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In much of Europe, the advent of low-input cereal farming regimes between c.ad 800 and 1200 enabled landowners—lords—to amass wealth by greatly expanding the amount of land under cultivation and exploiting the labour of others. Scientific analysis of plant remains and animal bones from archaeological contexts is generating the first direct evidence for the development of such low-input regimes. This article outlines the methods used by the FeedSax project to resolve key questions regarding the ‘cerealization’ of the medieval countryside and presents preliminary results using the town of Stafford as a worked example. These indicate an increase in the scale of cultivation in the Mid-Saxon period, while the Late Saxon period saw a shift to a low-input cultivation regime and probably an expansion onto heavier soils. Crop rotation appears to have been practised from at least the mid-tenth century.
The iconic Plaza Tree of Pueblo Bonito is widely believed to have been a majestic pine standing in the west courtyard of the monumental great house during the peak of the Chaco Phenomenon (AD 850–1140). The ponderosa pine (Pinus ponderosa) log was discovered in 1924, and since then, it has been included in “birth” and “life” narratives of Pueblo Bonito, although these ideas have not been rigorously tested. We evaluate three potential growth origins of the tree (JPB-99): Pueblo Bonito, Chaco Canyon, or a distant mountain range. Based on converging lines of evidence—documentary records, strontium isotopes (87Sr/86Sr), and tree-ring provenance testing—we present a new origin for the Plaza Tree. It did not grow in Pueblo Bonito or even nearby in Chaco Canyon. Rather, JPB-99 originated from the Chuska Mountains, over 50 km west of Chaco Canyon. The tree was likely carried to Pueblo Bonito sometime between AD 1100 and 1130, although why it was left in the west courtyard, what it meant, and how it might have been used remain mysteries. The origin of the Plaza Tree of Pueblo Bonito underscores deep cultural and material ties between the Chaco Canyon great houses and the Chuska landscape.
The Palaeoproterozoic Birimian Supergroup of the West African Craton (WAC) consists of volcanic belts composed predominantly of basaltic and andesitic rocks and intervening sedimentary basins composed predominantly of wackes and argillites. Mafic metavolcanic rocks and granitoid-hosted enclaves from the Palaeoproterozoic Lawra Belt of Ghana were analysed for geochemical and Sr–Nd isotopic data to constrain the geological evolution of the southeastern part of the WAC. The metavolcanic rocks display mainly tholeiitic signatures, whereas the enclaves show calc-alkaline signatures. The high SiO2 contents (48.6–68.9 wt%) of the enclaves are suggestive of their evolved character. The high Th/Yb values of the samples relative to that of the mantle array may indicate derivation of their respective magmas from subduction-modified source(s). The rocks show positive εNd values of +0.79 to +2.86 (metavolcanic rocks) and +0.79 to +1.82 (enclaves). These signatures and their Nd model ages (TDM2) of 2.31–2.47 Ga (metavolcanic rocks) and 2.39–2.47 Ga (enclaves) suggest they were probably derived from juvenile mantle-derived protoliths, with possible input of subducted pre-Birimian (Archean?) rocks in their source(s). Their positive Ba–Th and negative Nb–Ta, Zr–Hf and Ti anomalies may indicate their formation through subduction-related magmatism consistent with an arc setting. We propose that the metavolcanic rocks and enclaves from the Lawra Belt formed in a similar island-arc setting. We infer that the granitoids developed through variable degrees of mixing/mingling between basic magma and granitic melt during subduction, when blobs of basic to intermediate parental magma became trapped in the granitic magma to form the enclaves.
