Different States Of Preservation Research Articles

Correlation between thermal and density properties of chestnuts: preliminary results of experimental non-destructive testing

This study presents the preliminary outcomes of a methodology for the physical and mechanical characterization of various chestnut elements in different states of preservation. Strategizing conservation and retrofit interventions for timber is necessary, and to do this, it is necessary to establish an estimation of physical (transmissivity, thermal conductivity, humidity level, etc.) and mechanical properties (density, compressive or bending strength, etc.). This essential information is typically associated with timber defects, but there are lack of correlations. The primary objective is to establish correlations between thermal and density properties with the aim of preserving original assets. The investigation delves into the relationship between timber density and thermal properties through experimental non-destructive testing (NDT). Two NDTs were employed with the aim of correlating: penetrometric testing and active thermography investigations. The parametric study on the excitation period yielded valuable insights into the temporal dynamics of heat transfer within the timber, underscoring the significance of selecting appropriate excitation periods to capture precise thermal properties. Tabular data on relative humidity for salified, dried, and new samples provided a quantitative backdrop to these observations, unveiling the nuanced effects of humidity on the timber’s thermal response. The results of this study are positioned to inform future conservation efforts by laying the groundwork for a comprehensive understanding of timber’s mechanical properties. Particularly, the challenge lies in accurately estimating density, where surface tests are often less reliable than in-depth ones. Therefore, it is crucial to seek validation through other NDT tests, such as thermographic analysis and visual inspection, and hygrometric tests recognizing their importance in enhancing the reliability of density assessments. This approach will contribute to the development of more discerning preservation strategies.

Porotic hyperostosis and cribra orbitalia in samples from the Late Hillfort Period sites at Dětkovice - Za zahradama (district Prostějov) and Vídeňská street (district Brno), Czech Republic.

Porotic hyperostosis and cribra orbitalia are pathological changes occurring on the human skull. These changes were observed and evaluated on skeletal remains from Dětkovice - Za zahradama and Vídeňská Street in Brno; both sites are dated back to the 10th to 12th centuries AD. A total of 605 subjects were assessed for age, sex, and the above-stated pathologies using standard methods. The influence of age and sex on the occurrence of these pathologies was examined statistically. Results indicated that at the site of Dětkovice - Za zahradama, porotic hyperostosis, and cribra orbitalia do not depend on sex or age. However, at Vídeňská Street in Brno, these pathologies do not depend on sex, but they depend on age so a higher incidence of pathologies in juveniles is observed. Differences between both sites could be caused by different numbers of evaluated individuals or different state of preservation of skeletal remains. The aetiology of the origin of these pathologies could not be determined by the methodology used here, but with the prevailing lower age of pathological subjects, a lack of nutrition with consequent absence of iron and developing anaemia might be the cause. Based on our statistical data, we can observe that the pathologies we studied occur more frequently in children older than newborns and younger infants. This may indicate that these studied pathologies arise only during the lifetime of the individual and do not have a prenatal occurrence.

EXPERIMENTAL CUT MARK REPLICATION AS A MEANS FOR UNDERSTANDING LINEAR MARKS ON ARCHAEOLOGICAL BONES FROM THE MEDZHIBOZH LOWER PALAEOLITHIC SITES

The paper presents the first results of experimental modelling of a series of cut marks on bones in different states of preservation. We used experimental (quartz, flint) and technogenic (granite) flakes with sharp and blunt unretouched working edges and trimmed edges produced by the bipolar on-anvil technique. V-, П-, and U-shaped cut marks and surface damage were obtained. The data gained are useful for the reconstruction of conditions of occurrence of cut marks on bones found in the uppermost culture-bearing horizons of the Lower Palaeolithic sites near Medzhibozh, located in the upper reaches of the Southern Bug River and dated to MIS 11. The data can also be used for differentiating between anthropogenic and natural damage and as a significant statistical point of reference.

