Jan Heinemeier
Biographic Data
| ID | 169806 |
|---|---|
| NAME | Jan Heinemeier |
| GIVEN NAMES | Jan |
| FAMILY NAME | Heinemeier |
| SIGNATURE | HEINEMEIER J |
| AFFILIATIONS | Aarhus University |
| ORCID | 0000-0003-3024-6709 |
| VERIFIED | Yes |
| TOTAL WORKS | 112 |
| TOTAL CITATIONS | 1111 |
| AUTHOR COUNT | 112 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1983 |
| LATEST PUBLICATION YEAR | 2021 |
| H-INDEX | 16 |
A field guide to mortar sampling for radiocarbon dating
Radiocarbon dating of mortars is a method for absolute dating of historical mortared stone structures. Successful mortar dating studies have answered chronological questions, while other studies have revealed that mortar samples can have complications and contaminants. These can cause inconclusive results even with present state‐of‐the‐art techniques. Previous research shows that adequate and proper sampling of mortar samples is of fundamental im…
Delayed Hardening and Reactivation of Binder Calcite, Common Problems in Radiocarbon Dating of Lime Mortars
When sampling mortars for radiocarbon ( 14 C) dating it is crucial to ensure that the sample has hardened rapidly relative the resolution of the dating method. Soft and porous lime mortars usually fulfill this criterion if the samples are taken from an uncovered surface from less than a few centimeters deep. However, hard, concrete-like mortars may be impermeable for carbon dioxide and even the outermost centimeters may still contain uncarbonated…
Dating religious change
Mortuary customs frequently provide the principal archaeological evidence for religious identity. Such customs are often seen as a direct reflection of religion and therefore a change of religion should be expected to result in a change in burial rite. There is growing evidence that the relationship is not so straightforward. In this paper we report results from Viking Age Iceland which challenge the previous view of a relatively clear-cut transi…
Radiocarbon Dating Historical Mortars
Lime lumps and bulk mortars show different 14 C contamination when analyzed in several CO 2 fractions isolated from the effervescence of an ongoing hydrolysis reaction. Age profiles of both materials are therefore highly complementary and together they can provide a reliable date. Furthermore, they can also reveal the complexity of the radiocarbon ( 14 C) distribution within the mortar and thus prevent over-interpretation of the data. The lime lu…
Preparation and Dating of Mortar Samples—Mortar Dating Inter-Comparison Study (Modis)
Seven radiocarbon laboratories: Åbo/Aarhus, CIRCE, CIRCe, ETHZ, Poznań, RICH, and Milano-Bicocca performed separation of carbonaceous fractions suitable for 14 C dating of four mortar samples selected for the MOrtar Dating Inter-comparison Study (MODIS). In addition, optically stimulated luminescence (OSL) analyses were completed by Milano-Bicocca and IRAMAT-CRP2A Bordeaux. Each laboratory performed separation according to laboratory protocol. Re…
Radiocarbon Analysis on the New Aarams 1MV Tandetron
We report here on the radiocarbon performance on the AARAMS HVE 1MV Tandetron. 14 C analysis is carried out in charge state 2+. We have avoided Li interference by appropriate settings of the high-energy electrostatic analyzer and the 30° second high-energy magnet. The 14 C machine background is determined using unprocessed graphite, which yielded 58,650±2032 14 C yr determined as the average and standard deviation of four measurements. Internatio…
Mortar Dating Methodology
Absolute dating of mortars is crucial when trying to pin down construction phases of archaeological sites and historic stone buildings to a certain point in time or to confirm, but possibly also challenge, existing chronologies. To evaluate various sample preparation methods for radiocarbon ( 14 C) dating of mortars as well as to compare different dating methods, i.e. 14 C and optically stimulated luminescence (OSL), a mortar dating intercomparis…
AMS 14C dating at Can Ferrerons, a Roman octagonal building in Premià de Mar, Barcelona
A singular Roman dwelling, octagonal in ground-plan, was excavated in the year 2000, in Premià de Mar. It is a freestanding pavilion within a larger settlement called Gran Via-Can Ferrerons. It was not possible to date it archaeologically because the basement trenches did not contain any significant dating artefacts. Archaeological research undertaken into the architectural typology of the monument led us to the hypothesis that the structure is t…
