Pieter M Grootes
Dados Biográficos
| ID | 163050 |
|---|---|
| NOME | Pieter M Grootes |
| PRENOMES | Pieter M |
| SOBRENOME | Grootes |
| ASSINATURA | GROOTES P M |
| AFILIAÇÕES | Christian-Albrechts-Universität zu Kiel |
| ORCID | 0000-0003-4265-3168 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 59 |
| TOTAL DE CITAÇÕES | 4616 |
| TOTAL COMO AUTOR | 59 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1979 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 16 |
Turnover rates in human bone and tissue
Bone and tissue fractions, obtained in 2017 following hip replacement surgery on a healthy Caucasian male, born in 1944, reflect in their 14 C concentrations the integrated effect of the lifetime metabolic uptake and replacement of atmospheric bomb 14 C at different tissue-specific turnover rates. The 14 C content of hair and nails reflects recent carbon uptake. The 14 C values in healthy cartilage and bone collagen/apatite correspond to those of…
Modeling the contribution of carbon sources using cellulose 14C concentrations in subannual tree ring increments over the 1963 bomb spike
Measurements of the radiocarbon ( 14 C) content of subannual wood cellulose samples over the 1963 bomb spike have revealed an apparent delay between the increase in atmospheric radiocarbon content and that of wood cellulose. This delay is apparent in both coniferous and deciduous tree species and is of a magnitude of approximately 4 weeks. The delay in wood cellulose 14 C change as measured in a Sitka spruce from Washington state, USA, was previo…
Centennial to Millennial-Scale Fluctuations of the Lake Suigetsu Atmospheric 14 C Record Represent Authentic 14 C Features Over Last Glacial-to-Deglacial Times
Short-term fluctuations in atmospheric radiocarbon ( 14 C) concentration mark the tree-ring record for the last ∼15 kyr. Terrestrial macrofossils from sediment cores of Lake Suigetsu, Japan, extend this record of fluctuations back to >35 cal ka BP. Their significance, however, is under debate since the signal-to-noise ratio of the Suigetsu record is low and progressively decreases with increasing age. Coherent semi-millennial-scale structures of …
Unravelling the History of a Venetian Antiphonary
We present the results of a multifaceted study of an antiphonary—liturgical song book—presumably made in Venice in 1607, now in the Ringve, National Music Museum of Norway in Trondheim 1 . The book is hand-sewn on raised cords, bound in full leather on cardboard covers, originally with metal clamps. The paper block consists of pages printed in black and red that include both song texts and music scores. The red ink is based on vermillion and red …
The Radiocarbon Sample Archive of Trondheim
Atmospheric CO 2 samples have been collected by the Trondheim Radiocarbon Laboratory since the 1960s. The remaining material from the measurements has been precipitated as CaCO 3 and stored in glass containers. We investigated some of the stored samples to assess whether the material could still be used for remeasurements of atmospheric radiocarbon ( 14 C) content, or if it has been contaminated during the years of storage. We attempted different…
Hessel De Vries
Hessel de Vries contributed to radiocarbon ( 14 C) dating for only one short decade. Yet, his development of proportional CO 2 counting greatly facilitated 14 C measurements, improved their reproducibility, and lowered both the amount of carbon needed for a measurement and the 14 C detection limit by at least a factor ten. Validating Libby’s 14 C method by checking its basic assumptions with improved sensitivity, de Vries documented relatively mi…
University of Washington Quaternary Isotope Laboratory Retrospective
The Quaternary Isotope Laboratory (QIL) at the University of Washington was launched in 1969 and directed by Minze Stuiver until his retirement in 1998. Here we review some of the scientific work undertaken in the QIL and the memories of some of Minze’s former students and colleagues
Marine20—The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP)
The concentration of radiocarbon ( 14 C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14 C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-aver…
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Radiocarbon ( 14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth syste…
Status report of the Trondheim Radiocarbon Laboratory
The Trondheim radiocarbon ( 14 C) laboratory has evolved from a traditional radiocarbon decay counting laboratory to an accelerator mass spectrometry (AMS) facility primarily measuring 14 C. This evolution required adjustments in sample preparation and data handling to match the capacity of the AMS system and reduction in sample sizes to about 1 mgC. We summarize here the steps involved in dating a sample at the National Laboratory for Age Determ…