Fossil Wood Analyses: Several Examples from Five Case Studies in the Area of Central and NW Bohemia, Czech Republic.

In the area of the Central and NW Bohemia, Czech Republic, the fossil wood is quite abundant, found in different states of preservation and present from Paleozoic (Pennsylvanian), through Mesozoic (Upper Cretaceous), to Cenozoic (upper Eocene to lower Miocene). So, this small area is ideal to demonstrate various aspects of the fossil wood analyses, including anatomy (unifacial vs. bifacial cambium, formation of tyloses and its significance, early vs. late wood, unambiguity of scientific terminology, stem vs. root wood), taphonomy (completeness of fossil record, influence of environment on mode of preservation, influence of preservation on wood anatomy and preservation potential, discrepancy between the record of wood and other organs), systematics (stem vs. crown group, wide concept of fossil wood genera, "mosaic" species, wood of extinct plants), and palaeoclimatic reconstruction (definition of "wood type," subjective vs. objective methods). The majority of the studied woods were thin-sectioned following the standard techniques and observed with a compound light microscope.

Crystallinity assessment of anthropogenic calcites using Raman micro-spectroscopy

Anthropogenic calcite is a form of calcium carbonate produced through pyrotechnological activities, and it is the main component of materials such as lime binders and wood ash. This type of calcite is characterized by a significantly lower degree of crystallinity compared with its geogenic counterparts, as a result of different formation processes. The crystallinity of calcite can be determined using infrared spectroscopy in transmission mode, which allows decoupling particle size effect from atomic order and thus effectively distinguish anthropogenic and geogenic calcites. On the contrary, Raman micro-spectroscopy is still in the process of developing a reference framework for the assessment of crystallinity in calcite. Band broadening has been identified as one of the proxies for crystallinity in the Raman spectra of geogenic and anthropogenic calcites. Here we analyze the full width at half maximum of calcite bands in various geogenic and anthropogenic materials, backed against an independent crystallinity reference based on infrared spectroscopy. Results are then used to assess the crystallinity of anthropogenic calcite in archaeological lime binders characterized by different states of preservation, including samples affected by the formation of secondary calcite, and tested on micromorphology thin sections in which lime binders are embedded in sediments.

Military archaeology and LIDAR data visualizations: a non-invasive approach to detect historical remains

The present paper belongs to a line of research known as aerial archaeology and compares some specific visualizations of LIDAR data (hill-shading, openness, and sky view factor) to understand which of them can provide the best approach to suitably identify and unveil some archaeological permanences as function of different boundary conditions. In the present case, such permanences belong to the very special material heritage consisting of the "physical traces" of the Great War, although latent, they persist in the present landscapes at different states of preservation and visibility, waiting to be unearthed to express their cultural potential. They represent an indispensable palimpsest of "minor signs" such as, for example, fragments of entrenchments, gun emplacements, shelters, bomb craters, and temporary shelters. Such elements made the war machine work at that time while, nowadays, if properly recognized and enhanced, could foster the historical and cultural revitalization of the territories where they are placed.

