Lorenz Schwark | Christian-Albrechts-Universität zu Kiel (original) (raw)

Papers by Lorenz Schwark

Research paper thumbnail of Life and death in the Chicxulub impact crater: A record of the Paleocene-Eocene Thermal Maximum

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Research paper thumbnail of Microbial Mayhem in the Nascent Chicxulub Crater

29th International Meeting on Organic Geochemistry, 2019

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Research paper thumbnail of δ13C of terrestrial vegetation records Toarcian CO2 and climate gradients

Scientific Reports, 2020

Throughout Earth’s history, variations in atmospheric CO2 concentration modulated climate. Unders... more Throughout Earth’s history, variations in atmospheric CO2 concentration modulated climate. Understanding changes in atmospheric carbon cycle is therefore pivotal in predicting consequences of recent global warming. Here, we report stable carbon isotopes (δ13C) of molecular land plant fossils complemented by bulk organic and inorganic carbon fractions for early Toarcian (Early Jurassic) sediments that coincided with global warming and a carbon cycle perturbation. The carbon cycle perturbation is expressed by a negative excursion in the δ13C records established for the different substrates. Based on differences in the magnitude of the carbon isotope excursion recorded in land plants and marine substrates we infer that the early Toarcian warming was paralleled by an increase in atmospheric CO2 levels from ~500 ppmv to ~1000 ppmv. Our data suggest that rising atmospheric CO2 levels resulted from the injection of 12C-enriched methane and its subsequent oxidation to CO2. Based on the cyc...

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Research paper thumbnail of Climate driven Holocene erosion in central Ukraine

The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic... more The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical stimulated luminescence (OSL) and embedded artefacts. A suspicious non-coincidence between phases of soil erosion and the settlement history at the site over long periods of the Holocene is noticeable and suggests a climatically driven erosion at the site. The detected phases of erosion during the past >20,000 years coincide with global (cal 27.6 +/- 1.3 kyrs BP, 12.0 +/- 0.4 kyrs BP), northern hemispheric (cal 8.5 ± 0.3 kyrs BP), Mediterranean (cal 3.93 ± 0.1 kyrs BP) as well as western to central European (2,700 to 2,000 cal BP) climate anomalies. For these anomalies, characterized by colder th...

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Research paper thumbnail of Sustained volcanic impact and ecosystem disturbance over continental Europe during the Early Holocene

Estimating the environmental and societal impact of recent volcanic eruptions is a task aided by ... more Estimating the environmental and societal impact of recent volcanic eruptions is a task aided by direct measurements and historical sources. Beyond the reach of first-hand accounts, our understanding of pre-historic volcanism is often hindered by the dating uncertainties inherent to stratigraphic archives. Here, we minimise this source of error by analysing the annually laminated sequences of two European lakes. We focus on environmental transformations that occurred in the decades preceding and following the deposition of the Icelandic Saksunarvatn tephra, dated between ca. 10,300 and 10,200 cal. BP. Evidence for continuous eruptive activity pre-dates the tephra deposition by nearly two decades, revealing a period of sustained volcanism and its effects on aquatic and terrestrial ecosystems. These results provide a new insight into the spatial and temporal effects of clustered volcanic eruptions. As such, they might prove useful to refine the simulation of volcanic forcing on contin...

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Research paper thumbnail of Anaerobic ammonium oxidation is a major N-sink in aquifer systems around the world

The ISME Journal, 2019

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Research paper thumbnail of Epicuticular wax lipid composition of endemic European Betula species and its application to chemotaxonomy and paleobotany

Plants, in particular trees with specific habitat demands are excellent indicators of climate sta... more Plants, in particular trees with specific habitat demands are excellent indicators of climate state. Vegetation successions in subrecent and deep geologic time is recorded in fossil macro-remains or pollen accumulating in geological archives like limnic and marine sediments, peat bogs and mires. Birch trees in Europe form a major part in plant successions and constitute the dwarf species Betula nana and Betula humilis representing cold-adapted habitats or climates and two tree birches, Betula pubescens and Betula pendula characteristic for temperate habitats or climates. These birch species exhibit highly similar pollen shape and size, preventing their unambiguous application as paleoclimate/paleovegetation proxies. We here present a chemotaxonomic differentiation of the four European birch species based on their epicuticular wax lipids. The dominating lipid classes in epicuticular birch waxes were found to be n-alkanes (in the range of n-C23 to n-C33), straight-chain primary alcoho...

