Conventional Radiocarbon Ages Research Articles

Unexpected high alkyl carbon contents in organic matter-rich sandy agricultural soils of Northwest Central Europe

Carbon sequestration in Plaggic Anthrosols is most often investigated by bulk soil carbon inventories, without considering the form in which the carbon is stored (e.g., particulate or mineral-associated organic matter (OM), its capacity, or its chemical composition). Here, we focus on the unusual high organic carbon (OC) accumulation in sandy Plaggic Anthrosols and adjacent reference soils under agricultural use. In these soils, the mineral fraction ≤20 µm which is commonly assumed to be the major factor for OC stabilization, are very low in mass proportion. Soil organic matter (SOM) physical fractionation was done to evaluate the quantity and quality of OC in the topsoil (Ap horizon). For the fraction ≤20 µm (medium and fine silt-, and clay-sized particles), we measured the concentration of OC and calculated its OC storage capacity and contribution. The OC of the fraction ≤20 µm was radiocarbon-dated and analyzed for its chemical composition by solid-state 13C NMR spectroscopy. The highly sandy (∼90 % sand and coarse silt) soils showed an accumulation of OC much higher than the conventionally calculated saturation level controlled by the proportion of the fraction ≤20 µm. Unexpectedly, Plaggic Anthrosols and the respective reference soils showed similar fractional OC concentrations, radiocarbon ages, and OM composition. The isolated fraction ≤20 µm contained, on average, 81 % of the total soil OC in only 9 % of the corresponding soil mass. All soil fractions ≤20 µm are characterized by a high mean OC concentration in the topsoil (reference soils: 226 ± 66.5 mg OC g−1, Plaggic Anthrosols: 202 ± 59.0 mg OC g−1) with a C/N ratio of 15 on average for both soils. The OM composition of the fraction ≤20 µm was specifically rich in alkyl-C, with unusually low proportions of O-alkyl-C and low contents of aryl-C. The radiocarbon concentration (F14C) indicated that topsoil OM of the ≤20 µm fraction is stored for long time periods with high mean conventional radiocarbon ages (14C) not only for Plaggic Anthrosols (F14C: 0.92 ± 0.04; 14C: 639 yBP) but also for the reference soils (F14C: 0.93 ± 0.04; 14C: 575 yBP) and received low inputs of OC derived from recent photosynthesis. Our data indicate the existence of specific SOM accumulation processes in the investigated sandy agricultural soils, resulting particularly large SOM stocks which cannot be explained by mechanistic association of OM with mineral surfaces. It is not clear, if this inherited OM is stable under present-day soil and management conditions.

Growing a community’s sense of ‘heritage’: a former mataī forest from SW Ōtautahi Christchurch and its nitrogen status, 860–1430 CE

ABSTRACT As in many places, heritage narratives in Ōtautahi Christchurch remain focused on colonial times. To expand these narratives, we examined three subfossil mataī (Prumnopitys taxifolia) excavated along a 700 m arc during residential subdivision earthworks. Characterisation used δ 15N, radiocarbon, and ring width measurements. Conventional (uncalibrated) radiocarbon ages were 1222 BP (calibrated median 856 CE), 932 BP (1148 CE) and 545 BP (1425 CE). Mean δ 15N values of +1.0 ± 1.1‰ (±SD) were similar to nearby alluvial forest remnants, with no discernible change through the 550-year sampling interval. Ring widths in three trees from the 545 BP site were 0.58 ± 0.12 mm, half that of present day mataī from humid West Coast forests at a similar latitude. The 545 BP site included a burnt stump, and stumps with longhorn beetle (Cerambycidae) larval galleries that occur only in already dead trees. We conclude that the forest was slow growing and mesotrophic but dynamic due to periodic flooding, ending with fire around 1430 CE and inundation of the dead standing forest years or decades later. We are now using traditional and social media and artists to disseminate the narrative of a former mataī forest ‘beneath our feet’ through schools, community groups, and in public facilities.