Subsoil 14 C Dynamics in Different Types of Tropical and Subtropical Soils under Different Crop Management
Radiocarbon has been applied as a tracer to study carbon dynamics in different types of tropical soils, under paddy and non-paddy management on Java, Indonesia. The 14 C concentrations were measured in samples of total organic carbon as well as in alkali-soluble humic acids, insoluble humin, and plant remains (roots, seeds, leaves) obtained from three sites with Andosols, Alisols, and Vertisols at different altitudes. In addition, the abundance a…
Planktic and Benthic 14 C Reservoir Ages for Three Ocean Basins, Calibrated by a Suite of 14 C Plateaus in the Glacial-to-Deglacial Suigetsu Atmospheric 14 C Record
This article presents a compilation of planktic and benthic 14 C reservoir ages for the Last Glacial Maximum (LGM) and early deglacial from 11 key sites of global ocean circulation in the Atlantic and Indo-Pacific Ocean. The ages were obtained by 14 C plateau tuning, a robust technique to derive both an absolute chronology for marine sediment records and a high-resolution record of changing reservoir/ventilation ages (Δ 14 C values) for surface a…
Quantitative diet reconstruction of a Neolithic population using a Bayesian mixing model (FRUITS)
Objectives The island cemetery site of Ostorf (Germany) consists of individual human graves containing Funnel Beaker ceramics dating to the Early or Middle Neolithic. However, previous isotope and radiocarbon analysis demonstrated that the Ostorf individuals had a diet rich in freshwater fish. The present study was undertaken to quantitatively reconstruct the diet of the Ostorf population and establish if dietary habits are consistent with the tr…
Food Reconstruction Using Isotopic Transferred Signals (FRUITS)
Human and animal diet reconstruction studies that rely on tissue chemical signatures aim at providing estimates on the relative intake of potential food groups. However, several sources of uncertainty need to be considered when handling data. Bayesian mixing models provide a natural platform to handle diverse sources of uncertainty while allowing the user to contribute with prior expert information. The Bayesian mixing model FRUITS (Food Reconstr…
Towards the use of radiocarbon as a dietary proxy
Radiocarbon reservoir effects (RREs) are observed when the 14C concentration of aquatic reservoirs is lower than the contemporary atmosphere. Within these reservoirs, aquatic species will also have a 14C depleted signal, and humans feeding on these species will show a dietary RRE. Human dietary RREs are often viewed as a problem for the establishment of reliable chronologies. However, they also represent an opportunity to introduce radiocarbon as…
A preliminary study on the influence of cooking on the C and N isotopic composition of multiple organic fractions of fish (mackerel and haddock)
IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0–50,000 Years cal BP
The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14 C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were r…
A Freshwater Lake Saga
Recently, several case studies have demonstrated the presence of human radiocarbon dietary reservoir effects in inland contexts. Freshwater reservoir effects present a high degree of variability, making it difficult to define local reservoir effect reference values necessary for correcting chronologies based on 14 C dating of human bone material. Here, we investigate the hypothesis that 14 C ages of edible freshwater species are delimited by the …
Selection and Treatment of Data for Radiocarbon Calibration
High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14 C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14 C/ 12 C in these archives, i…
Origin of Subsoil Carbon in a Chinese Paddy Soil Chronosequence
Rice paddies are highly important agricultural soils in view of their relevance as major staple food provider in the world and their key role in the global carbon cycle, caused by special management practices. A soil chronosequence, consisting of paddy and upland soils, developed on reclaimed estuarine sediments in the Province of Zhejiang, China, was sampled to investigate the influence of duration of agricultural use (50 to 2000 yr) on soil com…
Dating Bulk Sediments from Limnic Deposits Using a Grain-Size Approach
Radiocarbon measurements on bulk subaqueous sediments typically provide ages significantly older than actual time of deposition. This is generally caused by the presence of reworked organic compounds, which are depleted in 14 C. To explore this issue of age heterogeneity, we collected 4 organic-rich samples from varying depths in a lake sediment core at the Gemündener Maar (Eifel, Germany), a lake of volcanic origin. We divided each sample into 5…
Mussels with Meat
