The biogenic origin of needle fibre calcite | Request PDF

Needle fibre calcite (NFC) is a habitus of calcium carbonate (CaCO 3 ) frequently observed in environments affected by pedogenic processes (Durand et al., 2018) as well as in caves as a component ...

Effect of different fibers on small-strain dynamic properties …

Microbially induced calcite precipitation (MICP)–fiber combined reinforcement through the addition of fibers during the MICP process is a novel, natural, and green technique for foundation improvement, which can effectively enhance the mechanical properties of cemented soil. However, the small-strain dynamic properties of this method remain ...

An Ultrastructural Approach to Analogies between

A comparison of similar ultrastructural characteristics of fungal hyphae and NFC has been performed to highlight analogies between both features and demonstrate the probable close relationship between fungal filaments and NFC and its associated nanofibers. Needle fiber calcite (NFC) is an ubiquitous terrestrial secondary calcium carbonate mineral often associated with …

Needle-fiber calcite; a critical review and a proposed …

From a review of the recent literature and our own observations, the different morphologies of needle-fiber calcite are classified. They can be characterized as …

A new form of needle-fiber calcite produced by physical …

1. Introduction. Needle-fiber calcite, also described as acicular calcite, is a common feature in carbonate soils, calcretes and caves. Many forms, shapes and arrangements of needle-fiber calcite have been identified and two processes are responsible for their formation: physicochemical precipitation; and biomineralization (Phillips and Self, 1987, Verrecchia and …

Needle-fiber Calcite: A Critical Review and a Proposed …

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Stable carbon and oxygen isotope signatures of pedogenic needle fibre

Needle fibre calcite (NFC) is one of the most common forms of secondary calcium carbonate in soil environments. It is a calcite monocrystal in the shape of a needle with a length 4 to 10 4 times its width (Verrecchia and Verrecchia, 1994). NFC is present over a large range of latitudes and altitudes (Cailleau et al., 2009a).

Bio-mineral needle fiber calcite (NFC) in Tunisian …

Acicular calcite or needle-fibers calcite occur as secondary calcite accumulations in the most recent calcareous surface soils and paleosols. Calcareous accumulations, which prevail in arid and semi-arid climates, are characterized by their lateral and vertical sequential organization often seen as friable conglomerates, nodules, crusts, compact slabs and laminar …

Calcium Carbonate Features

Needle-fibre calcite refers to needles and fibres of low-magnesium calcite, which are a few micrometres wide and up to several hundred micrometres long. In older micromorphological literature, especially from Eastern Europe and Russia, it has often been designated as lublinite (e.g., Ulrich, 1938, Kowalinski et al., 1972, Bal, 1975a, Bal ...

Reliability of stable carbon and oxygen isotope compositions …

Stable carbon and oxygen isotope analyses were conducted on pedogenic needle fibre calcite (NFC) from seven sites in areas with roughly similar temperate climates in Western Europe, including the Swiss Jura Mountains, eastern and southern …

Development and Analysis of Sisal and Plantain Fibre …

6-8 wt.% plantain fibre (PF) and 34 wt.% calcite particles-(CP). Specifically, the composite containing 6 wt.% PF and 3 wt.% CP achieved the highest ultimate tensile strength of 63.77 MPa, optimal elongation at break, and the best thermal insulating property of 0.24 W/m·K. In contrast, the composite with 8 wt.% PF and 4 wt.% CP exhibited the

Calcite fibre formation in modern brachiopod shells

The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer …

Stable carbon and oxygen isotope signature of pedogenic needle fibre

Carbon and oxygen isotope compositions of the needle fibre calcite (NFC) from two soils observed in quarries (Villiers and Savagnier) in the Swiss Jura Mountains are used to investigate the ...

(PDF) Origin of pedogenic needle-fiber calcite revealed by

The needle fibre calcite, as well as chambers lined with calcified microexcrement, show that the microbial degradation of organic matter and precipitation of calcite is closely related in the ...

The significance of needle‐fibre calcite in a Lower …

Needle-fibre calcite occurs in association with root structures in a Lower Carboniferous calcrete crust. The origin of this form of calcite is discussed and the scattered literature from soil science, microbiology and geology is reviewed. It is concluded that while needle-fibre calcite is not diagnostic of any environment its origin is related ...

