Differences In Provenance Research Articles

Provenance composition and evolution of marine black shales in the Yangtze platform from Ediacaran to Silurian

Provenance is important in understanding the evolution of geological structure and the coupling of the basin-mountain system. Although many geochemical data document the three sets of marine black shales (Ediacaran to Silurian) in the Yangtze Platform, the evolution characteristics of their sediment sources remain unclear. We gather a huge database from 307 published papers totaling 12,342 analyzed samples to establish provenance. Pearson correlation coefficient and multivariate statistical analyses were performed to establish the element and mineral links in the black shale. Nine immobile elemental ratios (Ti/Th, Th/Sc, Cr/Th, Ti/Zr, Sc/Ta, Ti/Nb, Sc/La, Zr/Sc, and La/Ti) were employed to indicate provenance. The results show that the black shales of the Longmaxi and Niutitang formations are relatively enriched in redox sensitive and productivity related elements such as V, Cr, Mo, U, Co, Ni, Cu, Zn, and Ba. The use of provenance analysis proxies, including V, Cr, Mo, Ce, Fe, P, Ba, Cu, Ni, and Si, should be approached with caution due to the potential interference of marine authigenic components. The three black shales have provenance compositions that gradually extend from intermediate to felsic from the Doushantuo to the Niutitang to the Longmaxi shale. This difference in provenance is a response to the Pan-African and Kwangsian orogenic structures which are likely to impact the paleomarine environment by variable biotrophic element inputs.

Differences in sediment provenance from rainfall and snowmelt erosion in the Mollisol region of Northeast China

AbstractDifferences in erosion patterns inevitably lead to different soil loss processes. However, the differences in sediment sources between rainfall and snowmelt erosion are not well studied. To address this gap, a study was conducted in a small agricultural catchment (3.5 km2) using the fingerprinting technique to quantify the various sources contributing to sediment, as well as determine the magnitude of sediment total nitrogen (TN), total phosphorus (TP), total potassium (TK) and soil organic matter (SOM) loads from three sources (cultivated land, unpaved roads and gullies) during the rainy season and spring thawing period. Sediment sources from 17 rainfall erosion and seven snowmelt erosion events of varying magnitudes were compared. The Collins and Bayesian mixing models, coupled with geochemical tracers (Cs, V, Cd, Pb and Ag), were applied to assess the contribution proportion of individual sediment sources to suspended sediment. According to the results obtained from the Bayesian mixing model with higher accuracy, cultivated land, unpaved roads and gullies contributed 60.3% (load‐weighted mean contribution [LMC] = 82.8%), 11.0% (LMC = 6.5%) and 28.7% (LMC = 10.7%) of the sediment in the rainy season, respectively. Cultivated land was the dominant sediment source for rainfall erosion, with high rainfall erosivity and sediment concentration. However, for snowmelt erosion, gullies were the primary sediment source (LMC = 66.2%), followed by cultivated land (LMC = 19.8%) and unpaved roads (load‐weighted = 14.0%). Meanwhile, in the spring thawing period, the contributions of unpaved roads to sediment were higher than in the rainy season. During the rainy season, the greatest contributions of TN, TP, TK and SOM were observed from cultivated land, with respective LMC values of 94.2%, 89.4%, 81.1% and 94.8%. With the increase of sediment contribution from gullies in the spring thawing period, its LMC of TN, TP, TK and SOM increased to 42.6%, 58.3%, 65.0% and 38.0%, respectively. The results of the study could be useful for understanding the processes of soil erosion, clarifying the driving mechanism of compound erosion, developing the compound erosion prediction model and optimizing the spatial configuration of erosion control measures.