Yakut tangalai clothing: cut, trimming, and technologies

Costume of the 17th–18th cc. is a little-studied subject in the history of the Yakut costume. This is due to the fact that costume of this period can be studied only on the materials of the funerary monuments of Yakutia (Eas-tern Siberia). There are scanty written and pictorial sources of this period, and they do not provide detailed infor-mation about the material and technique of making clothes. One of the outstanding examples of the clothing of that time is tangalai - ritual women's clothing with short sleeves embroidered with beads and metal plaques, which in the literature is called fur coat or caftan. Due to its beauty and ritual purpose, tangalai represents a most inte-resting and controversial element of the wardrobe. Such waistcoats were widespread among Turkic-Mongolian peoples of Eurasia and are often associated with the wedding ceremonial and status of married women. The aim of the work is to identify specifics of the make, cut, and decor of tangalai. For this purpose, four samples of clo-thing identified as tangalais were selected from museum collections. All samples were found in female burials of Central and Northern Yakutia and consist of fragments of the base and decorative trim in different states of pres-ervation. A comparative analysis showed that according to the material, cut, and principle of manufacture all sam-ples represent variations of the same type of clothing. Suede made of deer or elk skin, smoked and painted, was used as the basic material. The skin was supplemented with an edging made of expensive and rare furs, which at that time included beaver fur. Beads of predominantly blue color were used in all the samples, supplemented with white and black beads, metal stripes and pendants. Beaded embroidery emphasized certain parts of clothing: shoulders, chest, and back. Accentuation of similar zones preserved in elegant women's fur coats until the beginning of the 20th century. The manufacture of such clothing implied a complex and lengthy technological process from the processing of raw materials to the connection of all the numerous elements. The high quality of the processing of leather and fur and complex beaded decor indicate the presence of professional seamstresses and a more complex organization of the Yakut society of those times. Needle beds, scissors, and workpieces of fur and beads in very rich women's burials, as well as the folklore motifs on this subject may indicate the significance of the sewing workmanship.

Radiocarbon dating of archaeological textiles at different states of preservation

Archaeological textiles are suitable material for radiocarbon dating as they are mainly made of organic matter, such as plant and/or animal fibres. Radiocarbon dating provides objective age estimates of archaeological finds, based on measurements of the carbon-14 isotope present in the organic matter against an internationally used reference standard. However, the quantity and quality of carbon present in the organic matter of archaeological textiles can be affected either by the conditions under which the find was preserved (such as carbonisation, chemical change of organic matter to carbon, and mineralisation, which is the gradual replacement of organic matter by metal degradation products), or by the application of certain interventive methods of conservation (such as, consolidation and the application of organic adhesives that add foreign organic matter/carbon to the textile). Six case studies of archaeological textiles dated using the carbon-14 method are presented here. Two carbonised textile finds, two which were mineralised (one treated with adhesives in the past), and a final two which come from inhumation burials (similar to the textile previously treated with adhesives). This paper includes a discussion and review of the dating method, focusing on sample selection, sample preparation, and by evaluating the efficiency of the technique on textile finds at various states of preservation. This study shows that efficiency of the technique is highly dependable on the amount of carbon present in the finds, which does not seem to be affected by carbonisation, but is greatly affected by mineralisation and the incorporation of foreign organic matter, like synthetic consolidants.

НАУКОВІ ПЕРЕДПРОЄКТНІ ДОСЛІДЖЕННЯ ТА ФОРМУВАННЯ КОНЦЕПЦІЇ РЕСТАВРАЦІЇ АКТОВОЇ ЗАЛИ ГОЛОВНОГО КОРПУСУ НАЦІОНАЛЬНОГО УНІВЕРСИТЕТУ “ЛЬВІВСЬКА ПОЛІТЕХНІКА”

