Daniel Ariztegui

Daniel Ariztegui
University of Geneva | UNIGE · Department of Earth Sciences

PhD

About

312
Publications
64,932
Reads
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7,758
Citations
Citations since 2017
85 Research Items
3303 Citations
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
20172018201920202021202220230100200300400500600
Additional affiliations
November 2000 - October 2015
University of Geneva
Position
  • Professor
November 2000 - March 2016
University of Geneva
Position
  • Professor
July 1993 - October 2000
ETH Zurich
Position
  • Senior Researcher
Description
  • I was head of the Laboratory of Limnogeology of Prof. Judith A. McKenzie Earth System Science Group

Publications

Publications (312)
Article
Tierra del Fuego in Argentina is a unique location to examine past Holocene wind variability since it intersects the core of the Southern HemisphereWesterlyWinds (SHWW). TheSHWWare the most powerful prevailing winds on Earth. Their variation plays a role in regulating atmospheric CO2 levels and rainfall amounts and distribution, both today and in t...
Article
Strontium‐rich micropearls (intracellular inclusions of amorphous calcium carbonate) have been observed in several species of green microalgae within the class Chlorodendrophyceae, suggesting the potential use of these organisms for 90Sr bioremediation purposes. However, very little is known about the micropearl formation process and the Ca and Sr...
Article
Lipid-biomarkers have been used to reconstruct environmental changes in lacustrine systems on a range of time scales. Lake sediments are excellent archives to apply these tools due to their rapid and amplified response to environmental pressures. For the past thirty years, the hypersaline lagoons of the Rio de Janeiro coastal plain have been studie...
Article
Full-text available
High‐mountain lake records in semiarid foreland settings, such as the central Andes of North‐western Argentina, are highly restricted and often deprived of well‐preserved microstratigraphic information to analyze palaeoenvironmental changes and their causes, particularly for periods prior to the Last Glacial Maximum. Laguna La Salada Grande (23ºS/6...
Article
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In most habitats, fluctuating environmental conditions create periods of compromised survival for metabolically active organisms. In response, various survival strategies have evolved, including the formation of resilient resting cells. We assessed the biodiversity of the lysis‐resistant bacteria in three different environments by applying a harsh...
Article
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The hypersaline Dead Sea and its sediments are natural laboratories for studying extremophile microorganism habitat response to environmental change. In modern times, increased freshwater runoff to the lake surface waters resulted in stratification and dilution of the upper water column followed by microbial blooms. However, whether these events fa...
Article
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Interglacial periods are characterised by thick accumulations of halite units in the Dead Sea Basin. During these intervals, small water droplets (fluid inclusions) were entrapped in the halite crystals which serve as windows to estimate the chemistry and physical properties of the primary lake water conditions. Brillouin spectroscopy is used here...
Article
Full-text available
Changing redox conditions in water columns or sediment–water interfaces of lakes are captured as sedimentary archives, and are often influenced by climate. Their study therefore permits the reconstruction of past climate change on (sub‐) annual to longer timescales. In Lago Fagnano (54°S Argentina/Chile), a large oligotrophic and deep‐oxygenated la...
Article
Full-text available
In unicellular organisms, intracellular inclusions of amorphous calcium carbonate (ACC) were initially described in cyanobacteria and, later, in unicellular eukaryotes from Lake Geneva (Switzerland/France). Inclusions in unicellular eukaryotes, named micropearls, consist of hydrated ACCs, frequently enriched in Sr or Ba, and displaying internal osc...
Preprint
Full-text available
In unicellular organisms, intracellular inclusions of amorphous calcium carbonate (ACC) have been initially described in cyanobacteria and, later, in unicellular eukaryotes of Lake Geneva (Switzerland/France). Inclusions in unicellular eukaryotes ‒named micropearls‒ consist of hydrated ACCs, frequently enriched in Sr or Ba, displaying internal osci...
Article
The most favourable locations for the development of saline lakes are in the rain-shadow of mountain ranges, which provide large areas of precipitation catchment while the base of the basin is under arid climate and exposed to evaporation. These conditions are found in Extra-Andean Patagonia under the rain-shadow generated by the Andean cordillera....