Local reservoir ages are often estimated from the difference between the radiocarbon ages of aquatic material and associated terrestrial samples for which no reservoir effect is expected. Frequently, the selected aquatic material consists of bivalve shells that are typically well preserved in the archaeological record. For instance, large shell middens attest to the importance of mussel consumption at both coastal and inland sites. However, diffe…
A 14 000-year-old amber elk and the origins of northern European art
A Late Palaeolithic amber figurine has been skilfully recovered and reassembled from a ploughed open site in northern Germany. Dated between 11 800 and 11 680 cal BC it occupies a key point between the Magdalenian and the Mesolithic. The authors show that the figurine represents a female elk which was probably carried on the top of a wooden staff. They argue for continuity of art but change of belief in this crucial transition period
Macronutrient-based model for dietary carbon routing in bone collagen and bioapatite
Sampling Iron for Radiocarbon Dating
Before the 17th century, charcoal was regularly used in the production of iron (smelting and forging) and some of this charcoal carbon was incorporated into the iron. Depending on the age of the wood used to produce the charcoal, the age of the carbon incorporated in the iron lattice can reflect the age of manufacture of the iron artifacts. A reliable preparation method allowing for the routine dating of iron artifacts would permit the dating of …
IntCal09 and Marine09 Radiocarbon Age Calibration Curves, 0-50,000 Years cal BP
The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the 14 C and calendar timescales as established in 2002. No change was made to the curves…
IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0–50,000 Years cal BP
The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14 C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were r…
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Radiocarbon ( 14 C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14 C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth syste…
Macronutrient-based model for dietary carbon routing in bone collagen and bioapatite
Marine20—The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP)
The concentration of radiocarbon ( 14 C) differs between ocean and atmosphere. Radiocarbon determinations from samples which obtained their 14 C in the marine environment therefore need a marine-specific calibration curve and cannot be calibrated directly against the atmospheric-based IntCal20 curve. This paper presents Marine20, an update to the internationally agreed marine radiocarbon age calibration curve that provides a non-polar global-aver…
Quantitative diet reconstruction of a Neolithic population using a Bayesian mixing model (FRUITS)
Objectives The island cemetery site of Ostorf (Germany) consists of individual human graves containing Funnel Beaker ceramics dating to the Early or Middle Neolithic. However, previous isotope and radiocarbon analysis demonstrated that the Ostorf individuals had a diet rich in freshwater fish. The present study was undertaken to quantitatively reconstruct the diet of the Ostorf population and establish if dietary habits are consistent with the tr…
Mercury levels in Danish Medieval human bones
Lugovskoe
Artifacts were fi rst discovered at Lugovskoe in 1999 during the collection of faunal remains (Pavlov, Maschenko, 2001). The small collection included small debris, fl akes, a blade with a retouched proximal edge, and two large artifacts: a hammerstone made on a quartzite pebble, and a bidirectional core made on a gray fi ne-grained sandstone cobble. These artifacts suggested that the mammoth assemblage was associated with a Paleolithic site. To …
Chemical Removal of Conservation Substances by “Soxhlet“-Type Extraction
At the Leibniz radiocarbon lab, art and archaeological objects, often chemically conserved and thus potentially contaminated with respect to their 14 C content, are treated using a computer-controlled “Soxhlet”-type series extractor. This device uses a continuous procedure of boiling and condensation of different solvents for extraction and vacuum filtration under constant process conditions. An elutrope sequence of five solvents that dissolve mo…
A Cremated Bone Intercomparison Study
It is now almost 10 yr since radiocarbon dating of cremated bone was first developed using the small carbonate component contained within the hydroxyapatite-based inorganic fraction. Currently, a significant number of 14 C laboratories date cremated bone as part of their routine dating service. As a general investigation of cremated bone dating since this initial development, a small, cremated bone intercomparison study took place in 2005, involv…
Towards the use of radiocarbon as a dietary proxy
