P. M. Grootes

Kiel University | CAU · Institute for Ecosystem Research

Anecic Earthworm casting is the process explaining Chernozem genesis, properties and distribution across Europe. This has consequences for long-term carbon sequestering, sustainable management and protection of these valuable resource. Whereas climatic steppe Chernozems might form since epigeic and endogeic Earthworm species are limited by natural...

In Prague-Miškovice, a cemetery of the Únětice culture (UC) with a total of 44 graves was excavated between 1999 und 2001. The C14 dates range across the entire course of Central Europe’s Early Bronze Age – from the proto-Únětice phase to the “post-classical” phase of the UC. The high point of the mortuary activities occurred between 2000 and 1750...

Radiocarbon (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 C concentration. Although calibration curves are constructed from independently dated archives, they inva...

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 mg...

Sub-annual measurements, eight increments per year, of cellulose in a Scots pine tree growing in central Norway are presented as a proxy for tropospheric ¹⁴ CO 2 at biweekly to monthly resolution. The results are validated by comparison to direct atmospheric measurements in the years 1959–1965, and a new dataset is obtained for 1953–1958. In this p...

To resolve an inconsistency around AD 1895 between radiocarbon ( ¹⁴ C) measurements on oak from the British Isles and Douglas fir and Sitka spruce from the Pacific Northwest, USA, we measured the ¹⁴ C content in single-year tree rings from a Scots pine tree ( Pinus sylvestris L.), which grew in a remote location in Saltdal, northern Norway. The dat...

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 th...

The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. Although elevated ages in fluvially transported organic matter are usually explained by erosion of soils and sedimentary deposits, it is commonly assumed that mainly young organic material is discharged from flat t...

Modeling studies predict that changes in radiocarbon (14C) reservoir ages of surface waters during the last deglacial episode will reflect changes in both atmospheric 14C concentration and ocean circulation including the Atlantic Meridional Overturning Circulation. Tests of these models require the availability of accurate 14C reservoir ages in wel...

This paper presents highly unexpected paleobotanical data. Eight ¹⁴ C‐accelerator mass spectrometry ( AMS ) dates of soil macrocharcoal pieces, identified taxonomically, indicate the presence of oak and beech in the Younger Dryas, and pine in the Allerød, in the northernmost low mountain range of Central Europe, the Harz Mountains, in Germany. If t...

The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. While elevated ages in fluvially-transported organic matter are usually explained by erosion of soils and sediments, it is commonly assumed that mainly young organic material is discharged from flat tropical waters...

Modeling studies predict that changes in radiocarbon (14C) reservoir ages of surface waters during the last deglacial episode will reflect changes in both atmospheric 14C concentration and ocean circulation including the Atlantic Meridional Overturning Circulation. Tests of these models require the availability of accurate 14C reservoir ages in wel...

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...

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 recor...

Tracing the history of industrial fossil fuel combustion on the carbon stock in soil is challenging, since it is mixed with other soil organic carbon (SOC). Isolation of black carbon (BC) yields a mixture of diagenetic fossil C and pyrogenic BC from biomass and fossil fuel combustion. We investigated the degree to which fossil fuel combustion emiss...

Stable isotope analysis represents the principal scientific technique used in the reconstruction of ancient human diet. Characterisation of human diet requires that the isotopic baseline is established, i.e. the isotopic signals of consumed food groups. However, cooking may alter the bulk isotopic signal of food groups through the selective loss of...

Radiocarbon reservoir effects (RREs) are observed when the 14 C concentration of aquatic reservoirs is lower than the contemporary atmosphere. Within these reservoirs, aquatic species will also have a 14 C depleted signal, and humans feeding on these species will show a dietary RRE. Human dietary RREs are often viewed as a problem for the establish...

Here the apparent radiocarbon background signature of different organic materials such as crude oil, anthracite, plant remains, and bone is shown.

Deep water formation in the North Atlantic and Southern Ocean is widely thought to influence deglacial CO2 rise and climate change; here we suggest that deep water formation in the North Pacific may also play an important role. We present paired radiocarbon and boron isotope data from foraminifera from sediment core MD02-2489 at 3640 m in the North...

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 t...

Deep water formation in the North Atlantic and Southern Ocean is widely thought to influence deglacial CO2 rise and climate change; here we suggest that deep water formation in the North Pacific may also play an important role. We present paired radiocarbon and boron isotope data from foraminifera from sediment core MD02-2489 at 3640 m in the North...

We here present a compilation of planktic and benthic 14C 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 14C plateau tuning, a robust technique to derive both an absolute chronology for marine sediment records and a...

We used distinct 14C plateaus near 14.0, 13.3-12.8, and 12.3-12.1 (atm.) 14C ka in the Cariaco Basin record during deglacial stadial Heinrich 1 (H1) (Hughen et al., 2004) to tune past - 14C reservoir ages of ocean water masses and tie paleoceanographic signals to the ice core record of climate change. Reservoir ages of northwest Pacific surface wat...

