Bernd Zolitschka

Bernd Zolitschka
Universität Bremen | Uni Bremen · Institute of Geography

Prof. Dr.

About

314
Publications
64,377
Reads
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9,129
Citations
Citations since 2016
49 Research Items
3442 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Introduction
My focus of research lies on natural and anthropogenic control mechanisms on geomorphological and sedimentological processes, on Quaternary paleoclimatology and on the potential of annually laminated (varved) lake sediments for dating and high-resolution paleoenvironmental reconstruction.
Additional affiliations
April 2000 - present
Universität Bremen
Position
  • Professor (Full)
April 2000 - present
Universität Bremen
Position
  • Professor of physical geography with emphasis on geomorphology and polar research
August 1994 - March 2000
Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Position
  • PostDoc Position
Education
May 1990 - January 1997
Universität Potsdam
Field of study
  • Geosciences
May 1986 - April 1990
Universität Trier
Field of study
  • Geosciences
October 1980 - March 1986
Universität Trier
Field of study
  • Applied Physical Geography

Publications

Publications (314)
Article
Full-text available
Geochemical variations of sedimentary records contain vital information for understanding paleoenvironment and paleoclimate. However, to obtain quantitative data in the laboratory is laborious, which ultimately restricts the temporal and spatial resolution. Quantification based on fast-acquisition and high-resolution provides a potential solution b...
Article
Full-text available
The delineation of sediment facies provides essential background information for a broad range of investigations in geosciences but is often constrained in quality or quantity. Here we leverage improvements in machine learning and X-ray fluorescence core scanning to develop an improved approach to automatic sediment-facies classification. This appr...
Article
Lacustrine environmental archives with annually laminated (varved) sediments allow a calendar-year chronology and the calculation of precise sediment accumulation rates. We present multiproxy analyses of a varved sediment record from Holzmaar (West-Eifel Volcanic Field, Germany) for the last 16,000 years providing a continuous diatom stratigraphy s...
Preprint
Full-text available
This study gives an overview of different varve integration methods with Bacon. These techniques will become important for the future as technologies evolve with more sites being revisited for the application of new and high-resolution scanning methods. Thus, the transfer of existing chronologies will become necessary, because the recounting of var...
Article
Full-text available
Two loess sections from the Upper Palaeolithic site of Kammern-Grubgraben (Lower Austria) were analysed to test geochemical proxies, as well as radiocarbon data of different components, for their reliability and consistency in an archaeological context. Only a reliable basal age (28.9–27.8 ka cal BP) was obtained from charcoal fragments derived fro...
Article
Full-text available
There is little knowledge about testate amoebae in lakes and their responses to volcanic eruptions. To address this knowledge gap, we studied the paleoecology of these protists in a sediment record from Laguna Verde, a lake located east of the southern Patagonian Ice Field, in Santa Cruz Province, Argentina. The lake is under the influence of volca...
Article
Full-text available
The timing of the Monte Peron Landslide is revised to 2890 cal. BP based on a radiocarbon-dated sediment stratigraphy of Lago di Vedana. This age fosters the importance of hydroclimatic triggers in the light of accelerating global warming with a predicted increase of precipitation enhancing the regional predisposition to large landslides. Moreover,...
Article
Full-text available
There is little knowledge about testate amoebae in lakes and their responses to volcanic eruptions. To address this knowledge gap, we studied the paleoecology of these protists in a sediment record from Laguna Verde, a lake located east of the southern Patagonian Ice Field, in Santa Cruz Province, Argentina. The lake is under the influence of volca...
Article
High-resolution geochemical and sedimentological data have been obtained for a lacustrine sediment record from Lagoa Dourada (South Brazil). Four distinctly different depositional processes were determined: (1) Suspension fallout of fine-grained minerogenic particles transferred via fluvial activity dominates the Early Holocene and relates to open...
Conference Paper
The dearth of high-resolution climate records for the past millennium has largely limited our understanding of the impacts of natural (e.g., the Little Ice Age: LIA) and anthropogenic climate perturbations (i.e., the ongoing global warming) on the arid regions of West Asia (also referred to as the Middle East). Here, we present multiproxy records i...