Radiocarbon reservoir effects (RREs) are observed when the 14C concentration of aquatic reservoirs is lower than the contemporary atmosphere. Within these reservoirs, aquatic species will also have a 14C depleted signal, and humans feeding on these species will show a dietary RRE. Human dietary RREs are often viewed as a problem for the establishment of reliable chronologies. However, they also represent an opportunity to introduce radiocarbon as…
Selection and Treatment of Data for Radiocarbon Calibration
High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14 C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14 C/ 12 C in these archives, i…
Radiocarbon Levels in the Iceland Sea from 25–53 kyr and their Link to the Earth's Magnetic Field Intensity
By correlating the climate records and radiocarbon ages of the planktonic foraminifera N. pachyderma (s) of deep-sea core PS2644 from the Iceland Sea with the annual-layer chronology of the GISP2 ice core, we obtained 80 marine 14 C calibration points for the interval 11.4-53.3 ka cal BP. Between 27 and 54 ka cal BP the continuous record of 14 C/cal age differences reveals three intervals of highly increased 14 C concentrations coincident with lo…
How Clean is Ultrafiltration Cleaning of Bone Collagen
As part of our bone dating development, we have tested the ultrafiltration of bone gelatin using 2 different filters—Vivaspin 20TM (VS20), a polyethersulfone, and Vivaspin 15RTM (VS15R), a cellulose, both with a 30,000 molecular weight cutoff—and bone collagen from dated samples ranging in age from 1.5 to >50 kyr BP. A direct accelerator mass spectrometry (AMS) measurement yielded radiocarbon concentrations of ∼0.5 pMC (∼42 kyr) for the polyether…
The Carbonate 14 C Background and its Components at the Leibniz AMS Facility
After routine accelerator mass spectrometry (AMS) radiocarbon dating had been established at the Leibniz-Labor with the completion of systems for CO 2 production, graphitization, and target making, a systematic investigation was conducted to find the sources of 14 C concentrations observed in background materials. We quantified the contributions of the AMS-system, the reduction, CO 2 production from carbonate, carbonate contamination, and combust…
Lugovskoe, Western Siberia
Eleven woolly mammoth bone samples from Lugovskoe (central West Siberian Plain, Russia) were radiocarbon dated in 3 laboratories: Institute of Geology, Novosibirsk; Oxford University, Oxford; and Christian Albrechts University, Kiel. Each laboratory used its own protocol for collagen extraction. Parallel dating was carried out on 3 samples in Novosibirsk and Oxford. Two results are in good agreement. However, there is a major discrepancy between …
A preliminary study on the influence of cooking on the C and N isotopic composition of multiple organic fractions of fish (mackerel and haddock)
Carbonate 14 C Background
Measurements of the radiocarbon concentration of several carbonate background materials, either mineral (IAEA C1 Carrara marble and Icelandic double spar) or biogenic (foraminifera and molluscs), show that the apparent ages of diverse materials can be quite different. Using 0.07 pMC obtained from mineral samples as a processing blank, the results from foraminifera and mollusc background samples, varying from 0.12 to 0.58 pMC (54.0-41.4 ka), show …
Climate and pre‐Columbian settlement at Anse à la Gourde, Guadeloupe, Northeastern Caribbean
The authors present a reconstruction of precipitation, seasonality, and vegetation cover over the period from 200 cal yr B.C. to 1600 cal yr A.D. for the archaeological site of Anse à la Gourde, Guadeloupe, based on the oxygen and carbon isotope composition of accelerator mass spectrometry (AMS) 14 C‐dated aragonitic shells of the landsnail Bulimulus guadaloupensis. The results show that the Late Cedrosan Saladoid population ( ̃400–800 cal yr A.D…
Correlation of Marine 14 C Ages from the Nordic Seas with the Gisp2 Isotope Record
We present two new high-resolution sediment records from the southwestern Iceland and Norwegian Seas that were dated by numerous 14 C ages up to 54 14 C ka bp. Based on various lines of evidence, the local 14 C reservoir effect was restricted to 400–1600 yr. The planktic stable isotope records reveal several meltwater spikes that were sampled with an average time resolution of 50 yr in PS2644 and 130 yr in core 23071 during isotope stage 3. Most …
Mussels with Meat
Local reservoir ages are often estimated from the difference between the radiocarbon ages of aquatic material and associated terrestrial samples for which no reservoir effect is expected. Frequently, the selected aquatic material consists of bivalve shells that are typically well preserved in the archaeological record. For instance, large shell middens attest to the importance of mussel consumption at both coastal and inland sites. However, diffe…
A Freshwater Lake Saga