High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon cali- bration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, an...

a more detailed account is published (in German) in Grootes P, Meadows J, Nadeau M-J. 2016. Radiokarbondatierung der Gräber aus Miškovice, in Prag-Miškovice: Archäologische un naturwissenschaftliche Untersuchungen zu Grabbau, Bestattungssitten und Inventaren einer frühbronzezeitlichen Nekropole (M Ernée). Römisch-Germanische Kommission des Deutsche...

More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in sur...

Paddy and non-paddy soils from a chronosequence of 50-2000 years of agricultural use, developed on former estuarine sediments of the Yangtze River, were sampled near Cixi, Zhejiang Province, China, in the framework of the Research Unit "Biogeochemistry of paddy soil evolution" of the German Research Foundation (DFG). In addition samples of Yangtze...

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,...

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 14C. To explore this issue of age heterogeneity, we collected 4 organic-rich samples from varying depths in a lake sediment cor...

The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14C 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 h...

Ice core records demonstrate a glacial-interglacial atmospheric CO2 increase by ~100 ppm, while 14C calibration efforts document a strong decrease in atmospheric 14C concentration during this period. A calculated transfer of ~530 Gt of 14C depleted carbon is required to produce the deglacial coeval rise of carbon in the atmosphere and terrestrial b...

The thermal diffusion enrichment apparatus in use in Amsterdam before 1967, has been rebuilt in the Groningen Radiocarbon Dating Laboratory. It has been shown to operate reliably and reproducibly. A reasonable agreement exists between the theoretical calculations and the experimental results. The 14C enrichment of a CO sample is deduced from the si...

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,...

Carbon stable isotope ratios (δ 13 C), measured in human bone collagen (δ 13 C collagen) and bioapatite (δ 13 C bioapatite), are commonly used indicators in ancient human diet reconstruc-tion. The underlying assumption is that human tissues broadly reflect the δ 13 C signal of dietary food sources (δ 13 C diet) plus an isotopic offset. However, int...

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....

a b s t r a c t Radiocarbon dating of bone mineral (carbonate in the apatite lattice) has been the target of sporadic research for the last 40 years. Results obtained by different decontamination protocols have, however, failed to provide a consistent agreement with reference ages. In particular, quality criteria to assess bone mineral radiocarbon...

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 mid...

The aim of this research was to revisit the existing chronology on Funnel Beaker monumental collecti-ve graves in Northern Germany. Human bone and tooth material was collected within the scope of an ancient DNA (aDNA) research project from three Northern German Funnel Beaker collective burial sites -Odagsen, Großenrode, and Calden. This ma-terial w...

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. H...

The correct method to calculate conventional C-14 ages from the carbon isotopic ratios was summarised 35 years ago by Stuiver and Polach (1977) and is now accepted as the only method to calculate C-14 ages. There is, however, no consensus regarding the treatment of AMS data, mainly of the uncertainty of the final result. The estimation and treatmen...

At least 15 settlement layers, deposited above each other from the early Neolithic (ca. 5300 cal BC) until Roman Imperial Times (ca. 400 cal AD), have been discovered at Niederröblingen, Germany. Constituting the longest duration of prehistoric settlement in central Europe so far known (ca. 4000 yrs), the site is thought to represent the first mult...

Radiocarbon measurements have been performed on iron samples (iron girders) as well as organic samples (charcoal, wood) from the Aachener Cathedral

On the basis of the radiocarbon (14C) plateau-tuning method, a new age model for Timor Sea Core MD01-2378 was established. It revealed a precise centennial-scale phasing of climate events in the ocean, cryo-, and atmosphere during the last deglacial and provides important new insights into causal linkages controlling events of global climate change...

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 relia...

Interdisciplinary investigation of an ivory find from Cap Sim (Essaouira, Morocco) conducted as a part of the joint-venture between the Institut National des Sciences de l'Archéologie et du Patrimoine (Rabat) and the Deutsches Archäologisches Institut (Madrid) offer a point of departure for further research. By attributing the ivory to the African...

The long-term impact of lowland rice growing on C stocks in soils was evaluated in the coastal region of subtropical China. During the past 2000 years new farmland was created through consecutive land reclamation by protective dikes, providing a unique chronosequence of soil formation under agricultural use. Parts of the land were used for paddy ri...

This paper presents highly unexpected paleobotanical data. Eight 14 C-accelerator mass spectrometry (AMS) dates of soil macrocharcoal pieces, identified taxonomically, indicate the presence of oak and beech in the Younger Dryas, and pine in the Allerød, in the northernmost low mountain range of Central Europe, the Harz Mountains, in Germany. If the...

We studied the faulted Al Harif Roman aqueduct, located on the north-trending, ∼90-km-long Missyaf segment of the Dead Sea fault, using four archaeological excavations, three paleoseismic trenches, and the analysis of six tufa cores. Damage to the aqueduct wall exhibits successive left-lateral fault offsets that amount to 13.6 ± 0.2 m since the aqu...