Preprint
Full-text available
The timing of the Monte Peron Landslide is revised to 2890 cal. BP based on a radiocarbon-dated sediment stratigraphy of Lago di Vedana. This age fosters the importance of hydroclimatic triggers in the light of accelerating global warming with a predicted increase of precipitation enhancing the regional predisposition to large landslides. Moreover,...
Preprint
Full-text available
High-resolution geochemical and sedimentological data were analyzed for a lacustrine sediment record from Lagoa Dourada (South Brazil). Four distinctly different depositional processes were determined: (1) Suspension fallout of fine-grained minerogenic particles transferred via fluvial activity dominates the Early Holocene and relates to open grass...
Article
Full-text available
Sediment facies provide fundamental information to interpret palaeoenvironments, climatic variation, archaeological aspects and natural resource potentials since they are summary products of depositional processes, environmental conditions and biological activities for a given time and location. The conventional method of facies discrimination reli...
Article
The role of environmental change in the evolution of cultural traits is a topic of long-standing scientific debate with strongly contrasting views. Major obstacles for assessing environmental impacts on the evolution of material culture are the fragmentary nature of archaeological and – to a somewhat lesser extent – geoscientific archives and the i...
Article
Full-text available
Rapid North Atlantic cooling events during the last deglaciation caused atmospheric reorganizations on global and regional scales. Their impact on Asian climate has been investigated for monsoonal domains, but remains largely unknown in westerly wind-dominated semiarid regions. Here we generate a dust record from southeastern Iran spanning the peri...
Article
This study was carried out on sediment cores collected with a gravity corer from Laguna Cháltel, an almost circular crater lake located in Patagonia, Argentina (49.9°S, 71°W). The main magnetic carrier was Ti-magnetite in the pseudo–single domain range. A model using magnetic grain size and concentration, previously applied to Laguna Potrok Aike to...
Article
Full-text available
The collection of papers entitled “Annually Laminated Lake Sediments” illustrates the recent progress made in varved sediment research and highlights the variety of methodological approaches and research directions used. The contributions cover the monitoring of modern sediment fluxes using sediment traps, geochronological and sedimentological anal...
Article
The sedimentological and geochemical characteristics of sediments from Lake Szurpiły (northeastern Poland) can be used asa record of mass movement and climate dynamics since the Allerød. Late-glacial sediments suggest enhanced runoff conditions in the catchment after the retreat of the Scandinavian Ice Sheet, while Holocene varved sediments are int...
Article
Full-text available
Significance Using a compilation of ¹⁴ C and pollen data of lake sediment records from over 632 sites globally, we identified the timings of first increase in lake sedimentation. Changes in lake sediment rates at this time are closely linked to increased sediment supply from hillslope erosion. The analysis on the relative roles of the driving facto...
Article
Full-text available
Lacustrine sediment sequences were obtained from Lagunas Verde and Gemelas Este, two small lakes located east of the southern Patagonian Ice Field and close to the village of El Chaltén, in Argentinian Patagonia. Four tephra layers were identified in each of the short sediment sequences and characterised using individual glass-shard tephra chemistr...
Conference Paper
Annually laminated (varved) sediments and inserted mass-movement deposits of Lake Szurpiły track sedimentation dynamics since the Late Glacial and relate to natural and anthropogenic forcing. The chronology of this study is based on varves for the last 8400 years and extends back to the Allerød applying radiocarbon dating and pollen stratigraphy. I...
Article
Full-text available
This paper presents a detailed record of volcanism extending back to ~80 kyr BP for southern South America using the sediments of Laguna Potrok Aike (ICDP expedition 5022; Potrok Aike Maar Lake Sediment Archive Drilling Project-PASADO). Our analysis of tephra includes the morphology of glass, the mineral componentry, the abundance of glass-shards,...
Article
Ravine slopes at the recently discovered Nesseltalgraben site in southeastern Germany provide a unique last glacial sediment record for the Northern Calcareous Alps. The 21 m-long profile is dominated by fine-grained lacustrine-palustrine sediments overlain by several metres of glacifluvial gravels and lodgement tills of the Last Glacial Maximum an...
