Sublithospheric diamond ages and the supercontinent cycle.

Subduction related to the ancient supercontinent cycle is poorly constrained by mantle samples. Sublithospheric diamond crystallization records the release of melts from subducting oceanic lithosphere at 300-700 km depths1,2 and is especially suited to tracking the timing and effects of deep mantle processes on supercontinents. Here we show that four isotope systems (Rb-Sr, Sm-Nd, U-Pb and Re-Os) applied to Fe-sulfide and CaSiO3 inclusions within 13 sublithospheric diamonds from Juína (Brazil) and Kankan (Guinea) give broadly overlapping crystallization ages from around 450 to 650 million years ago. The intracratonic location of the diamond deposits on Gondwana and the ages, initial isotopic ratios, and trace element content of the inclusions indicate formation from a peri-Gondwanan subduction system. Preservation of these Neoproterozoic-Palaeozoic sublithospheric diamonds beneath Gondwana until its Cretaceous breakup, coupled with majorite geobarometry3,4, suggests that they accreted to and were retained in the lithospheric keel for more than 300 Myr during supercontinent migration. We propose that this process of lithosphere growth-with diamonds attached to the supercontinent keel by the diapiric uprise of depleted buoyant material and pieces of slab crust-could have enhanced supercontinent stability.

Sidon on the breadth of the wild sea: Movement and diet on the Mediterranean coast in the Middle Bronze Age.

OBJECTIVES: Excavations at Sidon (Lebanon) have revealed dual identities during the Middle Bronze Age (ca. 2000-1600 BCE): a maritime port and center for local distribution, as well as a settlement with a heavy subsistence dependence on the extensive inland hinterlands. We aim to investigate residential mobility at Sidon using isotopic analyses of 112 individuals from 83 burials (20 females, 26 males, and 37 subadults). Veneration and remembrance of the dead is evident from funerary offerings in and near the tombs. With marine fish a major component in funerary offerings, we predict major marine reliance in this coastal population. MATERIALS AND METHODS: New isotopic evidence of paleomobility (87 Sr/86 Sr, δ18 O) and diet (δ13 Ccarbonate ) is the focus of this research. Previous bulk bone collagen δ13 C and δ15 N analysis is strengthened by further sampling, along with δ34 S where collagen yield was sufficient. RESULTS: The five non-locals identified (8.9% of the 56 analyzed) come from constructed tombs with high-status grave goods except for one, which was heavily disturbed in antiquity. Dietary investigation of the population confirms reliance on terrestrial resources with no significant marine input. No significant differences in diet between the sexes or burial types are present. CONCLUSIONS: Although Sidon was part of a growing Mediterranean network evidenced through artefactual finds, relatively low immigration is evident. While religious feasts venerating the dead may have involved significant piscine components, no appreciable marine input in diet is observed. Fish may have been reserved for the deceased or only consumed on feast days alongside the dead rather than a regular part of the Bronze Age menu.

Scottish soldiers from the Battle of Dunbar 1650: A prosopographical approach to a skeletal assemblage.

After the Battle Dunbar between English and Scottish forces in 1650, captured Scottish soldiers were imprisoned in Durham and many hundreds died there within a few weeks. The partial skeletal remains of 28 of these men were discovered in 2013. Building on previous osteological work, here we report wide-ranging scientific studies of the remains to address the following questions: Did they have comparable diet, health and disease throughout their lives? Did they have common histories of movement (or lack of movement) during their childhoods? Can we create a collective biography of these men? Strontium and oxygen isotope analysis of tooth enamel investigated childhood movement. Carbon and nitrogen isotope analysis of incrementally sampled dentine addressed childhood diet and nutrition. Metaproteomic analysis of dental calculus investigated oral microbiomes and food residues; this was complemented by microscopic analysis of debris in calculus from ingested materials. Selected individuals were examined for dental microwear. The extent of hydroxylation of proline in collagen was examined as a potential biomarker for scurvy. An osteobiography for each man was created using the full range of data generated about him, and these were synthesised using an approach based on the historical method for a collective biography or prosopography. The childhood residences of the men were primarily within the Midland Valley of Scotland, though some spent parts of their childhood outside the British Isles. This is concordant with the known recruitment areas of the Scottish army in 1650. Their diets included oats, brassicas and milk but little seafood, as expected for lowland rather than highland diets of the period. Childhood periods of starvation or illness were almost ubiquitous, but not simultaneous, suggesting regionally variable food shortages in the 1620s and 1630s. It is likely there was widespread low-level scurvy, ameliorating in later years of life, which suggests historically unrecorded shortages of fruit and vegetables in the early 1640s. Almost all men were exposed to burnt plant matter, probably as inhaled soot, and this may relate to the high proportion of them with of sinusitis. Interpersonal violence causing skeletal trauma was rare. Based on commonalities in their osteobiographies, we argue that these men were drawn from the same stratum of society. This study is perhaps the most extensive to date of individuals from 17th century Scotland. Combined with a precise historical context it allows the lives of these men to be investigated and compared to the historical record with unprecedented precision. It illustrates the power of archaeological science methods to confirm, challenge and complement historical evidence.