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To investigate the potential of Fe/Mn concretions for the stabilization of SOM in the framework of the Research Unit "Biogeochemistry of paddy soil evolution" of the German Research Foundation (DFG), concretions were separated from a chronosequence of paddy and non-paddy soil profiles, developed on former estuarine sediments of the Yangtze River. T...

Paddy and non-paddy soils from a chronosequence of 50 to 2000 years of agricultural use, developed on former estuarine sediments of the Yangtze River, were sampled near Cixi, Zhejiang Province, China, in the framework of the Research Unit 'Biogeochemistry of paddy soil evolution' of the German Research Foundation (DFG). In addition samples of Yangt...

Changes in marine planktic reservoir age variations hamper severely our ability to age calibrate and use marine records as atmospheric 14C records. Genuine atmospheric 14C changes may overlap with changes induced by massive changes in surface ocean hydrography. However, the deglacial Cariaco Basin record (tuned to U/Th ages of the Hulu record) form...

ABSTRACTA detailed radial profile for the 14C concentration in tree stem cellulose, covering growth rings for the years 1962–1964, was obtained for a Sitka spruce of the US Pacific Coast using accelerator mass spectrometry. The tree cellulose 14C closely follows atmospheric 14CO2 concentrations, responding to changes with an apparent delay of 5 to...

On the basis of the radiocarbon (14C) plateau-tuning method a new age model for Timor Sea Core MD01-2378 was established. It revealed a precise centennial-scale phasing of climate events in the ocean, cryo-, and atmosphere during the last deglacial and provides important new insights into causal linkages controlling events of global climate change....

Various ocean mechanisms have been proposed to explain the abrupt warming of DO event 1 forming the onset of the Bølling/Allerød (BA) period near 14.7 cal. ka BP, for example invoking multiple equilibria of Atlantic meridional overturning circulation (AMOC) and southern hemisphere climate forcing. A transient state-of-the-art model simulation of th...

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 uncertain...

The centennial-scale phasing of climate events in the ocean, cryo-, and atmosphere provides crucial new insights into causal linkages that have controlled the events of global climate change during the last deglacial. During Termination Ia, a first significant sea level rise occurred as early as 19.4-18.7 ka (Hanebuth et al., 2008), a first Antarct...

The view that Aurignacian technologies and their associated symbolic manifestations represent the archaeologicalproxy for the spread of Anatomically Modern Humans into Europe, is supported by few diagnostic human remains, including those from the Aurignacian site of Les Rois in south-western France. Here we reassess the taxonomic attribution of the...

Ultrafiltration of bone collagen, dissolved as gelatin (M ~100,000 D), has received considerable attention as a means to remove small contaminants and thus produce more reliable dates (Brown et al. 1988; Bronk Ramsey et al. 2004; Higham et al. 2006; Mellars 2006). However, comparative dating studies have raised the question whether this cleaning st...

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 ...

We present a high-resolution (not, vert, similar 60-110 yr) multi-proxy record spanning Marine Isotope Stage 3 from IMAGES Core MD01-2378 (13°04.95'S and 121°47.27'E, 1783 m water depth), located in the Timor Sea, off NW Australia. Today, this area is influenced by the Intertropical Convergence Zone, which drives monsoonal winds during austral summ...

Recent efforts to link the isotopic composition of snow in Greenland with meteorological and climatic parameters have indicated that relatively local information such as observed annual temperatures from coastal Greenland sites, as well as more synoptic scale features such as the North Atlantic Oscillation (NAO) and the temperature seesaw between J...

Our study addresses fundamental questions of the mode and timing of orbital and millennial-scale changes in the meridional overturning circulation (MOC) of the subarctic North Pacific. Particular concerns are the vertical mixing, the present and past abundance of nutrients in surface waters despite strong stratification, and the North Pacific-North...

Near the end of the Last Glacial Maximum, deep and intermediate waters in the subarctic North Pacific had apparent ventilation ages of 3300-3600 yr. 14C reservoir ages of surface waters varied from 1200-1700 yr, if accepting the results of the 14C plateau tuning method (Sarnthein et al., 2007) instead of assuming a constant glacial average value of...

14C-AMS dates on iron objects from Nydam Bog

Mercury has been measured in Danish medieval bones interred at several cemeteries. Bone diagenesis is estimated to play an insignificant role based on measurements of soil samples taken vertically and horizontally away from the thighbone at three graves. Our study shows that mercury-containing medicine has been administered in 79% of the leprosy ca...

We present a high-resolution (∼ 60–110 yr) multi-proxy record spanning Marine Isotope Stage 3 from IMAGES Core MD01-2378 (13°04.95′ S and 121°47.27′ E, 1783 m water depth), located in the Timor Sea, off NW Australia. Today, this area is influenced by the Intertropical Convergence Zone, which drives monsoonal winds during austral summer and by the m...