Reimer, Andreas

[["dc.bibliographiccitation.firstpage","159"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Sedimentary Geology"],["dc.bibliographiccitation.lastpage","176"],["dc.bibliographiccitation.volume","126"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Thiel, Volker"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Michaelis, Walter"],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2019-11-06T10:58:31Z"],["dc.date.available","2019-11-06T10:58:31Z"],["dc.date.issued","1999"],["dc.description.abstract","Calcium carbonate precipitation and microbialite formation at highly supersaturated mixing zones of thermal spring waters and alkaline lake water have been investigated at Pyramid Lake, Nevada. Without precipitation, pure mixing should lead to a nearly 100-fold supersaturation at 40°C. Physicochemical precipitation is modified or even inhibited by the properties of biofilms, dependent on the extent of biofilm development and the current precipitation rate. Mucus substances (extracellular polymeric substances, EPS, e.g., of cyanobacteria) serve as effective Ca2+-buffers, thus preventing seed crystal nucleation even in a highly supersaturated macroenvironment. Carbonate is then preferentially precipitated in mucus-free areas such as empty diatom tests or voids. After the buffer capacity of the EPS is surpassed, precipitation is observed at the margins of mucus areas. Hydrocarbon biomarkers extracted from (1) a calcifying Phormidium-biofilm, (2) the stromatolitic carbonate below, and (3) a fossil 'tufa' of the Pleistocene pinnacles, indicate that the cyanobacterial primary producers have been subject to significant temporal changes in their species distribution. Accordingly, the species composition of cyanobacterial biofilms does not appear to be relevant for the formation of microbial carbonates in Pyramid Lake. The results demonstrate the crucial influence of mucus substances on carbonate precipitation in highly supersaturated natural environments."],["dc.identifier.doi","10.1016/S0037-0738(99)00038-X"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62576"],["dc.language.iso","en"],["dc.relation.issn","0037-0738"],["dc.title","Biofilm exopolymers control microbialite formation at thermal springs discharging into the alkaline Pyramid Lake, Nevada, USA"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","66"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Facies"],["dc.bibliographiccitation.lastpage","79"],["dc.bibliographiccitation.volume","51"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Peckmann, Jörn"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Schumann, G."],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T10:54:36Z"],["dc.date.available","2018-11-07T10:54:36Z"],["dc.date.issued","2005"],["dc.description.abstract","In the euxinic waters of the NW' Black Sea shelf, tower-like carbonate build-ups up to several metres in height grow at sites of cold methane seepage. These structures are part of an unique microbial ecosystem that shows a considerable biodiversity and a remarkable degree of organization. The accretion of the build-ups is promoted by the growth of centimetre-sized, methane-filled spheres constructed by calcifying microbial mats. Progressive mineralization of these spheres involves the early precipitation of strongly luminescent high-Mg-calcite rich in iron sulphides, and closely interfingered aragonite phases that finally create the stable (mega-) thrombolithic fabric of the towers. Within the microbial mats, microorganisms occur in distinctive spatial arrangements. Major players among the microbial consortia are the archaea groups ANME-1 and ANME-2, Crenarchaeota, and sulphate-reducing bacteria (SRB) of the Desulfosaricina/Desulfobacterium group. The intracellular precipitation of iron sulphides (greigite) by some of these bacteria, growing in close association with ANME-2, suggests iron cycling as an additional biogeochemical pathway involved in the anaerobic oxidation of methane (AOM)."],["dc.identifier.doi","10.1007/s10347-005-0059-4"],["dc.identifier.isi","000235005200010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49604"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0172-9179"],["dc.title","Methane-derived carbonate build-ups and associated microbial communities at cold seeps on the lower Crimean shelf (Black