Diagenesis of a drapery speleothem from Castañar Cave: from dissolution to dolomitization

Martín-Pérez, Andrea; Martín‐García, Rebeca; Alonso-Zarza, Ana María

doi:10.5038/1827-806x.41.2.11

Cited by 23 publications

(11 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Villarta Formation is interpreted to have formed on rimmed and unrimmed carbonate platform-blocks with localized ooidal shoals (García Hidalgo, 1984;Calvet Alonso & Salas, 1988), episodically recording phosphogenic episodes that are commonly recorded as phosphoritic crusts and clasts (Álvaro et al, 2016b). Diagenesis (mainly related to neomorphism and replacement to dolomite and magnesite) of the lower member limestone interbeds has been geochemically described and interpreted in Alonso-Zarza & Martín-Pérez (2008), Martín-García et al (2009, 2011, Martín-Pérez et al (2012) and García-Guinea et al (2013). These carbonates were the main source for the material incorporated into the megabreccia beds described below.…”

Section: Ibor Groupmentioning

confidence: 99%

Updated stratigraphic framework and biota of the Ediacaran and Terreneuvian in the Alcudia-Toledo Mountains of the Central Iberian Zone, Spain

et al. 2019

View full text Add to dashboard Cite

Se presenta en este trabajo una revisión actualizada de la estratigrafía del Ediacárico-Terranóvico del valle de Alcudia y los montes de Toledo, Zona Centroibérica. Se subdivide el Supergrupo infrayacente ediacárico del Alcudiense Inferior-Domo Extremeño en los Grupos del Guadiana (Formaciones de La Coronada y Sta. Ma de Zújar) y de Campanario (Formaciones de Botija, Monroy y Orellana). El supergrupo contiene varios acritarcos sin utilidad bioestratigráfica, así como dubiofósiles, pero su edad se ha establecido claramente a partir de zircones detríticos. Este litosoma siliciclástico aparece recubierto mediante contacto disconforme con el Grupo mixto de Ibor (Formaciones de Castañar, Villarta y Arrocampo) o la Formación siliciclástica del Cíjara. El contenido fósil del Grupo de Ibor incluye sabellidítidos, vendoténidos, macrofitas, bioacumulaciones y arrecifes con Cloudina, Sinotubulites, Protolagena y estromatolitos y trombolitos, así como una amplia variedad de icnofósiles; la Formación del Cíjara ha librado microfósiles bacterianos como Bavlinella y Palaeogomphosphaeria, y pistas fósiles simples (Gordia, Helminthoidichnites y treptícnidos). El límite Ediacárico-Cámbrico, a partir de icnofósiles, se sitúa en la parte basal de la Formación de Arrocampo y en la parte terminal de la del Cíjara. El valle del Alcudia ofrece algunas peculiaridades, lo que se refleja por el mantenimiento de una subdivisión litoestratigráfica propia: el Grupo de Ibor se divide en las Formaciones de Tamujar, Hinojosas (caracterizada por su contenido en icnofósiles, que incluye treptícnidos, Monomorphichnus, Psammichnites y Taphrelminthopsis) y Cabezarrubias (con Bergaueria y Planolites). Otra discontinuidad mayor se reconoce a techo del Grupo de Ibor y de la Formación del Cíjara, recubiertos respectivamente por la Formación de San Lorenzo y unas capas de megabrechas muy características. Las megabrechas, interpretadas como depósitos de talud y conocidas como las capas de Fuentes, Membrillar y Navalpino, se sitúan a base de la Formación del Pusa, de composición heterolítica y de edad Terranóvico a Serie cámbrica 2. Se subdivide el Pusa en tres miembros, destacando el intermedio por el registro de yacimientos de interés económico de fosfato (Capa de Fontanarejo). La Formación del Pusa contiene el fósil de cuerpo blando Beltanelliformis así como numerosos icnofósiles (Monomorphicnus y Treptichnus; miembro inferior), espículas de esponja asociadas con trombolitos (miembro intermedio) y Scenella, trilobites, arqueociatos e icnofósiles (Dactyloidites, Psammichnites, Rusophycus y Teichichnus; miembro superior). En ausencia de megabrechas, el Grupo de Ibor aparece directamente recubierto por las Formaciones de San Lorenzo y Fuentepizarra, esta última caracterizada por su contenido en calizas fosfáticas ricas en microfósiles, como Anabarella, que caracterizan la transición Fortuniense-Piso Cámbrico 2.

show abstract

Section: Ibor Groupmentioning

confidence: 99%

Updated stratigraphic framework and biota of the Ediacaran and Terreneuvian in the Alcudia-Toledo Mountains of the Central Iberian Zone, Spain

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The effect of biogenic spar micritization is expected to decrease -or change -with depth as light becomes limiting for phototrophic organisms and the dominant microbial community will change or cease activity (Jones, 2010). Further, in caves, the process of micritisation has often been reported as 'condensation corrosion' (Martín-García et al, 2011, 2014Martín-Pérez et al, 2012). During a hiatus in crystal growth, or along small inter-and intracrystalline pores and discontinuities, acidic atmospheric water condenses on and dissolves the speleothem surface.…”

