Daniel Birgel's research while affiliated with University of Hamburg and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (151)
Hydrocarbon seeps are ubiquitous along continental margins and can exhibit varying fluid compositions. Most seeps are dominated by methane, but different contributions of short-and long-chain hydrocarbons, as well as crude oil are common. The Campeche Knolls in the Southern Gulf of Mexico are known for extensive oil seepage, which has an inhibiting...
The Miocene-Pliocene transition (MPT) in the Mediterranean area represents one of the
unresolved geological riddles of the Neogene. The MPT coincides with the end of the Messinian salinity crisis (MSC, Hsü et al., 1977), an event that led to the deposition of massive volume of evaporite on the Mediterranean seafloor. The final stage of the MSC star...
Sterols are lipids that regulate multiple processes in eukaryotic cells, and are essential components of cellular membranes. Sterols are currently assumed to be kingdom specific, with phytosterol synthesis restricted to plants while animals are only able to synthesize cholesterol. Here, we challenge this assumption by demonstrating that the marine...
Archaeal lipids have a high biotechnological potential, caused by their high resistance to oxidative stress, extreme pH values and temperatures, as well as their ability to withstand phospholipases. Further, methanogens, a specific group of archaea, are already well-established in the field of biotechnology because of their ability to use carbon di...
Invertebrates living at methane seeps such as mussels and clams gain nutrition through symbiosis with chemosynthetic, chiefly methanotrophic and thiotrophic bacteria. Lipid biomarkers, including their compound-specific carbon stable isotope compositions, extracted from the host tissues are predestined for deciphering the various sources of diets an...
Oil seepage is widespread in the Gulf of Mexico, which also applies to the Bay of Campeche in the southern Gulf. The ascension of crude oil and oil-derived hydrocarbons poses a challenge to most seep-dwelling organisms. On the other hand, short- and long-chain hydrocarbons have been shown to be potentially degraded by a range of heterotrophic sulfa...
The mid-Cretaceous greenhouse climate was induced by volcanic outgassing and the release of biogenic or thermogenic methane into the ocean-atmosphere system. During this period, major episodes of oceanic anoxic conditions enabled the large scale deposition of marine black shales rich in organic carbon, serving as a source for methane production. St...
The microbial key players at methane seeps are methanotrophic archaea and sulfate-reducing bacteria. They form spherical aggregates and jointly mediate the sulfate-dependent anaerobic oxidation of methane (SD–AOM: CH₄ + SO₄²⁻ → HCO₃⁻ + HS⁻ + H₂O), thereby inducing the precipitation of authigenic seep carbonates. While seep carbonates constitute val...
Group I mesophilic Thaumarchaeota fix dissolved inorganic carbon (DIC), accompanied by a biosynthetic fractionation factor of ~20‰. Accordingly, the δ13C signature of their diagnostic biomarker crenarchaeol was suggested as a potential δ13CDIC proxy in marine basins if input from nonmarine Thaumarchaeota is negligible. Semi-enclosed basins are sens...
Primary gypsum deposits, which accumulated in the Mediterranean Basin during the
so-called Messinian salinity crisis (5.97–5.33 Ma), represent an excellent archive of
microbial life. We investigated the molecular fossil inventory and the corresponding compound-specific δ13C values of bottom-grown gypsum formed during the first
stage of the crisis i...
In the Maritime Alps (NW Italy - SE France), the Middle Triassic-Berriasian platform carbonates of the Provençal Domain are locally affected by an intense hydrothermal dolomitization. This dolomitization resulted from a large-scale hydrothermal circulation related to deep-rooted faults, and is indirect evidence of a significant earliest Cretaceous...
Gutless tubeworms obtain their nutrition from their bacterial endosymbiotic partners, and the metazoan hosts provide the bacteria with sulfide, carbon dioxide, and molecular oxygen taken up through the plume. At seeps, tubeworms take up sulfide using their posterior end, allowing them to fix carbon dioxide and synthesize organic molecules. Compared...
