Innovative nanomaterials for bone remains consolidation: performance evaluation and impact on 14C dating and on palaeogenetic analysis

An innovative protocol for the consolidation of ancient bone remains based on the use of nanometric hydroxyapatite (HAP) was set up and tested through a multidisciplinary approach. A new protocol for the synthesis of HAP nanoparticles was developed, and the composition of the obtained nanomaterial were investigated through Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD); sizes, shape and morphology of the synthesized particles were studied by Scanning Electron Microscopy (SEM). The consolidation performance was evaluated by testing the new nanomaterial on degraded ancient bone findings. An increase of the mineral density and of the micro-hardness of the bone were observed. The new consolidation method was also tested to assess possible effects on the palaeogenetic analysis and radiocarbon dating on the treated bones. The consolidation treatment has no substantial impact on the genetic characterisation of the skeletal remains and does not introduce any contaminations that could affect radiocarbon dating. This consolidation procedure represents a more compatible conservation tool with respect to traditional procedures: it has been shown that the treatment is effective, easily-applicable and not detrimental for 14C dating and palaeogenetic analysis.

Heavy Metals in Sapropel of Lakes in Suburban Territories of Vilnius (Lithuania): Reflections of Paleoenvironmental Conditions and Anthropogenic Influence

Geochemical and lithological parameters of sapropel in lakes, combined with pollen data and radiocarbon 14C dating, contain a wide spectrum of environmental information. This includes records of fluctuations of water level and changes of conditions of sedimentation, accumulation of organic matter and chemical elements due to climate change, human impacts and other environmental changes. Rising concentrations of hazardous substances in the natural sediments are likely to be a high risk to the natural environment. At the same time, they can greatly reduce opportunities for environmental engineering of lakes. Four lakes with different trophic states and anthropogenic pressures were chosen for this study in Lithuania. Higher concentrations of elements like Cr, Cu and Zn were not only detected in the top most layers of sapropel but also in deeper layers and are attributed to lithogenic association of trace elements in such deep layers. Concentrations of Pb were detected only in upper layers of sapropel which indicates the impact of anthropogenic activity. The main source of heavy metals was multidimensional anthropogenic pollution leading to a biogenic–anthropogenic association of elements. Sapropel with low concentrations of heavy metals exhibits a different inter-association matrix because most of the elements tend to form lithogenic–clastogenic associations.

Detection of organic carbon in Mars-analog paleosols with thermal and evolved gas analysis

Decades of space exploration have shown that surface environments on Mars were habitable billions of years ago. Ancient, buried surface environments, or paleosols, may have been preserved in the geological record on Mars, and are considered high-priority targets for biosignature investigation. Studies of paleosols on Earth that are compositionally similar to putative martian paleosols can provide a reference frame for constraining their organic preservation potential on Mars. However, terrestrial paleosols typically preserve only trace amounts of organic carbon, and it remains unclear whether the organic component of paleosols can be detected with Mars rover-like instruments. Furthermore, the study of terrestrial paleosols is complicated by diagenetic additions of organic carbon, which can confound interpretations of their organic preservation potential. The objectives of this study were a) to determine whether organic carbon in ~30-million-year-old Mars-analog paleosols can be detected with thermal and evolved gas analysis, and b) constrain the age of organic carbon using radiocarbon (14C) dating to identify late diagenetic additions of carbon. Al/ Fe smectite-rich paleosols from the Early Oligocene (33 Ma) John Day Formation in eastern Oregon were examined with a thermal and evolved gas analyzer configured to operate similarly to the Sample Analysis at Mars Evolved Gas Analysis (SAM-EGA) instrument onboard the Mars Science Laboratory Curiosity rover. All samples evolved CO2 with peaks at ~400 °C and ~700° C from the thermal decomposition of refractory organic carbon and small amounts of calcium carbonate, respectively. Evolutions of organic fragments co-occurred with evolutions of CO2 from organic carbon decomposition. Total organic carbon (TOC) ranged from 0.002 - 0.032 ± 0.006 wt. %. Like modern soils, the near-surface horizons of all paleosols had significantly higher TOC relative to subsurface layers. Radiocarbon dating of four samples revealed an organic carbon age ranging between ~6,200 – 14,500 years before present, suggesting there had been inputs of exogenous organic carbon during diagenesis. By contrast, refractory carbon detected with EGA and enrichment of TOC in near-surface horizons of all three buried profiles were consistent with the preservation of trace amounts of endogenous organic carbon. This work demonstrates that near-surface horizons of putative martian paleosols should be considered high priority locations for in-situ biosignature investigation and reveals challenges for examining organic matter preservation in terrestrial paleosols.