Article
The coastal area of the southern North Sea passed through several stages of development during the Holocene starting with swamps and bogs on Pleistocene sands. These were covered due to the rising sea-level by brackish and intertidal sediments with intercalated peat layers indicating repeated shoreline replacements. Such sedimentary archives are ex...
Article
Full-text available
Annually laminated lake sediments provide high-resolution and accurate timescales for reliable paleoenvironmental reconstructions. We investigated human activity in a low-human-impact region of Poland, taking advantage of varved sediments from Lake Szurpiły, which span the last 8200 years. Multiple sediment variables indicated that catchment evolut...
Article
Full-text available
The introduction and application of high resolution XRF core scanners has made an enormous contribution to palaeoclimate science over the last two decades. These core scanners have become essential analytical tools for the investigation of sedimentary and other natural cumulative records of environmental change. Their widespread adoption by the env...
Article
Multiproxy investigations of lacustrine sediments from Laguna Azul (52 °S) document multi-millennial Holocene influences of Southern Hemispheric Westerlies (SHW) on the hydroclimatic variability of south-eastern Patagonia. During the last 4000 years, this hydroclimatic variability is overprinted by centennial warm/dry periods. A cool/wet period fro...
Article
Paleomagnetic and rock magnetic studies performed on sediment cores from Laguna Cháltel (Patagonia, Argentina) show strong and stable remanence carried by pseudo-single domain (PSD) magnetite. Concentration of magnetic minerals varied between 0.01 and 0.08%. Paleomagnetic records from four cores document little scatter of directions with very good...
Article
This study provides a detailed geochemical record of one of the best studied loess-paleosol sequences (LPS) in Hungary covering Marine Isotope Stage (MIS) 6 to MIS 2. Süttő is situated in the northwestern Carpathian Basin at the transition between oceanic and continental climate. We investigated weathering intensity, dust provenance and sedimentati...
Article
X-ray fluorescence (XRF) scanning of discrete samples provides a time- and cost-efficient alternative to conventional geochemical analyses of discretely sampled paleoenvironmental archives. Loess-paleosol sequences (LPS) as complex terrestrial archives are thus predestinated for benchmarking this new application of the well-established XRF scanning...
Article
Full-text available
Recently exposed loess–palaeosol sequences in the northern Alpine foreland close to Bobingen (southern Germany) were investigated with a multi-proxy approach combining isotopic, geochemical, lithological, and micropalaeontological methods. Luminescence ages date the sections into the Middle and Upper Würmian periods corresponding to Marine Isotope...
Article
Full-text available
This study examines the multi-decadal to centennial variability of benthic ecosystems, depositional environments and biogeochemical processes in the Gulf of Taranto (Italy) over the last millennium. Our study is based on sediment cores from two sites in the eastern Gulf of Taranto (Mediterranean Sea), and benthic foraminifera data of 43 surface sed...
Article
Differentiating between regularly seasonal, irregular and event-based clastic sedimentation is difficult if sedimentation structures resemble and dating methods are imprecise. In this study - clastic light and dark laminae from lava-dammed Paleolake Alf in the Late Pleistocene in the Quaternary West Eifel Volcanic Field are analyzed to clarify how...
Article
Lacustrine sediments retrieved from Laguna Potrok Aike in the framework of the Potrok Aike Maar Lake Sediment Archive Drilling Project (PASADO) offer the possibility to investigate climate variations of the past ~51 cal ka BP in Southern Hemispheric midlatitudes, Argentinean Patagonia. This study focuses on short-term cyclicities in the Ca and magn...
Conference Paper
Full-text available
Temperature, precipitation and wind intensity of South America respond to the air-pressure gradient between polar and subtropical latitudes as well as to sea-surface temperatures of adjacent oceans, the extent of sea-ice and continental ice masses and to the pathway of the Southern Hemispheric Westerlies (SHW). The resulting variations of the regio...