Article
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There is still a paucity of hydrological data explaining the relationship between (rapid, millennial‐scale) climate forcing and Mediterranean rainfall since the Last Glacial. We show that distinct lake‐level fluctuations at Lake Trasimeno (Italy) are associated with changing aridity in the central Mediterranean during the last ˜47 800 years. The la...
Article
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Geometric morphometric methods are powerful tools to discriminate between closely related ostracods taxa as well as to study the relationship between their morphological variations, taxonomy and paleoecology. In this study, valve outline analysis allows the discrimination between the non-marine ostracod C. silvestrii and R. whatleyi juveniles, poin...
Article
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Rock falls and landslides plunging into lakes or small reservoirs can result in tsunamis with extreme wave run-ups. The occurrence of these natural hazards in populated areas have encouraged a recent sharp increase of studies that aim to mitigate their impact on human lives and assess infrastructure lost. This paper amalgamates in a novel fashion a...
Conference Paper
Full-text available
Since the seminal paper in 1998 (Coolen and Overmann), sedimentary ancient DNA (sedaDNA) has become a powerful tool in paleoecology to reconstruct past changes in terrestrial and aquatic biodiversity. Still, sedaDNA is an emerging tool and there is a need for calibrations and validations to ensure the reliability of sedaDNA as a proxy to reconstruc...
Article
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Deposition of ferruginous sediment was widespread during the Archaean and Proterozoic Eons, playing an important role in global biogeochemical cycling. Knowledge of organic matter mineralization in such sediment, however, remains mostly conceptual, as modern ferruginous analogs are largely unstudied. Here we show that in sediment of ferruginous Lak...
Article
Full-text available
An unsuspected biomineralization process, which produces intracellular inclusions of amorphous calcium carbonate (ACC), was recently discovered in unicellular eukaryotes. These mineral inclusions, called micropearls, can be highly enriched with other alkaline‐earth metals (AEM) such as Sr and Ba. Similar intracellular inclusions of ACC have also be...
Article
Full-text available
The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field in paleoecological research. Although largely applied nowadays, knowledge gaps remain in this field and there is therefore still research to be conducted to ensure the reliability of the sedimentary DNA signal. Building...
Article
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Environmental DNA (eDNA) metabarcoding of marine sediments has revealed large amounts of sequences assigned to planktonic taxa. How this planktonic eDNA is delivered on the seafloor and preserved in the sediment is not well understood. We address these questions by comparing metabarcoding and microfossil foraminifera assemblages in sediment cores t...
Article
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Lacustrine sediments are widely used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities are major actors of this cycling but can also affect the sedimentary record and overprint the original paleoenvironmental signal. We therefore investigated the subsurface microbial communi...
Article
Laguna Mar Chiquita (LMC, 30 54 0 S e 62 51 0 W) is a highly variable and shallow saline lake, located in the Pampean Plains of Argentina. The paleolimnological record of LMC contains information on the environmental variability that occurred in a large area of Southern South America since the Last Glacial Maximum (LGM) until the present. As inferr...
Article
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In order to characterize Patagonian (Argentina) ecoregions using non-marine ostracods, their associations in 69 environments were assessed. Twenty eight taxa were recorded, including 12 endemic of the Neotropical region. Our results indicate that Patagonian ostracods are mainly influenced by electrical conductivity (EC), altitude, pH, and temperatu...
Article
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The Opalinus Clay is an argillaceous to silty mudstone formation, notable in Switzerland as the selected host rock for deep geological disposal of radioactive waste. Its upper bounding unit (Passwang Formation and eastern equivalents) is composed of successions of mudstone, sandy bioclastic marl and limestone separated by ooidal ironstone beds. The...
Article
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Several species of the genus Tetraselmis (Chlorodendrophyceae, Chlorophyta) were recently discovered to possess unsuspected biomineralization capacities: they produce multiple intracellular inclusions of amorphous calcium carbonate (ACC), called micropearls. Early light-microscopists had spotted rows of refractive granules in some species, although...
Preprint
Full-text available
Ferruginous sediments were widespread during the Archaean and Proterozoic Eons, but our knowledge about organic matter mineralization remains mostly conceptual, as analogous modern ferruginous sediments are largely unstudied. In sediments of ferruginous Lake Towuti, Indonesia, methanogenesis dominates organic matter mineralization despite abundant...