Catchment Sediment Dynamics and the Role of Deep-Seated Landslide-Dams; Waipaoa Catchment, Raukumara Peninsula, New Zealand

<p>Sediment volumes retained by landslide-dams of the Waipaoa are small at 1.85x10⁶m³ compared to the 24.5km³ (Marden et al., 2008b) of sediment eroded in the landscape since the last glacial maximum. Landslide-dams do however represent a major perturbation to sediment transport, although due to their mainly short life span this disruption is discontinuous representing a pulsing in the transport network. The objective of this study is to investigate the sedimentary dynamics of the Waipaoa catchment by providing insights into the role that deep-seated landslides play and asks the questions: What is the impact on sediment transport imposed by the landslide-dams of the Waipaoa catchment? and; What do the sediments impounded in landslide-dammed lakes tell us about catchment sediment dynamics through time? The Waipaoa River on the East Cape of New Zealand‘s North Island delivers volumes of sediment to the coast which are considered high by global standards. Catchment erosion is controlled by soft marine sediments, combined with a history of tectonic fracturing and frequent intense rain storms. Erosion events are driven by intense cyclonic systems rain storms which deliver ≥200mm/24hr rainfall and induce catchment wide gully erosion as well as shallow surficial landslides. Under current land covers gully erosion provides the dominant source of sediments, with high degrees of slope channel coupling and steep gradient river profiles providing for efficient delivery to the coast. Offshore in the Poverty Bay, sediments delivered by the Waipaoa River show considerable variability over a range of temporal scales. Valley slopes within the Waipaoa catchment are also susceptible to large deep-seated landslide failures, with movement depths greater than 5 metres often on internal structural failure planes. These large slope movements can be produced by both extreme storm events (≥300mm/24hr) which occur on a return periods of 1 in 5 years and seismic ground shaking of 1 in 1000-2000 years. Where these large events block channels and are able to persist for long periods, sediments accumulated upstream to provide a unique record of the catchments sedimentary history. There have been some 1100 historic large scale features which have been identified within the Waipaoa region, with this study selecting seven that have shown evidence of channel blockage. The project aims to provide insights into the age of a sample of deep-seated landslides that have dammed channels to determine how long landslide-dams survive in the landscape and quantify the volumes of sediment they have trapped. Further, the project aims to determine what the spatial and temporal distribution of these blockages has meant to sediment delivery and whether there have been changes in sediment dynamics in their upper catchments over time. The project uses the detailed mapping of the trapped body of sediments, GIS modelling of the palaeo and present landscapes and age control determinations provided by tephra and 14C dating to provide both volumes and rates of sediment delivery.</p>

Catchment Sediment Dynamics and the Role of Deep-Seated Landslide-Dams; Waipaoa Catchment, Raukumara Peninsula, New Zealand