The Settlement Date of Iceland Revisited
The settlement time of Iceland has been debated for years as radiocarbon dates of bulk wood samples have been interpreted to set a timing 150–200 yr earlier than indicated by tephrochronology (later than AD 871±2) and the Sagas (AD 874). This early date is also in conflict with the dating results on extensive series of short-lived material such as grain and domestic animal and human bone remains of early settlers. The old-wood effect for the char…
Radiocarbon analysis of mortar from Roman and Byzantine water management installations in the Northwest Quarter of Jerash, Jordan
Jerash (Gerasa) in northwestern Jordan is an important Decapolis city displaying urban development for more than a millennium beginning in the late Hellenistic period (1st century CE). Despite more than a hundred years of archaeological explorations at the site there are still major questions about the city's urban development which are left open due to the nature of the archaeological investigations undertaken at the site. This in particular per…
The genetic prehistory of the New World Arctic
Arctic genetics comes in from the cold Despite a well-characterized archaeological record, the genetics of the people who inhabit the Arctic have been unexplored. Raghavan et al. sequenced ancient and modern genomes of individuals from the North American Arctic (see the Perspective by Park). Analyses of these genomes indicate that the Arctic was colonized 6000 years ago by a migration separate from the one that gave rise to other Native American …
Radiocarbon Dating of Dutch Mortars Made from Burned Shells
AMS-bascd radiocarbon dating was applied to Medieval lime mortars made from burned shells and aggregate including both shore sediments and neovolcanic rocks. Three mortar samples from the city of Leiden near Amsterdam were prepared using the same kind of acid hydrolysis technique as has been earlier used for dating mortars made from burned marble and limestone. Five consecutive CO 2 fractions were collected from each sample to form age profiles a…
Years of Mortar Dating
Since 1994, our team has gained extensive experience applying accelerator mass spectrometry (AMS) radiocarbon analysis for mortar dating, totaling over 465 samples and 1800+ measured CO 2 fractions. Several samples have been analyzed repeatedly. The research covers both Medieval and Classical archaeology. We therefore believe our experience can be helpful when developing preparation procedures for different kinds of mortars in different areas and…
The olive branch chronology stands irrespective of tree-ring counting
Cherubini et al. (above) question the reliability of identifying annual growth increments in olive trees, and therefore voice caution against the result of the wiggle-match of the four sections of a branch of an olive tree to the 14C calibration curve. Friedrich et al. (2006) were well aware of the problematic density structure of olive trees, and therefore assigned rather wide error margins of up to 50 per cent to the ring count. This still resu…
Freshwater Radiocarbon Reservoir Effects at the Burial Ground of Minino, Northwest Russia
If ancient carbon is incorporated into lakes and rivers, it can be transferred along the foodchain where it can cause radiocarbon dates to appear erroneously old. This effect is known as the 14 C freshwater reservoir effect (FRE), and causes particular problems when dating human remains. Several studies have attempted to use carbon and/or nitrogen stable isotopes to predict the size of the FRE, with mixed success. We have examined whether the FRE…
Freshwater Reservoir Effect Variability in Northern Germany
The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14 C dating of freshwater-based samples requires knowing the order of magnitude of the reservoir effect and its degree of variability. Measurements on modern riverine m…
Old wood’ effect in radiocarbon dating of prehistoric cremated bones
Bronze Age Burials without Distinct Archaeological Datings
Summary and Conclusion
B. Do reservoir age effects offer an explanation
