Mineralogical and stable isotope investigations of minerals from caves on Cerna Valley (Romania) (2025)

Revisiting three minerals from Cioclovina Cave (Romania)

International Journal of Speleology, 2011

Cioclovina Cave in Romania's Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) finds. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca 2 (Mg,Fe 2+ )(PO 4 ) 2 ·2H 2 O], atacamite [Cu 2 2+ Cl(OH) 3 ], and kröhnkite [Na 2 Cu 2+ (SO 4 ) 2 ·2H 2 O] 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, nearneutral 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.

The mineral assemblage of caves within Şălitrari Mountain (Cerna Valley, SW Romania): depositional environment and speleogenetic implications

Carbonates and Evaporites, 2010

Eighteen minerals belonging to eight chemical groups were identified from three caves within Ş ȃlitrari Mountain, in the upper Cerna River basin (Romania) by means of scanning electron microscopy, electron microprobe analysis, and X-ray powder diffraction. One passage in the Great Cave from Ş ȃlitrari Mountain, the largest cave investigated, exhibits abnormal relative humidity and temperature ranges, allowing for a particular depositional environment. The cave floor is covered by alluvial sediments (ranging from cobble, sand, and clay to silt-sized material), bear bones, bat guano, and rubble. These materials reacted with percolating meteoric water and hydrogen sulfide-rich hypogene hot solutions, precipitating a variety of secondary minerals. Most of these minerals are common in caves (e.g. calcite, gypsum, brushite), however, some of them (alunite, aluminite, and darapskite) require very particular environments in order to form and persist. Cave passage morphologies suggest a complex speleogenetic history that includes changes from phreatic to vadose conditions. The latter was punctuated by a sulfuric acid dissolution/precipitation phase, partly overprinted by present-day vadose processes. The cave morphology and the secondary minerals associated with the alluvial sediments in these caves are used to unravel the region's speleogenetic history.

Preliminary Data on the Mineralogy of Limestone and Skarn-Hosted Caves from B® Iþa (Bihor County, Romania)

2002

This paper presents the mineralization of five medium-size limestone-caves and eleven skarn-hosted caves from the upper part of Cri¿ul B¾ ißei River (Bihor Mountains). Apart from berlinite -AlPO 4 , the other minerals reported from the limestone caves are common carbonates, phosphates or oxyhydroxides. In turn, the skarn-hosted caves contain a diversity of minerals, including wittichenite, luzonite, natrolite, norsethite, rosasite, glaukosphaerite, aurichalcite, azurite, malachite and chalcanthite. Five of these minerals have never before been identified in a cave environment and moreover, three are new occurrences in Romania. Some of these minerals are hydrothermal in origin, whereas alteration and/or hydration of primary hydrothermal minerals formed the others. Considering the mineral assemblage, the morphology and the position of cavities within the skarn bodies, we assume these minerals formed during one of the following stages: hydrothermal, hydrothermal/vadose or vadose.

The Relationship Between Cave Minerals and H2S - Rich Thermal Waters along Cerna Valley (SW Romania)

Acta Carsologica, 2009

V dolini Cerne, na jugoza�odu Romunije, je bilo v jurski� in kredni� apnenci� oblikovano več kot 100 jam. Za jame v tej regiji so izstopajoče tri značilnosti: prisotnost veliki� količin izločene sadre, veliko guana in visoka jamska temperatura. Visoko temperaturne anomalije niso značilne za običajno jamsko okolje. V določeni� jama�, v nižji� deli� doline Cerne, ponekod temperatura doseže 40ºC. Ta situacija je posledica prisotnosti termalni� vod, ki tečejo skozi jamo ali se nabirajo v bazeni� ter vroči� par, ki se dvigajo iz globin skozi razpoke. Posledica našteti� posebnosti so izjemni pogoji v jamskem okolju, ki dovoljujejo izločanje niza redki� mineralov. Ta študija predstavlja rezultate preiskav 57 vzorcev z rentgensko difrakcijo, geokemijo, Fourierjevo-transformacijsko infrardečo spektroskopijo in elektronsko mikroskopijo z namenom, da povežemo prisotnost jamski� mineralov z verjetnimi �ipogenimi speleogenetskimi procesi. Tukaj dokumentiramo prisotnost dvaindvajseti� sekundarni� jamski� mineralov, med katerimi je prisotnost apjonita in tamarugita prvič zabeležena v okolju jame razvite v apnenci�. Minerali pripadajo trem različnim združbam: s prevladujočimi sulfati (Diana Cave), s prevladujočimi fosfati (Adam S�aft), in sulfatno-fosfatno-nitratno bogata združba (Great Sălitrari Cave). Dodatna merjenja izotopov (δ34S) izvedena na sulfatni� kapniki�, so prispevala dodatne informacije o izvoru mineralov in jam. Ključne besede: jamski minerali, termalne vode, stabilni izotopi, �ipogena speleogeneza, dolina Cerne, Romunija.