The occurrence and activity of aerobic methanotrophs are influenced by environmental conditions, including pH, temperature, salinity, methane and oxygen concentrations, and nutrient availability. Aerobic methanotrophs synthesize a variety of lipids important for cell functions. However, culture-based experiments studying the influence of environmen...
A mass occurrence of the thyasirid bivalve Thyasira montanita in a limestone bed, exposed at Punta Montañita on the northern side of the Santa Elena peninsula in southeastern Ecuador, is here identified as an ancient methane-seep deposit. The massive to nodular limestone shows carbonate phases and microfabrics typical of seep limestones, such as ba...
In the late Miocene, the Mediterranean Basin became a restricted basin because of its progressive tectonic isolation from the Global Ocean. The almost complete halt of the Atlantic-Mediterranean water exchange about 6 Ma ago triggered the deposition of the Mediterranean Salt Giant during the Messinian salinity crisis (MSC; 5.97-5.33 Ma). The enviro...
Il Miocene superiore (11,6 - 5,33 Ma) rappresenta il periodo di tempo in cui il Mediterraneo ha assunto il suo attuale carattere di bacino ristretto, a causa del quasi completo isolamento tettonico dagli Oceani. L’acme del restringimento del bacino fu raggiunta circa 6 milioni di anni fa, quando lo scambio con l’Oceano Atlantico venne fortemente ri...
The Holocene (<11.7 kyr BP) is characterized by several periods of distinct climate changes. Some of these climate variations had extensive effects on mankind and coincided with demises of extinct high civilizations. Annually-resolved climate reconstructions will certainly play an increasingly important role in public perception, when applying thes...
During Messinian time, the Mediterranean underwent hydrological modifications culminating 5.97 Ma ago with the Messinian salinity crisis (MSC). Evaporite deposition and alleged annihilation of most marine eukaryotes were taken as evidence of the establishment of basin-wide hypersalinity followed by desiccation. However, the palaeoenvironmental cond...
The environmental conditions under which the youngest Salt Giant of our Planet-the late Messinian Mediterranean Salt Giant-formed are debated to date, since most evaporites are buried beneath the modern Mediterranean seafloor and the accessible marginal successions contain scarce or no body fossils. To shed light on the environmental conditions cha...
The thickness of microbialite crusts in Holocene barrier and fringing reefs of Bora Bora was quantified in drill cores from windward and leeward settings to decipher possible spatial and temporal patterns as well as controlling environmental factors. Based on the analysis of 145 occurrences in nine rotary cores, microbialite thickness ranges from 0...
Since the discovery of the late Miocene (Messinian) Mediterranean Salt Giant more than 50 years ago, the environmental conditions that caused its formation have been debated. Such reconstruction suffers from the absence of modern analogues, the lack or scarcity of fossils (calcareous plankton and benthos, but also pollens), and the inaccessibility...
High-magnesium calcite (HMC) and aragonite are metastable minerals, which tend to convert into low-magnesium calcite (LMC) and dolomite. During this process, primary compositions are frequently altered, resulting in the loss of information regarding the formation environment and the nature of fluids from which the minerals precipitated. Petrologica...
Cold‐water coral (CWC) mounds are build‐ups comprised of coral‐dominated intervals alternating with a mixed carbonate‐siliciclastic matrix. At some locations, CWC mounds are influenced by methane seepage, but the impact of methane on CWC mounds is poorly understood. To constrain the potential impact of methane on CWC mound growth, lipid biomarker i...
The youngest and one of the largest saline deposits of Earth history formed in the Mediterranean during the
Messinian salinity crisis (MSC; 5.97–5.33 Ma, Late Miocene), when global climate was experiencing a trend of
cooling and aridification. However, recent paleoclimate reconstructions indicate strong climate gradients across
the Mediterranean Ba...