The late Bronze Age (periods IV-VI)
Discussions based on the archaeological evidence
Model duration of Bronze Age periods
Period II
Late Palaeolithic Nørre Lyngby – a northern outpost close to the west coast of Europe
Coast–inland mobility and diet in the Danish Mesolithic and Neolithic
Change of Diet of the Greenland Vikings Determined from Stable Carbon Isotope Analysis and 14 C Dating of Their Bones
Bone samples from the Greenland Viking colony provide us with a unique opportunity to test and use 14 C dating of remains of humans who depended upon food of mixed marine and terrestrial origin. We investigated the skeletons of 27 Greenland Norse people excavated from churchyard burials from the late 10th to the middle 15th century. The stable carbon isotopic composition (δ 13 C) of the bone collagen reveals that the diet of the Greenland Norse c…
Evaluating bone collagen extraction methods for stable isotope analysis in dietary studies
Mortar Dating Using AMS 14 C and Sequential Dissolution
Non-hydraulic mortars contain datable binder carbonate with a direct relation to the time when it was used in a building, but they also contain contaminants that disturb radiocarbon dating attempts. The most relevant contaminants either have a geological provenance and age or they can be related to delayed carbonate formation or devitrification and recrystallization of the mortar. We studied the mortars using cathodoluminescence (CL), mass spectr…
Freshwater Reservoir Effect in 14 C Dates of Food Residue on Pottery
Radiocarbon dates of food residue on pottery from northern European inland areas seem to be influenced significantly by the freshwater reservoir effect (“hardwater” effect) stemming from fish and mollusks cooked in the pots. Bones of freshwater fish from Stone Age åmose, Denmark, are demonstrated to be 100 to 500 14 C yr older than their archaeological context. Likewise, food residues on cooking pots, seemingly used for the preparation of freshwa…
Successful AMS 14 C Dating of Non-Hydraulic Lime Mortars from the Medieval Churches of the Åland Islands, Finland
Fifteen years of research on accelerator mass spectrometry (AMS) radiocarbon dating of non-hydraulic mortar has now led to the establishment of a chronology for the medieval stone churches of the Åland Islands (Finland), where no contemporary written records could shed light on the first building phases. In contrast to other material for dating, well-preserved mortar is abundantly available from every building stage. We have gathered experience f…
Characterisation and blind testing of radiocarbon dating of cremated bone
A Bronze Age battlefield? Weapons and trauma in the Tollense Valley, north-eastern Germany
Chance discoveries of weapons, horse bones and human skeletal remains along the banks of the River Tollense led to a campaign of research which has identified them as the debris from a Bronze Age battle. The resources of war included horses, arrowheads and wooden clubs, and the dead had suffered blows indicating face-to-face combat. This surprisingly modern and decidedly vicious struggle took place over the swampy braided streams of the river in …
Old wood’ effect in radiocarbon dating of prehistoric cremated bones
Dietary Habits and Freshwater Reservoir Effects in Bones from a Neolithic NE German Cemetery
Within a project on Stone Age sites of NE Germany, 26 burials from the Ostorf cemetery and some further Neolithic sites have been analyzed by more than 40 accelerator mass spectrometry (AMS) dates. We here present the results of stable isotope and radiocarbon measurements together with reference 14 C dates on grave goods from terrestrial animals such as tooth pendants found in 10 of the graves. Age differences between human individuals and their …
Preparation and Dating of Mortar Samples—Mortar Dating Inter-Comparison Study (Modis)
Seven radiocarbon laboratories: Åbo/Aarhus, CIRCE, CIRCe, ETHZ, Poznań, RICH, and Milano-Bicocca performed separation of carbonaceous fractions suitable for 14 C dating of four mortar samples selected for the MOrtar Dating Inter-comparison Study (MODIS). In addition, optically stimulated luminescence (OSL) analyses were completed by Milano-Bicocca and IRAMAT-CRP2A Bordeaux. Each laboratory performed separation according to laboratory protocol. Re…