In the last few decades, the discovery of large ditched enclosures in Iberia has revealed the diversity and complexity of deposition and manipulation of human bone remains. Alongside traditional ritual burials (mainly megalithic tombs and hypogea), fragmented and scattered human bones mixed with other kinds of material culture began to appear in many features. This is the case for Ditch 5 at Marroquíes, which offers an excellent opportunity to explore this ritual behaviour. Based on a multi-proxy approach, three main conclusions can be drawn: 1) the skeletal elements present show deliberate selection of particular categories of bones; 2) depositional episodes included the remains of people who died at different points in time and were subject to different taphonomic processes, and 3) mobility patterns indicate that all individuals, with one possible exception, were local. The movement and manipulations of body parts may reflect the active role of people after death as social and symbolic elements that retain agency and capacity for action.
Micropaleontological and geochemical data were applied to sediments from southeastern Brazil to study the hydrodynamics associated with the Holocene sea level rise. Sediment cores were taken around Vitória Bay, examined for dinoflagellate cysts and subjected to isotopic analysis. The cyst assemblage mainly dominated by autotrophic species most notably O. centrocarpum, L. machaerophorum and T. vancampoae. The influence of the marine transgression and subsequent regression observed during the Holocene along the coast of Brazil could have initially favored the establishment of an oligotrophic and higher energy environment. The inflow of continental water from tributaries combined with a higher inflow of saline water into the estuarine system could have favored the establishment and subsequent deposition of the dinocysts.
The Tengchong Block within the Sanjiang Tethys belt in the southeastern part of the Tibetan plateau experienced a widespread intrusion of a felsic magmatic suite of granites in its central domain during Late Cretaceous times. Here, we investigate the Guyong and Xiaolonghe plutons from this suite in terms of their petrological, geochemical, and Sr–Nd, zircon U–Pb and Lu–Hf–O isotopic features to gain insights into the evolution of the Neo-Tethys. The Guyong pluton (76 Ma) is composed of metaluminous monzogranites, and the Xiaolonghe pluton (76 Ma) is composed of metaluminous to peraluminous medium- and fine-grained syenogranite. A systematic decrease in Eu, Ba, Sr, P and Ti concentrations; a decrease in Zr/Hf and LREE/HREE ratios; and an increase in the Rb/Ba and Ta/Nb ratios from the Guyong to Xiaolonghe plutons suggest fractional crystallization of biotite, plagioclase, K-feldspar, apatite, ilmenite and titanite. They also show the characteristics of I-type granites. The negative zircon εHf(t) isotopic values (−10.04 to −5.22) and high δ18O values (6.69 to 8.58 ‰) and the negative whole-rock εNd(t) isotopic values (−9.7 to −10.1) and high initial 87Sr/86Sr ratios (0.7098–0.7099) of the Guyong monzogranite suggest that these rocks were generated by partial melting of the Precambrian basement without mantle input. The zircon εHf(t) isotopic values (−10.63 to −3.04) and δ18O values (6.54 to 8.69 ‰) of the Xiaolonghe syenogranite are similar to the features of the Guyong monzogranite, and this similarity suggests a cogenetic nature and magma derivation from the lower crust that is composed of both metasedimentary and meta-igneous rocks. The Xiaolonghe fine-grained syenogranite shows an obvious rare earth element tetrad effect and lower Nb/Ta ratios, which indicate its productive nature with respect to ore formation. In fact, we discuss that the Sn mineralization in the region was possible due to Sn being scavenged from these rocks by exsolved hydrothermal fluids. We correlate the Late Cretaceous magmatism in the central Tengchong Block with the northward subduction of the Neo-Tethys beneath the Burma–Tengchong Block.
The stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) and total mercury concentrations (THg) of the three marine catfish species Aspistor luniscutis, Bagre bagre and Genidens genidens were evaluated to understand their trophic relationship in northern Rio de Janeiro state, south-eastern Brazil. The δ13C was similar among the three marine catfishes, whereas δ15N was similar in A. luniscutis and B. bagre and lower in G. genidens. THg was higher in G. genidens and lower in B. bagre. The greater assimilation of Sciaenidae fishes and squids by A. luniscutis and B. bagre resulted in smaller isotopic niche areas and trophic diversity but higher isotopic niche overlap, trophic redundancy and evenness. For G. genidens, the similar assimilation of all prey items resulted in the broadest isotopic niche among the marine catfishes. The higher mercury content in G. genidens is consistent with an increased important contribution of prey with a higher Hg burden. The bioaccumulation process was indicated by significant correlations of δ15N and THg with total length and total mass. Additionally, a significant correlation between THg and δ15N reflected the biomagnification process through the food web.