Recently, several case studies have demonstrated the presence of human radiocarbon dietary reservoir effects in inland contexts. Freshwater reservoir effects present a high degree of variability, making it difficult to define local reservoir effect reference values necessary for correcting chronologies based on 14 C dating of human bone material. Here, we investigate the hypothesis that 14 C ages of edible freshwater species are delimited by the …
A 14 000-year-old amber elk and the origins of northern European art
A Late Palaeolithic amber figurine has been skilfully recovered and reassembled from a ploughed open site in northern Germany. Dated between 11 800 and 11 680 cal BC it occupies a key point between the Magdalenian and the Mesolithic. The authors show that the figurine represents a female elk which was probably carried on the top of a wooden staff. They argue for continuity of art but change of belief in this crucial transition period
Status report of the Trondheim Radiocarbon Laboratory
The Trondheim radiocarbon ( 14 C) laboratory has evolved from a traditional radiocarbon decay counting laboratory to an accelerator mass spectrometry (AMS) facility primarily measuring 14 C. This evolution required adjustments in sample preparation and data handling to match the capacity of the AMS system and reduction in sample sizes to about 1 mgC. We summarize here the steps involved in dating a sample at the National Laboratory for Age Determ…
The Gundestrup Cauldron
The Quaternary Isotope Laboratory Thermal Diffusion Enrichment System
The thermal diffusion enrichment system of the Quaternary Isotope Laboratory consists of 23 hot wire columns of 3m effective length combined to 2 separate systems of 3 and 3 separate systems of 4 columns at the top, each system in series with 1 bottom column. From ≈ 130 L NTP of CO (∼ 65g of carbon) it produces ≈ 8 L NTP of CO (~ 4g of carbon) enriched in 12 C 18 O by a factor 6 to 7 and in 14 C 16 O by a factor 7 to 8 in about 5 weeks. For 12 C …
Ross Ice Shelf Oxygen Isotopes and West Antarctic Climate History
The Ross Ice Shelf δ 18 O profile at station J-9 covers at least the last 30,000 yr. It identifies the depth in the core of ice from (i) the last glacial-interglacial transition (266 to 286 m) and (ii) the 1000-m surface elevation (about 140 m). Various processes contribute to the δ 18 O change observed in the core: (i) climatic warming, mainly caused by a decrease in winter sea ice extent around Antarctica of about 6° latitude early in the glaci…
Radiocarbon Dating with the University of Washington Accelerator Mass Spectrometry System
The University of Washington FN tandem accelerator mass spectrometry (AMS) system has been used in a series of 14 C studies. 1) The 14 C concentrations in annual growth rings for 1962, 1963, and 1964 of a Sitka spruce, each divided into ten sequential segments, were measured; a full and rapid response of tree-ring cellulose to atmospheric changes in 14 CO 2 is indicated, with a delay, if any, of not more than three weeks. 2) The C concentrations …
Subtle 14 C Signals
Atmospheric 14 C concentrations vary with time and latitude. These variations, measured directly on atmospheric samples, or in independently-dated organic material such as tree rings, supply data essential for the calibration of dynamic models of the global carbon cycle. Short variations in the production rate of atmospheric 14 C are strongly attenuated in the relatively large atmospheric CO 2 reservoir. In-situ production of 14 C should be negli…
Comparison of oxygen isotope records from the Gisp2 and GRIP Greenland ice cores
Abrupt increase in Greenland snow accumulation at the end of the Younger Dryas event
The ‘flickering switch’ of late Pleistocene climate change
The Gisp2 δ18O Climate Record of the Past 16,500 Years and the Role of the Sun, Ocean, and Volcanoes
Measured 18O/16O ratios from the Greenland Ice Sheet Project 2 (GISP2) ice core extending back to 16,500 cal yr B.P. provide a continuous record of climate change since the last glaciation. High-resolution annual 18O/16O results were obtained for most of the current millennium (A.D. 818-1985) and record the Medieval Warm Period, the Little Ice Age, and a distinct 11-yr 18O/16O cycle. Volcanic aerosols depress central Greenland annual temperature …
Implications of Stratigraphic and Paleoclimatic Records of the Last Interglaciation from the Nordic Seas
Climatic reconstruction of glacial to interglacial episodes from oxygen isotopes in sediment cores from the Nordic seas is complicated by strong local meltwater contributions to the oxygen isotope changes. Combination of benthic and planktic foraminiferal isotope data with foraminiferal abundances and ice-rafted debris (IRD) allows separation of local and global effects and subdivision of the marine oxygen isotope events 6.2–5.4, which include th…
Is There Evidence for Solar Forcing of Climate in the Gisp2 Oxygen Isotope Record?