Potentials of baobab in food systems

The current study aims to review the prospects for baobab domestication and cultivation, nutrient variability, food applications, industrial value and future potentials of the African baobab. The variations in nutrient content of baobab as seen in several studies could have arisen from differences in provenance the sample was obtained, age of the parent plant, as well as differences in soil and climate. Regardless, baobab is a rich source of nutrients, bioactives and functional polysaccharides, representing a huge market potential for food industries. It has garnered widespread interest as a functional ingredient for preventive health care and disease management. Due to approvals given by the United States Food and Drug Administration (FDA) and the European Commission (EC), baobab fruit pulp has gained widespread popularity as a novel food ingredient. In addition, baobab fruit pulp offered as a dietary supplement has been used in its naturally dehydrated form or processed into pills. There are huge information gaps on processing and safety of baobab seed oil, use of baobab seeds and leaf powder - a rich source of mucilage, in food systems. An industrially significant product from baobab are the functional polysaccharides which are a rapidly advancing application. Baobab plant parts, fruit pulp, kernels, whole seeds, funicles, leaves, empty fruit shells and roots all inclusive, are of significant value for their key role in nutrition and health, food security and economic welfare of the rural communities in regions where the trees are originally found. Both traditional and novel applications of the various parts of the baobab tree have been explored in this paper. These include use in edible products like gruels, jams, yoghurt, wines, juice etc. Application of extrusion processing as an economical means of value addition to baobab commodities has been reviewed, especially relating to the classification of baobab as a neglected and underutilized species (NUS).

Detection of Copper by the ChemCam Instrument Along Curiosity's Traverse in Gale Crater, Mars: Elevated Abundances in Glen Torridon

AbstractLaser‐induced breakdown spectroscopy, as utilized by the ChemCam instrument onboard the Curiosity rover, detected enhanced abundances of the element copper. Since landing in Gale crater (6 August 2012), 10 enhancements in copper abundance were observed during 3007 Martian days (sols) of rover operations and 24 km of driving (as of 20 January 2021). The most prominent ones were found in the Kimberley area on the crater floor (Aeolis Palus) and in Glen Torridon (GT) on the lower flanks of Aeolis Mons (Mt. Sharp). Enhancements in copper record the former existence of modestly acidic and oxidizing fluids, which were more oxidizing in Kimberley than in GT. Of the two main types of bedrock in the lowest part of GT, Mg‐rich “coherent” and K‐rich “rubbly” (named based on their outcrop expression), copper was detected only in coherent, not in rubbly bedrock. The difference between these two types of bedrock may be due to difference in provenance. Alternatively, based on a recently developed lacustrine‐groundwater mixing model, we suggest that rubbly bedrock was altered by modestly acidic, shallow‐subsurface lake water that leached out both copper and manganese, while coherent bedrock was affected by dominantly alkaline fluids which would be consistent with its mineralogical composition (including siderite) as returned by the CheMin instrument onboard the rover. Higher up in GT, ChemCam data indicated significant gradients in the copper concentration in coherent bedrock on a local scale of only a few meters, which suggests a different alteration style and possibly different types of diagenetic fluids.

Growth of the southern Tian Shan-Pamir and its impact on central Asian climate

Uplift and amalgamation of the high-elevation (>3000 m) Tian Shan and Pamir ranges in Central Asia restricts westerly atmospheric flow and thereby limits moisture delivery to the leeward Taklimakan Desert in the Tarim Basin (<1500 m), the second largest modern sand dune desert on Earth. Although some research suggests that the hyper-arid conditions observed today in the Tarim Basin developed by ca. 25 Ma, stratigraphic evidence suggests the first erg system did not appear until 12.2 Ma. To address this controversy and to understand the tectonic influences on climate in Central Asia, we studied a continuous, 3800-m-thick stratigraphic section deposited from 15.1 to 0.9 Ma now exposed within the western Kepintagh fold-and-thrust belt in the southern Tian Shan foreland. We present new detrital zircon data (n = 839), new carbonate oxygen (δ18Oc) and carbon (δ13Cc) stable isotope compositions (n = 368), structural modeling, and stratigraphic observations, and combine these data with recently published magnetostratigraphy and regional studies to reconstruct the history of deposition, deformation, and climate change in the northwestern Tarim Basin. We find that basins along the southern (this study) and northern (i.e., Ili Basin) margins of the Tian Shan were likely receiving similar westerly precipitation by 15 Ma (δ18Oc = ∼−8‰) and had similar lacustrine-playa environments at ca. 13.5 Ma, despite differences in sedimentary provenance. At ca. 12 Ma, an erg desert formed adjacent to the southern Tian Shan in the northwestern Tarim Basin, coincident with a mid- to late Miocene phase of deformation and exhumation within both the Pamir and southern Tian Shan. Desertification at ca. 12 Ma was marked by a negative δ18Oc excursion from −7.8 ± 0.4‰ to −8.7 ± 0.7‰ in the southern Tian Shan foreland (this study), coeval with a negative δ18Oc excursion (∼−11 to −13‰) in the Tajik Basin, west of the Pamir. These data suggest that only after ca. 12 Ma did the Pamir-Tian Shan create a high-elevation barrier that effectively blocked westerly moisture, forming a rain shadow in the northwestern Tarim Basin. After 7 Ma, the southern Tian Shan foreland migrated southward as this region experienced widespread deformation. In our study area, rapid shortening and deformation above two frontal foreland faults initiated between 6.0 and 3.5 Ma resulted in positive δ13Cc excursions to values close to 0‰, which is interpreted to reflect exhumation in the Tian Shan and recycling of Paleozoic carbonates. Shortening led to isolation of the study site as a piggy-back basin by 3.5 Ma, when the sediment provenance was limited to the exhumed Paleozoic basement rocks of the Kepintagh fold belt. The abrupt sedimentologic and isotopic changes observed in the southern Tian Shan foreland appear to be decoupled from late Cenozoic global climate change and can be explained entirely by local tectonics. This study highlights how tectonics may overprint the more regional and global climate signals in active tectonic settings.