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…
Years of Mortar Dating
Since 1994, our team has gained extensive experience applying accelerator mass spectrometry (AMS) radiocarbon analysis for mortar dating, totaling over 465 samples and 1800+ measured CO 2 fractions. Several samples have been analyzed repeatedly. The research covers both Medieval and Classical archaeology. We therefore believe our experience can be helpful when developing preparation procedures for different kinds of mortars in different areas and…
Mortar Dating Methodology
Absolute dating of mortars is crucial when trying to pin down construction phases of archaeological sites and historic stone buildings to a certain point in time or to confirm, but possibly also challenge, existing chronologies. To evaluate various sample preparation methods for radiocarbon ( 14 C) dating of mortars as well as to compare different dating methods, i.e. 14 C and optically stimulated luminescence (OSL), a mortar dating intercomparis…
The petrous bone—A new sampling site for identifying early dietary patterns in stable isotopic studies
Intraskeletal variation in the composition of carbon (δ 13 C) and nitrogen (δ 15 N) stable isotopes measured in collagen is tested from various human bones and dentine. Samples were taken from the femur, rib, and petrous part of the temporal bone from well‐preserved skeletons of both adults ( n = 34) and subadults ( n = 24). Additional samples of dentine from the root of 1st molars were taken from 16 individuals. The skeletal material is from a m…
Recent Reservoir Ages for Danish Fjords and Marine Waters
AMS 14 C dates were measured for 28 mollusk shells collected live in Danish waters over the period ad 1885 to 1945. Fourteen samples were from fjords and 14 were marine samples from the Danish Skagerrak-Kattegat coastal area and from the Belts. Reservoir ages were calculated for all samples on the basis of the tree-ring calibration curve. For the marine samples, which cover the period ad 1885–1916, we found a weighted-average reservoir age of 377…
A field guide to mortar sampling for radiocarbon dating
Radiocarbon dating of mortars is a method for absolute dating of historical mortared stone structures. Successful mortar dating studies have answered chronological questions, while other studies have revealed that mortar samples can have complications and contaminants. These can cause inconclusive results even with present state‐of‐the‐art techniques. Previous research shows that adequate and proper sampling of mortar samples is of fundamental im…
Radiocarbon Dating Historical Mortars
Lime lumps and bulk mortars show different 14 C contamination when analyzed in several CO 2 fractions isolated from the effervescence of an ongoing hydrolysis reaction. Age profiles of both materials are therefore highly complementary and together they can provide a reliable date. Furthermore, they can also reveal the complexity of the radiocarbon ( 14 C) distribution within the mortar and thus prevent over-interpretation of the data. The lime lu…
Radiocarbon Analysis on the New Aarams 1MV Tandetron
We report here on the radiocarbon performance on the AARAMS HVE 1MV Tandetron. 14 C analysis is carried out in charge state 2+. We have avoided Li interference by appropriate settings of the high-energy electrostatic analyzer and the 30° second high-energy magnet. The 14 C machine background is determined using unprocessed graphite, which yielded 58,650±2032 14 C yr determined as the average and standard deviation of four measurements. Internatio…
Diatom evidence of hydrographic changes and ice conditions in Igaliku Fjord, South Greenland, during the past 1500 years
Biostratigraphic diatom analyses were carried out on two sediment cores from Igaliku Fjord, South Greenland, in order to reconstruct hydrographic and climatic fluctuations during the late Holocene (AD 550 to present). Pronounced differences in hydrographic setting of the coring sites provide palaeoenvironmental information of both local and more regional character. Five diatom zones were identified from the subfossil diatom records, each describi…
High-Resolution AMS 14 C Dating of Post-Bomb Peat Archives of Atmospheric Pollutants