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Research paper thumbnail of A New Perspective on Exploring the Cooper/Eromanga Petroleum Province—Evidence of Oil Charging from the Warburton Basin

The APPEA Journal, 2006

The history of petroleum exploration in central Australia has been enlivened by vigorous debate a... more The history of petroleum exploration in central Australia has been enlivened by vigorous debate about the source(s) of the oil and condensate found in the Cooper/Eromanga basin couplet. While early workers quickly recognized the source potential of thick Permian coal seams in the Patchawarra and Toolachee Formations, it took some time for the Jurassic Birkhead Formation and the Cretaceous Murta Formation to become accepted as effective source rocks. Although initially an exploration target, the Cambrian sediments of the underlying Warburton Basin subsequently were never seriously considered to have participated in the oil play, possibly due to a lack of subsurface information as a consequence of limited penetration by only a few widely spaced wells. Dismissal of the Warburton sequence as a source of hydrocarbons was based on its low generative potential as measured by total organic carbon (TOC) and Rock-Eval pyrolysis analyses. As most of the core samples analysed came from the uppe...

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Research paper thumbnail of Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

Biogeosciences, 2015

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Research paper thumbnail of Molecular proxies as indicators of freshwater incursion-driven salinity stratification

Chemical Geology, 2015

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Research paper thumbnail of An open ocean record of the Toarcian oceanic anoxic event

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Research paper thumbnail of Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia

The Holocene, 2004

A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides informatio... more A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12 800-9300 cal. BP). The chronology of the sequence is constrainied by varve counting and AMS 14C measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and macrofossils) imply that cold and dry regional climatic conditions with sparse Arctic vegetation prevailed prior to 11500 cal. BP. Coincident with the transition to the Holocene at 11 500 cal. BP, air temperatures and lake productivity increased and Betula pubescens and Populus treinula started to migrate into the area, followed by Picea abies at 10 750 cal. BP. Although lake productivity decreased at around 11 000 cal. BP and remained low until 9600 cal. BP, pollen-based climate reconstructions imply variable climatic conditions in ...

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Research paper thumbnail of New evidence of Holocene atmospheric circulation dynamics based on lake sediments from southern Sweden: a link to the Siberian High

Quaternary Science Reviews, 2013

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Research paper thumbnail of Towards reconstruction of past fire regimes from geochemical analysis of charcoal

Organic Geochemistry, 2013

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Research paper thumbnail of Exceptional preservation of microbial lipids in Paleozoic to Mesoproterozoic sediments

Geology, 2013

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Research paper thumbnail of Extractable lipid contents and colour in particle-size separates and bulk arable soils

European Journal of Soil Science, 2006

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Research paper thumbnail of Macroecology of methane‐oxidizing bacteria: the β‐diversity of pmoA genotypes in tropical and subtropical rice paddies

Environmental Microbiology, 2013

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Research paper thumbnail of Intra- versus inter-site macroscale variation in biogeochemical properties along a paddy soil chronosequence

Biogeosciences, 2012

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Research paper thumbnail of Mineral and chemostratigraphy of a Toarcian black shale hosting Mn-carbonate microbialites (Úrkút, Hungary)

Palaeogeography, Palaeoclimatology, Palaeoecology, 2016

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Research paper thumbnail of Holocene soil erosion in Eastern Europe-land use and/or climate controlled? The example of a catchment at the Giant Chalcolithic settlement at Maidanetske, central Ukraine

