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Abstract Mercury (Hg) chemostratigraphy is an efficient tool for tracing distal volcanism, as suggested in many recent studies. In our research, we focused on Hg and other trace element contents in two Devonian-Carboniferous boundary sections from two different and spatially distant areas. The Lesni lom section (Czech Republic) was located in the south-eastern part of the Laurussia plate and the Duli (Guangxi, China) section in the South China Plate. In both studied sections, the highest Hg, Hg/Fexs or Hg/Al values occurred at the Devonian-Carboniferous boundary. In Lesni lom, organic matter remineralization was connected with origin of pyrite which sequestered a part of the Hg content. The decoupling of Hg and TOC within the Duli section strata and the significant correlation with Al and Fe may suggest that Hg is hosted primarily by clay particles, derived from the landmass into the marine realm. Mercury was also incorporated into pyrites but the poor correlation between Hg and TS (total sulfur) indicates a possible loss of S during oxygenation events. In the Lesni lom section, and partly in the Duli section, Fe and Mn redox cycling may have played an important role in sediment Hg content. Both sections were influenced by widespread hydrothermal and volcanic activity, indicated by positive Eu anomalies, MSI, Fe/Ti, Zr/Al2O3 and Ti/Al2O3 values. It remains to be clarified whether, besides the interplay of local magmatic activity and redox oscillations, there may have been some additional influence of the multi-phase Viluy Large Igneous Province, although its younger phase (364.4 ± 1.7 Ma) slightly precedes the Hg anomalies obtained.

We studied the transformation of a middle-to-late Holocene forested ecosystem using the highly indicative remains of land snails. The study areas were sandstone landscapes of northern Bohemia (Czech Republic) that provide extremely rich terrestrial fossil records. As far as we know, nowhere else in the world does such a type of sedimentary environment provide Holocene records of snail shells. Currently, these sandstone landscapes are covered by low productivity coniferous forests with very low species pools. In sharp contrast, in the middle Holocene, they were dominated by species-rich productive woodland communities. Such ecosystems were then supported by a favourable warm and wet climate and by nutrient-rich, calcareous substrata formed of late Pleistocene aeolian dust (loess). A radical transformation of this temporal ecological equilibrium began in the third millennium BC. Over the next millennia, the species-rich canopy forest mollusc assemblages almost completely disappeared, together with calciphilous rock dwellers. The main driving force of this transformation was gradual soil leaching that resulted in the loss of calcium carbonate and principal nutrients (like P and N) and subsequent ecosystem retrogression. Synergistically with this background trend, the unstable climatic regime of the late Holocene, along with long-term anthropogenic pressure that peaked for the first time during the late Bronze Age, accelerated the transformation.

The Amazon Basin is one of the most productive regions in the world and an important carbon sink. However, lake productivity has varied throughout the Holocene, as preserved in lacustrine sedimentary records. Concentrations of chlorophyll pigmented derivatives that are mainly derived from phytoplankton and macrophyte populations can be used to infer lake production levels. Here we use the chlorophyll derivatives concentrations analyzed by spectrophotometer in sediment cores from nine lakes distributed throughout the Brazilian Amazon Basin to document the continental-scale changes in lake production during the Holocene. Chlorophyll derivatives have varied with changes in precipitation rate throughout the last 10,000 years, similar to other climate records in tropical South America, including Ti concentration from the Cariaco Basin, δ13C from Lake Titicaca, and refractory black carbon in Nevado Illimani. Increasing precipitation is responsible for increasing the nutrient supply into the lake, which stimulates primary production. Our analysis was compared to climate-related parameters, suggesting an increasing trend of lake production rates during the wetter Late and Early Holocene, while lower production rates characterized the dry phase of the Middle Holocene. Therefore, the chlorophyll derivatives concentrations generally follow precipitation changes in the Amazon Basin during the Holocene.

This WG2 New Deliverable developed by Task Force 3 is a table summarising complementary methods (linked to D2.15) divided into 3 groups: -less applied geophysical methods in archaeology -airborne/remote sensing -geochemical & geotechnical methods AIM: Linked to WG2_D15 (review paper/white paper/integration in database) TASK Leader: Ekhine Garcia-Garcia TEAM: Jeroen, George, Jan, Andrei & Mahmut PROGRESS: The first draft was developed during the SAGA working group meeting and completed on 14 Feb 2020

This paper presents a study of the accuracy of two-dimensional (2D) finite-element predictions of a displacement field of retaining structures supporting the excavation next to the Komořany tunnel in Prague, Czech Republic. The ground material is a Komořany sand, which is a sand with some gravel and almost no fines. Two different constitutive models were used to represent the mechanical behavior of Komořany sand, namely the standard Mohr–Coulomb model and a hypoplastic model for sands with intergranular strain. High-quality laboratory investigation was performed and used for calibrating the model parameters. In addition, good-quality displacement field measurements were used as a benchmark for the models’ predictions. The simulation results suggest that the hypoplastic model predicts both the laboratory and field measurement results with more accuracy. A discussion about the importance of the correct selection of the constitutive model on the prediction of boundary value problems is also presented.

