Earth Sciences Commons^™

Bat Guano Minerals And Mineralization Processes In Chameau Cave, Eastern Morocco, Philippe Audra, Vasile Heresanu, Lionel Barriquand, Mohamed El Kadiri Boutchich, Stephane Jaillet, Edwige Pons-Branchu, Pavel Bosak, Hai Cheng, R Lawrence Edwards, Michel Renda

International Journal of Speleology

The decay of bat guano deposits in caves produces mineral accumulations, mainly phosphates and secondary sulfates. Chameau Cave, Eastern Morocco, is located in the semi-arid Bni Snassen Mountains. It is composed of semi-active and dry passages, and is featured by strong condensation-corrosion on the walls, presence of fluvial sediments, and old corroded flowstones. Due to forced and convective airflow, the cave is generally very dry, with some damp sites related to condensation. Samples collected on the surface of different passages and along two sediment profiles yielded minerals related to bat guano decay. On recent or fresh guano, precursor minerals correspond …

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele

International Journal of Speleology

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, …

Bat Urea-Derived Minerals In Arid Environment. First Identification Of Allantoin, C4H6N4O3, In Kahf Kharrat Najem Cave, United Arab Emirates, Philippe Audra, Pavel Bosák, Fernando Gázquez, Didier Cailhol, Roman Skála, Lenka Lisá, Šárka Jonášová, Amos Frumkin, Martin Knez, Tadej Slabe, Nadja Zupan Hajna, Asma Al-Farraj

International Journal of Speleology

Kahf Kharrat Najem Cave is a small cave in United Arab Emirates (UAE) that hosts a bat colony which is the source of guano deposits and peculiar centimeter-long yellowish stalactites. The mineralogy and geochemistry of these deposits were analyzed using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopic microanalysis (EDX), scanning electron microscope (SEM), and stable isotope composition (δ¹³C and δ¹⁵N). Urea CO(NH₂)₂ was found to be the main compound of these stalactites, while allantoin C₄H₆N₄O₃ was found to be an accessory urea byproduct. This paper …

Secondary Minerals From Salt Caves In The Atacama Desert (Chile): A Hyperarid And Hypersaline Environment With Potential Analogies To The Martian Subsurface, Jo De Waele, Cristina Carbone, Laura Sanna, Marco Vattano, Ermanno Galli, Francesco Sauro, Paolo Forti

International Journal of Speleology

Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in these caves are composed of halite, but also other halide, carbonate, sulphate, nitrate, phosphate, and silicate minerals have been found. Among the sixteen cave mineral species recognized, atacamite, darapskite, blödite, leonite, anhydrite, and especially antarcticite are worth mentioning. In one of the samples an …

Microstratigraphic Logging Of Calcite Fabrics In Speleothems As Tool For Palaeoclimate Studies, Silvia Frisia

International Journal of Speleology

The systematic documentation of calcite fabrics in stalagmites and flowstones provides robustness to palaeoclimate interpretation based on geochemical proxies, but it has been neglected because it is difficult to transform crystal morphologies into numerical values, and construct fabric time series. Here, general criteria that allow for coding fabrics of calcite composing stalagmites and flowstones is provided. Being based on known models of fabric development, the coding ascribes sequential numbers to each fabric, which reflect climate-related parameters, such as changes in drip rate variability, bio-mediation or diagenetic modifications. Acronyms are proposed for Columnar types, Dendritic, Micrite, Microsparite and Mosaic fabrics, whose …

Measurement Of Luminescent Banding In Speleothems: Some Techniques And Limitations, Bryan E. Crowell, William B. White

International Journal of Speleology

Speleothems, especially flowstone and cylindrical stalagmites, exhibit phosphorescence which is often banded on the scale of a few tens of micrometers. The luminescence bands are paleoclimatic records with a very high temporal resolution. A technique has been developed using a laser source and a high resolution Raman spectrometer with microscope and computer-controlled translation stage for both luminescence profiles and luminescence spectroscopy. Luminescence intensity could be measured as a function of traverse distance with a spatial resolution of 2 – 3 μm. Potential sources of error include loss of intensity due to radiation damage by the laser beam, irregularities, cracks, and …

Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback

International Journal of Speleology

A speleothem from Crovassa Azzurra, a mine cave in SW Sardinia (Italy), has been analysed for mineralogy, minor and trace elements and stable isotopes. It is composed of layers of primary calcite and aragonite, with a region of secondary calcite. The primary carbonate is strikingly rich in Zn and Pb, presumably as the result of transport in solution from overlying Pb-Zn deposits. Immediately below the transition between calcite and aragonite, concentrations of Zn, Cd and P increase. At the transition between aragonite and Pb-rich aragonite, concentrations of Pb and P increase. Stable isotopes indicate an evolution toward more humid periods …

The First Cave Occurrence Of Orpiment (As₂S₃) From The Sulfuric Acid Caves Of Aghia Paraskevi (Kassandra Peninsula, N. Greece), Georgios Lazaridis, Vasilios Melfos, Lambrini Papadopoulou

International Journal of Speleology

Orpiment, tamarugite and pickeringite occur in close association above the surface of thermal water cave pools in the active sulfuric acid caves of Aghia Paraskevi on the Kassandra peninsula, northern Greece. Gypsum also occurs as small interstitial crystals or encrustations. Orpiment is of high significance since it has not previously been reported as a cave mineral. In addition, tamarugite and pickeringite rarely occur in karst caves. Water from a borehole and a spring is of Na-Cl type and contains traces of CO₂ and H₂S. The B/Cl ratios indicate seawater participation with a possible mixing with geothermal water …

Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, Michal Filippi, Jiří Bruthans, Lukáš Palatinus, Mohammad Zare, Naser Asadi

International Journal of Speleology

This paper summaries 12 years of documentation of secondary halite deposits in the Iranian salt karst.

A variety of secondary halite deposits was distinguished and classified into several groups, on the basis of the site and mechanism of their origin. Deposits formed: i) via crystallization in/on streams and pools, ii) from dripping, splashing and aerosol water, iii) from evaporation of seepage and capillary water, and iv) other types of deposits. The following examples of halite forms were distinguished in each of the above mentioned group: i) euhedral crystals, floating rafts (raft cones), thin brine surface crusts and films; ii) straw …

Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban

International Journal of Speleology

Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) findings. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca₂(Mg,Fe²⁺)(PO₄)₂·2H₂O], atacamite [Cu₂²⁺Cl(OH)₃], and kröhnkite [Na₂Cu²⁺(SO₄)₂·2H₂O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanning electron microscope imaging. This is the first reported occurrence of kröhnkite …