Conference Paper
Full-text available
The up to 20 m thick loess-paleosol sequence (LPS) Sütt˝ o is located in the northwestern part of the Pannonian Basin in Hungary on a Danube terrace close to the Transdanubian Mountains. Different from other Hungarian LPS, Sütt˝ o comprises a quasi-continuous time sequence from MIS 6 to MIS 2 as documented by luminescence age estimates and supporte...
Article
Full-text available
Significance Using a compilation of data arising from over 1,500 European watersheds, we have identified the relative role of different drivers in initiating hypolimnetic hypoxia, a critical indicator of lake health. In particular, our regional synthesis of laminated lake sediments indicated a significant acceleration in the spread of lacustrine hy...
Conference Paper
Full-text available
Downcore counting of laminations in varved sediments offers a direct and incremental dating technique for high-resolution climatic and environmental archives with at least annual and sometimes even seasonal resolution 1,2. Once a varve chronology is established it can be applied to precisely date events like volcanic ash layers, earthquakes or huma...
Article
When using biomarkers such as n-alkanes as tools for paleo-environmental reconstructions, it is imperative to determine their specific sources for each setting. Towards that goal, we analysed a set of various potential organic matter (OM) sources such as aquatic and terrestrial plants, dust, and soils from Laguna Potrok Aike (LPA) and surrounding a...
Article
The Schwalbenberg II loess-paleosol sequence (LPS) denotes a key site for Marine Isotope Stage (MIS) 3 in Western Europe owing to eight succeeding cambisols, which primarily constitute the Ahrgau Subformation. Therefore, this LPS qualifies as a test candidate for the potential of temporal high-resolution geochemical data obtained by X-ray fluoresce...
Conference Paper
Full-text available
Over the past decade, we have come to appreciate that hypoxia (oxygen depletion) has become a prevalent phenomenon in coastal and inland waters worldwide. Given that oxygen is required for many forms of life, the widespread presence of hypoxia is altering the biodiversity of many aquatic systems, and impairing the delivery of numerous ecosystem goo...
Article
The global compilation of reported marine varved sedimentary records throughout the Quaternary contains 52 sites. Marine varve deposition and preservation typically depend on environmental and sedimentological conditions, such as a sufficiently high sedimentation rate, severe depletion of dissolved oxygen in bottom water to exclude bioturbation by...
Conference Paper
Full-text available
Loess-paleosol sequences (LPS) are recognized as valuable terrestrial environmental archives. Although LPS provide discontinuous archives, high-resolution sampling and analyzing strategies are required for a sound reconstruction of past environmental conditions. Up to now, proxies such as grain size, rock magnetic properties and calcium-carbonate c...
Article
Full-text available
Two sediment-cores out of the central part of Meerfelder Maar/Westeifel (F.R.G.) have been analysed microstratigtaphically. Diatomological investigations proved, that the prevailing organic deposits are annually laminated. Thereupon a varve-count has been carried out. In addition to precise absolute dating of the late- and postglacial deposits, var...
Article
The spread of hypoxia is a threat to aquatic ecosystem functions and services as well as to biodiversity. However, sparse long-term monitoring of lake ecosystems has prevented reconstruction of global hypoxia dynamics while inhibiting investigations into its causes and assessing the resilience capacity of these systems. This study compiles the onse...
Research
Full-text available
Palmarès des 10 découvertes de l'année 2012 du magazine Québec Science
Conference Paper
Full-text available
Annually laminated (varved) sediments are natural archives of paleoenvironmental conditions that offer accurate " internal " time control in calendar years, exceptional high temporal resolution and the possibility to calculate flux rates. The " Varve Image Portal " (http://www.pages-igbp.org/workinggroups/varves-wg/varves-image-library) displays im...
Conference Paper
Full-text available
XRF analysis of a loess-palaeosoil sequence: A new approach to decipher Pleistocene climatic and environmental variations applied to Rodderberg, Germany Bernd Zolitschka, a*, Christian Rolf, b, Felix Bittmann, c, Franz Binot, b, Manfred Frechen, b, Thomas Wonik, b, Nikolaus Froitzheim, d & Christian Ohlendorf, a a Geomorphology and Polar Research...