Detrital zircon geochronology and heavy mineral composition constraints on provenance evolution in the western Pearl River Mouth basin, northern south China sea: A source to sink approach

Investigating the provenance evolution of sedimentary basins with complex tectonic histories is challenging because of the continuously evolving tectonic framework and changing source areas. Pearl River Mouth Basin (PRMB) in the northern South China Sea preserves a large volume of Cenozoic sediments derived from both intrabasinal and extrabasinal sources. However, rare study has been conducted to investigate the provenance evolution of the western PRMB. In this study, we report new detrital zircon U–Pb geochronological and heavy mineral data from the western PRMB, attempting to identify its potential sources and provenance evolution from Eocene to early Miocene. Our data from distinct structural units and formations reveal spatial-temporal differences in provenance. In the northern part, a similar age pattern with a major peak at ∼425 Ma and a subordinate peak at ∼230 Ma is preserved in the Eocene-late Oligocene sediments and suggests that sediments were mainly derived from the Yunkai Massif via Nanduhe River. By contrast, in the southern part, the Eocene-late Oligocene sediments display a dominant age population ranging from 100 Ma to 300 Ma, which implies that the sediments were mainly eroded from nearby Shenhu Uplift and Hainan Island. The heavy mineral data also record such spatial differences in provenance. However, during the early Miocene, the northern and southern parts show similar detrital zircon age patterns with multiple clusters at ∼245 Ma, ∼450 Ma, ∼850 Ma, 970–980 Ma, 1825–1845 Ma, and ∼2500 Ma, indicating that the Miocene sediments across the whole basin were mainly provided by the Pearl River system. The increase of Paleozoic and Precambrian zircons in the lower Miocene sediments suggests a profound provenance shift from multiple nearby sources to the South China Block via the Pearl River between Oligocene and Miocene in the western PRMB, and its timing is posterior to other regions of the PRMB. Finally, four-stage source-to-sink evolution for the PRMB is proposed, showing that sediment provenance in the PRMB is controlled by regional tectonic movement, drainage evolution, and basin architecture. This study suggests that the small-scale drainage system Nanduhe River sourced by Yunkai Massif contributed significantly to the PRMB between Eocene and Oligocene, and highlights its complex processes of provenance evolution that are relevant to the evolution of marginal sea basins globally.