The article highlights the results of the first round of conservation works to return the lost image of the assembly hall (meeting hall of the great senate) – the main building of the oldest building of the university. The purpose of the works is to create the methodology basis to restore the wall painting and sculpture decoration of the hall, to return it to its original authentic appearance from 1880-1884. The decoration of the hall was realized in 1884 by the artist and architect Ivan Dolynskyi, according to the idea of the first rector, architect Julian Zahariewicz. However, the original artistic decoration of the assembly hall was lost in the subsequent periods after the First World War. The walls of the hall and decorative plastic were covered with new paint layers of a nondecorative nature. The first test studies in 2015 showed the possibility of removing layers and opening the original wall painting decoration. They also testified to the need for conservation and restoration works of the authentic wall painting decoration, which in some places had cracks, local losses, and unsatisfactory technical conditions (flaking from plaster). Complex scientific architectural and conservation studies of the interior of the assembly hall were carried out, including the performance of all necessary types of research – from archival searches to soundings in paint coatings and stucco, and laboratory analyzes of materials. Research has revealed the nature of layering and the different states of preservation of the authentic painting layer in all parts of the hall, at different levels of the walls and decor. As a result of research, it was established the possibility of cleaning all walls, decorative stucco, and sculptures by mechanical means. Due to the large volume, it was recommended to divide the cleaning and conservation works into several stages. According to the concept of the discussed and approved project, the following were recommended as the main methods and stages of restoration works: – mechanical cleaning of the entire wall plane; removal of paint coatings to the layer of authentic marbling; also removing putty from cracks and gaps in the plaster; – delicate wiping of the wall surface with distilled water to remove surface contamination; – injection of deep cracks with liquid restorative putty mass; – “bringing” plaster in places of losses, falls and chips, followed by its alignment in the plane of the wall and its priming; – strengthening of the places of the base where there are losses, shedding of the wall painting by the method of its structural strengthening with the help of impregnation with a special priming solution; – restoration reproduction and toning of the wall painting (exclusively within the limits of losses); – after the completion of the reproduction of the wall painting-marbling (when the toning has completely dried), applying a restoration wax-resin mastic to the entire surface of the wall; giving a gloss after the mastic has completely dried; if necessary, mastic can be re-applied on new layers of wall painting. In the article, we reveal the main results of the research work, as well as highlight the key positions of the conservation task and the conceptual project of conservation, and recommendations for planning executive works. We also reveal the process of implementation of conservation works at their first stage - in 2015-2016. The works were carried out by the restoration group of the Department of Architecture and Conservation with the involvement of students.

A new aspect of post-depositional alterations of lithic artefacts: the case of Medzhibozh Lower Palaeolithic assemblages

Flint artefacts have been identified in the materials of the Lower Palaeolithic sites of Medzhibozh, which have experienced the effects of post-depositional alterations (PDA). We suggest a particular combination of anthropogenic and natural effects on lithic artefacts. In the vicinity of Medzhibozh in the Khmelnytskyi region in the West of Ukraine, several multilayered stratified Lower Palaeolithic sites are currently known. Artefacts and accompanying fauna have been identified in subaerial buried soils, initial hydromorphic soils, and alluvial deposits. The ages of the artefact-bearing sediments are preliminarily estimated to be between 1.2 and 0.4 Ma. The lithic assemblages of all horizons contain technologically and typologically archaic artefacts, the industry being referred to as Mode 1. Various types of rock were used as raw materials, including locally occurring flints in the form of pebbles and flattened nodules. Flint products from many assemblages are characterized by rounding and sheen due to their extended exposure to water-permeable horizons. Most of the flint artefacts belonging to a particular assemblage are of a similar type of preservation. The assemblages also contain artefacts with surfaces of different states of preservation, suggesting that they are of different ages. These could either be products of reutilisation or natural alterations. However, more recent surfaces tend to be isolated and do not form a removals system. Moreover, most of the individual PDA pieces show a technological and morphological consistency of differently preserved surfaces, indicating that a force initiating detachment was applied simultaneously. We, therefore, consider artefacts showing a variate state of scar preservation to be PDA products. We assume we are dealing with a new aspect of post-depositional alterations of lithic artefacts. Natural alteration had subjected artefacts, which received internal damage to the structure earlier when processed by man. The bipolar-on-anvil technique was actively used at Medzhibozh. Many artefacts show signs of multiple attempts of knapping, accompanied by a change in the position of the segmenting item. Such signs are impact pits, visible cracks, and Herzian cones disturbing the rock's texture. We believe that the internal cracks that appeared in the area of the not detached spall contribute to the accelerated natural alteration of the item in this area and, ultimately, to the detachment of the flake. The probability of spalling depends on the intensity of the internal distress, the structure of the rock, the climatic conditions, and the post-depositional environment. The most responsible factor for the effect of the “time-delayed spalling” seems to be repeated cycles of temperature changes. A comprehensive study of post-depositional modifications of lithic artefacts is essential in studies of Lower Palaeolithic sites, particularly the technological Mode 1 (Oldowan). This is due to the highly heterogeneous raw materials used, the bipolar-on-anvil knapping technique, and a long period of post-discard behaviour of artefacts. Key words: Lower Palaeolithic, Medzhibozh, stone artefacts, post-depositional alterations, time-delayed spalling, taphonomy.