Znaczenie kalibracji radiowęglowej skali czasu dla chronostratygrafii późnego vistulianu

Znaczenie kalibracji radiowęglowej skali czasu dla chronostratygrafii późnego vistulianu

Multidisciplinary Studies on Canvas Nature of Paintings at IFIN-HH Romania

Radiocarbon dating of pictorial support is usually less used. It is accepted for paintings with the estimated age older than the Stradivarius limit (ca. 1600 - 1650 CE) as stated by A.J.T. Jull in 1997, and not as an authentication method. Considering this, a seventeenth century oil-based painting (Main Case Study) is reported. Based on the results obtained as terminus post quem , the painting cannot be attributed to the famous painter from the classical period, considered to be the author, according to the signature. Two other recently solved cases (Sample 1 and Sample 2) are briefly recorded and the information obtained was used for a more accurate interpretation of the Main Case Study. The multidisciplinary research aimed to put together, for the first time in the RoAMS Laboratory Romania, the information obtained through elemental analysis, ATR-FTIR, FT-Raman and XRF spectrometry. Radiocarbon dating process includes a comparative description of pictorial fragment pretreatments, of the textile fiber graphitization stage, and of AMS measurements used for determinations of isotopic ratio of carbon species, and general process parameter δ 13 C, of percent of Modern Carbon, and Conventional Radiocarbon Age, and of the Standard Deviations. The fragment of (Main Case Study) was first investigated using both FT-Raman and ATR-FTIR spectrometry. The spectra obtained reveal that the painting surface was covered with a thick layer of linseed oil, which hinders a complete analysis of the pigments through FT-Raman and ATR-FTIR spectrometry. However, the white pigment (lead white) and primer (calcium carbonate) were successfully identified. The findings from ATR-FTIR and FT-Raman spectra provide reliable information about the contaminants, information that is further used to select the most appropriate dating strategy. Before the AMS measurements, the cleaned textile fibers were investigated by elemental analysis, ATR-FTIR and micro-DRIFT spectrometry. The data obtained were compared with known natural and artificial textile fibers. The results reveal an almost complete decontamination, which additionally underlines the assumption that the textile support used exhibits a synthetic nature. Most likely, the canvas was made of synthetic nylon 6.6 fibers on a texture close to sailboat, used for sailing in the mid-twentieth century. The findings were finally confirmed by radiocarbon dating. 14 C/ 12 C isotopic ratios were close to RoAMS Laboratory background level, certifying a raw material from fossil deposits. The other fragments of canvas, those from recently solved cases (Sample 1 and Sample 2) are supposed to belong to the first part of the seventeenth, or to nineteenth / twentieth centuries (where the presumptions were made, and where the final results are placed, for Main Case Study). The comparative data reveal different particularities observed for each situation, offering pro and con arguments in determining the fibers age(s). The information provided by radiocarbon dating, elemental analysis and XRF spectrometry is in good agreement and demonstrates that it is unlikely that the authors designated for each case were those who created the paintings. The XRF spectrometry investigation highlighted the use of primers or pigments that generally appeared in the painting technique after the date when the painting creation was estimated.

Ageing and preservation of HgS-enriched ancient human remains deposited in confinement

Mankind has been exposed to mercury (Hg) for thousands of years, but little information on the role of Hg on the preservation of ancient human remains has been addressed. In particular, the Maya people were expose to cinnabar (HgS), a naturally occurring mineral. Because in the Maya culture the red colour was symbolic of blood and blood sacrifice and associated to death and rebirth, For these reason, they often decorated burial chambers and covered sarcophagi, and corpses of important members of their society with HgS. However, scarce information has become available on the effects of HgS on the preservation of Maya human remains. This paper reports on the preservation of HgS-human remains, kept in sarcophagi away from sunlight and environmental humidity. Two HgS-enriched human remains collected from the Temples of the Scriptures (TS) and Temple XIII (TXIII) in the archaeological site of Palenque, Chiapas, Mexico were studied by radiocarbon dating, high resolution scanning and transmission electron microscopy, and energy dispersive X-ray spectroscopy. Conventional radiocarbon ages for S-TS and S-TXIII were 1360 ± 30 CE and 3100 ± 30 BCE, respectively, evidencing difference in age between the archaeological remains proximal to 1740 yrs. The more ancient specimen, S-TXIII, was linked to the excellent preservation of collagen preservation of collagen fibrils. The more recent remains (S-TS) displayed more abundant and richly diverse biological components, including highly porous tubules with irregular low and high accumulation of Hg in the walls, and ovoid protuberances. Micrographs showed excellently preserved biotubules denoting calcite permineralization, however, the presence of Hg provoked mineral dissolution explained in terms of biological activity. Mercury was found abundantly in ancient bone, which was explained because the dissolution of HgS after interacting with bioorganic material, and the formation of Hg-organic complexes. S-TS showed trace amounts of Hg and S, which were attributed to metabolic activity of microorganisms causing Hg volatilization and S decomposition. Furthermore, although microelemental analysis for both specimens showed the association of Hg with S, and HgS to be the source of these elements, the distribution of Hg clearly showed that the two royal characters held different lifestyle. On the one hand, Hg distribution in bone for the specimens showed that S-TXIII contained Hg in the regions covered by HgS; on the other hand, S-TS contained Hg throughout the bone structure. These results were interpreted to mean that both specimens S-TXII were covered by S-TS after dead and in addition, S-TS belonged in life to a character who was also exposed to Hg via inhalation or consumption of contaminated food, or liquids.