Peat deposits in Greenland and Denmark were investigated to show that high-resolution dating of these archives of atmospheric deposition can be provided for the last 50 years by radiocarbon dating using the atmospheric bomb pulse. 14 C was determined in macrofossils from sequential one cm slices using accelerator mass spectrometry (AMS). Values were calibrated with a general-purpose curve derived from annually averaged atmospheric 14 CO 2 values …
Freshwater Reservoir Effect Variability in Northern Germany
The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14 C dating of freshwater-based samples requires knowing the order of magnitude of the reservoir effect and its degree of variability. Measurements on modern riverine m…
New Information on the Stone Age Graves at Dragsholm , Denmark
First cross-matched floating chronology from the marine fossil record
Integrated understanding of phasings within the climate system over the last glacial cycle, and at higher frequencies, is inhibited because no absolute timescale for the marine environment currently exists. This precludes identification of forcings and feedbacks, accurate temporal calibration of the marine radiocarbon reservoir effect, and the application of radiocarbon as a proxy of short-timescale ocean ventilation. This has prompted a search f…
Human Diet and Subsistence Patterns in Norse Greenland AD C.980—AD c. 1450
In this concluding paper of the JONA special volume on the Norse Greenland isotope study, we summarize the archaeological interpretations of the previous, technical papers. The study supports the conclusions and widens the results of our earlier limited study, i.e., that the diet of the Norse Greenlanders became more dependent on marine resources over time. The isotope data provide information at the level of the individual, and the study indicat…
Production of C − Directly from CO 2 Using the Anis Sputter Source
Micro-ampere beams of C – have been produced with the Aarhus negative-ion source, operated on CO 2 gas. The efficiency of the source and memory effects have been measured, using 13 C-enriched CO 2 , in order to evaluate the applicability of the source to 14 C dating by accelerator mass spectroscopy
Clams before Columbus?
Participants
From the 14th International Radiocarbon Conference held in Tucson, AZ, May 20-24, 1991
Radiocarbon Anomalies Observed for Plants Growing in Icelandic Geothermal Waters
We have studied plant remains in thick beds of lacustrine sediments in the upper part of the Markarfljót drainage area in southern Iceland. We collected small samples of plant species from the same horizon and 14 C dated them at the Aarhus AMS Dating Laboratory. Terrestrial plants yielded an age of 9 ka BP, whereas aquaic moss ( Fontinalis antipyretica Hedw.) yielded the surprisingly old 14 C age of 16 ka bp. We believe the age of the terrestrial…
Radiocarbon AMS dating of Holocene wolf (Canis lupus) remains from Greenland
Radiocarbon AMS dating of seven polar wolf (Canis lupus) remains from east and north Greenland and one from Ellesmere Island document the presence of this large carnivore in Greenland at around 6800, 1600, 800 and 500 BP, corresponding to calibrated ages of 5620 BC, AD 530, AD 1260 and AD 1420. Three of the remains yielded modem ages. These results demonstrate the presence of the wolf in Greenland since the early mid-Holocene and it is argued tha…
Conference Participants
This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries
Origin of 14 C in Icelandic Groundwater
We report the first attempt to date Icelandic groundwater by the radiocarbon dating technique. We propose that boron concentrations of the water samples can be taken as a measure of the amount of dead CO 2 in the groundwater leached from rock. By assuming that the ratio of boron to CO 2 is the same in the rock and groundwater it is possible to correct the 14 C concentration for the contribution of rock-derived carbon in the groundwater and thus c…
Recent Reservoir Ages for Danish Fjords and Marine Waters
AMS 14 C dates were measured for 28 mollusk shells collected live in Danish waters over the period ad 1885 to 1945. Fourteen samples were from fjords and 14 were marine samples from the Danish Skagerrak-Kattegat coastal area and from the Belts. Reservoir ages were calculated for all samples on the basis of the tree-ring calibration curve. For the marine samples, which cover the period ad 1885–1916, we found a weighted-average reservoir age of 377…