A reconstruction of the occupation layer of archaeological sites according to a statistical analysis of multispectral imaging

AbstractIn the modern era and especially in the 20th century, the territory with most of the archaeological sites in central Russia and the Urals was used as agricultural land. The history of long‐term studies of medieval Finno‐Ugric settlements (Cis‐Urals) makes it possible to distinguish segments of an occupation layer in various states of preservation: superficially disrupted, replaced and transported. Superficially disrupted and replaced layers are found at the settlement site and are believed to be residential and economic areas​​. The transported layer is mainly transported to the slopes of the terraces to which the sites of the Chepetskaya culture are assigned. Therefore, it is necessary to study not only the site of the settlement itself but also the adjacent territory. To reconstruct the boundaries and structure of medieval settlements, a new methodological approach has been proposed. Initially, a statistical analysis of multispectral aerial photography data was carried out: the calculation of Haralick's textural features; the reduction in the number of features by principal component analysis and the segmentation of images based on the obtained features using the k‐means method. This makes it possible to divide the settlement site and the surrounding area into areas with fundamentally different vegetation intensities. A comparison with the geophysical, soil and archaeological survey data allows the interpretation of the identified areas. The research was carried out at the settlement of Kushman‐3 (9th–13th centuries AD). Two lines of defensive structures, which are not manifested in the relief, were identified; the structural parts of the settlement were determined and an interpretation of the way they were used in the Middle Ages was proposed. As a result of the application of the new statistical algorithm, the locations of occupation layer segments in different states of preservation were determined, and the boundaries of the Kushman‐3 settlement were substantiated.

The floors of Smolensk churches of the 12th–13th centuries

In 17 of 21 Smolensk’ 12-13 century buildings there were found floor remains with different state of preservation. Some were found quite intact in significant area in situ, and other are represented with single findings of glazed tiles. Neither smalt, nor slate slabs were used in that buildings. In two churches there were found sandstone slabs, imitating the slate. In another two churches was mainly used lime mortar grouting. The most widespread materials for the decoration of the floors were the plinth and the glazed tiles. The plinth was mostly used for decorating of the main area of the buildings, for example, in naos and galleries. The glazed tiles more often were found in the separated compartments: choirs, apses and in some special parts of galleries. There is no great variety of shapes and dimensions of ceramic tiles of that time. The square and triangle ones prevail. Their side dimension is normally 11-12 sm, the thickness is 1,8 – 2,8 sm. This proportion remains unchanged, unlike plinth size, which during 12 century becomes smaller and smaller. And also some figured tiles were found in Smolensk’ buildings of that time.

Structural Assessment of Ancient Masonry Structures: An Experimental Investigation on Rubble Stone Masonry

ABSTRACT Non-destructive investigation procedures are appropriate approaches for the qualitative mechanical assessment of heritage masonry structures. This study aims to contribute to the knowledge of one of the most common ancient masonry typologies, particularly in Roman archaeological sites, the rubble stone masonry, that is the ancient opus incertum, with an extensive experimental program carried out in the archaeological site of Pompeii. The research focused on archaeological masonry structures with different states of preservation and with or without modern interventions. A non-destructive investigation procedure was carried out including detailed geometrical and material surveys, visual inspections and an extensive program of sonic pulse velocity tests, with a total of 1965 acquired velocities. The paper describes the adopted investigation protocol and detailed analysis and discusses the experimental outcomes. Comparisons with available literature data concerning different masonry typologies at the Pompeii site are also presented. Furthermore, the results of the non-destructive investigation have been compared with available mechanical information from destructive and non-destructive tests performed by the authors on Pompeii-like masonry panels. The unique set of data collected may represent a sound tool for the estimation of the mechanical parameters of the ancient masonry structures, which is a crucial step for the definition of preservation actions.