Hydrocarbon-rich brine seeps – representing extreme environments typified by halophilic and chemotrophic organisms – may provide insight into the ecology of microorganisms on an early Earth and possibly other planetary bodies. Authigenic low magnesium calcite (LMC) is common at brine seeps and represents an archive of fluid compositions, fluid orig...
![Figure 2. Total lipids [ng mg −1 dw] vs. total amino acids [µ mol L −1...](profile/Simon-Rittmann/publication/337262992/figure/fig1/AS:825316641628160@1573782229306/Total-lipids-ng-mg-1-dw-vs-total-amino-acids-mol-L-1-The-colors-are-in_Q320.jpg)
Lipids and amino acids are regarded as important biomarkers for the search for extraterrestrial life in the Solar System. Such biomarkers may be used to trace methanogenic life on other planets or moons in the Solar System, such as Saturn’s icy moon Enceladus. However, little is known about the environmental conditions shaping the synthesis of lipi...
Aerobic methanotrophic bacteria are known to synthesize a variety of cyclic terpenoids which are typified by ¹³C-depleted, methane-derived carbon. This peculiarity facilitates identification of methanotroph biomarkers in natural samples. However, the current biomarker database does not always allow biomarker patterns of marine samples to be assigne...
Thirteen fossiliferous limestone deposits from Cenozoic strata in the Talara Basin in northern Peru are identified as ancient methane-seep deposits. Planktonic foraminifera and the existing stratigraphic framework of the Talara Basin indicate an early Oligocene, or possibly late Eocene, age of these deposits. They are found in three distinct areas-...
Authigenic low-magnesium calcite (LMC)—a mineral phase that should precipitate in calcite seas rather than today’s aragonite sea—was recently discovered at the seafloor of the Gulf of Mexico (GoM) at water depths of 65 m (site SS296) and 189 m (site GC53). This study investigates the mineralogical, petrographic, and geochemical characteristics of L...
In marginal Mediterranean sub-basins, the early phase of the Messinian salinity crisis (MSC) is recorded by cyclic successions of gypsum and shales, which in deeper parts of the sub-basins make lateral transition into organic-rich shales, marls, and carbonates. The cyclic stacking pattern of the gypsum-bearing sequences is assumed to reflect period...
Sponges host a remarkable diversity of microbial symbionts, however, the benefit their microbes provide is rarely understood. Here, we describe two new sponge species from deep-sea asphalt seeps and show that they live in a nutritional symbiosis with methane-oxidizing (MOX) bacteria. Metagenomics and imaging analyses revealed unusually high amounts...
Mussels and tubeworms thriving at many methane seeps typically live in symbiosis with chemosynthetic, chiefly methanotrophic or thiotrophic bacteria. It has been shown that the activities of chemosymbiotic animals can result in large differences in the sedimentary environments of their habitats. Here, we put forward the concept that such environmen...
Microbialites are volumetrically abundant components in Last Glacial Maximum and deglacial reefs in the Australian Great Barrier Reef sampled by IODP Expedition 325 in 34 holes from 17 sites (M0030–M0058), along four transects on the shelf edge. Detailed radiometric datings show that four distinct reef phases developed between 28and 10 ka, displayi...
For the first time, a comprehensive documentation of the core and intact polar lipid composition of the hydrogenotrophic, (hyper)thermophilic, methanogenic archaea Methanocaldococcus villosus strain DSM 22612T and Methanothermococcus okinawensis strain DSM 14208T is provided. Intact polar lipids of both organisms consist almost exclusively of glyco...
During the Messinian salinity crisis (MSC; 5.97-5.33 Ma) the progressive isolation of the Mediterranean Sea from the Atlantic Ocean led to the establishment of extreme environmental conditions, including hypersalinity, dysoxia and anoxia. Generally, in marginal shallow basins the advent of the MSC is marked by the deposition of primary massive gyps...
After the latest Permian mass extinction event, microbial mats filled the ecological niche previously occupied by metazoan reefs, resulting in widespread microbialites. This study focuses on the lipid biomarker (molecular fossil) and invertebrate fossil records from Neotethyan platform margin sections to understand microbial-metazoan bioherm format...