Section: Bio-erosion and Micritisationmentioning

confidence: 99%

“…Though dolomite is more rarely present in cave deposits, it has been reported as a replacement product of metastable, hydrous phases (hydromagnesite, huntite) (Sánchez-Román et al, 2011;Martín-Pérez et al, 2012, 2015a and as a product of dolomitization in relation to the alteration of CaCO 3 in contact with Mg-rich fluids (Alonso-Zarza and Martín-Pérez, 2008). Mg-enrichment of speleothem-depositing fluids occurs through dissolution of adjacent dolostone lithologies, followed by fluid evaporation and the progressive crystallization of Ca-rich minerals, leaving the residual fluid enriched in Mg. Mg-rich carbonates have been reported as forming microcrystalline to coarse, fan-shaped and spheroidal crystals that cover aragonite textures, partly replacing the precursor CaCO 3 phase ( Fig.…”

Section: Replacementmentioning

confidence: 99%

“…Mg-enrichment of speleothem-depositing fluids occurs through dissolution of adjacent dolostone lithologies, followed by fluid evaporation and the progressive crystallization of Ca-rich minerals, leaving the residual fluid enriched in Mg. Mg-rich carbonates have been reported as forming microcrystalline to coarse, fan-shaped and spheroidal crystals that cover aragonite textures, partly replacing the precursor CaCO 3 phase ( Fig. 6D; Martín-Pérez et al, 2012, 2015a.…”

Section: Replacementmentioning

confidence: 99%

See 1 more Smart Citation

What do we really know about early diagenesis of non-marine carbonates?

Boever

Brasier

Foubert

et al. 2017

Sedimentary Geology

View full text Add to dashboard Cite

Non-marine carbonate rocks including cave, spring, stream, calcrete and lacustrine-palustrine sediments, are susceptible to early diagenetic processes. These can profoundly alter the carbonate fabric and affect paleoclimatic proxies. This review integrates recent insights into diagenesis of non-marine carbonates and in particular the variety of early diagenetic processes, and presents a conceptual framework to address them. With ability to study at smaller and smaller scales, down to nanometers, one can now observe diagenesis taking place the moment initial precipitates have formed, and continuing thereafter. Diagenesis may affect whole rocks, but it typically starts in nano-and micro-environments. The potential for diagenetic alteration depends on the reactivity of the initial precipitate, commonly being metastable phases like vaterite, Ca-oxalates, hydrous Mg-carbonates and aragonite with regard to the ambient fluid. Furthermore, organic compounds commonly play a crucial role in hosting these early transformations. Processes like neomorphism (inversion and recrystallization), cementation and replacement generally result in an overall coarsening of the fabric and homogenization of the wide range of complex, primary microtextures. If early diagenetic modifications are completed in a short time span compared to the (annual to millennial) time scale of interest, then recorded paleoenvironmental signals and trends could still acceptably reflect original, depositional conditions. However, even compact, non-marine carbonate deposits may behave locally and temporarily as open systems to crystal-fluid exchange and overprinting of one or more geochemical proxies is not unexpected. Looking to the future, relatively few studies have examined the behaviour of promising geochemical records, such as clumped isotope thermometry and (non-conventional) stable isotopes, in well-constrained diagenetic settings. Ongoing and future in-vitro and in-situ experimental approaches will help to investigate and detangle sequences of intermediate, diagenetic products, processes and controls, and to quantify rates of early diagenesis, bridging a gap between nanoscale, molecular lab studies and the fossil field rock record of non-marine carbonates.

show abstract

“…Massive dolostones consist of a coarse mosaic of impure dolomite including scattered silt-sized quartz grains, ghosts of Cloudina and successive dolomitization and magnesitization phases (see Herrero et al, 2011). Within Castañar de Ibor, the upper member of the Villarta Formation hosts a hydrothermally induced giant karstic cave famous for aragonite, calcite, dolomite and magnesite speleothems (Martín-Pérez et al, 2012.…”

Section: Stop 3 Slope-related Interbeds Castañar Formationmentioning

confidence: 99%

Guía de campo pre-congreso, 17-18 de Octubre de 2019: Ediacárico, Paleozoico Inferior y panorámicas en el Geoparque de la UNESCO Villuercas-Ibores-Jara

2019

View full text Add to dashboard Cite

Several stratigraphic units characteristic of the Ediacaran-Cambrian transition between Guadalupe and Castañar de Ibor, north of the Villuercas-Ibores-Jara Geopark (Cáceres), are described and illustrated here. The outcrops of (i) the Castañar and Villarta formations (Ibor Group, terminal Ediacaran and Terreneuvian), together with their content in vendotaenids, sabelliditids and microbial reefs with Cloudina; and (ii) the San Lorenzo Formation (Terreneuvian) and its palaeoichnological content, are detailed. Finally, the palaeoichnological record of the Armorican Quartzite (Lower Ordovician), mainly of Cruziana and Daedalus, which characterize some sites of geological interest (geosites) in the Geopark, are highlighted.

show abstract

Diagenesis of a drapery speleothem from Castañar Cave: from dissolution to dolomitization

Cited by 23 publications

References 30 publications

Updated stratigraphic framework and biota of the Ediacaran and Terreneuvian in the Alcudia-Toledo Mountains of the Central Iberian Zone, Spain

Updated stratigraphic framework and biota of the Ediacaran and Terreneuvian in the Alcudia-Toledo Mountains of the Central Iberian Zone, Spain

What do we really know about early diagenesis of non-marine carbonates?

Guía de campo pre-congreso, 17-18 de Octubre de 2019: Ediacárico, Paleozoico Inferior y panorámicas en el Geoparque de la UNESCO Villuercas-Ibores-Jara

Contact Info

Product

Resources

About