A new carbon isotope record for two high-latitude sedimentary successions that span the Jurassic–Cretaceous boundary interval in the Sverdrup Basin of Arctic Canada is presented. This study, combined with other published Arctic data, shows a large negative isotopic excursion of organic carbon (δ13Corg) of 4‰ (V-PDB) and to a minimum of −30.7‰ in the probable middle Volgian Stage. This is followed by a return to less negative values of c. −27‰. A smaller positive excursion in the Valanginian Stage of c. 2‰, reaching maximum values of −24.6‰, is related to the Weissert Event. The Volgian isotopic trends are consistent with other high-latitude records but do not appear in δ13Ccarb records of Tethyan Tithonian strata. In the absence of any obvious definitive cause for the depleted δ13Corg anomaly, we suggest several possible contributing factors. The Sverdrup Basin and other Arctic areas may have experienced compositional evolution away from open-marine δ13C values during the Volgian Age due to low global or large-scale regional sea levels, and later become effectively coupled to global oceans by Valanginian time when sea level rose. A geologically sudden increase in volcanism may have caused the large negative δ13Corg values seen in the Arctic Volgian records but the lack of precise geochronological age control for the Jurassic–Cretaceous boundary precludes direct comparison with potentially coincident events, such as the Shatsky Rise. This study offers improved correlation constraints and a refined C-isotope curve for the Boreal region throughout latest Jurassic and earliest Cretaceous time.
The Toarcian Oceanic Anoxic Event (T-OAE, c. 182 Ma) represents a major perturbation of the carbon cycle marked by widespread black shale deposition. Consequently, the onset of the T-OAE has been linked to the combined effects of global warming, high productivity, basin restriction and salinity stratification. However, the processes that led to termination of the event remain elusive. Here, we present palynological data from Arctic Siberia (Russia), the Viking Corridor (offshore Norway) and the Yorkshire Coast (UK), all spanning the upper Pliensbachian – upper Toarcian stages. Rather than a ‘dinoflagellate cyst black-out’, as recorded in T-OAE strata of NW Europe, both the Arctic and Viking Corridor records show high abundance and dinoflagellate diversity throughout the T-OAE interval as calibrated by C-isotope records. Significantly, in the Arctic Sea and Viking Corridor, numerous species of the Parvocysta and Phallocysta suites make their first appearance in the lower Toarcian Falciferum Zone much earlier than in Europe, where these key dinoflagellate species appeared suddenly during the Bifrons Zone. Our results indicate migrations of Arctic dinoflagellate species, driven by relative sea-level rise in the Viking Corridor and the establishment of a S-directed circulation from the Arctic Sea into the Tethys Ocean. The results support oceanographic models, but are at odds with some interpretations based on geochemical proxies. The migration of Arctic dinoflagellate species coincides with the end of the T-OAE and marks the arrival of oxygenated, low-salinity Arctic waters, triggering a regime change from persistent euxinia to more dynamic oxygen conditions.
Ice cores contain a record of climate change going back close to, and in some cases more than a million years. The record is shorter but more detailed in cores from places with high accumulation rates. The age of ice in cores can be determined by counting sedimentary layers defined by depth hoar or dust, and by analysis of certain chemical species that vary seasonally. The most important of the latter is δ18O. Where records are too low resolution to detect seasonal variations, numerical modeling can be used, although it is less precise. Through study of ice cores we know that concentrations of CO2 in the atmosphere have varied in phase with ice sheet volume over the past 900 ky or so, but it is not clear whether the CO2 led or lagged ice sheet volume. Analysis of a core from the Allen Hills Blue Ice area suggests that the amplitude of oscillations in atmospheric CO2 was smaller prior to 900 ka, when ice sheet volume was varying on a 40 ky time scale. Core records from the Holocene show that atmospheric CO2 and CH4 began to increase when humans began farming; had humans not begun to modify the atmosphere at that time, we would likely be in the middle of an ice age now.
