The role of biomineralization in the origin of sepiolite and dolomite

Leguey, Santiago; León, David Ruiz De; Ruiz, A.; Cuevas, Jaime

doi:10.2475/03.2010.02

Cited by 34 publications

(24 citation statements)

References 55 publications

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“…Palygorskite and sepiolite fibers have high surface areas (150-600 m 2 /g) (Cases et al, 1991;Galan, 1996;Güngör et al, 2006), low to moderate CEC values (5-45 meq/100 g) (Birkeland, 1999), and pore volumes ranging from 0.13 to 0.34 cm 3 /g (Güngör et al, 2006). Fiber arrangement and high surface area create a microporous environment within the soil matrix (Grillet et al, 1988;VarasMuriel and Molina-Ballesteros, 2004) and also make these clays highly desirable for sorption of organic and inorganic materials (Galan, 1996;Leguey et al, 2010). Pore space diameters between palygorskite and sepiolite fibers measured in this study range from b1-10 μm, thus classifying them as micropores (Brewer, 1976) (Fig.…”

Section: Discussionmentioning

confidence: 97%

Micromorphological investigation of pedogenic barite in Mormon Mesa petrocalcic horizons, Nevada USA: Implication for genesis

2012

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Section: Discussionmentioning

confidence: 97%

Micromorphological investigation of pedogenic barite in Mormon Mesa petrocalcic horizons, Nevada USA: Implication for genesis

2012

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“…In modern lacustrine deposits, dolomite occurs in close association with micro‐organisms that facilitate its nucleation (Wright, ; Pérez et al ., ; Wright & Wacey, ; Last et al ., ). Based on a number of morphological and chemical biosignatures, different authors have suggested that micro‐organisms also played a role in the precipitation of ancient lacustrine dolomites (García del Cura et al ., ; Sanz‐Montero et al ., , ; Huerta & Armenteros, ; Leguey et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Microbial dolomite in fresh water carbonate deposits

et al. 2013

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This article reports evidence for biologically mediated precipitation of dolomite in a fresh water spring in the south‐east of Spain. Build‐ups in the spring consisted of calcite, minor dolomite, barite and gypsum crystals formed by the mineralisation of microbial biofilms and bryophytes. A detailed microscopic study, coupled with geochemical analysis of the dolomite‐precipitating biofilms, showed that dolomite crystals occurred in association with living coccoid micro‐organisms, providing strong evidence that micro‐organisms play a fundamental role in the precipitation of this mineral. Many of the calcite crystals observed were associated with extracellular polymeric substances. Moreover, microbial involvement in the precipitation of calcite was further supported by the presence of living cyanobacteria within the calcite crystals. Two different types of build‐up were found in the spring: soft spongy moss tufa and laminated crusts. Two types of crusts were identified as follows: simple pink crusts and laminated crusts, the latter forming in both sub‐aquatic and sub‐aerial environments. Sub‐aquatic accumulation of simple detached pink crust fragments occurred sporadically. Both tufa and the carbonate crusts hosted cyanobacterial‐dominated biofilms with different bacteria and diatoms and their extracellular polymeric substances. The δ13C values of calcite showed some biogenic involvement in the origin of this mineral. The δ18O values were similar in the tufa and carbonate crusts and corresponded to current climatological characteristics. The occurrence of different groups of minerals (carbonates and sulphates) in close spatial association with micro‐organisms suggests the presence of different macro‐environmental and micro‐environmental conditions that facilitate mineral precipitation within biofilms. These findings extend the known range of aerobic microbial dolomites to include springs, and show that the precipitation of both dolomite and calcite carbonates occurs while organisms are alive.

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“…The vacuolar dolomite cylinders are similar to those described as biomorphs by Leguey et al . () from the sepiolite‐rich layers (either with gypsum, chert or dolomite) of the shallow lacustrine and mudflat sediments of the Miocene Madrid Basin. Various researchers have interpreted dolomitic microspheres as the dolomitized remains of cyanobacteria (Rao et al ., ; Sanz‐Montero et al ., ; Ayllón‐Quevedo et al ., ; Lindtke et al ., ; Calça et al ., ), but it is the first time that other shapes such as the vacuolar dolomite cylinders or the tubes are described.…”

Section: Discussionmentioning

confidence: 99%

“…The δ 13 C PDB dolomite values (−8·93 to −3·96‰) (Table ) for the Deza Formation (DF) appear in the range of those dolomites which formed in lacustrine environments and under the influence of: (i) sulphate reduction (García Del Cura et al ., ; Sanz‐Montero et al ., ; Lindtke et al ., ); and (ii) biofilms and EPS (Sanz‐Montero et al ., ; Leguey et al ., ). However, Wacey et al .…”

Section: Discussionmentioning

confidence: 99%

Dolomitization, gypsum calcitization and silicification in carbonate–evaporite shallow lacustrine deposits

2017

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This paper describes and interprets the mineral and facies assemblages that occur in carbonate–evaporite shallow lacustrine deposits, considering the importance of the processes pathway (i.e. dolomitization, gypsum calcitization and silicification). The Palaeogene deposits of the Deza Formation (Almazán Basin, central‐northern Spain) are selected as a case study to determine the variety of physicochemical processes taking place in carbonate–evaporite shallow lakes and their resulting diagenetic features. Dolostones are the predominant lithology and are composed mainly of dolomite with variable amounts of secondary calcite (5 to 50%), which mainly mimic lenticular gypsum (pseudomorphs). Five morphological types of dolomite crystal were identified as follows: dolomite tubes, dolomite cylinders, rhombohedral dolomite, spheroidal and quasi‐rhombohedral dolomite, and cocoon‐shaped dolomite. The dolomite cylinders and tubes are interpreted as the dolomitized cells of a widespread microbial community. The sequence of diagenetic processes started with growth of microlenticular interstitial gypsum in a calcareous mud deposited on the playa margin mudflats, and that sometimes included microbial sediments. Immediately following growth of gypsum, dolomite replaced the original calcite (or possibly aragonite) muds, the microbial community and the gypsum. Partial or total replacement of gypsum by dolomite was related mainly to the biomineralization of endolithic microbial communities on gypsum crystals. Later calcitization took place under vadose, subaerial exposure conditions. The development of calcrete in distal alluvial settings favoured the release of silica and subsequent silicification on the playa margin mudflats. Stable isotope compositions of calcite range from −9·02 to −5·83‰ δ13CPDB and −7·10 to 1·22‰ δ18OPDB; for the dolomite, these values vary from −8·93 to −3·96‰ δ13CPDB and −5·53 to 2·4‰ δ18OPDB. Quartz from the cherts has δ18OSMOW values ranging from 27·1 to 31·1‰. Wide variation and relatively high δ18OSMOW values for dolomite indicate evaporitic and closed hydrological conditions; increased influx of meteoric waters reigned during the formation of secondary calcite spar.

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The role of biomineralization in the origin of sepiolite and dolomite

Cited by 34 publications

References 55 publications

Micromorphological investigation of pedogenic barite in Mormon Mesa petrocalcic horizons, Nevada USA: Implication for genesis

Micromorphological investigation of pedogenic barite in Mormon Mesa petrocalcic horizons, Nevada USA: Implication for genesis

Microbial dolomite in fresh water carbonate deposits

Dolomitization, gypsum calcitization and silicification in carbonate–evaporite shallow lacustrine deposits

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