Article
Full-text available
Downcore counting of laminations in varved sediments offers a direct and incremental dating technique for high-resolution climatic and environmental archives with at least annual and sometimes even seasonal resolution. The pioneering definition of varves by De Geer (1912) had been restricted to rhythmically deposited proglacial clays. One century l...
Conference Paper
Full-text available
X-ray fluorescence (XRF) core scanning is influenced by numerous sample-specific effects such as water content, sediment matrix and grain size. All these parameters affect the characteristics of fluorescent X-rays recorded by the detector. Subsequently, the recorded spectra are translated into element-specific counts by mathematical peak fitting st...
Article
First results of strontium, calcium, carbon and oxygen isotope analyses of bulk carbonates from a 106m long sediment record of Laguna Potrok Aike, located in southern Patagonia are presented. Morphological and isotopic investigations of μm-sized carbonate crystals in the sediment reveal an endogenic origin for the entire Holocene. During this time...
Data
The sedimentary archive from Laguna Potrok Aike is the only continuous record reaching back to the last Glacial period in continental southeastern Patagonia. Located in the path of the Southern Hemisphere westerly winds and in the source region of dust deposited in Antarctica during Glacial periods, southern Patagonia is a vantage point to reconstr...
Data
The Schwalbenberg II loess-paleosol sequence (LPS) denotes a key site for Marine Isotope Stage (MIS 3) in Western Europe owing to eight succeeding cambisols, which primarily constitute the Ahrgau Subformation. Therefore, this LPS qualifies as a test candidate for the potential of temporal high-resolution geochemical data obtained X-ray fluorescence...
Article
Full-text available
century to describe minerogenic proglacial lake sediments of Sweden as annually laminated. Later on, the term varve was extended to other lacustrine as well as marine sediment types with preserved annual successions and seasonal sub-laminae. The large diversity of sediments featuring a varved character sometimes led to the misconception that most,...
Chapter
Full-text available
Varved or annually laminated lake sediments offer an incremental dating technique that also provides high-resolution climatic and environmental data and information about related forcing mechanisms. The first definition of varves by De Geer (1912) was restricted to rhythmically deposited proglacial clays. A century later the meaning was extended to...
Conference Paper
Full-text available
The sedimentary archive from Laguna Potrok Aike is the only continuous record reaching back to the last Glacial period in continental southeastern Patagonia. Here we use high-resolution u-channel, as well as discrete rock-magnetic and physical grain size data from the 106 m long core (~51,200 cal BP) of site 2 of the ICDP Potrok Aike maar lake Sedi...
Article
Full-text available
The Southern Hemisphere Westerlies (SHW) play a crucial role in large-scale ocean circulation and global car-bon cycling. Accordingly, the reconstruction of how the lati-tudinal position and intensity of the SHW belt changed dur-ing the last glacial termination is essential for understand-ing global climatic fluctuations. The southernmost part of t...
Article
Full-text available
During the lake deep drilling campaign PASADO in 2008, more than 500 m of lacustrine sediment was recovered from the maar lake Laguna Potrok Aike, Argentina. The major element composition was assessed at high resolution with an ITRAX X-ray fluorescence core scanner. The sharp boundary between a carbonate-bearing and a carbonate-free depositional sy...
Article
Hydrological changes that occurred during the last 4700 years have been reconstructed using multi-proxy analyses of sediment cores from the volcanic crater lake of Laguna Cháltel (50°S, 71°W). The chronology is based on AMS 14C age modeling constrained by paleomagnetic secular variations. Chemical and physical properties of the lake water together...
Article
Full-text available
Crater sediments from the Rodderberg Volcanic Complex (East Eifel, Germany) provide a climate and environmental record spanning several glacial-to-interglacial cycles. We document and describe the lithology and demonstrate that the composition of this sediment record can be interpreted with regard to environmental variations as well as to changes i...
Article
Full-text available
Lake sediments are excellent sources of palaeoenvironmental and palaeoclimatic information because they provide continuous and high-resolution records. South America is of particular interest because it is the only landmass that stretches southward into the Pacific and Atlantic Oceans towards Antarctica. The aim of this study is to explore the rela...