The introduction of agriculture is a key defining element of the Neolithic, yet considerable debate persists concerning the nature and significance of early farming practices in north-west Europe. This paper reviews archaeobotanical evidence from 95 Neolithic sites (c. 4000–2200 cal bc) in Wales, focusing on wild plant exploitation, the range of crops present, and the significance of cereals in subsistence practices. Cereal cultivation practices in Early Neolithic Wales are also examined using cereal grain stable carbon (δ13C) and nitrogen (δ15N) isotope analysis. The Early Neolithic period witnessed the widespread uptake of cereals alongside considerable evidence for continued wild plant exploitation, notably hazelnuts and wild fruits. The possibility that wild plants and woodlands were deliberately managed or altered to promote the growth of certain plants is outlined. Small cereal grain assemblages, with little evidence for chaff and weed seeds, are common in the Early Neolithic, whereas cereal-rich sites are rare. Emmer wheat was the dominant crop in the Early Neolithic, while other cereal types were recorded in small quantities. Cereal nitrogen isotope (δ15N) values from Early Neolithic sites provided little evidence for intensive manuring. We suggest that cultivation conditions may have been less intensive when compared to other areas of Britain and Europe. In the later Neolithic period, there is evidence for a decline in the importance of cereals. Finally, the archaeobotanical and crop isotope data from this study are considered within a wider European context.
El objetivo de este trabajo es evaluar, a través del estudio de isótopos estables (δ13Cap, δ13Ccol y δ15N), paleodietas y patrones de subsistencia en grupos cazadores-recolectores de la transición pampeano-patagónica oriental (Argentina) durante el Holoceno medio-tardío (ca. 6000–250 aP). Se analizaron 44 individuos adultos de ambos sexos. Los resultados indican que durante el Holoceno medio los herbívoros terrestres, peces marinos y, posiblemente, pinnípedos tuvieron un rol importante en la dieta. Sin embargo, hacia el Holoceno tardío se observó un predominio en el consumo de herbívoros terrestres y peces fluviales, con la consecuente disminución en la ingesta de recursos marinos. También se detectó una ingesta mayor de vegetales a partir de aproximadamente 1000 aP. Durante el Holoceno medio y, probablemente, el Holoceno tardío inicial se registró una tendencia en la distribución espacial de los valores de isótopos estables, ya que los individuos enterrados hasta una distancia de aproximadamente 20 km de la costa presentan dietas marinas y mixtas, mientras que aquellos localizados a una distancia mayor (hasta ca. 130 km) se caracterizan por dietas terrestres. Estas diferencias podrían estar relacionadas con rangos de acción acotados o una demarcación del espacio que pudo involucrar comportamientos territoriales. Los cambios en la dieta a través del tiempo se asemejan a los reportados para el sudeste de Pampa Húmeda, ya que se observa una tendencia hacia una dieta más continental durante el Holoceno tardío.
The Ordovician–Silurian (O–S) transition was a critical interval in geological history. Multiple geochemical methods are used to explore the changes in oceanic environment. The Nd isotopic compositions in the Yangtze Sea are controlled by two sources: the continental erosion and the Panthalassa Ocean. High εNd(t) values during the Katian, late Hirnantian and Rhuddanian intervals are associated with the high sea level, which resulted in less terrestrial input based on the low Ti/Al and Zr/Al ratios. In contrast, low εNd(t) values during the early Hirnantian interval are related to the sea-level fall; in this case, the exposure of submarine highs and the growth of Yangtze Oldlands could lead to more continental materials being transported into the Yangtze Sea based on high Ti/Al and Zr/Al ratios. In addition, the negative εNd(t) excursion can also be attributed to the weak circulation between the Yangtze Sea and Panthalassa Ocean when sea level was low. Furthermore, the sea-level eustacy plays a significant role in the changes in redox water conditions. The redox indices, mainly UEF, Ce/Ce* and Corg/PT, across the O–S transition show a predominance of anoxic ocean over the Yangtze Sea during the Katian, late Hirnantian and Rhuddanian intervals, and an oxygenated episode was briefly introduced during the early Hirnantian period because of the fall in sea level. The Late Ordovician biotic crisis was marked by two-phase extinction events, and the change in sea level and redox chemistry may be the important kill mechanisms.