Changes in solar constant over an 11 yr cycle suggest a certain, but limited, degree of solar forcing of climate. The high-resolution climate (oxygen isotope) record of the Greenland GISP2 (Greenland Ice Sheet Project 2) ice core has been analyzed for solar (and volcanic) influences. The atmospheric 14 C record is used as a proxy of solar change and compared to the oxygen isotope profile in the GISP2 ice core. An annual oxygen isotope profile is …
Correlation of Marine 14 C Ages from the Nordic Seas with the Gisp2 Isotope Record
We present two new high-resolution sediment records from the southwestern Iceland and Norwegian Seas that were dated by numerous 14 C ages up to 54 14 C ka bp. Based on various lines of evidence, the local 14 C reservoir effect was restricted to 400–1600 yr. The planktic stable isotope records reveal several meltwater spikes that were sampled with an average time resolution of 50 yr in PS2644 and 130 yr in core 23071 during isotope stage 3. Most …
The Carbonate 14 C Background and its Components at the Leibniz AMS Facility
After routine accelerator mass spectrometry (AMS) radiocarbon dating had been established at the Leibniz-Labor with the completion of systems for CO 2 production, graphitization, and target making, a systematic investigation was conducted to find the sources of 14 C concentrations observed in background materials. We quantified the contributions of the AMS-system, the reduction, CO 2 production from carbonate, carbonate contamination, and combust…
Gisp2 Oxygen Isotope Ratios
The GISP2 oxygen isotope record, with its high-resolution detail, yields crucial information on past climate change. The glacial δ 18 O oscillations of the GISP2 core, with their very fast onsets, are templates of a prototype oscillation of variable duration with an amplitude of 3.9‰. The halfway mark of the cold–warm transition is reached in 2 years; the top is reached in 50 years. The δ 18 O–time gradient of the leading front is about 7.8‰ per …
Rapid Flooding of the Sunda Shelf
The increase in sea level from the last glacial maximum has been derived from a siliciclastic system on the tectonically stable Sunda Shelf in Southeast Asia. The time from 21 to 14 thousand calendar years before the present has been poorly covered in other records. The record generally confirms sea-level reconstructions from coral reefs. The rise of sea level during meltwater pulse 1A was as much as 16 meters within 300 years (14.6 to 14.3 thous…
Radiocarbon Levels in the Iceland Sea from 25–53 kyr and their Link to the Earth's Magnetic Field Intensity
By correlating the climate records and radiocarbon ages of the planktonic foraminifera N. pachyderma (s) of deep-sea core PS2644 from the Iceland Sea with the annual-layer chronology of the GISP2 ice core, we obtained 80 marine 14 C calibration points for the interval 11.4-53.3 ka cal BP. Between 27 and 54 ka cal BP the continuous record of 14 C/cal age differences reveals three intervals of highly increased 14 C concentrations coincident with lo…
The Taylor Dome Antarctic 18 O Record and Globally Synchronous Changes in Climate
The 18 O/ 16 O profile of a 554-m long ice core through Taylor Dome, Antarctica, shows the climate variability of the last glacial–interglacial cycle in detail and extends at least another full cycle. Taylor Dome shares the main features of the Vostok record, including the early climatic optimum with later cool phase of the last interglacial period in Antarctica. Taylor Dome δ 18 O fluctuations are more abrupt and larger than those at Vostok and …
Carbonate 14 C Background
Measurements of the radiocarbon concentration of several carbonate background materials, either mineral (IAEA C1 Carrara marble and Icelandic double spar) or biogenic (foraminifera and molluscs), show that the apparent ages of diverse materials can be quite different. Using 0.07 pMC obtained from mineral samples as a processing blank, the results from foraminifera and mollusc background samples, varying from 0.12 to 0.58 pMC (54.0-41.4 ka), show …