Drugs in bone: Detectability of substances of toxicological interest in different states of preservation.

In forensic contexts of advanced decomposition, when conventional matrices are no longer available for toxicological analyses, finding alternative matrices is necessary. The skeleton, which is fundamental for anthropologists and geneticists, could be useful also for toxicological purposes. The present study aims to examine what kind of information toxicological analysis performed on bones (the cranium and the ribs) in different states of preservation could provide to the forensic practitioner. Thirty cadavers with known pharmacological history, subjected to forensic autopsy at the Institute of Legal Medicine of Milan, were selected. Rib and cranium samples were collected from each body and separated into two parts in order to create two different states of preservation: One was cleaned from soft tissues and analyzed as a well-preserved bone sample; the other was submitted to a long maceration process, simulating complete skeletonization. All specimens were then processed with accelerated solvent extraction and the eluates analyzed using Q-Exactive™ Orbitrap™ Mass Spectrometer. The analysis of blood and skeletal matrices showed positive results for the tested substances in 63% of cases, mainly benzodiazepines, antidepressants, and drug abuse. Significant Pearson correlations were observed between non-macerated vs. macerated bone samples: r=0.79 for rib samples, r=0.61 for cranium samples, and r=0.69 for all bone samples. As a consequence, the positive results confirm the potential of the bone tissue as an alternative matrix in forensic toxicology, even in cases of extremely decomposed bodies. This study also highlighted important elements for reconstructing the biological profile in cases of forensic anthropological concern.

Effects of sample processing on XRF results from archeological pottery

ABSTRACT The aim of this paper is to present the results of XRF analysis of archeological samples in two different states of preservation: intact vessel surfaces and transformed into powder. To investigate the effect of sample processing for XRF analysis, a handheld spectrometer was used. In total, 41 pottery samples were measured. The samples were extracted from Late Bronze Age and Early Iron Age ceramic vessels of two different technological traditions: local (hand-made pottery) and exogenous (wheel-thrown pottery) from the archeological site of Setefilla (western Andalusia, Spain). Multiple statistical tests were used to examine the effect of sample processing on the semi-quantitative outcome of XRF analysis of pottery. The results obtained from intact samples are considerably different from the results obtained from pulverized samples. The analyses revealed that levels of Co, Sb, Sn, Al, Si, Ca, Fe, S, K, Sr and Nb were higher in the group of intact samples. This study underlines the need to evaluate sample preparation when designing archeometric research programs.

STR analysis of skeletal remains exhumed from a dry “water well” used as a massive clandestine burial in Argentina

The military dictatorship that took power in Argentina from 1976 to 1983, brought enforced disappearance and death to thousands of people in the country. “Pozo de Vargas” is a 3.5 m wide and 60 m deep dry water well used as a massive clandestine burial site in Tucumán, Argentina. The site contained commingled remains as well as partially articulated body parts. Since 2011, EAAF Forensic Genetics Laboratory (LGF-EAAF) has been processing post mortem (PM) samples exhumed from the well to achieve the intra-skeletal re-association and the identification of the bodies or body parts. 981 skeletal remains, with different states of preservation, were analyzed for STR typing using commercial available kits. Different bone elements were exhumed for intra-skeletal re-associations (PM-PM genetic comparisons): teeth, femur and tibia represented more than 65% of sampling and almost all of them were successfully re-associated; spongy bones as scapula, vertebrae and clavicles yielded worse results, although almost 80% of them were also re-associated. 871 skeletal remains (89%) were successfully typed for autosomal STR markers and re-associated into 147 unique STR profiles meaning that at least 147 different individuals were thrown into the water well. After re-association, unique STR profiles obtained from the skeletal remains were compared to ante mortem (AM) family reference database in order to identify victims (AM-PM genetic comparisons), being possible to restore 113 victims to their families. Another challenge of this identification project was the presence of biologically related victims inside the well.