The effect of depositional conditions on mineral transformation, chemical composition, and preservation of organic material in archaeological Hg-enriched bone remains

Archaeological bone remains are exposed to depositional conditions that profoundly affect their preservation. This manuscript reports on the mineral transformation, chemical composition, and preservation of organic material in pre-Hispanic archaeological Hg-enriched bone remains exposed to different depositional conditions, namely, open and confined environments. Here, we studied 2 vertebrae specimens collected inside Temple XIII of the archaeological site of Palenque, Mexico. Specifically, the 2 vertebrae were collected inside and outside a sarcophagus (VIS and VOS) located in a burial chamber and belonged to a 30-yr-old woman and an 11-yr-old boy, respectively. Subsections of the vertebrae specimens were characterized by radiocarbon dating, high-resolution electron microscopy (HRSEM), and energy-dispersive X-ray spectroscopy analyses (EDS). VIS and VOS showed conventional radiocarbon ages dating of 5050±30BP and 5440±30BP respectively. HRSEM-EDS analysis for VIS showed a high content of Hg (~30%) in the upper layer and below the detection limit in the lower layer. In contrast, HRSEM-EDS analysis for VOS confirmed the lack of a layered structure, for which the accumulation of Hg was as high as 30%. Furthermore, VIS was the only vertebrae that showed the presence of S. This was because VIS belonged to a pre-Hispanic character exposed to HgS, typically used in Mayan royal rituals; VOS did not contain S because the Hg source in this case was probably from cooking utensils, the elaboration of paintings or murals, or the ingestion of contaminated food or water. In addition, VOS contained a particularly low content of P, which was attributed to hydroxyapatite undergoing higher rates of transformation in the open environment. Moreover, the incorporation of Hg in hydroxyapatite via Hg-for-Ca substitution further accelerated the mineral transformation pathway(s). Finally, the pre-Hispanic archaeological Hg-enriched bones preserved the genetic material, regardless of the depositional environments (exposed or unexposed). Therefore, the prevailing preservation mechanisms differ from those underpinned by physical protection by collagen fibrils or natural antibacterial mechanisms.

EDITORIAL

Almost exactly 50 years ago this month, at a conference held in Monaco, nuclear physicist Hans Suess unveiled the first calibration curve for radiocarbon dates. The crucial paper, ‘Bristlecone pine calibration of the radiocarbon time scale from 4100 B.C. to 1500 B.C.', pushed back conventional radiocarbon ages by several centuries and so ushered in the Second Radiocarbon Revolution, soon leading to a new interpretation of European prehistory that severed the long-held connections between Europe and the Near East. Hitherto, diffusionism had held centre stage, with maps full of arrows showing people and artefacts incessantly on the move. With radiocarbon calibration, independent regional development became the order of the day for explaining cultural change. Fifty years on, however, a range of promising new techniques have become available that seem to reinstate some of the earlier narratives.