Authigenic carbonates retrieved from sites ROV1 and ROV2 of the Haima hydrocarbon seeps of the South China Sea at approximately 1390 m water depth were studied using lipid biomarker analyses. Abundant molecular fossils of anaerobic methane oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB) with strong ¹³C-depletions (δ¹³C values as low as...
Serpentinite-hosted ecosystems are potential sites where life may first have evolved on Earth. Serpentinization reactions produce strongly reducing and highly alkaline fluids that are typified by high concentrations of molecular hydrogen (H2) and methane (CH4), which can be used as an energy source by chemosynthetic life. Low-temperature serpentini...
A late Pleistocene to Holocene submerged and encrusted speleothem exhibits a complex history including a meteoric phase and two marine phases. A combined study using petrography, mineralogy, and inorganic and organic geochemistry, as well as geochronology has shown that phototrophic and heterotrophic biological activity impacted carbonate precipita...
Glycerol monobiphytanyl glycerol diethers (GMGDs) have recently been identified as degradation products of glycerol dibiphytanyl glycerol tetraethers (GDGTs) and occur as regioisomers. The distribution patterns of GMGD regioisomers are diagnostic for the glycerol configuration of their precursor GDGTs. We systematically examined the distributions o...
Metazoan reef ecosystems suffered a substantial collapse following the latest Permian mass extinction event. This collapse is hypothesized to have been caused by increased sea surface temperatures, deoxygenation, and ocean acidification. After the mass extinction, impoverished microbial-metazoan reefs filled the ecological niche previously occupied...
The Messinian Salinity Crisis (MSC) is one of the most severe, but short-timed crises in recent Earth history. During the Messinian, the Mediterranean Sea was transformed into one of the largest salt basins on Earth, resulting in the deposition of a huge volume of evaporites. The water column conditions became progressively harsher and lethal for m...
In basins with deep to intermediate water depths, the progressive restriction of the gateway(s) connecting the Atlantic Ocean with the Mediterranean Sea during the Messinian salinity crisis (MSC) is recorded by organic-rich sediments, which are thought to represent the deep water counterpart of primary evaporites in shallow basins. The deposition o...
A sudden change from normal marine to extreme paleoenvironmental conditions occurred approximately 6 Ma ago in the Mediterranean Basin at the onset of the late Miocene Messinian salinity crisis, one of the most severe ecological crises in Earth history. Strong evaporation and tectonics led to hypersaline conditions, resulting in widespread depositi...
Interpretation of bacteriohopanepolyol (BHP) biomarkers tracing microbiological processes in modern and ancient sediments relies on understanding environmental controls of production and preservation. BHPs from methanotrophs (35-aminoBHPs) were studied in methane-amended aerobic river-sediment incubations at different temperatures. It was found tha...
The Cretaceous-Palaeogene sequence of Egypt is a part of a giant belt of organic-rich deposits in North Africa and the Middle East. The present work focuses on changes in trace element, bulk organic, and lipid biomarker inventories archived in sediments of the Duwi and Dakhla formations of the Quseir section in the Red Sea area. The studied section...
During field mapping of Ellef Ringnes Island, Canadian Arctic Archipelago, 139 isolated Early Cretaceous methane seep deposits were found from 75 field sites. Stable isotopes of the carbonates have values of δ¹³C = −47‰ to −35‰ and δ¹⁸O = −4.0‰ to +0.7‰. Isoprenoids in organics from one of the seeps are significantly depleted in ¹³C, with the most...
During the Cretaceous major episodes of oceanic anoxic conditions triggered
large scale deposition of marine black shales rich in organic carbon. Several
oceanic anoxic events (OAEs) have been documented including the Cenomanian
to Turonian OAE 2, which is among the best studied examples to date. This
study reports on a large limestone body that oc...