Geochemical characterization of major elements in Gurbantunggut Desert sediments, northwestern China and their regional variations

• Mineralogical maturity increased from the piedmont to the desert center. • Provenance controls the regional differences in major element compositions. • Transport, sorting, recycling, and chemical weathering affect the sand compositions. • River sands constitute a significant source of sands in this desert. • Extensive vegetation coverage contributes to the regional differences in this desert. Identifying the geochemical composition of desert sands in the Gurbantunggut Desert is essential for understanding the formation of desert dunes in the mid-latitudes. In this study, we collected samples of desert sands (125–250 μm), fluvial sands, and lacustrine sands across the Gurbantunggut Desert and calculated the sand drift potential at four meteorological stations. The sand samples from the Gurbantunggut Desert were mostly enriched in SiO 2 , while the other major elements were depleted compared to those of the Upper Continental Crust (UCC). The chemical weathering indices (α Al E, CIA, and WIP) indicate that the sand-sized sediments in the Gurbantunggut Desert are in the initial stage of continental chemical weathering. SiO 2 and K 2 O contents as well as mineralogical maturity of the desert sands increased from the piedmont to the desert center. UCC-normalized distribution patterns were also consistent along this transect due to the homogenization of desert sand composition, whereas the concentrations of other major elements (except for TiO 2 and MnO) decreased. We conclude that (1) regional variations in the composition of the Gurbantunggut Desert sands primarily reflect differences in provenance, transport, sorting, recycling of the sediments, and vegetation cover as well as the chemical weathering; and (2) differences in indices describing the major element composition of the sands reflect regional variations in provenance from the mountains to the depositional basin. Sands within piedmont rivers possess major element characteristics similar to those of dune sands in the region, suggesting that rivers represent a significant source of sands in the desert.

Radiology report generation for proximal femur fractures using deep classification and language generation models

Proximal femur fractures represent a major health concern, and substantially contribute to the morbidity of elderly. Correct classification and diagnosis of hip fractures has a significant impact on mortality, costs and hospital stay. In this paper, we present a method and empirical validation for automatic subclassification of proximal femur fractures and Dutch radiological report generation that does not rely on manually curated data. The fracture classification model was trained on 11,000 X-ray images obtained from 5000 electronic health records in a general hospital. To generate the Dutch reports, we first trained an embedding model on 20,000 radiological reports of pelvic region fractures, and used its embeddings in the report generation model. We trained the report generation model on the 5000 radiological reports associated with the fracture cases. Our report generation model is on par with state-of-the-art in terms of BLEU and ROUGE scores. This is promising, because in contrast to those earlier works, our approach does not require manual preprocessing of either images or the reports. This boosts the applicability of automatic clinical report generation in practice. A quantitative and qualitative user study among medical students found no significant difference in provenance of real and generated reports. A qualitative, in-depth clinical relevance study with medical domain experts showed that from a human perspective the quality of the generated reports approximates the quality of the original reports and highlights challenges in creating sufficiently detailed and versatile training data for automatic radiology report generation.

Soil nutritional status in KwaZulu-Natal drives symbiotic interactions and plant performance in

Context Cancer bush (Lessertia frutescens L.) is a multipurpose medicinal legume endemic to southern Africa, reported to grow in a variety of soils, from very poor to fertile ones. However, there is limited knowledge on how L. frutescens is able to thrive in diverse soils and, particularly, nothing has been reported on the benefits from the microbe symbiosis, plant growth and acclimation to low nutrient soils. Aims Therefore, this study examined the effect of soil nutrient deficiency in plant–microbe symbiosis, nitrogen (N) nutrition and associated plant performance of L. frutescens plants, growing in four different impoverished soils from the KwaZulu-Natal region. Methods Experimental soil samples collected from four geographical distinct KwaZulu-Natal (KZN) locations (Hluhluwe, Izingolweni, Bergville and Ashburton) representing grasslands and savanna were used as natural inoculum and growth substrate. Key results Soil analysis showed significant differences in soil pH, exchange acidity, total cations, organic carbon (C), phosphorus (P) and N related to differences in the soil provenance. L. frutescens root nodules were dominated by Bacillus sp. in all soil treatments, except in plants grown in Bergville soil that did not nodulate. In all, 68–90% of total plant N concentration was reduced from atmospheric N. L. frutescens plants also relied on soil-available N for growth. Hluhluwe and Ashburton soil-grown plants showed a significantly higher biomass than did other soil-grown plants. Conclusions These current findings demonstrated that L. frutescens root nodules were dominated by bacteria characterised as phospho-bacteria and N2-fixing bacteria in these impoverished soils. This enabled L. frutescens to fix atmospheric N and assimilate soil available N to reduce energy demand. Implications These strategies may collectively contribute to L. frutescens resilience in nutrient-deficient savanna and grassland ecosystems.