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The Paleoindian burial from the Brazilian rockshelter site of Toca dos Coqueiros was discovered in July 1997 (Guidon et al., 1998). The site is one of several known Paleoindian sites in the immediate region of the Serra da Capivara National Park, located in the northeastern Brazilian state of Piaui (Guidon and Arnaud, 1991). The interred individual, carrying a calibrated date of 11,060 years BP (conventional radiocarbon age of 9,870 50 years BP; beta 109844; Guidon et al., 1998), is significant in being one of the oldest human skeletons recovered in the New World, and was described as female (Lessa and Guidon, 2002). I had the opportunity to examine the Coqueiros individual and reconstruct the skull. I present illustrative data to support the view that the Coqueiros skeleton represents a gracile male. Comparative craniofacial morphometrics suggest as well that Paleoindian groups living in South America at this distant temporal horizon may not have been closely related to later and recent Amerind populations (Neves and Pucciarelli, 1991; Neves et al., 1998, 1999). Our craniometric evaluation of this individual supports that as well (Nelson et al., in press). The cranial vault and much of the enveloping matrix had been stabilized with B72 resin, as these had been subjected to some crushing and fragmentation over the course of time. They did not, however, appear to be particularly deformed, but much of the vault was obscured by soil matrix impregnated with B72. The loose fragment assemblage included a considerable amount of facial material: nasals, maxillary frontal processes, the left malar, and superorbital portions of the frontal, including the glabella. Several basilar fragments were also present, representing the margins of the foramen magnum, sphenoid alae, portions of the occipital squamous, and temporals. In addition to a significant quantity of diagnostic cranial fragments, the assemblage included numerous postcranial fragments. Among this material was the inferior ramus of the right pubis and enough of the posterior inferior iliac spine to reconstruct the posterior margin of the left greater sciatic notch. In addition, both femoral heads and the right humeral and radial heads were available for study. A full reconstruction of the skull was undertaken. Sections of vault bone and matrix embedded in B72 were soaked in acetone, taken apart, cleaned, dried, and reassembled using a plastic-resin DucoTM cement. Loose craniofacial fragments were sorted, sided, and assembled. The bony facial reconstruction was articulated to the vault reconstruction. On the pelvis, the ventral ramus was reconstructed onto the larger portion of the right pubis in order to aid in identification of sex-based morphology. In addition, the posterior inferior iliac spine was reconstructed back to the left innominate, in order to establish the form of the greater sciatic notch. The greater sciatic notch tends to be wider in females and narrower in males, though Fulginiti (1993) demonstrated variability in this tendency. In the dorsal midline, there is sex-based variability in the morphology of the sacrum as well. In males, the centrum of the first sacral vertebra tends to be wider than the alae, by approximately three-fifths vs. onefifth for alar widths, while in females these widths tend to be more evenly apportioned at one-third each of the total sacral width across the top. In the collections at the Fundacao Museu do Homem Americanos (FUMDHAM) is an unambiguous female Paleoindian skeleton dated to within 1,200 years of Coquieros. Lessa and Guidon (2002) mentioned this individual (Toca da Janela da Barro do Antoniao), but stated that they could not use it for comparison. In addition, an unambiguous female os pubis, from a relatively recent burial context (within the past 500 years), was chosen from the collections for purposes of comparison (Fig. 1). Figure 1 is a comparative photograph of the pubic bones from the Coqueiros, Antoniao, and recent female skeletons. The Antoniao individual is in a poor enough state of preservation that visualizing morphology beyond the width of the ventral surface and a hint of the subpubic angle is challenging. In the recent burial (see above), even though the ventral ramus is poorly reconstructed, form is clearly evident, and the width of the ventral surface of the element (with the attendant ventral arc) and subpubic angle are all clearly visible. These stand in stark

Fluvial radiocarbon and its temporal variability during contrasting hydrological conditions

To study the significance of land use and catchment hydrology for the age of exported carbon, we measured the radiocarbon abundances in two mountainous streams in Germany. The Hassel catchment was characterized by wider-stretched riparian areas and by a significant contribution of arable land and pasture to land use compared to the Rappbode catchment. Although soil cultivation is considered to mobilize old carbon from deep soil layers, in six out of eight situations dissolved organic carbon (DOC) was younger in Hassel stream compared to Rappbode. In contrast, we estimated annual exports of radiocarbon on the basis of yield weighed, bulked biweekly samples and found that older DOC was delivered from Hassel compared to Rappbode catchment (352 years conventional radiocarbon age as well as carbon near to modern origin, respectively). This result characterized primarily the fluxes during wet conditions, which dominated the annual exports. In a winter base flow situation, we found that old (~2550 years) snow-bound organic carbon deriving from atmospheric deposition contributed 29–43 % to stream exports. Overall, there was significant intra-annual variability of stream 14C-DOC. Within the catchments, the standard deviations of ∆14C values (47–63 ‰) were comparable to the difference of annual exports between the contrasting catchments (46 ‰). Infrequent storm flow events should be included not only in export budgets but also in studies of carbon sources.