Sea)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","579"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Geology"],["dc.bibliographiccitation.lastpage","580"],["dc.bibliographiccitation.volume","30"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2018-11-07T10:27:58Z"],["dc.date.available","2018-11-07T10:27:58Z"],["dc.date.issued","2002"],["dc.identifier.doi","10.1130/0091-7613(2002)030<0579:COCFGA>2.0.CO;2"],["dc.identifier.isi","000176152100024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43327"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0091-7613"],["dc.title","Calcification of cyanobacterial filaments: Girvanella and the origin of lower Paleozoic lime mud: Comment and reply - Comment"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","59"],["dc.bibliographiccitation.lastpage","63"],["dc.contributor.author","Kempe, Stefan"],["dc.contributor.author","Kazmierczak, Jozef"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.editor","Reitner, Joachim"],["dc.contributor.editor","Neuweiler, Fritz"],["dc.contributor.editor","Gunkel, Felix"],["dc.date.accessioned","2020-05-05T14:25:22Z"],["dc.date.available","2020-05-05T14:25:22Z"],["dc.date.issued","1996"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/64843"],["dc.language.iso","en"],["dc.publisher","Geologische Institute, Georg-August-Universität"],["dc.publisher.place","Göttingen"],["dc.relation.ispartof","Göttinger Arbeiten zur Geologie und Paläontologie. Sonderband"],["dc.title","Microbialites and hydrochemistry of the crater lake of Satonda, a status report"],["dc.type","book_chapter"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1701"],["dc.bibliographiccitation.issue","5522"],["dc.bibliographiccitation.journal","Science"],["dc.bibliographiccitation.lastpage","1704"],["dc.bibliographiccitation.volume","292"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2018-11-07T09:02:39Z"],["dc.date.available","2018-11-07T09:02:39Z"],["dc.date.issued","2001"],["dc.description.abstract","Photosynthetic carbon assimilation is commonly invoked as the cause of calcium carbonate precipitation in cyanobacterial biofilms that results in the formation of calcareous stromatolites. However, biofilm calcification patterns in recent lakes and simulation of photosynthetically induced rise in calcium carbonate supersaturation demonstrate that this mechanism applies only in settings Low in dissolved inorganic carbon and high in calcium. Taking into account paleo-partial pressure curves for carbon dioxide, we show that Phanerozoic oceans sustaining calcified cyanobacteria must have had considerably higher calcium concentrations than oceans of today. In turn, the enigmatic lack of calcified cyanobacteria in stromatolite-bearing Precambrian sequences can now be explained as a result of high dissolved inorganic carbon concentrations."],["dc.identifier.doi","10.1126/science.1057204"],["dc.identifier.isi","000169031800040"],["dc.identifier.pmid","11387471"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24737"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1095-9203"],["dc.relation.issn","0036-8075"],["dc.title","Photosynthesis-induced biofilm calcification and calcium concentrations in phanerozoic oceans"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","105"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Sedimentary Research"],["dc.bibliographiccitation.lastpage","127"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Reitner, Joachim"],["dc.date.accessioned","2018-11-07T10:42:37Z"],["dc.date.available","2018-11-07T10:42:37Z"],["dc.date.issued","2003"],["dc.description.abstract","The crater lake of the small volcanic island Satonda, Indonesia, is unique for its red-algal microbial reefs thriving in marine-derived water of increased alkalinity. The lake is a potential analogue for ancient oceans sustaining microbialites under open-marine conditions. Current reef surfaces are dominated by living red algae covered by non-calcified biofilms with scattered cyanobacteria and diatoms. Minor CaCO3 precipitates are restricted to the seasonally flooded reef tops, which develop biofilms up to 500 mum thick dominated by the cyanobacteria Pleurocapsa, Calothrix, Phormidium, and Hyella. Microcrystalline aragonite patches form within the biofilm mucilage, and fibrous aragonite cements grow in exopolymer-poor spaces such as the inside of dead, lysed green algal cells, and reef framework voids. Cementation of lysed hadromerid sponge resting bodies results in the formation of \"Wetheredella-like\" structures. Hydrochemistry data and model calculations indicate that CO2 degassing after seasonal mixis can shift the carbonate equilibrium to cause CaCO3 precipitation. Increased concentrations of dissolved inorganic carbon limit the ability of autotrophic biofilm microorganisms to shift the carbonate equilibrium. Therefore, photosynthesis-induced cyanobacterial calcification does not occur. Instead, passive, diffusion-controlled