Tracing mantellic vs. crustal sources of clastic sediments in continental rifts using geochemical and Sm[sbnd]Nd and Sr isotope compositions: Insights from paleogene alluvial deposits of the Resende Basin, SE-Brazil

This work presents combined whole-rock element and SmNd and Sr isotopes of the Eocene syn-rift I alluvial sediments of the Resende Basin (SE-Brazil), aiming the assessment of sedimentary provenance. Geochemical compositions are used to evaluate the potential effects of hydrodynamic sorting and weathering in the SmNd and Sr isotopic compositions. Mudstone, sandstone, and conglomerate samples were collected for analysis. Chemical data indicate that the major element composition of the Resende Basin sediments is compromised by present-day weathering conditions and cannot be used for source areas weathering interpretations. Similar trace and rare earth elements composition in sandstones and mudstones imply poorly mixed sediments and provenance is associated with felsic and intermediated igneous sources with a subordinate mafic component. Mudstones are enriched in elements typically associated with heavy minerals (Ti, Zr, Hf, and Y). Weathering and mineral sorting affect mainly the major and trace element compositions of the Resende Basin sediments, while most of the isotopic composition's variations are due to differences in provenance caused by different source areas and/or degrees of source mix. Based on its conspicuous contrasting isotopic signature, the Cretaceous alkaline igneous source component can be tracked in the Resende Basin sedimentary record. Samples with εNd(t) < −10 have more than 60% of alkaline-derived provenance. The Resende Basin was compartmentalized by at least two depocenters separated by a structural high. The depocenters had very proximal sources but were connected by an axial fluvial system. The structural high acted as a barrier, retaining the sediment supply coming from the Itatiaia alkaline massif. These results are compatible with what is seen in other rift-related sedimentary environments, such as the Rio Grande and the North Sea deposits, where Nd and Sr composition of first-cycle clastic sediments reflect their parental source isotopic signature.

Change in Sediment Provenance on the Inner Slope of the Chukchi Rise and Their Paleoenvironmental Implications

The Arctic Ocean is one of the world’s most remarkable regions with respect to global climate change. The core ARA09C-St03 was analyzed for mineral composition and Nd isotope to determine the sediment provenance and reconstruct the paleoenvironment in the inner slope of the Chukchi Rise. Core ARA09C-St03 represents overall cycles of brown and gray color with three distinct dark brown layers and two pinkish-white layers and is divided into eight sedimentary units based on the lithological feature. The core has a continuous record of the late marine isotope stage (MIS) 5 to the Holocene and in particular provides a particularly high-resolution record from the Last Glacial Maximum (LGM). Sediment is derived mainly from the adjacent East Siberian Sea and the North American region, and changes in sediment provenance are controlled by climate-dependent particle size. During the glacial/stadial periods, sediments in Units 3, 5, and 8 were supplied by the East Siberian Sea via meltwater-derived suspension. The major ice-rafted debris (IRD) events in Units 2, 4, and 7, characterized by abundant dolomite and K/C ratio, were sourced from North America. The North America-derived materials reflect the initiation and disintegration of the Laurentide Ice Sheet and icebergs transported them across the open Arctic Ocean. The differences in provenance within these periods may be related to the scale of the Laurentide Ice Sheet. Interglacial sediments, including those from Units 1 and 6, are of mixed origin from Eurasia and the Canadian Archipelago and may have been transported by oceanic current and seasonal sea ice. These periods are likely associated with the negative Arctic Oscillation (AO) intensifying the Beaufort Gyre.