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

Unusual C35 to C38 alkenones were identified in mid-Holocene (8–3.5kyr BP) sediments from a restricted estuary in southwest Florida (Charlotte Harbor). The distribution was dominated by a C36 diunsaturated (ω15,20) ethyl ketone, identical to the one present in Black Sea Unit 2 sediments. Other unusual alkenones were tentatively assigned as a C35:2 (ω15,20) methyl ketone, a C37:2 (ω17,22) methyl ketone and a C38:2 (ω17,22) ethyl ketone. In late Holocene sediments<3.5kyr BP, the common C37 to C39 alkenones were found. Compound-specific 14C, 13C, and D isotope measurements were used to constrain the possible origin of the alkenones. Conventional radiocarbon ages of alkenones and higher plant-derived long chain n-alcohols indicated no significant difference in age between mid-Holocene alkenones and higher plant n-alcohols. Both alcohols and alkenones were offset vs. calibrated ages of shell fragments in the same sediment core, which suggests they were pre-aged by 500–800yr, implying resuspension and redistribution of the fine-grained sedimentary particles with which they are associated. The hydrogen isotopic (δD) composition (−190‰ to −200‰) of the C37 and C38 alkenones in the late Holocene sediments is in line with values for coastal haptophytes in brackish water. However, the unusual C36 and C38 alkenones from the mid Holocene sediments were enriched in D (by ca. 100‰) vs. the late Holocene alkenones. Also, δ13C values of mid-Holocene alkenones were consistently offset compared with late Holocene alkenones (−21‰ to −22‰ and −22‰ to −23‰, respectively). We suggest that the alkenones in Charlotte Harbor were produced by unknown alkenone-producing haptophyte.

Conventions for Reporting Radiocarbon Determinations

Current conventions for reporting radiocarbon determinations do not cover the reporting of calibrated dates. This article proposes revised conventions that have been endorsed by many 14C scientists. For every determination included in a scientific paper, the following should apply: (1) the laboratory measurement should be reported as a conventional radiocarbon age in 14C yr BP or a fractionation-corrected fraction modern (F14C) value; (2) the laboratory code for the determination should be included; and (3) the sample material dated, the pretreatment method applied, and quality control measurements should be reported. In addition, for every calibrated determination or modeled date, the following should be reported: (4) the calibration curve and any reservoir offset used; (5) the software used for calibration, including version number, the options and/or models used, and wherever possible a citation of a published description of the software; and (6) the calibrated date given as a range (or ranges) with an associated probability on a clearly identifiable calendar timescale.

Conventions for Reporting Radiocarbon Determinations

Current conventions for reporting radiocarbon determinations do not cover the reporting of calibrated dates. This article proposes revised conventions that have been endorsed by many14C scientists. For every determination included in a scientific paper, the following should apply: (1) the laboratory measurement should be reported as a conventional radiocarbon age in14C yr BP or a fractionation-corrected fraction modern (F14C) value; (2) the laboratory code for the determination should be included; and (3) the sample material dated, the pretreatment method applied, and quality control measurements should be reported. In addition, for every calibrated determination or modeled date, the following should be reported: (4) the calibration curve and any reservoir offset used; (5) the software used for calibration, including version number, the options and/or models used, and wherever possible a citation of a published description of the software; and (6) the calibrated date given as a range (or ranges) with an associated probability on a clearly identifiable calendar timescale.

Sequestration of atmospheric CO2 in a weathering-derived, serpentinite-hosted magnesite deposit: 14C tracing of carbon sources and age constraints for a refined genetic model

The Attunga magnesite deposit is texturally and geochemically distinct from other spatially associated, serpentinite-hosted magnesite deposits in the Great Serpentinite Belt, New South Wales, Australia, such as the hydrothermal Piedmont magnesite deposit or widespread silica–carbonate alteration zones. Cryptocrystalline magnesite at Attunga predominantly occurs in nodular masses and irregular, desiccated veins that occupy pre-existing cracks and pore spaces resulting from fracturing and weathering of the host rock. Incipient weathering of the serpentinite host rock is accompanied by a decrease in volume and the mobilisation of MgO and CaO from the serpentinite. Pore spaces and permeability created during weathering and fracturing of the host rock provide access for CO2-, MgO- and CaO-bearing meteoric waters which led to an increase of volume during carbonation. SiO2 is only mobilised during more advanced stages of weathering and late stage infiltration of SiO2-bearing waters and precipitation of opal-A lead to local silicification of the serpentinite.Stable carbon and oxygen isotope signatures show that nodular magnesite at Attunga has formed under near-surface conditions incorporating carbon from C3-photosynthetic plants and oxygen from meteoric waters. Radiocarbon concentrations in the magnesite preclude subducted carbonaceous sediments as the source of carbon and, together with distinct stable carbon and oxygen isotope signatures, indicate that magnesite at Attunga precipitated from low temperature, supergene fluids. Even though there is no direct geochemical and isotopic evidence, some textural observations and field relationships for weathering-derived magnesite deposits suggest the prior existence of a possibly Early Triassic, hydrothermal magnesite deposit at Attunga. The presence of a pre-existing magnesite deposit may entail the localised formation of the weathering-derived magnesite at Attunga, but the predominance of weathering-related textures and geochemical signatures indicate that weathering is the integral magnesite mineralisation process at Attunga. Conventional radiocarbon ages of about 50ka represent a maximum age constraint for the formation of the magnesite deposit during Quaternary weathering. A significant amount of atmospheric CO2 has been sequestered via the biosphere and carbonation of serpentinite at Attunga.