<p>Sediment volumes retained by landslide-dams of the Waipaoa are small at 1.85x10⁶m³ compared to the 24.5km³ (Marden et al., 2008b) of sediment eroded in the landscape since the last glacial maximum. Landslide-dams do however represent a major perturbation to sediment transport, although due to their mainly short life span this disruption is discontinuous representing a pulsing in the transport network. The objective of this study is to investigate the sedimentary dynamics of the Waipaoa catchment by providing insights into the role that deep-seated landslides play and asks the questions: What is the impact on sediment transport imposed by the landslide-dams of the Waipaoa catchment? and; What do the sediments impounded in landslide-dammed lakes tell us about catchment sediment dynamics through time? The Waipaoa River on the East Cape of New Zealand‘s North Island delivers volumes of sediment to the coast which are considered high by global standards. Catchment erosion is controlled by soft marine sediments, combined with a history of tectonic fracturing and frequent intense rain storms. Erosion events are driven by intense cyclonic systems rain storms which deliver ≥200mm/24hr rainfall and induce catchment wide gully erosion as well as shallow surficial landslides. Under current land covers gully erosion provides the dominant source of sediments, with high degrees of slope channel coupling and steep gradient river profiles providing for efficient delivery to the coast. Offshore in the Poverty Bay, sediments delivered by the Waipaoa River show considerable variability over a range of temporal scales. Valley slopes within the Waipaoa catchment are also susceptible to large deep-seated landslide failures, with movement depths greater than 5 metres often on internal structural failure planes. These large slope movements can be produced by both extreme storm events (≥300mm/24hr) which occur on a return periods of 1 in 5 years and seismic ground shaking of 1 in 1000-2000 years. Where these large events block channels and are able to persist for long periods, sediments accumulated upstream to provide a unique record of the catchments sedimentary history. There have been some 1100 historic large scale features which have been identified within the Waipaoa region, with this study selecting seven that have shown evidence of channel blockage. The project aims to provide insights into the age of a sample of deep-seated landslides that have dammed channels to determine how long landslide-dams survive in the landscape and quantify the volumes of sediment they have trapped. Further, the project aims to determine what the spatial and temporal distribution of these blockages has meant to sediment delivery and whether there have been changes in sediment dynamics in their upper catchments over time. The project uses the detailed mapping of the trapped body of sediments, GIS modelling of the palaeo and present landscapes and age control determinations provided by tephra and 14C dating to provide both volumes and rates of sediment delivery.</p>

The Geomorphology of Farewell Spit and Its Sensitivity to Sea-Level Rise

<p>Sand-dominated barriers are highly sensitive coastal systems which alter their morphology in response to rising sea level, undergoing extensive sediment reworking as wave activity reaches further inland. Farewell Spit, South Island, New Zealand, is a sand-dominated barrier spit which extends 25kms eastward from the mainland, enclosing the northwestern corner of the macro-tidal Golden Bay. During spring tide cycles low-lying areas of the Spit become completely inundated. The aim of this study is to establish the morphological stability of Farewell Spit and its potential response to the latest IPCC projected eustatic sea-level rise of 0.48m (A1B scenario) by the end of this century. GIS analysis of aerial photographs and the identification of 137Cs signatures within the dunes have shown a high degree of mobility in the Spit's features over the past 55 years. Vegetation increased by 75%, mainly due to the introduction of A arenaria, which has also led to the development of foredunes prograding up to 142m over the tidal flats. Barchan dunes on the Spit are also highly mobile migrating at up to 30m/y. The high amount of sediment movement along the spit is reflected in the sedimentology of the tidal flats, which show layers of aeolian transported fine, well-sorted sand several centimetres thick. The predominance of medium sand shows that reworking appears to have occurred on these flats due to storm events in Golden Bay, and like the dunes, 14C dating indicates they are very young features Projected sea-level rise was modelled to assess the vulnerability of low-lying areas of the Spit to tidal flooding. Deeper water levels in the two tidal channels which currently flood across the Spit are expected and there is a risk of additional channels opening, one being very near to the contact between the Spit and mainland. The mobility of the dune systems may however buffer some of these processes by providing natural defences against the sea. Barrier roll over does not appear to be an important process as it appears to be too wide to allow for washover. It is concluded that under current sea-level rise predictions Farewell Spit will not transgress landward but will be subject to exacerbated erosion.</p>