Geomorphology, 2020

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Research paper thumbnail of Life and death in the Chicxulub impact crater: A record of the Paleocene-Eocene Thermal Maximum

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Research paper thumbnail of Microbial Mayhem in the Nascent Chicxulub Crater

29th International Meeting on Organic Geochemistry, 2019

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Research paper thumbnail of δ13C of terrestrial vegetation records Toarcian CO2 and climate gradients

Scientific Reports, 2020

Throughout Earth’s history, variations in atmospheric CO2 concentration modulated climate. Unders... more Throughout Earth’s history, variations in atmospheric CO2 concentration modulated climate. Understanding changes in atmospheric carbon cycle is therefore pivotal in predicting consequences of recent global warming. Here, we report stable carbon isotopes (δ13C) of molecular land plant fossils complemented by bulk organic and inorganic carbon fractions for early Toarcian (Early Jurassic) sediments that coincided with global warming and a carbon cycle perturbation. The carbon cycle perturbation is expressed by a negative excursion in the δ13C records established for the different substrates. Based on differences in the magnitude of the carbon isotope excursion recorded in land plants and marine substrates we infer that the early Toarcian warming was paralleled by an increase in atmospheric CO2 levels from ~500 ppmv to ~1000 ppmv. Our data suggest that rising atmospheric CO2 levels resulted from the injection of 12C-enriched methane and its subsequent oxidation to CO2. Based on the cyc...

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Research paper thumbnail of Climate driven Holocene erosion in central Ukraine

The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic... more The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical stimulated luminescence (OSL) and embedded artefacts. A suspicious non-coincidence between phases of soil erosion and the settlement history at the site over long periods of the Holocene is noticeable and suggests a climatically driven erosion at the site. The detected phases of erosion during the past >20,000 years coincide with global (cal 27.6 +/- 1.3 kyrs BP, 12.0 +/- 0.4 kyrs BP), northern hemispheric (cal 8.5 ± 0.3 kyrs BP), Mediterranean (cal 3.93 ± 0.1 kyrs BP) as well as western to central European (2,700 to 2,000 cal BP) climate anomalies. For these anomalies, characterized by colder th...

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Research paper thumbnail of Sustained volcanic impact and ecosystem disturbance over continental Europe during the Early Holocene

Estimating the environmental and societal impact of recent volcanic eruptions is a task aided by ... more Estimating the environmental and societal impact of recent volcanic eruptions is a task aided by direct measurements and historical sources. Beyond the reach of first-hand accounts, our understanding of pre-historic volcanism is often hindered by the dating uncertainties inherent to stratigraphic archives. Here, we minimise this source of error by analysing the annually laminated sequences of two European lakes. We focus on environmental transformations that occurred in the decades preceding and following the deposition of the Icelandic Saksunarvatn tephra, dated between ca. 10,300 and 10,200 cal. BP. Evidence for continuous eruptive activity pre-dates the tephra deposition by nearly two decades, revealing a period of sustained volcanism and its effects on aquatic and terrestrial ecosystems. These results provide a new insight into the spatial and temporal effects of clustered volcanic eruptions. As such, they might prove useful to refine the simulation of volcanic forcing on contin...

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Research paper thumbnail of Anaerobic ammonium oxidation is a major N-sink in aquifer systems around the world

The ISME Journal, 2019

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Research paper thumbnail of Epicuticular wax lipid composition of endemic European Betula species and its application to chemotaxonomy and paleobotany

Plants, in particular trees with specific habitat demands are excellent indicators of climate sta... more Plants, in particular trees with specific habitat demands are excellent indicators of climate state. Vegetation successions in subrecent and deep geologic time is recorded in fossil macro-remains or pollen accumulating in geological archives like limnic and marine sediments, peat bogs and mires. Birch trees in Europe form a major part in plant successions and constitute the dwarf species Betula nana and Betula humilis representing cold-adapted habitats or climates and two tree birches, Betula pubescens and Betula pendula characteristic for temperate habitats or climates. These birch species exhibit highly similar pollen shape and size, preventing their unambiguous application as paleoclimate/paleovegetation proxies. We here present a chemotaxonomic differentiation of the four European birch species based on their epicuticular wax lipids. The dominating lipid classes in epicuticular birch waxes were found to be n-alkanes (in the range of n-C23 to n-C33), straight-chain primary alcoho...