Article
Full-text available
Geneses of microbialites and, more precisely, lithification of microbial mats have been studied in different settings to improve the recognition of biogenicity in the fossil record. Living microbial mats and fossil microbialites associated with older paleoshorelines have been studied in the continental Maquinchao Basin in southernmost South America...
Preprint
Fe speciation and Fe isotopes have been widely used to reconstruct past basin dynamics and water redox conditions. However, sedimentation and early diagenesis of such proxies eventually alter any primary climate signal. In this work, we disentangled the processes occurring at the redox front below the sediment-water interface of a ventilated deep-w...
Article
This study presents, for the first time, a detailed quantitative reconstruction of winter (January) and summer (July) palaeotemperatures from the Late Pleistocene to Holocene transition in central Italy based on ostracod assemblages in an 8.59-m-long sediment core retrieved in Lake Trasimeno. Of 19 ostracod species recovered, 13 were calibrated acc...
Article
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Reservoirs hold a detailed record of the changes in the input of sediments and nutrients over decades to centuries. Paleolimnological multi-proxy analysis makes it possible to reconstruct baseline conditions to infer early evidence of environmental change. Our study aims to reconstruct historical human impacts derived from urban development on the...
Article
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Ferruginous lacustrine systems, such as Lake Towuti, Indonesia, are characterized by a specific type of phosphorus cycling in which hydrous ferric iron (oxyhydr)oxides trap and precipitate phosphorus to the sediment, which reduces its bioavailability in the water column and thereby restricts primary production. The oceans were also ferruginous duri...
Preprint
Full-text available
Understanding the response of geo- and biosystems to past climatic disturbance is primordial to assess the short to long terms effects of current global change. Lacustrine sediments are commonly used to investigate the impact of climatic change on biogeochemical cycling. In these sediments, subsurface microbial communities play a primordial role in...
Article
Halite traps inclusions of the mother fluid when precipitating. When unchanged, the density of these fluid inclusions (FIs) records the water temperature Tf at the time of crystal formation. As halite is ubiquitous on Earth and geological time, its FIs possess a high potential as temperature archives. However, the use of FIs in halite as an accurat...
Preprint
Full-text available
Ferruginous lacustrine systems, such as Lake Towuti, Indonesia, can experience restricted primary production due to phosphorus trapping by hydrous ferric iron (oxyhydr)oxides that reduce P concentrations in the water column. The oceans were also ferruginous during the Archean, so understanding the dynamics of phosphorus in modern-day ferruginous an...
Article
Here we present the first tephrostratigraphic, palaeomagnetic, and multiproxy data from a new ~98 m-deep sediment core retrieved from the Fucino Basin, central Italy, spanning the last ~430 kyr. Palae-oenvironmental proxy data (Ca-XRF, gamma ray and magnetic susceptibility) show a cyclical variability related to interglacial-glacial cycles since th...
Article
Full-text available
Structure from Motion–Multi-View Stereo (SfM-MVS) is a relatively new technique that is being adopted in the analysis of sedimentary systems. The technique is especially applicable to studies which focus on the distribution, geometry and quantification of geological bodies including the analysis of sedimentary forms and tectonic structures. This ph...
Article
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In a seminal paper regarding the mechanisms of carbonate stromatolite formation, Ginsburg (1991) emphasized the need to question to the relative role of microbes versus environment in their formation. The Maquinchao Basin is a continental lacustrine system in southern Argentina. It provides an ideal site to study carbonate buildups, the role of mic...
Article
Full-text available
The Pampean Plains comprise a flat area of southeastern South America (SESA), encompassing the most populated and productive area of Argentina. Several floods and droughts have been reported in the region during the last 50 years affecting lakeshore villages. In spite of the well-known importance of monitoring hydrological systems in flood-risk are...
Article
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Qualitative and quantitative changes of organic and carbonate carbon in sedimentary records are frequently used to reconstruct past environments, paleoproductivity and sediment provenance. Amongst the most commonly used proxies are Total organic carbon (TOC), Mineral carbon (MinC), as well as Hydrogen (HI) and Oxygen Indices (OI) of organic matter...
