Janet Rethemeyer
Biographic Data
| ID | 1236684 |
|---|---|
| NAME | Janet Rethemeyer |
| GIVEN NAMES | Janet |
| FAMILY NAME | Rethemeyer |
| SIGNATURE | RETHEMEYER J |
| AFFILIATIONS | University of Cologne |
| ORCID | 0000-0001-6698-4186 |
| VERIFIED | Yes |
| TOTAL WORKS | 14 |
| TOTAL CITATIONS | 42 |
| AUTHOR COUNT | 14 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2004 |
| LATEST PUBLICATION YEAR | 2024 |
| H-INDEX | 3 |
Preparation and Handling of Methane for Radiocarbon Analysis at Cologneams
CH 4 is the second most important anthropogenic greenhouse gas and originates from different sources. The use of radiocarbon ( 14 C) analysis of CH 4 opens up the possibility to differentiate geological and agricultural origin. At the CologneAMS facility, the demand for 14 C analysis of CH 4 required the development of a sample handling routine and a vacuum system that converts CH 4 to CO 2 for direct injection of CO 2 into the AMS. We evaluated …
First Δ 13 C Results With a New Connection Between the Ea-Irms System and the Gas Injection System at Cologneams
This work presents the integration of an elemental analyzer (EA) and an isotope ratio mass spectrometer (IRMS) into the 6 MV AMS system at the Institute for Nuclear Physics, University of Cologne. The AMS measurement of δ 13 C values for IAEA-C6 reference material resulted in –11.39(226)‰, compared to –10.28(32)‰ obtained by IRMS. The EA-IRMS system was also tested with IAEA-C3, IAEA-C5, and IAEA-C7 reference materials, yielding –24.79(9), –25.18…
Holocene glacier fluctuations and environmental changes in subantarctic South Georgia inferred from a sediment record from a coastal inlet
The subantarctic island of South Georgia provides terrestrial and coastal marine records of climate variability, which are crucial for the understanding of the drivers of Holocene climate changes in the subantarctic region. Here we investigate a sediment core (Co1305) from a coastal inlet on South Georgia using elemental, lipid biomarker, diatom, and stable isotope data to infer changes in environmental conditions and to constrain the timing of l…
Exploring sample size limits of AMS gas Ion Source 14 C analysis at Cologneams
Increasing demands for small-scale radiocarbon ( 14 C) analyses required the installation of a “SO-110 B” type ion source (HVE Europa B.V.) at our 6 MV Tandetron AMS (HVE) dedicated for the direct injection of CO 2 using either the gas injection system (GIS) from Ionplus AG or a EuroVector EA 3000 elemental analyzer (EA). We tested both systems with multiple series of 14 C-free and modern standards (2.5–50 μg C) combusted in quartz ampoules or EA…
Roman traces in Germania magna: New thermoluminescence and pIrir 290 data from a lime kiln at Bergisch Gladbach, Germany
The applicability of a post‐infrared infrared stimulated luminescence (pIRIR 290 ) protocol and two different thermoluminescence (TL) protocols—a single aliquot regeneration (SAR) and a multiple aliquot additive dose (MAAD)—was tested on six polymineral fine‐grain (4–11 μm) samples extracted from the wall remains of a Roman lime kiln and a Roman roof tile. These remains had been excavated close to Bergisch Gladbach, which was at that time part of…
The rock shelter Abrigo del Molino (Segovia, Spain) and the timing of the late Middle Paleolithic in Central Iberia
The timing of the late Middle Paleolithic and late disappearance of Neanderthals in the Iberian Peninsula are hotly debated subjects in Paleolithic archeology. Several studies suggested a late survival in South and Central Iberia until about 32 ka, but were probably subject to significant age underestimation due to contamination of dating samples, undiagnostic lithic assemblages, and/or lack of stratigraphic integrity. We conducted a radiocarbon …
Testing feldspar and quartz luminescence dating of sandy loess sediments from the Doroshivtsy site (Ukraine) against radiocarbon dating
Organic geochemical and palynological evidence for Holocene natural and anthropogenic environmental change at Lake Dojran (Macedonia/Greece)
In this study, we present lipid biomarker and palynological data for a sediment core from Lake Dojran (Macedonia/Greece), which covers the entire Holocene period. We analyzed vascular plant-derived n-alkanes, combustion-derived polycyclic aromatic hydrocarbons (PAHs), fecal steroids, and bacterial and archaeal glycerol dialkyl glycerol tetraether (GDGT) lipids in concert with microcharcoal and pollen assemblages to reconstruct climatic, environme…