Chemical Removal of Conservation Substances by “Soxhlet“-Type Extraction
At the Leibniz radiocarbon lab, art and archaeological objects, often chemically conserved and thus potentially contaminated with respect to their 14 C content, are treated using a computer-controlled “Soxhlet”-type series extractor. This device uses a continuous procedure of boiling and condensation of different solvents for extraction and vacuum filtration under constant process conditions. An elutrope sequence of five solvents that dissolve mo…
Two Tephra Layers Bracketing Late Holocene Paleoecological Changes in Northern Germany
Paleoecological records from two Holocene peat bogs in northern Germany are linked by two microscopic volcanic ash layers, correlated by petrology and geochemistry to explosive volcanism on Iceland. The younger “Microlite tephra” cannot be correlated to any known eruption, while the older tephra layer is identified as a deposit of the Hekla 3 eruption. The tephra layers are dated by an age–depth regression of accelerator mass spectrometry 14 C ag…
Climate change at the 4.2 ka BP termination of the Indus valley civilization and Holocene south Asian monsoon variability
Planktonic oxygen isotope ratios off the Indus delta reveal climate changes with a multi‐centennial pacing during the last 6 ka, with the most prominent change recorded at 4.2 ka BP. Opposing isotopic trends across the northern Arabian Sea surface at that time indicate a reduction in Indus river discharge and suggest that later cycles also reflect variations in total annual rainfall over south Asia. The 4.2 ka event is coherent with the terminati…
C Ages of a Varved Last Glacial Maximum Section Off Pakistan
In a core off Pakistan, we obtained 38 14 C analyses by accelerator mass spectrometry (AMS) from a 4.4-m-thick, expanded, annually-laminated Last Glacial Maximum (LGM) section, bracketed by bioturbated intervals ascribed to the Heinrich-1 (H1) and Heinrich-2 (H2) equivalent events (52 14 C analyses between 24–15 kyr BP). A floating varve age scale, anchored to the oxygen isotope record of the layer-counted GISP2 ice core at the H2/LGM boundary, r…
Unexpectedly recent dates for human remains from Vogelherd
Lugovskoe, Western Siberia
Eleven woolly mammoth bone samples from Lugovskoe (central West Siberian Plain, Russia) were radiocarbon dated in 3 laboratories: Institute of Geology, Novosibirsk; Oxford University, Oxford; and Christian Albrechts University, Kiel. Each laboratory used its own protocol for collagen extraction. Parallel dating was carried out on 3 samples in Novosibirsk and Oxford. Two results are in good agreement. However, there is a major discrepancy between …
Complexity of Soil Organic Matter
Radiocarbon measurements of different lipid fractions and individual compounds, isolated from soil samples collected on 2 different agricultural long-term study sites, located in the rural area of Rotthalmünster (Germany) and in the city of Halle/Saale (Germany), were analyzed to obtain information about sources and the stability of soil organic matter (SOM). Different lipid compound classes were isolated by automated solvent extraction and subse…
Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired 230Th/234U/238U and 14C dates on pristine corals
Geology and Paleoclimatology Research (39 obras) · Archaeology and ancient environmental studies (35 obras) · Radiocarbon dating (34 obras) · Geography (28 obras) · Geology (28 obras) · Isotope Analysis in Ecology (27 obras) · Archaeology (22 obras) · Paleontology (21 obras) · Chemistry (20 obras) · Physical geography (17 obras)