The Wulanba granite, consisting of biotite monzogranite and syenogranite, is located in the southern part of the Great Xing’an Range, NE China. Whole-rock major- and trace-element geochemistry suggests the Wulanba granite is a high-K–shoshonitic, slightly peraluminous and highly differentiated I-type granite. The Sr–Nd–Hf isotopes indicate that it originated from partial melting of juvenile crust derived from the depleted mantle with a minor input of old crust. The relatively young T2DM and tDM2 ages indicate it was most likely derived from a Late Neoproterozoic to Early Palaeozoic source. We have demonstrated that the biotite monzogranite is the ore-related intrusion of the Haobugao Zn–Fe mineralization based on the following geological, geochronological and geochemical evidence: (1) the chalcopyrite/pyrite in the biotite monzogranite and the continuous mineralization of drill core ZK2508; (2) the consistence of the emplacement age of the biotite monzogranite (~141–140/138 Ma) with the skarn mineralization age (~142 Ma); and (3) the presence of rich ore-forming elements (Fe–Zn–Cu) in the biotite monzogranite, and the similar Pb compositions of the sulfides from the Haobugao deposit and the biotite monzogranite. Compared to the barren syenogranite, the fertile biotite monzogranite is more oxidized, while the edges of the apatite grains in the biotite monzogranite are more oxidized than the centres. The average F/Cl ratio of the fertile biotite monzogranite (~123.45) is much higher than that of the barren syenogranite (~73.98). We conclude that these differences reflect unique geochemical signatures, and the geochemical composition of the apatite can be used to infer the economic potential of granites.
In this paper we present data from the measurements of carbon isotopes (Δ14C and δ13C) from α-cellulose extracted from pine tree-rings. The samples were collected in four forests located in the most industrialized part of Poland, where coal mining and coal-based energy are an important branch of industry. The investigated period of time (1975–2012) covers the period of development in coal mining and other industry sectors. Stable isotope composition has been determined with using IRMS and radiocarbon concentration was determinate by AMS.
We focused on the Pirin–Pangeon–Thasos carbonate sequence of the Rhodope thrust system, combining Sr isotopes from marble with U–Pb dating of detrital zircons from interlayered schists with outcrop near the villages of Ilindentsi and Petrovo in Bulgaria. The youngest zircon age at Ilindentsi is 266 Ma, i.e. Middle Permian, while the youngest zircon at Petrovo yielded an age of 290 Ma, i.e. Early Permian. Strontium isotopes range from 0.707420 to 0.707653, and are consistent with a Middle Permian maximum depositional age. Middle Permian sedimentation of this carbonate platform most likely occurred along the Eurasian margin rather than the Gondwana margin.
Un trabajo de rescate arqueológico en la cuenca alta del Río Loa (norte de Chile) resultó en el hallazgo de una inhumación prehispánica de un infante asociado a variados atavíos y ofrendas, junto a los restos óseos parciales de una adolescente. Ambos individuos fueron sometidos a análisis de isótopos estables para establecer paleodieta (δ13C y δ15N) y movilidad (δ18O y 87Sr/86Sr). Además, se efectuaron dataciones radiocarbónicas pareadas de los restos bioantropológicos y culturales con el fin establecer la cronología de la inhumación y, a la vez, evaluar la existencia de un posible efecto reservorio marino. Los resultados isotópicos sugieren consumo de dieta principalmente terrestre y un origen local para los individuos, aunque con una ingesta moderada de recursos marinos. Los fechados radiocarbónicos presentan una inesperada diferencia entre las edades de las ofrendas y los restos humanos, indicando la existencia de un importante efecto reservorio. Dichos resultados dan nuevas luces sobre el consumo de alimentos marinos durante el Formativo temprano en la región, a la vez que permiten ejemplificar los alcances de efectuar dataciones pareadas de restos humanos y culturales.