EPS-mediated permineralization of biofilm mucus at contact with the considerably supersaturated open lake water takes place. In contrast to extreme soda lakes, the release of Ca2+ from aerobic degradation of extracellular polymeric substances does not support CaCO3 precipitation in Satonda because the simultaneously released CO2 is insufficiently buffered. Subfossil reef parts comprise green algal tufts encrusted by micro-stromatolites with layers of fibrous aragonite and an amorphous, unidentified Mg-Si phase. The microstromatolites probably formed when Lake Satonda evolved from seawater to Ca2+-depleted raised-alkalinity conditions because of sulfate reduction in bottom sediments and pronounced seasonality with deep mixing events and strong CO2 degassing. The latter effect caused rapid growth of fibrous aragonite, while Mg-Si layers replaced the initially Mg-calcite-impregnated biofilms. This could be explained by dissolution of siliceous diatoms and sponge spicules at high pH, followed by Mg-calcite dissolution and Mg-silica precipitation at low pH due to heterotrophic activity within the entombed biofilms."],["dc.identifier.doi","10.1306/071002730105"],["dc.identifier.isi","000180490900011"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?goescholar/2202"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/46842"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1938-3681"],["dc.relation.issn","1527-1404"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Microbialite formation in seawater of increased alkalinity, Satonda crater lake, Indonesia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","6"],["dc.bibliographiccitation.journal","Frontiers in Earth Science"],["dc.bibliographiccitation.volume","3"],["dc.contributor.author","Heim, Christine N."],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Ionescu, Danny"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","de Beer, Dirk"],["dc.contributor.author","Quéric, Nadia Valérie"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2019-07-09T11:41:14Z"],["dc.date.available","2019-07-09T11:41:14Z"],["dc.date.issued","2015"],["dc.description.abstract","Microbial iron oxyhydroxides are common deposits in natural waters, recent sediments, and mine drainage systems. Along with these minerals, trace and rare earth elements (TREE) are being accumulated within the mineralizing microbial mats. TREE patterns are widely used to characterize minerals and rocks, and to elucidate their evolution and origin. However, whether and which characteristic TREE signatures distinguish between a biological and an abiological origin of iron minerals is still not well-understood. Here we report on long-term flow reactor studies performed in the Tunnel of Äspö (Äspö Hard Rock Laboratory, Sweden). The development of microbial mats dominated by iron-oxidizing bacteria (FeOB), namely Mariprofundus sp. and Gallionella sp were investigated. The feeder fluids of the flow reactors were tapped at 183 and 290 m below sea-level from two brackish, but chemically different aquifers within the surrounding, ~1.8 Ga old, granodioritic rocks. The experiments investigated the accumulation and fractionation of TREE under controlled conditions of the subsurface continental biosphere, and enabled us to assess potential biosignatures evolving within the microbial iron oxyhydroxides. After 2 and 9 months, concentrations of Be, Y, Zn, Zr, Hf, W, Th, Pb, and U in the microbial mats were 103- to 105-fold higher than in the feeder fluids whereas the rare earth elements and Y (REE+Y) contents were 104- and 106-fold enriched. Except for a hydrothermally induced Eu anomaly, the normalized REE+Y patterns of the microbial iron oxyhydroxides were very similar to published REE+Y distributions of Archaean Banded Iron Formations (BIFs). The microbial iron oxyhydroxides from the flow reactors were compared to iron oxyhydroxides that were artificially precipitated from the same feeder fluid. Remarkably, these abiotic and inorganic iron oxyhydroxides show the same REE+Y distribution patterns. Our results indicate that the REE+Y mirror closely the water chemistry, but they do not allow to distinguish microbially mediated from inorganic iron precipitates. Likewise, all TREE studied showed an overall similar fractionation behavior in biogenic, abiotic, and inorganic iron oxyhydroxides. Exceptions are Ni and Tl, which were only accumulated in the microbial iron oxyhydroxides and may point to a potential utility of these elements as microbial biosignatures."],["dc.identifier.doi","10.3389/feart.2015.00006"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11851"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/58377"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","Frontiers