Who were the Hyksos? Challenging traditional narratives using strontium isotope (87Sr/86Sr) analysis of human remains from ancient Egypt.

A foreign dynasty, known as the Hyksos, ruled parts of Egypt between c. 1638-1530 BCE. Their origins are thought to be rooted in the Near East, which is supported by architectural features and grave accoutrements of Tell el-Dabca. In this former Hyksos capital in the Eastern Nile Delta, burial culture is characterized by a blend of Egyptian and Near Eastern elements. However, investigations are still ongoing as to where the Hyksos came from and how they rose to power. The aim of this study is to elucidate the question of possible provenience. We present the results of strontium isotope (87Sr/86Sr) ratios of human tooth enamel (n = 75) from Tell el-Dabca, focusing on comparing pre- and during Hyksos rule and sex-based differences. An influx of non-locals can be observed in the pre-Hyksos period (12th and 13th Dynasties, c. 1991-1649 BCE) during the constitution of this important harbor town, while the number of individuals already born in the Delta is larger during the Hyksos period. This is consistent with the supposition that, while the ruling class had Near Eastern origins, the Hyksos' rise to power was not the result of an invasion, as popularly theorized, but an internal dominance and takeover of foreign elite. There is a preponderance of non-local females suggesting patrilocal residence. We discuss our findings against the current evidence of material culture and historiography, but more investigation in Near Eastern comparative sites has to be conducted to narrow our future search for the actual origins of the Hyksos.

At the world's edge: Reconstructing diet and geographic origins in medieval Iceland using isotope and trace element analyses.

OBJECTIVES: A multi-isotope study was conducted on individuals buried at Skriðuklaustur monastery (AD 1493-1554) to investigate their geographic origins and dietary composition. Comparative material from individuals excavated from Skeljastaðir, an inland farm site was also analyzed. MATERIALS AND METHODS: Bone collagen was extracted from 50 humans (Skriðuklaustur and Skeljastaðir) and 25 animals (Skriðuklaustur) and analyzed for δ13 C, δ15 N, and δ34 S. Dental enamel samples from 31 individuals (Skriðuklaustur) were also analyzed for 87 Sr/86 Sr, δ18 O, δ13 C, and trace elements (Pb, Sr, Zn, Ba). RESULTS: The mean value determined from individuals from Skriðuklaustur (n = 36) was δ13 C = -18.7 ± 0.8‰, δ15 N = 12.8 ± 1.1‰, and δ34 S = 9.0 ± 1.6‰, whereas at Skeljastaðir (n = 14), it was δ13 C = -20.5 ± 0.8‰, δ15 N = 7.8 ± 0.9‰, and δ34 S = 9.4 ± 1.6‰. At Skriðuklaustur, human dental enamel samples (n = 31) provided a 87 Sr/86 Sr range of 0.7060-0.7088, δ18 Ophosphate from 13.9 to 16.1‰ and δ13 Ccarbonate from -16.6 to -12.9‰. Inferred drinking water (δ18 Odw ) values range from -12.3 to -8.9‰. Sr concentrations range from 25.8 to 156.7 ppm, Ba from 0.11 to 0.81 ppm, Zn from 43.8 to 145.8 ppm, and Pb from 0.13 to 9.40 ppm. DISCUSSION: A combination of results indicates that the people from Skriðuklaustur were born in Iceland, but some lived inland during childhood while others lived closer to the coast. Since Skriðuklaustur was a hospital, these individuals may have sought medical treatment at the monastery. The δ13 C and δ15 N values determined from bone collagen indicate that the people residing at Skriðuklaustur consumed a diet high in marine protein, while those residing at Skeljastaðir exhibit values more consistent with terrestrial resources.

Highly saline fluids from a subducting slab as the source for fluid-rich diamonds.