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The Paleoindian burial from the Brazilian rockshelter site of Toca dos Coqueiros was discovered in July 1997 (Guidon et al., 1998). The site is one of several known Paleoindian sites in the immediate region of the Serra da Capivara National Park, located in the northeastern Brazilian state of Piaui (Guidon and Arnaud, 1991). The interred individual, carrying a calibrated date of 11,060 years BP (conventional radiocarbon age of 9,870 50 years BP; beta 109844; Guidon et al., 1998), is significant in being one of the oldest human skeletons recovered in the New World, and was described as female (Lessa and Guidon, 2002). I had the opportunity to examine the Coqueiros individual and reconstruct the skull. I present illustrative data to support the view that the Coqueiros skeleton represents a gracile male. Comparative craniofacial morphometrics suggest as well that Paleoindian groups living in South America at this distant temporal horizon may not have been closely related to later and recent Amerind populations (Neves and Pucciarelli, 1991; Neves et al., 1998, 1999). Our craniometric evaluation of this individual supports that as well (Nelson et al., in press). The cranial vault and much of the enveloping matrix had been stabilized with B72 resin, as these had been subjected to some crushing and fragmentation over the course of time. They did not, however, appear to be particularly deformed, but much of the vault was obscured by soil matrix impregnated with B72. The loose fragment assemblage included a considerable amount of facial material: nasals, maxillary frontal processes, the left malar, and superorbital portions of the frontal, including the glabella. Several basilar fragments were also present, representing the margins of the foramen magnum, sphenoid alae, portions of the occipital squamous, and temporals. In addition to a significant quantity of diagnostic cranial fragments, the assemblage included numerous postcranial fragments. Among this material was the inferior ramus of the right pubis and enough of the posterior inferior iliac spine to reconstruct the posterior margin of the left greater sciatic notch. In addition, both femoral heads and the right humeral and radial heads were available for study. A full reconstruction of the skull was undertaken. Sections of vault bone and matrix embedded in B72 were soaked in acetone, taken apart, cleaned, dried, and reassembled using a plastic-resin DucoTM cement. Loose craniofacial fragments were sorted, sided, and assembled. The bony facial reconstruction was articulated to the vault reconstruction. On the pelvis, the ventral ramus was reconstructed onto the larger portion of the right pubis in order to aid in identification of sex-based morphology. In addition, the posterior inferior iliac spine was reconstructed back to the left innominate, in order to establish the form of the greater sciatic notch. The greater sciatic notch tends to be wider in females and narrower in males, though Fulginiti (1993) demonstrated variability in this tendency. In the dorsal midline, there is sex-based variability in the morphology of the sacrum as well. In males, the centrum of the first sacral vertebra tends to be wider than the alae, by approximately three-fifths vs. onefifth for alar widths, while in females these widths tend to be more evenly apportioned at one-third each of the total sacral width across the top. In the collections at the Fundacao Museu do Homem Americanos (FUMDHAM) is an unambiguous female Paleoindian skeleton dated to within 1,200 years of Coquieros. Lessa and Guidon (2002) mentioned this individual (Toca da Janela da Barro do Antoniao), but stated that they could not use it for comparison. In addition, an unambiguous female os pubis, from a relatively recent burial context (within the past 500 years), was chosen from the collections for purposes of comparison (Fig. 1). Figure 1 is a comparative photograph of the pubic bones from the Coqueiros, Antoniao, and recent female skeletons. The Antoniao individual is in a poor enough state of preservation that visualizing morphology beyond the width of the ventral surface and a hint of the subpubic angle is challenging. In the recent burial (see above), even though the ventral ramus is poorly reconstructed, form is clearly evident, and the width of the ventral surface of the element (with the attendant ventral arc) and subpubic angle are all clearly visible. These stand in stark