Media S.A."],["dc.relation.eissn","2296-6463"],["dc.relation.issn","2296-6463"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Assessing the utility of trace and rare earth elements as biosignatures in microbial iron oxyhydroxides"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","29"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Geomicrobiology Journal"],["dc.bibliographiccitation.lastpage","65"],["dc.bibliographiccitation.volume","29"],["dc.contributor.author","Arp, Gernot"],["dc.contributor.author","Helms, Gert"],["dc.contributor.author","Karlinska, Klementyna"],["dc.contributor.author","Schumann, Gabriela"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Trichet, Jean"],["dc.date.accessioned","2018-11-07T09:15:30Z"],["dc.date.available","2018-11-07T09:15:30Z"],["dc.date.issued","2012"],["dc.description.abstract","Aragonitic microbialites, characterized by a reticulate fabric, were discovered beneath lacustrine microbial mats on the atoll of Kiritimati, Republic of Kiribati, Central Pacific. The microbial mats, with cyanobacteria as major primary producers, grow in evaporated seawater modified by calcium carbonate and gypsum precipitation and calcium influx via surface and/or groundwaters. Despite the high aragonite supersaturation and a high photosynthetic activity, only minor aragonite precipitates are observed in the top parts of the microbial mats. Instead, major aragonite precipitation takes place in lower mat parts at the transition to the anoxic zone. The prokaryotic community shows a high number of phylotypes closely related to halotolerant taxa and/or taxa with preference to oligotrophic habitats. Soil-and plant-inhabiting bacteria underline a potential surface or subsurface influx from terrestrial areas, while chitinase-producing representatives coincide with the occurrence of insect remains in the mats. Strikingly, many of the clones have their closest relatives in microorganisms either involved in methane production or consumption of methane or methyl compounds. Methanogens, represented by the methylotrophic genus Methanohalophilus, appear to be one of the dominant organisms in anaerobic mat parts. All this points to a significant role of methane and methyl components in the carbon cycle of the mats. Nonetheless, thin sections and physicochemical gradients through the mats, as well as the C-12-depleted carbon isotope signatures of carbonates indicate that spherulitic components of the microbialites initiate in the photosynthesis-dominated orange mat top layer, and further grow in the green and purple layer below. Therefore, these spherulites are considered as product of an extraordinary high photosynthesis effect simultaneous to a high inhibition by pristine exopolymers. Then, successive heterotrophic bacterial activity leads to a condensation of the exopolymer framework, and finally to the formation of crevice-like zones of partly degraded exopolymers. Here initiation of horizontal aragonite layers and vertical aragonite sheets of the microbialite occurs, which are considered as a product of high photosynthesis at decreasing degree of inhibition. Finally, at low supersaturation and almost lack of inhibition, syntaxial growth of aragonite crystals at lamellae surfaces leads to thin fibrous aragonite veneers. While sulfate reduction, methylotrophy, methanogenesis and ammonification play an important role in element cycling of the mat, there is currently no evidence for a crucial role of them in CaCO3 precipitation. Instead, photosynthesis and exopolymer degradation sufficiently explain the observed pattern and fabric of microbialite formation."],["dc.identifier.doi","10.1080/01490451.2010.521436"],["dc.identifier.isi","000301982400004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27707"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0149-0451"],["dc.title","Photosynthesis versus Exopolymer Degradation in the Formation of Microbialites on the Atoll of Kiritimati, Republic of Kiribati, Central Pacific"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","18"],["dc.bibliographiccitation.issue","1-3"],["dc.bibliographiccitation.journal","Palaeogeography Palaeoclimatology Palaeoecology"],["dc.bibliographiccitation.lastpage","30"],["dc.bibliographiccitation.volume","227"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","Peckmann, Jörn"],["dc.contributor.author","Blumenberg, Martin"],["dc.contributor.author","Michaelis, Walter"],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Thiel, Volker"],["dc.date.accessioned","2018-11-07T10:54:53Z"],["dc.date.available","2018-11-07T10:54:53Z"],["dc.date.issued","2005"],["dc.description.abstract","Gas