We have analysed a 6100-year record of benthic and planktonic foraminifera from inner neritic sediments from Core SK291/GC13, off the Goa coast, eastern Arabian Sea, to understand the response of benthic foraminifera to shallow-marine processes. The benthic foraminiferal assemblage is dominated by Nonion cf. asterizans, Ammonia beccarii, A. gaimardii and Virgulinella fragilis, which have been selected on the basis of a population of 10% or more in any three samples analysed. The planktonic foraminiferal population is sporadic and rare, with Globigerinoides ruber as the predominant species showing a variable trend. The foraminiferal proxies combined with total organic carbon (wt%) and δ13C and δ18O values of Ammonia gaimardii suggest distinct variations, indicating changes in productivity and salinity in the shallow eastern Arabian Sea. The coastal waters off Goa were relatively warmer and less saline between 6100 and 4600, or perhaps to 4200, calibrated years before the present (cal yr BP), corresponding to a stronger monsoon in South and East Asia. The shallow sea was cooler from ~4200 to 2600 cal yr BP in the study area, coinciding with a lower sea surface temperature in the northeastern Arabian Sea and an arid phase in the Indian subcontinent. From 2900 to 2600 cal yr BP the study core exhibits the impacts of short-term cold events, which have earlier been observed in the northeastern Arabian Sea, off Pakistan. During the Little Ice Age, the shallow sea off Goa was less productive.
The Great Orme Bronze Age copper mine in Wales is one of Europe's largest, although its size has been attributed to a small-scale, seasonal labour force working for nearly a millennium. Here, the authors report the results of interdisciplinary research that provides evidence that Great Orme was the focus of Britain's first mining boom, c. 1600–1400 BC, probably involving a full-time mining community and the wide distribution of metalwork from Brittany to Sweden. This new interpretation suggests greater integration than previously suspected of Great Orme metal into the European Bronze Age trade/exchange networks, as well as more complex local and regional socio-economic interactions.
It has been suggested that dust generation was closely linked to the development of global ice sheets and/or cooling. This feature has allowed Asian dust to be a potential chronostratigraphic tool in North Pacific Ocean (NPO) sediments. The orbital-scale age control in NPO sediments is usually established by adjusting the benthic-foraminiferal δ18O to the global δ18O stack (LR04). However, it would become difficult if the sediments did not contain enough foraminifera. This study investigates Sr and Nd isotopes, trace elements, mineralogy and grain size of the ‘operationally defined aeolian dust’ (ODED) extracted from the sediments recovered at Ocean Drilling Program (ODP) site 1209B on the Shatsky Rise in the NPO covering the past five glacial–interglacial cycles. The geochemical results show that the ODED at site 1209B is actually a mixture of Asian dust and volcanic ash. The variation of Nd isotope mimics the cycles of glacial–interglacial ice sheets as revealed by the global benthic foraminifera’s oxygen isotope stack (LR04) over the past 500 ka. The low (high) ϵNd values corresponded with the cool (warm) periods. We propose that ϵNd variation reflects the evolving aeolian dust in site 1209 sediments. The excellent agreement between ϵNd values at site 1209B and LR04 stack over the past 500 ka allows establishing the orbital-timescale age control by tuning ϵNd to the LR04 curve. We thus propose that Nd isotope provides a chronostratigraphic technique in NPO sediments, especially for sediments with a limited amount of foraminifera.