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Research paper thumbnail of A New Perspective on Exploring the Cooper/Eromanga Petroleum Province—Evidence of Oil Charging from the Warburton Basin

The APPEA Journal, 2006

The history of petroleum exploration in central Australia has been enlivened by vigorous debate a... more The history of petroleum exploration in central Australia has been enlivened by vigorous debate about the source(s) of the oil and condensate found in the Cooper/Eromanga basin couplet. While early workers quickly recognized the source potential of thick Permian coal seams in the Patchawarra and Toolachee Formations, it took some time for the Jurassic Birkhead Formation and the Cretaceous Murta Formation to become accepted as effective source rocks. Although initially an exploration target, the Cambrian sediments of the underlying Warburton Basin subsequently were never seriously considered to have participated in the oil play, possibly due to a lack of subsurface information as a consequence of limited penetration by only a few widely spaced wells. Dismissal of the Warburton sequence as a source of hydrocarbons was based on its low generative potential as measured by total organic carbon (TOC) and Rock-Eval pyrolysis analyses. As most of the core samples analysed came from the uppe...

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Research paper thumbnail of Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

Biogeosciences, 2015

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Research paper thumbnail of Molecular proxies as indicators of freshwater incursion-driven salinity stratification

Chemical Geology, 2015

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Research paper thumbnail of An open ocean record of the Toarcian oceanic anoxic event

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia

The Holocene, 2004

A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides informatio... more A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12 800-9300 cal. BP). The chronology of the sequence is constrainied by varve counting and AMS 14C measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and macrofossils) imply that cold and dry regional climatic conditions with sparse Arctic vegetation prevailed prior to 11500 cal. BP. Coincident with the transition to the Holocene at 11 500 cal. BP, air temperatures and lake productivity increased and Betula pubescens and Populus treinula started to migrate into the area, followed by Picea abies at 10 750 cal. BP. Although lake productivity decreased at around 11 000 cal. BP and remained low until 9600 cal. BP, pollen-based climate reconstructions imply variable climatic conditions in ...

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Research paper thumbnail of New evidence of Holocene atmospheric circulation dynamics based on lake sediments from southern Sweden: a link to the Siberian High

Quaternary Science Reviews, 2013

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Research paper thumbnail of Towards reconstruction of past fire regimes from geochemical analysis of charcoal

Organic Geochemistry, 2013

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Research paper thumbnail of Exceptional preservation of microbial lipids in Paleozoic to Mesoproterozoic sediments

Geology, 2013

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Research paper thumbnail of Extractable lipid contents and colour in particle-size separates and bulk arable soils

European Journal of Soil Science, 2006

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Research paper thumbnail of Macroecology of methane‐oxidizing bacteria: the β‐diversity of pmoA genotypes in tropical and subtropical rice paddies

Environmental Microbiology, 2013

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Research paper thumbnail of Intra- versus inter-site macroscale variation in biogeochemical properties along a paddy soil chronosequence

Biogeosciences, 2012

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Research paper thumbnail of Mineral and chemostratigraphy of a Toarcian black shale hosting Mn-carbonate microbialites (Úrkút, Hungary)

Palaeogeography, Palaeoclimatology, Palaeoecology, 2016

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Research paper thumbnail of Holocene soil erosion in Eastern Europe-land use and/or climate controlled? The example of a catchment at the Giant Chalcolithic settlement at Maidanetske, central Ukraine

Geomorphology, 2020

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