession in the Dolomites of northeast Italy, to infer palaeoclimate and palaeoenvironmental changes. This interval comprises hemipelagic carbonate-terrigenous facies deposited in a marginal marine setting and includes a well-known allochthonous plant fossil assemblage at one horizon. We obtained two datasets: (1) carbon isotope records of bulk samples (dispersed organic carbon), which comprise a mixture of terrestrial and marine sources, for the whole 200 m thick succession, and (2) taxon-specific records for the plant bed at a single horizon. Analyses of the dispersed organic matter reveal several significant positive excursions through the Kühwiesenkopf/Monte Prà della Vacca section, some of which may be related to local conditions, whereas others match climate shifts recorded elsewhere in the Tethys Realm. For taxon-specific studies of the plant bed, isotopic values show a correspondence with the spectrum of habitats inferred to have been occupied by the plants. Species inferred to have grown in habitats along environmental gradients are characterized by wide isotopic ranges, whereas those restricted to narrow environmental conditions show a low isotopic variability. Our study highlights how organic carbon isotopic analyses on well-preserved plant remains are excellent tools to define the palaeoecology of plants and to improve our palaeoenvironmental reconstructions of the past.

Taphonomy and its significant role in palaeoenvironmental reconstruction of the upper Turonian actaeonellid gastropod concentrations of Abu Roash, Western Desert, Egypt

Taphonomy and its significant role in palaeoenvironmental reconstruction of the upper Turonian actaeonellid gastropod concentrations of Abu Roash, Western Desert, Egypt

Molecular and carbon isotope composition of hydrocarbons from ambers of the Eocene Shenbei coalfield (Liaoning Province, NE China)

The molecular and (bulk and compound-specific) stable carbon isotope composition of ambers from the Shenbei coalfield, northeastern China, were analysed to determine their origin and palaeobotanical affinitions. The applicability of the δ13C data of saturated diterpenoid hydrocarbons for palaeoenvironmental reconstruction was addressed by comparison with published carbon isotope ratios of diterpenoids from adjacent areas. The detected sesquiterpenoids are common biomarkers for the gymnosperm families of Pinaceae and Cupressaceae. The diterpenoids dominate the saturated hydrocarbon fraction with high abundances of kaurane-type compounds. Abietane-type, cadalene-type and alkylated compounds are the main biomarkers in the aromatic hydrocarbons in the ambers. Proposed typical biomarkers for amber (e.g., amberene and homoamberene) have also been detected and probably derived from the diagenesis of the abietane-type terpenoids in the studied ambers. The biomarker composition suggest that the ambers probably originated from gymnosperms such as Taxodium and Pinus. The δ13C values of bulk amber and individual compounds fall within the range of ancient ambers, but the δ13C values of bulk amber are isotopically more enriched than modern ambers. The δ13C values of compounds in hydrocarbon fractions vary in broad ranges. In the saturated hydrocarbon fraction, the δ13C value of sesquiterpenoids (–28.0‰ to –24.5‰) fluctuates more than that of diterpenoids (–22.5‰ to –21.8‰), and the average δ13C value of the latter is approximately 4‰ higher than the former. Aromatic hydrocarbons are on average enriched in 13C by around 2‰ compared to the δ13C of non-aromatic compounds, the result is influenced by isotopically light sesquiterpenoids in the saturated fraction. The similar carbon isotope compositions of aromatic abietane-type compounds and abietane confirm that progressive aromatization does not have a significant impact on the δ13C value of compounds. The obtained higher δ13C values of saturated diterpenoids in contrast to that of lower Eocene lignite from the nearby regions provide evidence for growth of the precursor plants of the amber in dryer habitats or differences in precipitation distribution between different locations and ages.

Nonmarine Ostracoda as proxies in (geo‐)archaeology — A review

AbstractOstracods as bioindicators are extremely useful for reconstructing palaeoenvironment and palaeoclimate and can also indicate the provenance of sediments and materials, for example, in studies on ancient commercial networks. Ostracods are small crustaceans that live in almost all aquatic habitats, both natural and man‐made. Due to their calcitic carapace, they have high fossilization potential, and their use in geoarchaeology has been steadily increasing during the last decades. Their small size needs mean that only small volumes of sediment samples are needed, and species‐specific ecological tolerances and preferences allow detailed palaeoenvironmental reconstructions. Typical methods of their application are palaeoecological analyses of associations based on ecological information and taphonomy, morphometric variability and stable isotope and chemistry analyses of their shells. The present paper aims to present an overview of applications of non‐marine ostracods in (geo‐)archaeological research, recommending sampling and analytical techniques for addressing archaeological research questions on palaeoclimate, habitat and landscape changes, water availability and quality, land use and other anthropogenic impacts, the provenance of materials and commercial networks to promote the application of Ostracoda in geoarchaeology/environmental archaeology.

Palaeoecological reconstructions of the Middle to Late Pleistocene occupations in the Southern Caucasus using rodent assemblages

Located at the crossroads between Africa, Europe and Asia, the Southern Caucasus is a prime location to study occupations by H. heidelbergensis, H. neanderthalensis and anatomically modern humans. Azokh Cave is an important site for the understanding of human evolution in its archaeological, palaeontological, environmental and ecological context. The main objective of this work is to use rodents to infer the climatic and environmental conditions that prevailed during the formation of the site. The small-mammal remains come from the archaeological excavation campaigns carried out in Azokh 1 in 2003, 2005, 2014, 2015 and 2018; they are from Unit V, Units III–IV and Unit II. The small-mammal assemblage is composed of at least 13 taxa: seven arvicoline, two cricetine, two gerbilline, one dipodid and one murine species. Units III–IV do not yield enough material to draw palaeoclimatic inferences. The palaeoclimatic conditions for Units V and II, ascertained by means of the bioclimatic model, suggest temperatures and precipitation similar to nowadays; the climate seems to be relatively warm-temperate in both units. The palaeoenvironmental reconstruction by means of habitat weighting points to an environment mainly composed of desert and steppe habitats, as well as portions of grassland and forest. This interpretation differs from that inferred from the large-mammal and archaeobotanical data, which indicate a woodland environment. These differences could be explained by the origin of the accumulation. There was no evidence of a major palaeoenvironmental or palaeoclimatic change between the Middle and Late Pleistocene layers, indicating favourable conditions throughout the study period.