Insights into evolution of a rift basin: Provenance of the middle Eocene-lower Oligocene strata of the Beibuwan Basin, South China Sea from detrital zircon

Investigating rift basins and their provenance is difficult because their tectonic framework is continuously evolving. The Beibuwan Basin in the South China Sea is a typical rift basin that shares many characteristics of major rift basins worldwide. We present new detrital zircon UPb ages from the Beibuwan basin and, by combining with published data from surrounding drainages, are able to define its potential sources and to investigate its provenance evolution from the middle Eocene-lower Oligocene. Detrital zircon age spectra from distinct structural units and formations of the rift basin reveal spatial-temporal differences in provenance. In the middle-upper Eocene, a similar age pattern with major peaks at 263–253 Ma and 450–416 Ma is preserved across the basin and suggests that sediment was uniformly derived from the Yunkai Massif and Hainan Island. In contrast, during the lower Oligocene the basin displays markedly diverse ages with peaks at 250–243, 416, 756, 967–945, 1096–1084 Ma. The increase of Neoproterozoic zircons in the lower Oligocene stratum suggests that a major change in provenance occurred, most likely associated with the reorganization of the paleo-Pearl River along its central reaches due to a topography reversal associated with the uplift of Tibet and the onset of seafloor spreading in the South China Sea. Our spatial analysis of ages indicates that during the lower Oligocene, the detrital input varied across the basin. Rifting processes in the Beibuwan Basin generated multiple isolated depocenters separated by intra-basinal highs. The basin's architecture greatly affected sediment routing, with structural highs serving as barriers to sediment transport. Sediment provenance in the Beibuwan Basin is primarily controlled by drainage evolution and isolated depocenters associated with an evolving topography, processes which are relevant to the evolution of rift basins globally.

Lead isotopes in Celtiberian denarii from Turiasu and Roman asses minted in cities of the Conventus Caesaraugustanus (Hither Spain)

Isotope analysis is a flexible and powerful tool for provenance studies of archaeological objects. In the present study, lead isotopic analysis was used in order to gain insight into the origin of the mineral sources of coins minted in the Celtiberian mint of Turiasu and in six coloniae and municipia of the Conventus Caesaraugustanus (Hither Spain) under Augustus and Tiberius (27 BC-37 AD). In the case of Turiasu denarii, argentum from the Iberian Range mines was used, and in the Roman asses coined in civitates of the middle Ebro River, the copper minerals had a diverse origin (Pyrenean, from the Iberian Range, from the southeastern Iberian Peninsula and from the Central Iberian Zone). Differences in ore provenance and in bulk composition (investigated through X-ray fluorescence) were not only detected among the early Augustan, late Augustan and early Tiberian periods, but also among the mints under study. Moreover, differences were also detected among the mints of the Conventus Caesaraugustanus and the official mint of Rome, evidencing that the former enjoyed autonomy in terms of the choice of ore origin and processing.

SEM-EDX and FTIR analysis of archaeological ceramic potteries from southern Italy.

Sherds of ancient ceramics potteries, dating back to the seventh century BC and excavated from southern Italy, were analyzed in terms of microstructure and porosity (SEM), elemental composition (EDX), chemical bonding and mineralogical components (FTIR) in order to establish correlation with firing temperature, firing condition and provenance. Si/Al ratio from EDX analysis showed three major categories of raw materials (illite/montmorillonite, kaolinite and mullite), suggesting difference in provenance. Uniformly sized silica nanoparticle (0.7μm diameter) and trace amount of silver are being reported for the first time in one sample. Anorthite mineral and quartz inclusion was detected by FTIR in certain samples. All samples showed a prominent band for Si-O stretching, which shifted from 1062cm-1, broadened and appeared as doublet, relative to processing temperature. FTIR results proved incomplete dihydroxylation and undissociated carbonate in three samples, indicating a firing temperature of 700-800°C, whereas other samples were fired above 900°C. Only one sample among these three showed bloating pores in between interconnecting glassy matrix in SEM image, indicating a firing temperature of 1100-1200°C. The absence of magnetite along with significant Fe and Mn content indicated the formation of jacobsite, an iron manganese spinel complex, MnFe2O4, which is responsible for the black gloss effect in two particular samples and can be further confirmed by XRD. The presence of numerous small pores in SEM image of one of these two samples (1.2μm diameter) was indicative of extended vitrification at higher temperature than the other one. However, magnetite was responsible for black gloss effect in two other samples, proving difference in provenance. Therefore, SEM-EDX and FTIR results can offer valuable insight into the firing conditions, gloss decoration and provenance of ancient ceramic potteries.

