Vincent Barbin

Cathodoluminescence in geosciences

1 Cathodoluminescence in Geosciences: An Introduction.- 2 Physical Parameters for the Identification of Luminescence Centres in Minerals.- 3 Information Encoded in Cathodoluminescence Emission Spectra.- 4 Importance of Instrumental and Experimental Factors on the Interpretation of Cathodoluminescence Data from Wide Band Gap Materials.- 5 Systematic Cathodoluminescence Spectral Analysis of Synthetic Doped Minerals: Anhydrite, Apatite, Calcite, Fluorite, Scheelite and Zircon.- 6 The Status of the Standards Program of the Society for Luminescence Microscopy and Spectroscopy.- 7 Geologic Application of Cathodoluminescence of Silicates.- 8 Cathodoluminescence Microcharacterisation of Silicon Dioxide Polymorphs.- 9 Brittle Deformation in Sandstone Diagenesis as Revealed by Scanned Cathodoluminescence Imaging with Application to Characterization of Fractured Reservoirs.- 10 High-Resolution Cathodoluminescence Studies of Feldspar Minerals.- 11 Application of Cathodoluminescence to Carbonate Diagenesis.- 12 Cathodoluminescence of Carbonate Shells: Biochemical vs Diagenetic Process.- 13 Quantitative High Resolution Spectral Analysis of Mn2+ in Sedimentary Calcite.- 14 Systems of Interacting Luminescence Centers in Natural Diamonds: Laser-Induced Time-Resolved and Cathodoluminescence Spectroscopy.- 15 Use of Cathodoluminescence for U-Pb Zircon Dating by Ion Microprobe: Some Examples from the Western Alps.- 16 A Combination of Single Zircon Dating by TIMS and Cathodoluminescence Investigations on the Same Grain: The CLC-Method - U-Pb Geochronology For Metamorphic Rocks.- 17 Relevance of Cathodoluminescence for the Interpretation of U-Pb Zircon Ages, with an Example of an Application to a Study of Zircons from the Saxonian Granulite Complex, Germany.- 18 Cathodoluminescence in Applied Geosciences.- 19 Cathodoluminescence as a Tool in Gemstone Identification.

Mn2+-activated luminescence in dolomite, calcite and magnesite: quantitative determination of manganese and site distribution by EPR and CL spectroscopy

Abstract Dolomite, calcite and magnesite were studied by EPR and CL spectroscopy. Mn2+-activated luminescence in calcite and magnesite is characterized by single Gaussian peaks at 16,250 cm−1 (615 nm) and at 15,300 cm−1 (654 nm), respectively. In calcite the Mn2+ content and the normalized EPR area are linearly correlated when the Mn2+ content is Deconvolution of corrected CL spectra from dolomite shows two overlapping peaks at 17,315 cm−1 (578 nm) and 15,270 cm−1 (655 nm). In rare cases only the 15,270 cm−1 (655 nm) Gaussian peak is present. The CL peak at 17,315 cm−1 (578 nm, Ia) is due to Mn2+ in the Ca site and the peak at 15,270 cm−1 (655 nm, Ib) to Mn2+ in the Mg position. The Mn2+ content in dolomite is linearly correlated with the normalized EPR areas of the two sites. The distribution ratio (KD) of Mn2+ in the two sites of dolomite, i.e. the Ca and the Mg position, was determined by EPR and CL spectroscopy. A linear correlation exists between KD from EPR and the intensity ratio ( I b I a from CL. CL spectroscopy is thus an appropriate method to determine KD in dolomite. Evaporitic dolomites may be differentiated from non-evaporitic dolomites by their KD-values.

Cathodoluminescence of recentarticulate brachiopod shells. Implications for growth stages and diagenesis evaluation

Abstract Recent and living brachiopods representative of the main superfamilies from different environments and bathymetrieswere observed using cathodoluminescence. The internal part of their shells is often luminescent and consists of bands correlated with periods of slow growth rates such as winter, spawning seasons and environmental disturbances. The idea that all unalterated brachiopods are non-luminescent is therefore contradicted. Non-luminescent calcite of brachiopods may correspond to particular periods and/or environmental conditions during the life of the organisms. These findings and their implications must be considered in future studies of geochemical paleo-oceanic reconstructions.