Detection and localization of chamber tombs in the environs of ancient Olympia, Peloponnese, Greece, based on a combination of archaeological survey and geophysical prospection

AbstractMycenaean chamber tombs are composed of air‐filled burial cavities and, therefore, can be detected by non‐invasive geophysical methods. In this study, an electrical resistivity tomography (ERT)‐based approach was used to detect graves at three different sites in the area surrounding ancient Olympia. We collected ERT data at the necropolis of Mageiras‐Kioupia, where a number of chamber tombs had already been located and partly excavated in order to ground‐truth the ERT response for chamber tombs in different states of preservation. Near the village of Epitalio, a preceding archaeological survey discovered remains of a one chamber tomb in mid‐slope position of a larger hill. There, we applied the ERT‐approach, calibrated at Mageiras‐Kioupia, to the tomb and detected ten more tomb candidates at this site. In addition to ERT, we carried out ground penetrating radar (GPR) studies at the Epitalio site. In general GPR, data are highly consistent with ERT results. We were thus able to localize an unknown, most probably Mycenaean cemetery where no systematic archaeological information previously existed. In the third area of investigation, the Dartisa plateau, no potential chamber tomb comparable to the ones excavated and measured at Mageiras‐Kioupia and Epitalio were identified.

Environmental changes promote larger species of Odonata (Insecta) in Amazonian streams

Species occurrence can be affected by the availability of environments that fit within the limits of variation of its niche and by interaction with other species. Modifications in the environment, especially those caused by mankind, are considered the leading cause for species extinction. Such a response from the species is not random, with patterns that can follow functionality and/or morphology of each taxa. In this context, the objective of this study was to assess how environmental factors affect adult Odonata species, testing the hypotheses: a) that the environment acts as a filter upon the species by means of facilitating or excluding specific characteristics and b) that because of the order’s requirements for thermoregulation and reproduction, thorax width and oviposition type are the variables most affected in the group. A total of 97 streams were sampled in eastern Amazonia, distributed along a gradient of different states of preservation, from completely preserved to heavily impacted by plantations and livestock. Six functional characteristics and seven environmental descriptors were selected, and to assess their relationships, a combination of Fourth Corner and RLQ analysis was used. The Habitat Integrity Index was the descriptor with the biggest impact on the Odonata community, presenting a negative correlation with wing width, thorax width and exophytic oviposition, and a positive correlation with endophytic oviposition. Macrophyte cover was the next most relevant environmental descriptor, showing a negative correlation with abdomen length, and positive correlation with thorax width and exophytic oviposition. The results show that poorly preserved environments favour the occurrence of organisms with a wider thorax and the substitution of endophytic oviposition with the exophytic type. Since changes to the environment do not usually alter Odonata richness but rather the composition, these results show a favouritism for groups with mentioned characteristics, such as Libellulidae, to the detriment of other groups (especially Zygoptera), which can result in community homogeneity and both biodiversity and functional loss. The maintenance of well-preserved environments is therefore indispensable in assuring Odonata biodiversity, as well as the best way to preserve the different behavioural and ecophysiological groups in the order. The Odonata community’s response, directed through its morphological and behavioural characteristics, sheds light on ecological patterns, and thus the addition of oviposition habits in conservation measures aimed at preserving the order can render them more adequate, as this is a critical aspect of population maintenance and colonization of new sites.