Article
Full-text available
Ferruginous conditions prevailed in the world’s deep oceans during the Archean and Proterozoic Eons. Sedimentary iron formations deposited at that time may provide an important record of environmental conditions, yet linking the chemistry and mineralogy of these sedimentary rocks to depositional conditions remains a challenge due to a dearth of inf...
Article
The Dead Sea Deep Drilling Project allowed us to retrieve a continuous sedimentary record spanning the two last glacial cycles. This unique archive, in such an extreme environment, has permitted the development of new proxies and the refinement of already available paleoenvironmental studies. Although life is pushed to its extremes in the Dead Sea...
Article
Full-text available
Archaea and Bacteria that inhabit the deep subsurface (known as the deep biosphere) play a prevalent role in the recycling of sedimentary organic carbon. In such environments, this process can occur over millions of years and requires microbial communities to cope with extremely limited sources of energy. Because of this scarcity, metabolic process...
Article
Changes in the ostracod assemblages from two sediment cores collected from Lago Cardiel in southeastern Patagonia (49°S) reflect the main regional abrupt climatic changes over the last 15.6 cal. ka BP. Shifts in species abundance and switches in dominances suggest that these were mainly driven by variable salinity. During the Late Pleistocene, Limn...
Preprint
Full-text available
Changing redox conditions in lakes are captured in their sediments, and are often influenced by climate. Their study therefore allows tracing past climate change on (sub-) annual to longer time-scales. In Lago Fagnano (54°S Argentina/Chile), an oligotrophic and deep-ventilated soft-water lake, cyclic alternations of light grey clay and dark green t...
Article
Full-text available
The endorheic nature of Lake Trasimeno in combination with its position in central Italy makes it a relevant site to better constrain spatial differences in Holocene climatic variability in the Mediterranean area. Herein, we present a high-resolution ostracod record from the Holocene section of an 8.59-m-long sedimentary core, which is compared wit...
Article
Full-text available
A hot spring at Ilia in the Greek Island of Euboea precipitates iron‐rich travertine at an ore‐grade concentration (up to 35.3 wt% Fe). This hydrothermal chemical sediment system deposits bands of iron oxihydroxides (ferrihydrite), millimetres to centimetres thick, alternating with calcium carbonate dominated layers, creating “Banded Iron Travertin...
Article
Full-text available
Unicellular algae play important roles in the biogeochemical cycles of numerous elements, particularly through the biomineralization capacity of certain species (e.g., coccolithophores greatly contributing to the organic carbon pump of the oceans), and unidentified actors of these cycles are still being discovered. This is the case of the unicellul...
Article
Full-text available
At present, Lake Chad ( ∼ 13°′N, ∼ 14°E) is a shallow freshwater lake located in the Sahel/Sahara region of central northern Africa. The lake is primarily fed by the Chari–Logone river system draining a ∼ 600000km² watershed in tropical Africa. Discharge is strongly controlled by the annual passage of the intertropical convergence zone (ITCZ) and m...
Article
Full-text available
At present, Lake Chad ( ~13°0 N, ~14° E) is a shallow freshwater lake located in the Sahel/Sahara region of central northern Africa. The lake is primarily fed by the Chari-Logone river system draining a ~600 000 km2 watershed in tropical Africa. Discharge is strongly controlled by the annual passage of the intertropical convergence zone (ITCZ) and...
Conference Paper
Full-text available
Los estromatolitos son estructuras biosedimentarias producidas principalmente por la actividad de cianobacterias. Estos organismos son fotosintetizadores, por lo que se desarrollan en las zonas de menor profundidad de los cuerpos de agua, cercanos a la línea de costa, hasta una profundidad aproximada de 5 m (Hunger, 2012). A pesar de las contribuci...
Article
South American paleoreconstructions are of global interest because it is the only landmass extending from the tropics to the southern high latitudes and intersecting the entire southern westerly wind belt. In this context, endorheic environments, as Lake Cari-Laufquen Grande (LCLG; 41º35’S, 69º25’W) are excellent sites for paleoenvironmental studie...
Preprint
The Dead Sea Deep Drilling Project allowed to retrieve a continuous sedimentary record spanning the two last glacial cycles. This unique archive, in such an extreme environment, has allowed for the development of new proxies and the refinement of already available paleoenvironmental studies. In particular, the interaction of the lake and sediment b...