The Geomorphology of Farewell Spit and Its Sensitivity to Sea-Level Rise

<p>Sand-dominated barriers are highly sensitive coastal systems which alter their morphology in response to rising sea level, undergoing extensive sediment reworking as wave activity reaches further inland. Farewell Spit, South Island, New Zealand, is a sand-dominated barrier spit which extends 25kms eastward from the mainland, enclosing the northwestern corner of the macro-tidal Golden Bay. During spring tide cycles low-lying areas of the Spit become completely inundated. The aim of this study is to establish the morphological stability of Farewell Spit and its potential response to the latest IPCC projected eustatic sea-level rise of 0.48m (A1B scenario) by the end of this century. GIS analysis of aerial photographs and the identification of 137Cs signatures within the dunes have shown a high degree of mobility in the Spit's features over the past 55 years. Vegetation increased by 75%, mainly due to the introduction of A arenaria, which has also led to the development of foredunes prograding up to 142m over the tidal flats. Barchan dunes on the Spit are also highly mobile migrating at up to 30m/y. The high amount of sediment movement along the spit is reflected in the sedimentology of the tidal flats, which show layers of aeolian transported fine, well-sorted sand several centimetres thick. The predominance of medium sand shows that reworking appears to have occurred on these flats due to storm events in Golden Bay, and like the dunes, 14C dating indicates they are very young features Projected sea-level rise was modelled to assess the vulnerability of low-lying areas of the Spit to tidal flooding. Deeper water levels in the two tidal channels which currently flood across the Spit are expected and there is a risk of additional channels opening, one being very near to the contact between the Spit and mainland. The mobility of the dune systems may however buffer some of these processes by providing natural defences against the sea. Barrier roll over does not appear to be an important process as it appears to be too wide to allow for washover. It is concluded that under current sea-level rise predictions Farewell Spit will not transgress landward but will be subject to exacerbated erosion.</p>

Geochemistry and Holocene Sedimentary Environment Evolution of Subaqueous Clinoform off Shandong Peninsula (Yellow Sea)

As a key sedimentary body connecting the north and South Yellow Sea, the subaqueous clinoform off Shandong Peninsula plays an important role in the sedimentary system of China seas, and it is also a studied example in the study among the major “source to sink” systems. Based on AMS 14C dating, sediment grain size, major and trace element contents from core WH-05 located at the edge of the clinoform, we discuss changes in the deposition rate, analyze sediment provenance and controlling factors, and reveal the environmental evolution of the source area since the Holocene. Results from core WH-05 show that marine sedimentation began at about 8.5 ka B.P. The deposition rate decreased from the initial 28.37 m/ka to 0.52 m/ka. Sediment provenance suggests that the Huanghe river sediments have been the main source for the study area since the Holocene. The As/Al, V/Sc indicators show that the environmental oxidation environment was gradually weakened and then increased slightly starting from 7.0 ka B.P. The change in redox is consistent with the change in sea level, the deposition rate, and depositional depth.

14C DATING OF THE ERLITOU SITE

ABSTRACT This article outlines the research progress on radiocarbon (14C) dating of the Erlitou site. The Erlitou site, belonging to the Bronze Age, located in Yanshi, Henan province, China, was discovered by archaeologists in 1959 when they investigated the Xia people’s remains in the area where the Xia people lived according to the records of ancient documents. Since then, there has been a standing debate about whether the site belongs to the Xia or Shang dynasty. By the mid-1990s, several hundred discussion articles on the issue had been published, but the question was still unresolved. Therefore, evidence from the chronology has attracted a great amount of attention. The dating of the Erlitou site began in the 1970s, and since the Xia-Shang-Zhou Chronology Project began in the mid-1990s, by application of wiggle-matching on the basis of improving the dating accuracy, the date of the Erlitou site has gradually become clear, which provides a basis for the archaeological research on the Xia and Shang dynasties.