Age and source of different forms of carbon released from boreal peatland streams during spring snowmelt in E. Finland

Isotopic data are increasingly being used to quantify and understand the processes that control the release of carbon (C) from northern peatlands. We used δ13C and 14C measurements to investigate the source and age of different forms of aquatic C (DOC, POC and evasion CO2) released from 2 contrasting (undrained v drained) forested peatland catchments at the end of the winter snowmelt period in boreal E Finland. The δ13CVPDB values of DOC (range −28.3 to −28.8 ‰) were generally more 13C depleted than evasion CO2 (range −22.7 to −31.5 ‰) and showed no clear differences between the pre-flood, flood and post-flood periods. Both forms of C had evidence of bomb-14C (i.e. >100%modern), indicating that they contained substantial quantities of C fixed since the mid AD 1950s. However, DOC was 14C enriched compared to evasion CO2, with 14C concentrations suggesting that, on average, DOC-C was ~5–6 years younger than evasion CO2–C, with the most recently fixed C being released when temperatures were highest. POC was significantly depleted in 14C with conventional (uncalibrated) radiocarbon ages of 805–1135 BP. In contrast to other studies, the isotopic compositions of DOC and evasion CO2 were very similar, suggesting a predominantly single and consistent C source (decomposition of soil organic matter; SOM) during the snowmelt period. Whilst we found no evidence to suggest that old (pre-bomb) C was being released at the end of the winter period, the drained site was associated with more 14C depleted and 13C enriched evasion CO2, suggesting a closer link to the atmospheric CO2 pool. Our isotopic data suggest that the various forms of C released to the aquatic system from these forested Finnish peatlands are closely related, largely unaffected by drainage and (at least in the case of evasion CO2 and DOC) indicate strong connectivity between C cycling in the soil–plant–water system.

Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)

The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr(-1). The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the Río de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current - Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators of the paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level - mbsl), 8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).

A Dingo Burial From the Arnhem Land Plateau

The skeleton of a mature dingo was found wrapped in paperbark and cached on a ledge in a rockshelter on the Arnhem Land plateau. Such burials have not previously been recorded from the region and are considered uncommon by contemporary Jawoyn elders. Radiocarbon dating of a vertebra from the skeleton provided a conventional radiocarbon age of 77±35 BP. This finding is discussed in relation to other recorded aspects of the dingo’s relationship with humans in the ethnography and also its presentation in the rock art of Arnhem Land and elsewhere in Australia.

Estimation of the Recurrence Period of Strong Earthquakes in Zones of the Main Sayan and Tunka Faults according to the Data of Radiocarbon Dating and Statistical Analysis

The conventional radiocarbon ages of soil horizons limiting the timing of six fault-generating dis- placements within the East Sayan structure of the Main Sayan Fault and four displacements within the Tora structure of the Tunka Fault (M > 7) have been calibrated according to the IntCal04 calibration curve. It was revealed that between time periods of 12 Ka and 5.4 Ka years ago, the recurrence of earthquakes associated with movements along the faults in the East Sayan structure occurred once every 3000 years. After seismic quiescence, since 1100 years, one earthquake has occurred every 440 years. Using the Monte Carlo method, the possibility of the recurrence of strong earthquakes at different probability levels was considered. At a fre- quency probability of 95% the Main Sayan fault may be hazardous, dating from about 2120 AD. When low- ering the threshold probability to 72%, the beginning of the period of potential hazard is reduced to about 2030 AD. In both cases the maximum possibility of the occurrence of the next strong earthquake is not earlier than in the 22nd century. For the Tora structure, the periodicity of the recurrence of the earthquakes was esti- mated as 2800 yearsfor the past 11Ka with a probability of over 95% of the recurrence of earthquakes. This allows us to assume that currently the Tora structure is within the time interval of the potential risk of the recurrence of a strong earthquake.