seeps in the euxinic northwestern Black Sea provide an excellent opportunity to study anaerobic, methane-based ecosystems with minimum interference froin oxygen -dependent processes. An integrated approach using fluorescence- and electron microscopy, fluorescence in situ hybridization, lipid biomarkers, stable isotopes (delta(13)C), and petrography revealed insight into the anatomy of concretionary methane-derived carbonates currently forming within the sediment around seeps. Some of the carbonate concretions have been found to be surrounded by microbial mats. The mats harbour colonies of sulphate-reducing bacteria (DSS-group), and archaea (ANME-1), putative players in the anaerobic oxidation of methane. Isotopically-depleted lipid biomarkers indicate an uptake of methane carbon into the biomass of the mat biota, Microbial metabolism sustains the precipitation of concretionary carbonates, significantly depleted in C-13. The concretions consist of rectangularly orientated, rod- to dumbbell-shaped crystal aggregates made of fibrous high Mg-calcite. The sulphate-reducing bacteria exhibit intracellular storage inclusions, and magnetosomes with greigite (Fe3S4), indicating that iron cycling is involved in the metabolism of the microbial population. Transfer of Fe3+ into the cells is apparently mediated by abundant extracellular vesicles resembling known bacterial sideropbore vesicles (marinobactine) in size (20 to 100 nm) and structure. (c) 2005 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.palaeo.2005.04.033"],["dc.identifier.isi","000233028600003"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11247"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49667"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0031-0182"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Concretionary methane-seep carbonates and associated microbial communities in Black Sea sediments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","170"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Geobiology"],["dc.bibliographiccitation.lastpage","180"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Ionescu, Danny"],["dc.contributor.author","Spitzer, S."],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Schneider, D."],["dc.contributor.author","Daniel, Roy Thomas"],["dc.contributor.author","Reitner, Joachim"],["dc.contributor.author","de Beer, Dirk"],["dc.contributor.author","Arp, Gernot"],["dc.date.accessioned","2018-11-07T10:00:39Z"],["dc.date.available","2018-11-07T10:00:39Z"],["dc.date.issued","2015"],["dc.description.abstract","Microbialite-forming microbial mats in a hypersaline lake on the atoll of Kiritimati were investigated with respect to microgradients, bulk water chemistry, and microbial community composition. O-2, H2S, and pH microgradients show patterns as commonly observed for phototrophic mats with cyanobacteria-dominated primary production in upper layers, an intermediate purple layer with sulfide oxidation, and anaerobic bottom layers with sulfate reduction. Ca2+ profiles, however, measured in daylight showed an increase of Ca2+ with depth in the oxic zone, followed by a sharp decline and low concentrations in anaerobic mat layers. In contrast, dark measurements show a constant Ca2+ concentration throughout the entire measured depth. This is explained by an oxygen-dependent heterotrophic decomposition of Ca2+-binding exopolymers. Strikingly, the daylight maximum in Ca2+ and subsequent drop coincides with a major zone of aragonite and gypsum precipitation at the transition from the cyanobacterial layer to the purple sulfur bacterial layer. Therefore, we suggest that Ca2+ binding exopolymers function as Ca2+ shuttle by their passive downward transport through compression, triggering aragonite precipitation in the mats upon their aerobic microbial decomposition and secondary Ca2+ release. This precipitation is mediated by phototrophic sulfide oxidizers whose action additionally leads to the precipitation of part of the available Ca2+ as gypsum."],["dc.description.sponsorship","German research Foundation (DFG) [64]"],["dc.identifier.doi","10.1111/gbi.12120"],["dc.identifier.isi","000350053400006"],["dc.identifier.pmid","25515845"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37855"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1472-4669"],["dc.relation.issn","1472-4677"],["dc.title","Calcium dynamics in microbialite-forming exopolymer-rich mats on the atoll of Kiritimati, Republic of Kiribati, Central Pacific"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]