(PDF) Mollusc shell | Matthew Canti

This needle-fiber calcite is monocrystalline and prismatic, and is associated with the physical weathering of Mytilus edulis (Linnaeus) bivalve shells found in soils from anthropic shell middens located on the northern coast of the Beagle Channel (Argentina). The effects of freeze-thaw cycles can be observed in the local soils and would be ...

The biogenic origin of needle fibre calcite

Needle fibre calcite is one of the most ubiquitous habits of calcite in vadose environments (caves deposits, soil pores, etc.). Its origin, either through inorganic, indirect or …

Origin of strontium and calcium in pedogenic needle fibre …

Needle fibre calcite (NFC) is formed by fungal activity in soils. NFC morphotypes show different Ca and Sr isotope signatures. The primary simple needles form at low …

Stable carbon and oxygen isotope signatures of pedogenic needle fibre

adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86ANNX16AC86A

Origin of pedogenic needle-fiber calcite revealed by …

Needle-fiber calcite represents one of the peculiar forms of pedogenic carbonates in soils, paleosols and calcretes. Its formation is thought to be related to organic or inorganic processes mostly independent from each other: needles-fibers may be products of fungal biomineralization or physicochemical precipitation from soil solution (Verrecchia and …

Needle-fiber Calcite: A Critical Review and a Proposed …

ABSTRACT From a review of the recent literature and our own observations, the different morphologies of needle-fiber calcite are classified. They can be characterized as monocrystalline rods (with or without serrated edges) or as polycrystalline chains. The simplest monocrystalline habit of needle-fiber calcite is the individual micro-rod (M). Larger …

Calcite fibre formation in modern brachiopod shells

The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium (OME) secrete calcite material and generate the characteristic fibre morphology and composite microstructure of the shell.

‪Eric Verrecchia‬

The biogenic origin of needle fibre calcite. G Cailleau, EP Verrecchia, O Braissant, L Emmanuel. Sedimentology 56 (6), 1858-1875, 2009. 138: 2009: Translation of energy into morphology: simulation of stromatolite morphospace using a stochastic model. C …

Tracing soil carbon cycle and the origin of needle fibre calcite

Strontium (Sr) and calcium (Ca) isotopic compositions and Sr/Ca ratios have been analysed in different fractions of pedogenic needle fibre calcite (NFC) from the Swiss Jura Mountains (Villiers ...

Characterization of tensile behaviour of hybrid short glass fibre …

The tensile properties of hybrid, injection molded, short glass fibre (SGF)/calcite particle/acrylonitrile-butadiene-styrene (ABS) composites have been investigated. To gain an insight into some possible combined effect of the SGF/ABS interfacial adhesion strength and the calcite particle/ABS adhesion strength on the tensile properties of the ...

Morphology crystallography and origin of needle fiber calcite …

In several calcrete profiles from South Australia, needle-fibre calcite is concentrated in the channels and voids of nodules, hardpans, carbonate silt and platy calcrete. The morphology, spatial arrangements and crystallography of the needle-fibre calcite were determined using scanning and transmission electron microscopy. Needle-fibre calcite is composed of single …

Calcite moonmilk: crystal morphology and environment of formation …

Calcite moonmilk, which is a cave deposit formed of calcite crystals and water, is found in many caves in the Italian Alps. These modern and ancient deposits are formed of fiber calcite crystals, 50-500 nm wide and 1 to Ͼ 10 m long, and polycrystalline chains that have few crystal defects.

Calcite fibre formation in modern brachiopod shells

The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium...

Origin of pedogenic needle-fiber calcite revealed by …

Pedogenic needle-fiber calcite was studied regarding its morphology, texture and stable isotope composition from the paleosol of the Quaternary Várhegy travertine (Budapest, Hungary). The needle-fiber calcite is composed of 40–200 μm long monocrystals. Smooth rods as well as serrated-edged crystals with calcite overgrowths were identified by SEM. Needles have …

(PDF) The formation of antitaxial calcite veins with well …

The fibre width is controlled by the structure of the vein surface, which is composed of a thin rim of quartz crystals in case of the antitaxial calcite veins from Oppaminda Creek, and other examples from across the world.

Reliability of stable carbon and oxygen isotope compositions …

Reliability of stable carbon and oxygen isotope compositions of pedogenic needle fibre calcite as environmental indicators: examples from Western Europe

Needle-fiber Calcite: A Critical Review and a …

From a review of the recent literature and our own observations, the different morphologies of needle-fiber calcite are classified. They can be characterized as monocrystalline rods (with or...