Modern rather than Mesoarchaean oxidative weathering responsible for the heavy stable Cr isotopic signatures of the 2.95 Ga old Ijzermijn iron formation (South Africa)

Previously reported stable Cr isotopic fractionation in Archaean paleosols and iron formations (IFs) have been interpreted as a signature of oxidative weathering of Cr(III) to Cr(VI) in soils, and delivery of isotopically heavy Cr(VI) into the oceans. One of the oldest reported fingerprints of this process is isotopically heavy Cr preserved in the 2.95 Ga old Ijzermijn IF, Sinqeni Formation of the Mozaan Group (Pongola Supergroup), South Africa and could suggest that atmospheric free oxygen was present ca. 600 million years earlier than the Great Oxidation Event (GOE). However, fractionated stable Cr isotopic signatures have only been found to date in surface outcrop samples of the White Mfolozi Inlier exposed along the White Mfolozi River Gorge. In this study, the latter outcrop was resampled along with two drill cores of the Ijzermijn IF and a drill core of the Scotts Hill IF to represent multiple exposures of Mozaan Group IFs with different states of preservation. A detailed geochemical comparison on bulk samples of different units was undertaken using stable Cr isotopes coupled with trace and major elements. Outcrop iron-rich mudstones (Fe - lutites) show very low LOI [wt] %, and very low Fe(II)/Fetot ratios, and lower Ca and Mg relative to equivalent facies in drill cores, indicating the effects that oxidative recent surface weathering had on Fe/Mn-rich carbonate minerals of the IF. Overall rare earth element and yttrium (REE + Y) mixing models agree well with previous studies, confirming that they were minimally disturbed by weathering and are consistent with a high magnitude of continental solutes delivered in a near–shore depositional environment, with a minor contribution of hydrothermally derived fluids that upwelled into shallower depositional setting. Importantly, all drill core samples of this study revealed δ53/52Cr values within the igneous inventory, despite variable amounts of detrital Cr input that includes nearly detritus-free, chert/jasper-rich units. By contrast, a specific group of Fe-lutite samples near the base of White Mfolozi River outcrop bear fractionated Cr isotopic signatures with δ53/52Cr values up to 0.418‰. These outcrop samples also display unusually high U/Th ratios (max. 12.6) as well as enrichments of other elements (W, Tl, As, MREE) that far exceed that observed in correlative drill core units. These observations together with the lack of Cr isotopic fractionation in drill core samples lead us to propose that the heavy δ53/52Cr values of Fe-lutites from outcrop Ijzermijn IF samples reported here and in a previous study are the product of modern oxidative weathering rather than an indicator for Mesoarchaean oxidative weathering at ca. 2.95 Ga.

Postmortem CT in the investigation of decomposed human remains: advantages and limitations

The investigation of decomposed bodies is a difficult task for the forensic practitioner due to the effect of taphonomy on the remains. Facial characteristics are missing, soft tissue is altered, and the remains are often disarticulated and/or scattered, which makes both the identification and the reconstruction of the death scene very challenging. These cases require maceration, which often is not possible in routine forensic pathology facilities. Postmortem Computed Tomography (PMCT) has emerged a few decades ago as a complementary modality to forensic autopsy and offers an alternative way of investigation of human remains1,2. This paper presents a series of cases from two forensic pathology departments in Scotland and Crete where PMCT was used in the investigation of human remains in different states of preservation (varying post-mortem interval) recovered from different environments (terrestrial, aquatic). Fig. 1 illustrates the 3D reconstruction from a PMCT of a decomposed body recovered in the northern coast of Crete. PMCT offered in all cases a quick inspection of the remains for the presence of foreign bodies and traumatic lesions, morphological information for the reconstruction of the biological profile and comparative material for positive identification. In addition, post-autopsy PMCT has proven to be very helpful in providing answers to specific forensic questions. The preliminary results of this study confirm the advantages in incorporating PMCT in the protocol for the examination of heavily decomposed remains, as a complement to the forensic pathology examination.