Radiocarbon Dating of Shells and Foraminifera from the Skagen Core, Denmark
We report on 69 radiocarbon dates of mollusk shells and benthic foraminifera from the upper 132 m of the marine shelf sediments of the Skagen Core (220 m total length). The dated sequence covers the Late Glacial and the Holocene (from 15 ka bp to Recent). Sedimentation rates range from 1 to 70 m ka −1 . The macrofossil shell dates follow a smooth curve constituting an age model for dating the sediments. The foraminiferal dates fall into two group…
C AMS Dating of Icelandic Lake Sediments
We report an age-depth profile for the sediments of the Lake Hesrvatn, southern Iceland, based on 14 C analyses of the organic fraction of bulk sediment samples, molluscs and foraminifera. Our age-depth curve is supported by the occurrence of the well-dated Vedde ash in the lowermost part of the sediments. Comparison of foraminifera dates with the age of the Vedde ash indicates a reservoir age of ca. 400 yr. The results suggest that the sediments…
Study of the Effect of Fossil Organic Carbon on 14 C in Groundwater from Hvinningdal, Denmark
The carbonate hydrochemistry of groundwater from the Hvinningdal aquifer (Denmark) was studied by radiocarbon (accelerator mass spectrometry (AMS)) and δ 13 C measurements as a preliminary step towards 14 C groundwater dating. The 14 C concentrations varied between 30 and 100 percent modern carbon (pMC) in apparent contradiction with tritium ( 3 H) data, which in most cases indicate a post-bomb date. The dilution of 14 C can be explained as being…
North Atlantic Ice Sheet Fluctuations 10,000–70,000 Yr Ago as Inferred from Deposits on the Reykjanes Ridge, Southeast of Greenland
Marine records from the Reykjanes Ridge indicate ice sheet variations and abrupt climate changes. One of these records, ice-rafted detritus (IRD), serves as a proxy for iceberg discharges that probably indicates ice sheet fluctuations. The IRD records suggest that iceberg discharge 68,000–10,000 yr B.P. happened more frequently than the 7000- to 10,000-yr spacing of the Heinrich events. An IRD peak 67,000 to 63,000 yr B.P. further suggests that t…
Change of Diet of the Greenland Vikings Determined from Stable Carbon Isotope Analysis and 14 C Dating of Their Bones
Bone samples from the Greenland Viking colony provide us with a unique opportunity to test and use 14 C dating of remains of humans who depended upon food of mixed marine and terrestrial origin. We investigated the skeletons of 27 Greenland Norse people excavated from churchyard burials from the late 10th to the middle 15th century. The stable carbon isotopic composition (δ 13 C) of the bone collagen reveals that the diet of the Greenland Norse c…
New Dates from Submerged Late Pleistocene Sediments in the Southern Sea of Galilee, Israel
Unusual low water levels in the Sea of Galilee (Dead Sea Fault, Israel) have caused the recent exposure of submerged Late Pleistocene prehistoric sites and lacustrine sediments along the southern shores of the lake. The Ohalo II site is a large fisher-hunter-gatherers camp with in-situ brush hut floors, hearths, and a human grave. The site is radiometrically dated by 25 charcoal dates to 19,430 BP (average, uncalibrated). The archaeological remai…
Is Comparability of 14 C Dates an Issue
For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Gulliksen and Scott 1995; Scott et al. 1997). In this report, we provide an update on the current 14 C laboratory intercomparison and reflect on future issues linked to the laboratory intercomp…
High-Resolution AMS 14 C Dating of Post-Bomb Peat Archives of Atmospheric Pollutants
Peat deposits in Greenland and Denmark were investigated to show that high-resolution dating of these archives of atmospheric deposition can be provided for the last 50 years by radiocarbon dating using the atmospheric bomb pulse. 14 C was determined in macrofossils from sequential one cm slices using accelerator mass spectrometry (AMS). Values were calibrated with a general-purpose curve derived from annually averaged atmospheric 14 CO 2 values …
Dating of Prehistoric Burial Mounds by 14 C Analysis of Soil Organic Matter Fractions
