Chiropterite Deposits In Moorba Cave, Jurien Bay, Western Australia, 1975, Bridge P. J. , Hodge L. C. , Marsh N. L. , Thomas A. G.

An old guano pile deposited by Macroderma gigas has been examined chemically and mineralogically. Sixteen sectional analyses of a profile are presented and discussed. The main soluble components are P2O5, CaO and SO3 (present as brushite, ardealite, gypsum and collophane) with insoluble quartz. Taranakite occurs as a minor constituent.

Sequence of secondary phosphates deposition in a karst environment: evidence from Magurici Cave (Romania), 2003, Onac Bogdan P. , Veres Daniel S. ,

M[IMG]f1.gif' ALT='a' BORDER='0'>gurici Cave hosts a diverse assemblage of minerals. The phosphatization of illite and montmorillonite clay rich sediments, located on the cave's floor, lead to the formation of taranakite and francoanellite. Mineral assemblages precipitated at the boundary between limestone bedrock and guano deposits are dominantly hydroxylapatite, brushite, ardealite, and monetite. A number of sulphate minerals (gypsum, bassanite, mirabilite, and cesanite) were precipitated along with the phosphates, strengthen the physico-chemical conditions of the depositional environment. The major parameters controlling the environments under which these mineral assemblages were deposited are: pH, relative humidity, alkali content, and Ca/P ratio. In addition, this study presents the second worldwide reported occurrence of phosphammite discovered in a cave environment. This rare mineral occurs as small transparent crystals within the guano deposit, precipitated in an early stage from the liquid fraction of guano

Vashegyite from Gaura cu Musc? Cave., 2006, Onac Bogdan P. , Zaharia Lumini?a, Kearns Joe, Veres Daniel

This study investigated the occurrence of vashegyite from a guano-rich deposit located in the Gaura cu Musc? Cave, Romania. Analytical methods used include optical microscopy, X-ray powder diffraction (XRD), scanning electron-microscopy (SEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), thermal investigations and Fourier-transform infrared (FT-IR) analyses. Vashegyite occurs as friable, chalky white, irregular nodules of up to 2.5 cm in diameter, within a 15 cm thick sequence of organic and minerogenic sediments. The chemical structural formula is: (Al10.91Fe3+ 0.06Na0.1Ca0.02Mg0.08)?=11.17[(PO4)8.78(SiO4)0.056]?=8.83(OH)6.17·43.79H2O. Electron microscope images show vashegyite crystals to be flattened on (001). The orthorhombic lattice constants of vashegyite determined by XRD are a = 10.766(2) Å, b = 15.00(4) Å, c = 22.661(1) Å, and V = 3660.62 Å3 (Z = 4). The major weight loss, reflected in 3 endothermic peaks, was observed between 40° and 200°C, corresponding to the removal of water molecules. Vashegyite FT-IR absorption bands are comparable in position and relative intensity to other Al-phosphates. Water percolating through guano becomes strongly acidic and reacts with the clay-rich sediment laid down by the underground stream to form vashegyite. In the lower part of the investigated profile, crandallite and ardealite were also found.

Revisiting three minerals from Cioclovina Cave (Romania), 2011, Onac Bogdan P. , Effenberger Herta S. , Collins Nathan C. , Kearns Joe B. , Breban Radu C.

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 in a cave environment. Atacamite represents the weathering product (in the presence of Lower-Cretaceous limestone-derived chlorine) of copper minerals washed into the cave from nearby ore bodies. Atacamite, and kröhnkite have similar sources for copper and chlorine, whereas sodium probably originates from weathered Precambrian and Permian detrital rocks. Collinsite is believed to have precipitated from bat guano in a damp, near-neutral pH environment. The results show the following sequence of precipitation: ardealite-brushite-(gypsum)-atacamite-kröhnkite. This suggests that the observed mineral paragenesis is controlled by the neutralization potential of the host-rock mineralogy and the concentrations of Ca, Cl, Cu, and Na.

Sulfate and Phosphate Speleothems at Jenolan Caves, New South Wales, Australia , 2011, Pogson Ross E. , Osborne R. Armstrong L. , Colchester David M. , Cendón Dioni I.

Sulfate and phosphate deposits at Jenolan Caves occur in a variety of forms and compositions including crusts, ‘flowers’ and fibrous masses of gypsum (selenite), and clusters of boss-like speleothems (potatoes) of ardealite (calcium sulphate, phosphate hydrate) with associated gypsum. This boss-like morphology of ardealite does not appear to have been previously described in the literature and this is the first report of ardealite in New South Wales. Gypsum var. selenite occurs in close association with pyrite-bearing palaeokarst, while the ardealite gypsum association appears to relate to deposits of mineralised bat guano. Isotope studies confirm that the two gypsum suites have separate sources of sulfur, one from the weathering of pyrite (-1.4 to +4.9 δ34S) for gypsum (selenite) and the other from alteration of bat guano (+11.4 to +12.9 δ34S) for the ardealite and gypsum crusts.

THE SCIENT IFIC RELEVANCE OF MINE, QUARRY, AND MINED CAVES OF ROMANIA: A REVIEW, 2013, Onac, Bogdan P.

Evidences show humans must have entered caves in Romania prior to 65,000 years ago. Their interest in mining activities came, however, much later, with the first documented signs pre-dating the arrival of Romans in Dacia (present-day Romania), in the 2nd century BC. Although writings about minerals in Romanian caves date back to the 18th and 19th century, the first scientific texts on minerals found in caves discovered during mining and quarrying activities only appeared after 1850s. From a mineralogical point of view, two distinct categories are recognizable: 1) caves displaying speleothems of monotonous carbonate mineralogy and 2) caves with unusual mineral paragenesis. The latter group could further be subdivided into: i) cavities located near or within nonmetalliferous or polymetallic ore fields, ii) skarn-hosted caves, and iii) caves in which H2Srich thermo-mineral waters discharge. The study of these caves resulted in the discovery of minerals, either new for science (ardealite) or to the cave environment (anhydrite, burbankite, foggite, ikaite, konyaite, etc.). However, the scientific relevance of mine, quarry, and mined caves is not restricted to mineralogy but also encompasses anthropology, archeology, Quaternary geology, biospeleology, karst science (speleothems, speleogenesis, etc.), and tourism.