New investigations at the Middle Stone Age site of Pockenbank Rockshelter, Namibia
In southern Africa, Middle Stone Age sites with long sequences have been the focus of intense international and interdisciplinary research over the past decade (cf. Wadley 2015). Two techno-complexes of the Middle Stone Age-the Still Bay and Howiesons Poort-have been associated with many technological and behavioural innovations of Homo sapiens. The classic model argues that these two techno-complexes are temporally separated 'horizons' with homo…
Early and Middle Holocene Human Occupation of the Egyptian Eastern Desert: Sodmein Cave
In this paper, we discuss human occupation during the Early and Middle Holocene in the Eastern Desert of Egypt, based mainly on the data provided by excavated deposits from the Sodmein Cave, which produced an important Holocene stratigraphic sequence. This sequence is dated by a large number of conventional and AMS 14C dates. It appears that the area was empty of human occupation during the Late Glacial Maximum (LGM) and the earliest Holocene. Wi…
Ultrafiltration of Bone Samples is Neither the Problem nor the Solution
We conducted analyses to identify the most suitable bone pretreatment protocol to be used by the recently established Radiocarbon Laboratory at the University of Cologne, CologneAMS. In 2 sets of analyses, we determined 14 C ages for subsamples taken from 3 14 C bone standards (Oxford Mammoth, VIRI I, and VIRI H) complemented by age determinations of 12 unknown bone samples. Our results suggest that the strength and duration of the acid and alkal…
Climatic change recorded in the sediments of the Chew Bahir basin, southern Ethiopia, during the last 45,000 years
Evaluation of Soil 14 C Data for Estimating Inert Organic Matter in the Rothc Model
Changes in soil organic carbon stocks were simulated with the Rothamsted carbon (RothC) model. We evaluated the calculation of a major input variable, the amount of inert organic matter (IOM), using measurable data. Three different approaches for quantifying IOM were applied to soils with mainly recent organic matter and with carbon contribution from fossil fuels: 1) IOM estimation via total soil organic carbon (SOC); 2) through bulk soil radioca…
Complexity of Soil Organic Matter: AMS 14 C Analysis of Soil Lipid Fractions and Individual Compounds
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…
Ultrafiltration of Bone Samples is Neither the Problem nor the Solution
We conducted analyses to identify the most suitable bone pretreatment protocol to be used by the recently established Radiocarbon Laboratory at the University of Cologne, CologneAMS. In 2 sets of analyses, we determined 14 C ages for subsamples taken from 3 14 C bone standards (Oxford Mammoth, VIRI I, and VIRI H) complemented by age determinations of 12 unknown bone samples. Our results suggest that the strength and duration of the acid and alkal…
Early and Middle Holocene Human Occupation of the Egyptian Eastern Desert: Sodmein Cave
In this paper, we discuss human occupation during the Early and Middle Holocene in the Eastern Desert of Egypt, based mainly on the data provided by excavated deposits from the Sodmein Cave, which produced an important Holocene stratigraphic sequence. This sequence is dated by a large number of conventional and AMS 14C dates. It appears that the area was empty of human occupation during the Late Glacial Maximum (LGM) and the earliest Holocene. Wi…
Exploring sample size limits of AMS gas Ion Source 14 C analysis at Cologneams
Increasing demands for small-scale radiocarbon ( 14 C) analyses required the installation of a “SO-110 B” type ion source (HVE Europa B.V.) at our 6 MV Tandetron AMS (HVE) dedicated for the direct injection of CO 2 using either the gas injection system (GIS) from Ionplus AG or a EuroVector EA 3000 elemental analyzer (EA). We tested both systems with multiple series of 14 C-free and modern standards (2.5–50 μg C) combusted in quartz ampoules or EA…
Roman traces in Germania magna: New thermoluminescence and pIrir 290 data from a lime kiln at Bergisch Gladbach, Germany
