Cathodoluminescent Features and Raman Spectroscopy of Miocene Hydrothermal Bio-mineralization Embedded in Cryptocrystalline Silica Varieties, Central Europe, Hungary

Müller, Axel; Polgári, Márta; Pál-Molnár, Elemér; Koós, M.; Vereš, M.; Götze, Jens; Nagy, Szilvia; Cserháti, Cs.; Németh, Tibor; Hámor-Vidó, Mária; Gucsik, A.

doi:10.1063/1.3222889

Cited by 3 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(Hungary), in the neighborhood of Gyöngyöstarján, variable cryptocrystalline silica varieties occur together with iron mineralization in fractures and cavities of an andesite host rock (Czakó and Zelenka 1981). The genesis is related to the near surface interaction of microbial activities with an inorganic hydrothermal vent system (Müller et al 2009b). The fine-grained silica matrix, consisting of cryptocrystalline quartz with traces of moganite and opal-CT, is characterized by bright yellow CL (sample CQMa, Fig.…”

Section: Sample Materialsmentioning

confidence: 98%

“…There are a few reports from hydrothermal sulfide ore deposits (e.g., Moura et al 2003;Drechsel et al 2003;Ioannou et al 2003) and hydrothermal gold deposits (e.g., Graupner et al 2000;Takahashi et al 2008;Gueye et al 2013), where the yellow luminescent quartz was mostly detected in late mineralization sequences. In addition, quartz with yellow CL occurs in agate, silicified wood and hydrothermal veins related to mineralization and alteration processes in volcanic rocks (Götze et al 1999;Götze and Rössler 2000;Möckel and Götze 2007), as well as hydrothermal biomineralization (e.g., Müller et al 2009b). Sometimes, yellow luminescent quartz is associated with quartz showing transient blue CL, which is characteristic for quartz crystallized from low-temperature aqueous solutions (compare Figs.…”

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Götze

Pan

Stevens‐Kalceff

et al. 2015

American Mineralogist

View full text Add to dashboard Cite

The origin of yellow cathodoluminescence (CL) in quartz has been investigated by a combination of CL microscopy and spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, and spatially resolved trace-element analysis by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The study shows that the appearance of a ~570 nm (2.17 eV) emission band can be attributed to high oxygen deficiency and local structural disorder in quartz. A proposed luminescence center model implies self-trapped exciton (STE) emission from localized amorphized regions in quartz. Although the high-intensity emission at 570 nm is in general consistent with high concentrations of E′ 1 defects detected by EPR spectroscopy, CL studies with different electron beam parameters and annealing experiments up to 600 °C show a temperature and irradiation dependence of the luminescence related defects excluding the role of E′ 1 centers as direct luminescence activators for the 570 nm emission. The evaluation of geochemical data shows that quartz with yellow CL occurs in low-temperature hydrothermal environment (mostly <250 °C) and is related to fast crystallization in an environment with oxygen deficiency.

show abstract

Section: Sample Materialsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 95%

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Götze

Pan

Stevens‐Kalceff

et al. 2015

American Mineralogist

View full text Add to dashboard Cite

show abstract

“…Altered rocks and sediments in oceans as well as in surface and subsurface environments are the most common and widely distributed habitats of bacteria in geological settings. Numerous studies have shown that both rock alteration and mineral formation due to microbial activities are possible, even under extreme conditions [76][77][78][79]. In particular, the common tubular alteration of The detailed morphometric analysis revealed that the typical micro-textures observed in the filamentous fabrics from the MDP are clearly distinct from similar types of non-biological aggregates such as fibrous minerals, speleothems (stalactite-type) or inorganic precipitates similar to "chemical gardens" [69][70][71].…”

Section: Biogenic Origin and Formation Mechanism Of Sffmentioning

confidence: 99%

“…Altered rocks and sediments in oceans as well as in surface and subsurface environments are the most common and widely distributed habitats of bacteria in geological settings. Numerous studies have shown that both rock alteration and mineral formation due to microbial activities are possible, even under extreme conditions [76][77][78][79]. In particular, the common tubular alteration of basaltic glass in submarine environments was attributed by several authors to microbial boring as euendoliths and interpreted as evidence of biogenicity, but this was also critically debated [80][81][82][83][84][85][86].…”