Black-crust growth and interaction with underlying limestone microfacies

Abstract Black crust growth mechanisms on three French building stones are described using diagenetic models that reveal the close links between the crust–stone interfaces and the microfacies of the host limestone. Each limestone is representative of a specific sedimentary facies and displays mixed pore structure: crinoidal limestone (Euville limestone), oolitic limestone (Savonnières limestone) and bioclastic matrix-supported limestone (Courville limestone). The crinoidal limestone is mainly made of well-developed calcitic cement (spar syntaxial calcite) with low macrocroporosity (15–20 vol. %). The oolitic limestone is macroporous (30–40 vol. %), oolite nucleus being partially or completely dissolved. The third building stone studied is less porous (14 vol. %) but presents a significant microporosity. Weathering of the Euville limestone proceeds primarily through preferential exploitation of cleavages and microcracks and secondly by progressive recrystallization in the areas separated by previous gypsum fill-in (micro-box work). In the Savonnières limestone (oolitic limestone), gypsum recrystallization could occur without microcracks: elements are sometimes nearly totally weathered, while the palisadic calcitic cement surrounding the oolites was still preserved. In the matrix-supported limestone (Courville limestone), weathering could deeply affect the matrix while elements are not weathered. When a layer of microcrystalline calcite is observed on the surface of the limestone, however, the black crust growth seems to be limited to the external part of the stone. Porous characteristics of limestones directly depend on sedimentary and diagenetic phases developed. The pore network controls moisture movement and also determines the reactivity of the stone to gypsum recrystallization.

Application of cathodoluminescence microscopy to recent and past biological materials: a decade of progress

Cathodoluminescence (CL) microscopy is a powerful technique for studying biominerals. New progress on CL observation of biological materials is discussed especially the Mn2+ incorporation in shells during life and the relationship with environmental and/or diagenetic parameters. The aragonite-calcite transformation temperature during heating is reviewed, for example, in order to trace the chemical alteration of archaeological fired shells. New data are presented for Mn2+ activated luminescence in crystalline vaterite.

Similarity in Cephalopod shell biogeochemistry since carboniferous: Evidence from cathodoluminescence

Abstract Comparative cathodoluminescence study of Recent and fossil shells of Cephalopods was undertaken in order to test the continuity of shell biogeochemistry since Carboniferous times, and research phylogenetic trends. Cephalopod shells from Carboniferous (Michelinoceras sp.), Eocene (Euciphoceras regale) and Holocene (Nautilus pompilius) ages exhibit Mn2+ activated yellow and green luminescence bands representing lirae while Comatoceras sp. (Carboniferous) and Nautilus macromphalus (Holocene) only show a weak blue-green luminescence. Thus, since 300 Ma, the shell biogeochemistry of Cephalopoda show similar patterns of Mn2+ incorporation. These observations may allow new insights on phylogenetic and paleoecological reconstructions.

Cathodoluminescence and laser-excited luminescence spectroscopy of Eu3+ and Eu2+ in synthetic CaF2: a comparative study

Abstract A comparative study of laser-excited luminescence and cathodoluminescence of CaF 2 :0.1 % EuF 3 at room temperature was performed to determine the position and relative intensity of Eu 3+ and Eu 2+ main emission lines in CaF 2 . Cathodoluminescence spectra show a major peak at 424 nm which is related to the electric dipole allowed 4f 6 5d-4f 7 transition of the Eu 2+ ion. The cathodoluminescence peaks of the Eu3+ ion are very weak and are not easily identifiable. Photoluminescence spectra recorded under different laser excitation conditions (corresponding to the 7 F 0 →a- 5 D 0 transition of the Eu 3+ ion) reveal major peaks around 590 nm due to the magnetic dipole allowed 7 F 0 → 5D 1 transition of the Eu 3+ ion in three different environments: tetragonal, dimer and cubic. We emphasize the necessity of using a tunable laser to unambiguously identify the Eu 3+ ions in the minerals.