The applicability of a post‐infrared infrared stimulated luminescence (pIRIR 290 ) protocol and two different thermoluminescence (TL) protocols—a single aliquot regeneration (SAR) and a multiple aliquot additive dose (MAAD)—was tested on six polymineral fine‐grain (4–11 μm) samples extracted from the wall remains of a Roman lime kiln and a Roman roof tile. These remains had been excavated close to Bergisch Gladbach, which was at that time part of…
Organic geochemical and palynological evidence for Holocene natural and anthropogenic environmental change at Lake Dojran (Macedonia/Greece)
In this study, we present lipid biomarker and palynological data for a sediment core from Lake Dojran (Macedonia/Greece), which covers the entire Holocene period. We analyzed vascular plant-derived n-alkanes, combustion-derived polycyclic aromatic hydrocarbons (PAHs), fecal steroids, and bacterial and archaeal glycerol dialkyl glycerol tetraether (GDGT) lipids in concert with microcharcoal and pollen assemblages to reconstruct climatic, environme…
Complexity of Soil Organic Matter: AMS 14 C Analysis of Soil Lipid Fractions and Individual Compounds
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…
Preparation and Handling of Methane for Radiocarbon Analysis at Cologneams
CH 4 is the second most important anthropogenic greenhouse gas and originates from different sources. The use of radiocarbon ( 14 C) analysis of CH 4 opens up the possibility to differentiate geological and agricultural origin. At the CologneAMS facility, the demand for 14 C analysis of CH 4 required the development of a sample handling routine and a vacuum system that converts CH 4 to CO 2 for direct injection of CO 2 into the AMS. We evaluated …
Complexity of Soil Organic Matter: AMS 14 C Analysis of Soil Lipid Fractions and Individual Compounds
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…
Evaluation of Soil 14 C Data for Estimating Inert Organic Matter in the Rothc Model
Changes in soil organic carbon stocks were simulated with the Rothamsted carbon (RothC) model. We evaluated the calculation of a major input variable, the amount of inert organic matter (IOM), using measurable data. Three different approaches for quantifying IOM were applied to soils with mainly recent organic matter and with carbon contribution from fossil fuels: 1) IOM estimation via total soil organic carbon (SOC); 2) through bulk soil radioca…
Climatic change recorded in the sediments of the Chew Bahir basin, southern Ethiopia, during the last 45,000 years
Ultrafiltration of Bone Samples is Neither the Problem nor the Solution
We conducted analyses to identify the most suitable bone pretreatment protocol to be used by the recently established Radiocarbon Laboratory at the University of Cologne, CologneAMS. In 2 sets of analyses, we determined 14 C ages for subsamples taken from 3 14 C bone standards (Oxford Mammoth, VIRI I, and VIRI H) complemented by age determinations of 12 unknown bone samples. Our results suggest that the strength and duration of the acid and alkal…
Early and Middle Holocene Human Occupation of the Egyptian Eastern Desert: Sodmein Cave
In this paper, we discuss human occupation during the Early and Middle Holocene in the Eastern Desert of Egypt, based mainly on the data provided by excavated deposits from the Sodmein Cave, which produced an important Holocene stratigraphic sequence. This sequence is dated by a large number of conventional and AMS 14C dates. It appears that the area was empty of human occupation during the Late Glacial Maximum (LGM) and the earliest Holocene. Wi…
New investigations at the Middle Stone Age site of Pockenbank Rockshelter, Namibia
In southern Africa, Middle Stone Age sites with long sequences have been the focus of intense international and interdisciplinary research over the past decade (cf. Wadley 2015). Two techno-complexes of the Middle Stone Age-the Still Bay and Howiesons Poort-have been associated with many technological and behavioural innovations of Homo sapiens. The classic model argues that these two techno-complexes are temporally separated 'horizons' with homo…
Testing feldspar and quartz luminescence dating of sandy loess sediments from the Doroshivtsy site (Ukraine) against radiocarbon dating