Eastern Mediterranean amphorae from Late Antique urban centers of the northeastern Iberian Peninsula: archaeometric characterization

Amphorae from Palestine, Turkey, the Aegean and other areas of the eastern Mediterranean are frequently documented in Late Antique archaeological contexts in northeastern Spain, in relation to the transport of wine and other products. In order to gain further information on their compositional variability, provenance and production technology, a series of these amphorae was archaeometrically characterized. The amphorae were sampled from various contexts found in consumption centres of the current Catalan coastal territory, dated between the 5th and 7th centuries AD. Various types of eastern Mediterranean amphorae were characterized, including the most common ones, such as LRA 1, LRA 4, LRA 2 and LRA 3, but also others less represented in the ceramic assemblages. The selected samples were analyzed using a combination of techniques (WD-X-ray fluorescence, X-ray powder diffraction and optical microscopy by thin section analysis) for their chemical, mineralogical and petrographic characterization. The results show the presence of well differentiated fabrics and chemical compositions for each of the amphora types analyzed as well as certain variability in some of them, related to differences in provenance and/or production technology. Comparison with available archaeometric and archaeological data from eastern Mediterranean production centers enabled for provenance hypotheses for many of the amphorae under study.

Provenance and palaeogeographic implications of detrital zircons from the lower Carboniferous Riwanchaka Formation of the central Tibetan Plateau

AbstractThe Longmu Co–Shuanghu suture zone, which divides the Qiangtang terrane into the northern and southern Qiangtang blocks, is regarded as a key locality in reconstructing the evolutionary history of the Palaeo-Tethys Ocean and the break-up of Gondwana. However, although low-temperature – high-pressure metamorphic rocks and ophiolites have been documented within the Longmu Co–Shuanghu suture zone, it remains unclear whether it is an in situ suture zone and represents the relic of the main Palaeo-Tethys Ocean. The uncertainty stems mainly from the limited systematic studies of the provenance, palaeontological evidence and depositional settings of strata on either side of the Longmu Co–Shuanghu suture zone (i.e. northern and southern Qiangtang blocks). Here we report new detrital zircon U–Pb ages and palaeontological data from Lower Carboniferous strata (Riwanchaka Formation) of the northern Qiangtang block, central Tibet. The Riwanchaka Formation contains warm-climate biota with Cathaysian affinities. Provenance analysis reveals that the formation has detrital zircon spectra similar to those from strata of the Yangtze Plate, and it contains a large proportion of zircons with ages (~360 Ma) similar to the timing of synsedimentary magmatic arc activity, implying an active continental margin setting associated with northward subduction of the Palaeo-Tethyan oceanic lithosphere. Conversely, the Carboniferous–Permian strata from the southern Qiangtang block contain cool-water faunas of Gondwanan affinity and exhibit minimum zircon crystallization ages that are markedly older than their depositional ages, suggesting a passive continental margin setting. The differences in provenance, palaeontological assemblages and depositional settings of the Carboniferous to Permian strata either side of the Longmu Co–Shuanghu suture zone indicate the existence of an ancient ocean between the northern and southern Qiangtang blocks. Combining the new findings with previous studies on high-pressure metamorphic rocks, arc magmatism and ophiolites, we support the interpretation that the Longmu Co–Shuanghu suture zone is an in situ suture zone that represents the main suture of the Palaeo-Tethys Ocean.

Different provenance of separate loess sites in Yangtze River Basin and its paleoenvironmental implications

The dust deposits in the Yangtze River Basin (YRB) have been widely distributed along the Yangtze River valley. Previous studies mainly concentrated in its provenance of each loess site, however, the differences in provenance of loess among different sites in this area have rarely been studied. Here, the geochemical characteristics of the <20 µm fraction in the loess in separate Jiujiang, Xuancheng and Nanjing sites were analyzed. The result shows that the loess in Jiujiang and Nanjing sites, near Yangtze River riverway, share similar geochemical characteristics that may commonly derived from the detrital materials of Yangtze River. However, both sites have significantly different elemental compositions compared with Xuancheng site, which is ∼60 km away from the Yangtze River riverway. These sites share different geochemical characteristics with Eastern Qinling Mountains and Xifeng section on the Chinese Loess Plateau, North China. Combining the distribution of the aeolian sand hills and the loess in this area published by previous studies, we suggest that the exposed river valley floodplain caused by weak summer monsoon provided abundant materials to form local dust cells controlled by strong winter monsoon during the glacial periods. Therefore, those local loess deposits should be identified as the “valley-sourced loess”. These reveal the inherent connection between the monsoon system and the loess deposits in Yangtze River Basin.