The infiltration of fluids into continental lithospheric mantle is a key mechanism for controlling abrupt changes in the chemical and physical properties of the lithospheric root, as well as diamond formation, yet the origin and composition of the fluids involved are still poorly constrained. Such fluids are trapped within diamonds when they form and so diamonds provide a unique means of directly characterizing the fluids that percolate through the deep continental lithospheric mantle. Here we show a clear chemical evolutionary trend, identifying saline fluids as parental to silicic and carbonatitic deep mantle melts, in diamonds from the Northwest Territories, Canada. Fluid-rock interaction along with in situ melting cause compositional transitions, as the saline fluids traverse mixed peridotite-eclogite lithosphere. Moreover, the chemistry of the parental saline fluids--especially their strontium isotopic compositions--and the timing of host diamond formation suggest that a subducting Mesozoic plate under western North America is the source of the fluids. Our results imply a strong association between subduction, mantle metasomatism and fluid-rich diamond formation, emphasizing the importance of subduction-derived fluids in affecting the composition of the deep lithospheric mantle.

Community differentiation and kinship among Europe's first farmers.

Community differentiation is a fundamental topic of the social sciences, and its prehistoric origins in Europe are typically assumed to lie among the complex, densely populated societies that developed millennia after their Neolithic predecessors. Here we present the earliest, statistically significant evidence for such differentiation among the first farmers of Neolithic Europe. By using strontium isotopic data from more than 300 early Neolithic human skeletons, we find significantly less variance in geographic signatures among males than we find among females, and less variance among burials with ground stone adzes than burials without such adzes. From this, in context with other available evidence, we infer differential land use in early Neolithic central Europe within a patrilocal kinship system.

Enriched Pt-Re-Os isotope systematics in plume lavas explained by metasomatic sulfides.

To explain the elevated osmium isotope (186Os-187Os) signatures in oceanic basalts, the possibility of material flux from the metallic core into the crust has been invoked. This hypothesis conflicts with theoretical constraints on Earth's thermal and dynamic history. To test the veracity and uniqueness of elevated 186Os-187Os in tracing core-mantle exchange, we present highly siderophile element analyses of pyroxenites, eclogites plus their sulfides, and new 186Os/188Os measurements on pyroxenites and platinum-rich alloys. Modeling shows that involvement in the mantle source of either bulk pyroxenite or, more likely, metasomatic sulfides derived from either pyroxenite or peridotite melts can explain the 186Os-187Os signatures of oceanic basalts. This removes the requirement for core-mantle exchange and provides an effective mechanism for generating Os isotope diversity in basalt source regions.

A phase I and pharmacodynamic study of fludarabine, carboplatin, and topotecan in patients with relapsed, refractory, or high-risk acute leukemia.

PURPOSE: A novel regimen designed to maximize antileukemia activity of carboplatin through inhibiting repair of platinum-DNA adducts was conducted in poor prognosis, acute leukemia patients. EXPERIMENTAL DESIGN: Patients received fludarabine (10 to 15 mg/m(2) x 5 days), carboplatin (area under the curve 10 to 12 by continuous infusion over 5 days), followed by escalated doses of topotecan infused over 72 hours (fludarabine, carboplatin, topotecan regimen). Twenty-eight patients had acute myelogenous leukemia (7 untreated secondary acute myelogenous leukemia, 11 in first relapse, and 10 in second relapse or refractory), 1 patient had refractory/relapsed acute lymphoblastic leukemia, and 2 patients had untreated chronic myelogenous leukemia blast crisis. Six patients had failed an autologous stem cell transplant. Patients ranged from 19 to 76 (median 54) years. Measurement of platinum-DNA adducts were done in serial bone marrow specimens. RESULTS: Fifteen of 31 patients achieved bone marrow aplasia. Clinical responses included 2 complete response, 4 complete response with persistent thrombocytopenia, and 2 partial response. Prolonged myelosuppression was observed with median time to blood neutrophils >/=200/microl of 28 (0 to 43) days and time to platelets >/=20,000/microl (untransfused) of 40 (24 to 120) days. Grade 3 or greater infections occurred in all of the patients, and there were 2 infection-related deaths. The nonhematologic toxicity profile was acceptable. Five patients subsequently received allografts without early transplant-related mortality. Maximum tolerated dose of fludarabine, carboplatin, topotecan regimen was fludarabine 15 mg/m(2) x 5, carboplatin area under the curve 12, and topotecan 2.55 mg/m(2) over 72 hours. An increase in bone marrow, platinum-DNA adduct formation between the end of carboplatin infusion and 48 hours after the infusion correlated with bone marrow response. CONCLUSIONS: Fludarabine, carboplatin, topotecan regimen is a promising treatment based on potential pharmacodynamic interactions, which merits additional study in poor prognosis, acute leukemia patients.