Section: Biogenic Origin and Formation Mechanism Of Sffmentioning

confidence: 99%

Biosignatures in Subsurface Filamentous Fabrics (SFF) from the Deccan Volcanic Province, India

et al. 2020

View full text Add to dashboard Cite

The morphology, chemical, and mineralogical composition of subsurface filamentous fabrics (SFF) from the Deccan Volcanic Province (DVP) were investigated to determine the origin of these spectacular aggregates. SFF occur in a wide variety of morphologies ranging from pseudo-stalactites to irregular fabrics and are classified as SFFIr (irregular) or SFFMa (matted). The SFF samples exhibit a thread-like (or filament-like) center from which mineral precipitation starts to form the final macroscopic morphologies. Detailed investigations revealed organic material (fungal chitin) in the innermost filamentous core, which may have acted as an initial nucleus for the mineralization processes. The morphometric characteristics of certain filamentous fabrics are very similar to those of microbial filaments and the fabrics formed from them but are clearly distinct from similar types of non-biological precipitates (fibrous minerals, speleothems, and “chemical gardens”). These features indicate that the filamentous cores might be products of microbial communities that were active in the basaltic cavities. The SFF cross-sections display similar concentric layers of the mineral succession and reach thicknesses of several centimeters with spectacular lengths up to 100 cm and constant diameters. The typical mineralization sequence points to temporal variation in the chemical composition of the mineralizing fluids from Fe(Mg)-rich (Fe-oxides/-hydroxides, Fe-rich sheet silicates such as celadonite and di-/tri-smectite) to Ca-dominated (Ca-rich zeolites) and finally pure SiO2 (opal-CT, chalcedony, and macro-crystalline quartz). Assuming biological activity at least during the early mineralization processes, circumneutral pH conditions and maximum temperatures of 100–120 °C were supposed. The formation of filamentous cores including Fe-bearing phyllosilicates probably occurred near the surface after cooling of the lava, where the elements necessary for mineral formation (i.e., Si, Mg, Al, Fe) were released during alteration of the volcanic host rocks by percolating fluids.

show abstract

“…Müller et al [220] found Fe-rich cryptocrystalline silica masses with agate-like structures in the southern part of the Mátra Mts. (Hungary), in the neighbourhood of the Gyöngyöstarján and Gyönggyösoroszi area (Figure 34f).…”

Section: Microstructural Peculiarities and Possible Biosignatures In Agatesmentioning

confidence: 99%

Mineralogy, Geochemistry and Genesis of Agate—A Review

2020

View full text Add to dashboard Cite

Agate—a spectacular form of SiO2 and a famous gemstone—is commonly characterized as banded chalcedony. In detail, chalcedony layers in agates can be intergrown or intercalated with macrocrystalline quartz, quartzine, opal-A, opal-CT, cristobalite and/or moganite. In addition, agates often contain considerable amounts of mineral inclusions and water as both interstitial molecular H2O and silanol groups. Most agate occurrences worldwide are related to SiO2-rich (rhyolites, rhyodacites) and SiO2-poor (andesites, basalts) volcanic rocks, but can also be formed as hydrothermal vein varieties or as silica accumulation during diagenesis in sedimentary rocks. It is assumed that the supply of silica for agate formation is often associated with late- or post-volcanic alteration of the volcanic host rocks. Evidence can be found in association with typical secondary minerals such as clay minerals, zeolites or iron oxides/hydroxides, frequent pseudomorphs (e.g., after carbonates or sulfates) as well as the chemical composition of the agates. For instance, elements of the volcanic rock matrix (Al, Ca, Fe, Na, K) are enriched, but extraordinary high contents of Ge (>90 ppm), B (>40 ppm) and U (>20 ppm) have also been detected. Calculations based on fluid inclusion and oxygen isotope studies point to a range between 20 and 230 °C for agate formation temperatures. The accumulation and condensation of silicic acid result in the formation of silica sols and proposed amorphous silica as precursors for the development of the typical agate micro-structure. The process of crystallisation often starts with spherulitic growth of chalcedony continuing into chalcedony fibers. High concentrations of lattice defects (oxygen and silicon vacancies, silanol groups) detected by cathodoluminescence (CL) and electron paramagnetic resonance (EPR) spectroscopy indicate a rapid crystallisation via an amorphous silica precursor under non-equilibrium conditions. It is assumed that the formation of the typical agate microstructure is governed by processes of self-organization. The resulting differences in crystallite size, porosity, kind of silica phase and incorporated color pigments finally cause the characteristic agate banding and colors.

show abstract

Cathodoluminescent Features and Raman Spectroscopy of Miocene Hydrothermal Bio-mineralization Embedded in Cryptocrystalline Silica Varieties, Central Europe, Hungary

Cited by 3 publications

References 5 publications

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Origin and significance of the yellow cathodoluminescence (CL) of quartz

Biosignatures in Subsurface Filamentous Fabrics (SFF) from the Deccan Volcanic Province, India

Mineralogy, Geochemistry and Genesis of Agate—A Review

Contact Info

Product

Resources

About