During field mapping of Ellef Ringnes Island, Canadian Arctic Archipelago, 139 isolated Lower Cretaceous methane seep deposits were found from 75 field sites. Stable isotopes of the carbonates have values of δ13C= -47‰ to -35‰ and δ18O= -4.0‰ to +0.7‰. Isoprenoids in organics from one of the seeps are significantly depleted in 13C, with the most ne...
Ikaite (CaCO3·6H2O) forms at near-freezing temperatures and its precipitation is favored by high alkalinity and high concentrations of dissolved phosphate. With increasing temperatures during early burial, ikaite transforms into its calcite pseudomorph referred to as glendonite. To further constrain the biogeochemical processes that impact the tran...
Ikaite (CaCO3·6H2O) forms at near-freezing temperatures and its precipitation is favored by high alkalinity and high concentrations of dissolved phosphate. With increasing temperatures during early burial, ikaite transforms into its calcite pseudomorph referred to as glendonite. To further constrain the biogeochemical processes that impact the tran...
Microbial carbonates are important components of postglacial tropical coral reef frameworks. Curious calcium carbonate protrusions in a submarine karst cave in the Belize Barrier Reef platform were initially interpreted as being largely the product of physicochemical precipitation around a meshwork of serpulid tubes. New petrographical, mineralogic...
Présentation for the congres of Earth Sciences held in Geneva next november.
Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to...
Concentrations of other BHPs in marine sediment samples.
Concentration (μg/g sediment) of other BHPs in marine sediments samples presented in this study.
(XLSX)
Identification of novel BHP compounds in methanotroph cultures.
(DOCX)
Multi-proxy biomarker measurements were applied on two sediment cores (PS51/154, PS51/159) to reconstruct sea ice cover (IP25), biological production (brassicasterol, dinosterol) and river run-off (campesterol, β-sitosterol) in the western Laptev Sea over the last ∼17 ka with unprecedented temporal resolution. The absence of IP25 from 17.2 to 15.5...
The Messinian salinity crisis (MSC), one of the largest environmental crises in Earth history, occurred in the Mediterranean Basin about 6 Ma ago. The isolation of the Mediterranean from the Atlantic Ocean caused the transformation of the Mediterranean sea into a giant salina. The establishment of harsh conditions (hypersalinity and anoxia) in the...
Glycerol dialkyl glycerol tetraethers (GDGTs) are ubiquitous microbial lipids with extensive demonstrated and potential roles as paleoenvironmental proxies. Despite the great attention they receive, comparatively little is known regarding their diagenetic fate. Putative degradation products of GDGTs, identified as hydroxyl and carboxyl derivatives,...
Multi-proxy biomarker measurements were applied on two sediment cores (PS51/154, PS51/159) to reconstruct sea ice cover (IP25), biological production (brassicasterol, dinosterol) and river run-off (campesterol, beta-sitosterol) in the western Laptev Sea over the last ~17 ka with unprecedented temporal resolution. The absence of IP25 from 17.2 to 15...
Authigenic carbonate deposits have been sampled with the remotely operated vehicle 'MARUM-QUEST 4000 m' from five methane seeps between 731 and 1823 m water depth along the convergent Makran continental margin, offshore Pakistan (northern Arabian Sea). Two seeps on the upper slope are located within the oxygen minimum zone (OMZ; ca. 100 to 1100 m w...
Carbonate concretions from two distinct settings have been studied for their petrography, carbon and oxygen stable isotope patterns, and lipid biomarker inventories. Siderite concretions are enclosed in a Paleocene-Eocene deep-marine succession with sandy to silty turbidites and marl layers from the Gosau Basin of Gams in northern Styria. Septarian...
The thick gypsum deposits formed in the Mediterranean Basin during the Messinian salinity crisis incorporate dense mazes of fila-mentous fossils, which were interpreted as algae or cyanobacteria, thus pointing to a shallow-marine subtidal or intertidal environment. The data presented here reveal that these filaments represent remains of colorless,...