Dating of prehistoric anthropogenic earthworks requires either excavation for archaeological artifacts or macroscopic organic matter suitable for 14 C analysis. Yet, the former, in many cases, is undesirable and the latter is difficult to obtain. Here we present a soil science procedure, which has the potential to overcome these problems. It includes careful sampling of buried former soil surfaces, acid-alkali-acid fractionation of soil organic m…
Freshwater Reservoir Effect in 14 C Dates of Food Residue on Pottery
Radiocarbon dates of food residue on pottery from northern European inland areas seem to be influenced significantly by the freshwater reservoir effect (“hardwater” effect) stemming from fish and mollusks cooked in the pots. Bones of freshwater fish from Stone Age åmose, Denmark, are demonstrated to be 100 to 500 14 C yr older than their archaeological context. Likewise, food residues on cooking pots, seemingly used for the preparation of freshwa…
How reliable are radiocarbon laboratories? A report on the Fourth International Radiocarbon Inter-comparison (Firi) (1998-2001)
Radiocarbon laboratories undertake rigorous programmes of internal quality control (QC) and overall quality assurance (QA). In a laboratory "inter-comparison" samples of the same age are dated at different laboratories using a range of techniques and the results are then compared. The authors summarise the results of the fourth of these scientific audits
Diatom evidence of hydrographic changes and ice conditions in Igaliku Fjord, South Greenland, during the past 1500 years
Biostratigraphic diatom analyses were carried out on two sediment cores from Igaliku Fjord, South Greenland, in order to reconstruct hydrographic and climatic fluctuations during the late Holocene (AD 550 to present). Pronounced differences in hydrographic setting of the coring sites provide palaeoenvironmental information of both local and more regional character. Five diatom zones were identified from the subfossil diatom records, each describi…
Precision and accuracy in applied 14C dating
C Dating of the Settlement of Iceland
The dating of the settlement of Iceland has been debated for many years. According to written sources (sagas) from the early 12th century, the first Norwegian settlers arrived in Iceland in AD 874. However, some 14 C dates from the earliest archaeological sites in Iceland, invariably from samples of birch and other indigenous wood species, have yielded surprisingly old ages, older by 100–150 yr than the historical date, suggesting that the settle…
Late Holocene sea-level changes and isostasy in western Denmark
Cores and exposed cliff sections in salt marshes around Ho Bugt, a tidal embayment in the northernmost part of the Danish Wadden Sea, were subjected to 14 C dating and litho- and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late Holocene relative sea-level history. Four stages in the late Holocene development of Ho Bugt can be identified: (1) groundwater-table rise and growth of basal peat (from at leas…
Santorini Eruption Radiocarbon Dated to 1627-1600 B.C.
Precise and direct dating of the Minoan eruption of Santorini (Thera) in Greece, a global Bronze Age time marker, has been made possible by the unique find of an olive tree, buried alive in life position by the tephra (pumice and ashes) on Santorini. We applied so-called radiocarbon wiggle-matching to a carbon-14 sequence of tree-ring segments to constrain the eruption date to the range 1627‐1600 B.C. with 95.4% probability. Our result is in the …
A synchronized dating of three Greenland ice cores throughout the Holocene
As part of the effort to create the new Greenland Ice Core Chronology 2005 (GICC05) a synchronized stratigraphical timescale for the Holocene parts of the DYE‐3, Greenland Ice Core Project (GRIP), and North Greenland Ice Core Project (NGRIP) ice cores is made by using volcanic reference horizons in electrical conductivity measurements to match the cores. The main annual layer counting is carried out on the most suited records only, exploiting tha…
Archaeology (85 works) · Geography (74 works) · Archaeology and ancient environmental studies (61 works) · Geology (56 works) · History (55 works) · Radiocarbon dating (51 works) · History (43 works) · Paleontology (38 works) · Geology and Paleoclimatology Research (33 works) · Ancient history (32 works)