Aspartic acid geochronology of sediments from the ocean margin off of India

Aspartic acid racemization was studied in the clay and coarse fractions of sediments from southwestern Bay of Bengal (Core 1) in order to understand the role of terrestrial organic matter in the amino acid geochronology of Indian marginal sediments. Conventional radiocarbon ages were determined for the coarse carbonate fraction (>25 μm) of sediments, the core covering an age back to ∼40 kyr BP. Aspartic acid racemization rate constants ( k asp) were calculated for clay and coarse fractions of bulk sediments using a first order kinetic model and three horizons with constant k asp values were identified, corresponding to the periods from 0 to 5.5 kyr, 5.5 to 19 kyr and >19 kyr. Best fit models of high significance were derived from the relationship between aspartic acid D/ L ratio and calibrated radiocarbon ages as an alternative to racemization rate constants. To test the applicability of these first order kinetic and logarithmic models derived for Core 1, they were used to calculate ages for another sediment core (Core 2), calculated aspartic acid ages being consistent with radiocarbon ages. However, the logarithmic model gave better results than the first order kinetic model for older samples, suggesting that the logarithmic model is a better choice for the amino acid geochronology of Indian margin sediments. For both sediment fractions, aspartic acid ages based on the logarithmic model gave similar ages, consistent with radiocarbon ages and suggesting that there is no significant difference in aspartic acid racemization between both fractions of bulk sediment. As a result, the clay fraction can also be used for amino acid dating of Indian margin sediments.

62 RECOVERY OF CELL NUCLEI FROM 15 000-YEAR-OLD MAMMOTH TISSUES AND INJECTION INTO MOUSE ENUCLEATED MATURED OOCYTES

Since the report of “Dolly” (Wilmut et al. 1997 Nature 385, 810-813), cloned animals have been successfully produced by somatic cell nuclear transfer (SCNT). In those reports, cultured or fresh cells were mainly used as nuclear donor cells in SCNT. Meanwhile, there was a report of the birth of offspring by SCNT with the nuclear donor cell derived from frozen whole body kept at -20°C for 16 years without cryoprotectant (Wakayama et al. 2008 Proc. Natl. Acad. Sci. USA 105, 17 318-17 322). This report suggests that if tissues or cells are cryopreserved postmortem without cryoprotectant, resurrection of the postmortem animal individual might be possible by SCNT. Furthermore, in cases of extinct or endangered species, it is difficult to use oocytes derived from same species as the recipient cytoplasm. However, there was a report of the birth of offspring by SCNT with oocytes derived from closely related species (Lanza et al. 2000 Cloning 2, 79-90). This result suggests that if oocytes from closely related species are available as the recipient cytoplasm, it would be possible to resurrect extinct or endangered species by SCNT. Woolly mammoth (Mammuthus primigenius) is a famous animal that existed during the ice ages and became extinct at the end of the last ice age. Its relics have been excavated from permafrost. Recently, the prospect of the resurrection of woolly mammoth by SCNT has heightened. However, even if the soft tissue of the woolly mammoth is excavated, it is not clear whether its cell nuclei retain their biological characteristics for more than several thousand years. In this study, we recovered cell nuclei from 15 000-year-old mammoth tissues and injected them into mouse enucleated matured oocytes as the nuclear donor in SCNT. Frozen mammoth legs were excavated from Northeast Siberian permafrost at the point of 71°34′56.9″ N and 141°37′37.6″ E. The conventional radiocarbon age of the sample after 13C correction was 13 100 to 12800 BC or 12400 to 11 800 BC. Cell nucleus-like structures were successfully recovered from skin and muscle tissues. Those nuclei were then injected into enucleated BDF1 mouse oocytes, and more than half of the injected oocytes were able to survive (67%; 12/18 for oocytes injected with skin-derived nucleus, 55%; 72/131 for oocytes injected with muscle-derived nucleus and 33%; 26/80 for oocytes injected with frozen-thawed mouse bone marrow-derived nucleus as the control group). Injected nuclei were not taken apart and retained their nuclear structure. Those oocytes did not show disappearance of nuclear membrane or premature chromosome condensation at 1 h after injection and did not form pronuclear-like structures at 7 h after injection. Because one-half of the oocytes injected with nuclei derived from frozen-thawed mouse bone marrow cells were able to form pronuclear-like structures (46%; 12/26), it might be possible to promote the cell cycle of nuclei from ancient animal tissues by suitable pretreatment in SCNT. This is the first report of SCNT with nuclei derived from mammoth tissues. This study was funded in part by Gifu Prefecture, Japan.