Abstract The middle Homerian biotic crisis resulted in the almost complete eradication of graptolites. The shale-dominated Kosov Quarry section, central Bohemia, preserves the most complete graptolite record across the crisis in peri-Gondwanan Europe. The pre-extinction graptolite assemblage of the upper lundgreni Biozone, composed of ten species vanished in three extinction phases recognized in an interval 1.6 m thick. The crisis commenced with the increasing dominance of generalist taxa and subsequent extinction of several abundant species including Cyrtograptus lundgreni. The second phase coincided with the extinctions of genera Cyrtograptus and Testograptus, whereas long-ranging, generalist monograptids prevailed before they became extinct as the crisis culminated in its third phase in the flemingii Biozone. The lower part of the overlying parvus Biozone contains only Pristiograptus parvus, which became abundant in the upper part of the biozone, together with incoming Gothograptus nassa. The recovery interval is marked by a moderate diversification of monograptids and retiolitids. The extinction did not affect the diversity of pelagic cephalopods although their abundance was reduced. A bivalve-dominated benthic fauna disappeared throughout the extinction interval and re-appeared not earlier than in the latest Homerian. It was temporarily replaced by a time-specific fauna of anachronistic trilobites and brachiopods. The extinction interval coincided with sea-level fall, indicated by limestone slump-beds in a generally shaly succession. The post-extinction interval corresponds with a lowstand systems tract with deposition of condensed shelly limestone and burrowed shale. A positive carbon isotope excursion started in the flemingii Biozone and δ13C values increased up to the lower parvus Biozone above which the plateau of the first peak started. The beginning of the graptolite extinction predated the early phase of the late Homerian carbon isotope excursion. The terminal phase of the extinction, nevertheless coincided with the onset of the carbon isotope excursion and change in benthic fauna.

In the text, the authors demonstrate that a Czech open-air museum was founded in Prague in 1895, well ahead other European countries. It was the first open-air museum in the then Europe south of Scandinavia. It was far ahead of its time also through the connection with a large collection museum. The original exhibition village changed into a permanent open-air museum. The Czech „skansen”, likewise the Swedish one, meant an inspiration for further exhibition and museum projects. From the very beginning of the existence of an ethnographic village at the Czechoslavic Ethnographic Exhibition, it was planned to maintain it. For subsequent six years, the village was used for ethnographic and cultural purposes, just as current open-air museums are. Its spaces were not closed and non-functional. For this reason, we could consider the ethnographic village to be „wooden heritage ̋, which does no longer exist now. Despite its uniqueness, and scholar, social and cultural benefits, the ethnographic village from the year 1895 has not survived. Its extinction in the year 1901 was caused by a wood-decay fungus. The authors believe there is still a possibility of renewing this ethnographic village.

The paper presents the enhancement of an existing constitutive model for argillaceous hard soils–weak rocks to incorporate non-isothermal conditions, to be used in coupled thermo-hydro-mechanical (THM) simulations of underground excavations subjected to temperature variations within the context of deep geological nuclear waste disposal. The proposed thermo-elastoplastic extension accounts for the effect of temperature on the yield and plastic potential functions and on the elastic stiffness. The resulting model is validated through the simulation of relevant non-isothermal laboratory tests reported in the literature. The model is then applied to the coupled THM simulation of an in situ heating test conducted at the Meuse/Haute-Marne underground research laboratory in Bure, France, excavated in the Callovo-Oxfordian claystone. Results show that the incorporation of thermal effects into the constitutive description of the host rock plays a significant role in the behaviour of the excavation when subjected to thermal loading, particularly in the evolution of the excavation fractured zone.

AbstractCraniovascular traits in the endocranium (traces of middle meningeal vessels and dural venous sinuses, emissary foramina) provide evidence of vascular anatomy in osteological samples. We investigate the craniovascular variation in four South American samples and the effect of artificial cranial modifications (ACM). CT scans of human adult crania from four archeological samples from southern South America (including skulls with ACM) are used for the analyses. The craniovascular features in the four samples are described, skulls with and without ACM are compared, and additionally, South Americans are compared to a previously analyzed sample of Europeans. Of the four South American samples, the Southern Patagonian differs the most, showing the most distinct cranial dimensions, no ACM, and larger diameters of the emissary foramina. Unlike previous studies, we did not find any major differences in craniovascular features between modified and non‐modified skulls, except that the skulls with ACM present somewhat smaller foramina. South Americans significantly differed from Europeans, especially in the anteroposterior dominance of the middle meningeal artery, in the pattern of sinus confluence, in the occurrence of enlarged occipito‐marginal sinuses, and in foramina frequencies and diameters. Craniovascular morphology is not affected by the cranial size, even in skulls with ACM, indicating a minor or null influence of structural topological factors. Concerning the samples from distinct geographic and climatic environments, it must be evaluated whether the craniovascular morphogenesis might be partially influenced by specific functions possibly associated with thermoregulation, intracranial pressure, and the maintenance of intracranial homeostasis.