Systematic estimation of potential risk caused by the replacement of aconite's cultivar

Background: Aconite is a famous toxic medicinal plant in the world. But in China, the aconite cultivar, Qingchuan cultivar, which has been stably used for 2000 years, are being rapidly replaced by the Liangshan cultivar, a new cultivar with better agronomic traits. However, the risk of the replacement is still unknown. Materials and Methods: We combine field research and cultivation experiments to clarify differences in provenance and differences in agronomic traits. We used high-performance liquid chromatography (HPLC) to analyze the content of key ingredients in commercially available medicines and semi-finished drugs. We then performed a transcriptome analysis of the two resources to study the key differential pathways of the two species and conducted a systematic discussion. Statistical Analysis Used: Statistical differences were assessed by analysis of variance or least significant difference. P

Trajectories of allostatic load among older Americans and Britons: longitudinal cohort studies

BackgroundDifference in life expectancy between males and females has been suggested to rest on sex difference in physiological dysregulation. But allostatic load, a physiological index, has not been carefully examined for an extended period beyond middle age. We aim to draw longitudinal trajectories of allostatic load in a national sample of older Americans and Britons; also to examine sex-based trajectories and factors behind their differences.MethodsWe studied men and women aged ≥50 years participating in the Health and Retirement Study Waves 8–11, 2006–2012 (N = 15,583 person-years) and the English Longitudinal Study of Ageing Waves 2, 4 and 6, 2004–2012 (N = 14,765 person-years). Because of the difference in provenance, we included different number of biomarkers to calculate allostatic load in HRS and ELSA. In HRS we used 8 biomarkers (systolic and diastolic blood pressure, haemoglobin A1c, high-density lipoprotein, total cholesterol, waist circumference, cystatin C, and C-reactive protein), while ELSA allostatic load was constructed from 10 biomarkers (systolic and diastolic blood pressure, haemoglobin A1c, high-density lipoprotein, total cholesterol, waist circumference, BMI, triglyceride, fibrinogen and C-reactive protein). A growth curve model was fitted to repeated observations of allostatic load, demographic characteristics, socioeconomic position, comorbidities and health behaviours (smoking, drinking, and physical exercise). To account for attrition, a joint model was applied.ResultsThe analysis showed that allostatic load increases linearly with age in the U.S. However, there are different levels for males and females. In England allostatic load follows such different paths that their trajectories cross in later life.ConclusionsSex-based trajectories of allostatic load showed distinct female advantage and are mostly consistent with female advantage in life expectancy.

Seasonal variability of 7Be in suspended sediments from the Copper River, Alaska: implications for quantifying recent flood deposits in coastal environments

Over the past three decades, particle-reactive cosmogenic 7Be (t1/2 = 53.3 d) has frequently been used to quantify recent fluvial sediment inputs to estuaries and coastal marine environments, providing an important tool to understand the timing and pathways of sediment dispersal. This study utilizes a 2-year high-resolution time series collected from the Copper River, Alaska, to examine the seasonal fluctuation in 7Be activity of suspended sediments near the river mouth. We show that there is considerable variability (particulate 7Be = ≤ 3.3–47 Bq kg−1) throughout the hydrograph, with a significant negative correlation to discharge and suspended sediment concentration. This variability is interpreted to be driven by a combination of fluctuations in atmospheric deposition, water aging, and dilution by 7Be-depleted sediments, reflecting erosion within the streambed/watershed and/or differing freshwater/sediment source. Particularly within this high-latitude setting, seasonal differences in provenance (snowpack/glacial melting vs. rainfall) likely influence 7Be activities. Importantly, 7Be was below detectable limits in river suspended sediments during peak discharge periods in both years, indicating that the flood signal in adjacent coastal environments will be negligible at this time. These results suggest that 7Be will not be an effective tracer of fluvial sediment deposition in some coastal environments.