Organic geochemical and palynological evidence for Holocene natural and anthropogenic environmental change at Lake Dojran (Macedonia/Greece)
In this study, we present lipid biomarker and palynological data for a sediment core from Lake Dojran (Macedonia/Greece), which covers the entire Holocene period. We analyzed vascular plant-derived n-alkanes, combustion-derived polycyclic aromatic hydrocarbons (PAHs), fecal steroids, and bacterial and archaeal glycerol dialkyl glycerol tetraether (GDGT) lipids in concert with microcharcoal and pollen assemblages to reconstruct climatic, environme…
The rock shelter Abrigo del Molino (Segovia, Spain) and the timing of the late Middle Paleolithic in Central Iberia
The timing of the late Middle Paleolithic and late disappearance of Neanderthals in the Iberian Peninsula are hotly debated subjects in Paleolithic archeology. Several studies suggested a late survival in South and Central Iberia until about 32 ka, but were probably subject to significant age underestimation due to contamination of dating samples, undiagnostic lithic assemblages, and/or lack of stratigraphic integrity. We conducted a radiocarbon …
Holocene glacier fluctuations and environmental changes in subantarctic South Georgia inferred from a sediment record from a coastal inlet
The subantarctic island of South Georgia provides terrestrial and coastal marine records of climate variability, which are crucial for the understanding of the drivers of Holocene climate changes in the subantarctic region. Here we investigate a sediment core (Co1305) from a coastal inlet on South Georgia using elemental, lipid biomarker, diatom, and stable isotope data to infer changes in environmental conditions and to constrain the timing of l…
Exploring sample size limits of AMS gas Ion Source 14 C analysis at Cologneams
Increasing demands for small-scale radiocarbon ( 14 C) analyses required the installation of a “SO-110 B” type ion source (HVE Europa B.V.) at our 6 MV Tandetron AMS (HVE) dedicated for the direct injection of CO 2 using either the gas injection system (GIS) from Ionplus AG or a EuroVector EA 3000 elemental analyzer (EA). We tested both systems with multiple series of 14 C-free and modern standards (2.5–50 μg C) combusted in quartz ampoules or EA…
Roman traces in Germania magna: New thermoluminescence and pIrir 290 data from a lime kiln at Bergisch Gladbach, Germany
The applicability of a post‐infrared infrared stimulated luminescence (pIRIR 290 ) protocol and two different thermoluminescence (TL) protocols—a single aliquot regeneration (SAR) and a multiple aliquot additive dose (MAAD)—was tested on six polymineral fine‐grain (4–11 μm) samples extracted from the wall remains of a Roman lime kiln and a Roman roof tile. These remains had been excavated close to Bergisch Gladbach, which was at that time part of…
Preparation and Handling of Methane for Radiocarbon Analysis at Cologneams
CH 4 is the second most important anthropogenic greenhouse gas and originates from different sources. The use of radiocarbon ( 14 C) analysis of CH 4 opens up the possibility to differentiate geological and agricultural origin. At the CologneAMS facility, the demand for 14 C analysis of CH 4 required the development of a sample handling routine and a vacuum system that converts CH 4 to CO 2 for direct injection of CO 2 into the AMS. We evaluated …
First Δ 13 C Results With a New Connection Between the Ea-Irms System and the Gas Injection System at Cologneams
This work presents the integration of an elemental analyzer (EA) and an isotope ratio mass spectrometer (IRMS) into the 6 MV AMS system at the Institute for Nuclear Physics, University of Cologne. The AMS measurement of δ 13 C values for IAEA-C6 reference material resulted in –11.39(226)‰, compared to –10.28(32)‰ obtained by IRMS. The EA-IRMS system was also tested with IAEA-C3, IAEA-C5, and IAEA-C7 reference materials, yielding –24.79(9), –25.18…
Geology (10 works) · Archaeology and ancient environmental studies (8 works) · Radiocarbon dating (7 works) · Chemistry (6 works) · Geography (6 works) · Paleontology (6 works) · Pleistocene-Era Hominins and Archaeology (6 works) · Geology and Paleoclimatology Research (5 works) · Materials Science (5 works) · Mineralogy (5 works)