Cathodoluminescence in Geosciences: An Introduction

A wide variety of processes induces different kinds of luminescence, which is an emission of photons mainly in the visible domain (Marfunin 1979; Machel et al. 1991): Radioluminescence is excited by X-ray photons, γ-rays, and α and β nuclear particles bombardment. Chemiluminescence is the result of chemical reactions (chemical radicals, oxidation of phosphorus, etc.). Electroluminescence is generated by application of an electric field. Triboluminescence is due to mechanical deformation (breaking of crystals bonds). Ionoluminescence is generated under energetic ion beam, for example in an ion microprobe. Bioluminescence is generated by biological processes. Thermoluminescence is light emission due to an activator in a mineral when the mineral is heated and is also referred to as thermally stimulated relaxations (McKeever 1985). Photoluminescence involves the selective energy of photons to excite electronic levels of luminescent centers. Cathodoluminescence is produced by energetic electrons.

Multi-method radiometric dating of volcano-sedimentary layers from northern Italy: Age and duration of the Priabonian stage

Abstract A comparison between conventional K Ar (biotite) ages and fission track (zircon and apatite) and U Pb (zircon) ages obtained from stratigraphically well-constrained Priabonian (Late Eocene) volcano-sedimentary deposits of northern Italy is presented. Two sections at Priabona (one level) and Possagno (two levels) were dated. The application of fission track dating appears fruitful for obtaining reasonably precise (±4 to 5% 2σ errors) ages useful for time-scale calibration. The concordancy of apatite and zircon fission track ages, and the reproducibility of results provide the time of volcanic eruption and deposition. The U Pb analysis of the zircons has not been unsuccessful, but discordancy does not permit accurate dating. Significant dates obtained from Possagno are: K Ar method, 35.0 ± 0.5 Ma (duplicate analysis on K-rich biotite from the same level); fission track dating method, 35.8 ± 1.4 Ma (weighted mean age on 2 apatite and 3 zircon separates from the same level); U Pb method, 36.7 ± 1.0 Ma (maximum age of discordant zircons from the same level). The comparison between the present results and recent multi-method and multi-laboratory results obtained from time equivalent Priabonian (Late Eocene) biotite-rich layers from the Apennines shows perfect agreement and supports the location of a Priabonian stage between about 37.5 Ma and about 33.7 (±0.5) Ma; the alternative ages preferred by the Decade of North American Geology convention should be abandoned and a large portion of this scale revised accordingly.

Diagenetic history of lower Pliocene rhodoliths of the Azores Archipelago (NE Atlantic): Application of cathodoluminescence techniques

The diagenetic history of calcareous fossils is required for their application as palaeoenvironmental indicators. In this study, cathodoluminescence-microscopy (CL microscopy) and back scatter electron image-energy dispersive X-ray spectroscopy (BSE-EDS microscopy) were applied to Pliocene rhodoliths from the Azores Archipelago (NE Atlantic) in order to gain additional insight regarding the trace element content distribution throughout the algae thalli, and to ascertain palaeoenvironmental interpretations. Two types of luminescence were obtained: (1) high and (2) low luminescence. Rhodoliths with high luminescence are related with high concentrations of Mn(2+) in seawater and low luminescence rhodoliths are related with low concentrations of Mn(2+) in seawater. When the rhodoliths were deposited at about 4.0-4.5 Ma, the shoreline configuration of Santa Maria Island was much different than today. The influence of volcanic activity due to the extrusion of lavas and associated products and/or the presence of active shallow-water hydrothermal vents, was reflected in the sea water chemistry, with penecontemporaneous palaeoshores of the island featuring a high sea water concentration of Mn(2+), which mirrored on the rhodolith Mn(2+) high concentration. By contrast, rhodoliths located about 2.8 and 2.9 km from the shore, in areas with low seawater Mn(2+) concentration, had low luminescence, reflecting the low Mn(2+) concentration in seawater. Rhodoliths chemical data and the geological history of the island proved to be congruent with the palaeogeographical reconstruction of Santa Maria Island at the time of the formation of the rhodoliths.