Preliminary data on the Mineralogy of Limestone and Skarn-Hosted caves from Băița (Bihor County, Romania)

2012

This paper presents the mineralization of five medium-size limestone-caves and eleven skarn-hosted caves from the upper part of Cri¿ul B¾ ißei River (Bihor Mountains). Apart from berlinite -AlPO 4 , the other minerals reported from the limestone caves are common carbonates, phosphates or oxyhydroxides. In turn, the skarn-hosted caves contain a diversity of minerals, including wittichenite, luzonite, natrolite, norsethite, rosasite, glaukosphaerite, aurichalcite, azurite, malachite and chalcanthite. Five of these minerals have never before been identified in a cave environment and moreover, three are new occurrences in Romania. Some of these minerals are hydrothermal in origin, whereas alteration and/or hydration of primary hydrothermal minerals formed the others. Considering the mineral assemblage, the morphology and the position of cavities within the skarn bodies, we assume these minerals formed during one of the following stages: hydrothermal, hydrothermal/vadose or vadose.

High-temperature and "exotic" minerals from the Cioclovina Cave, Romania: a review

Studia Universitatis Babes-Bolyai, Geologia, 2007

This paper reports on the identification of four rare minerals in the phosphate deposit in Cioclovina Cave, Romania. Berlinite, AlPO 4 and hydroxylellestadite, Ca 5 [(Si,P,S)O 4 ] 3 (OH,F,Cl) are minerals that can form only at high temperatures, and would not be expected in a sedimentary environment. In this study we review the characteristics of berlinite and hydroxylellestadite from a heated sedimentary sequence in Cioclovina Cave (Romania) and refine their structure from single-crystal X-ray data. Two other minerals, churchite-(Y), YPO 4 ⋅2H 2 O and foggite, CaAl(PO 4 )(OH) 2 ⋅H 2 O are, for the first time, described from a cave environment. The minerals were documented by means of single-crystal X-ray investigations, X-ray powder diffraction, and electron-microprobe (EMPA) analyses. In addition, laboratory synthesis of berlinite was conducted and vibrational spectroscopy data were collected for hydroxylellestadite and churchite-(Y). Based on these investigations, we suggest that locally the heavily compacted phosphate-bearing clay sediments underwent a natural heating process. It is likely that in-situ bat guano combustion is responsible for generating the high-temperature environment needed for the genesis of berlinite and hydroxylellestadite. The occurrence of churchite-(Y) and foggite is related to guano-leaches that reacted with subjacent limestone and different allogenic cave sediments.

Mineralogy of speleothems from four caves in the Purcăreț-Boiu Mare Plateau and the Baia Mare Depression (NW Romania)

Studia Universitatis Babes-Bolyai, Geologia

The Purcăreţ -Boiu Mare Plateau and the southern edge of the Baia Mare Depression, in Sălaj and Maramureş Counties, NW Romania, host over 200 caves located in limestones ranging in age from Upper Eocene to Badenian. The carbonate rocks are interposed with non-karst rocks consisting of shales, sandstones and marls. Four caves hosted by limestones of different lithologies have been investigated for secondary minerals in the composition of their speleothems. Calcite, gypsum, goethite, jarosite, brushite, hydroxylapatite and taranakite were found in the composition of crusts, crystals, aggregates and earthy masses. The mineral association was characterized by means of X-ray diffraction and scanning electron microscopy. Gypsum, goethite and jarosite resulted from sulfide oxidation, whereas the phosphate associations formed through the interaction of phosphoric acid from bat guano with the limestones and detrital sediments. In Lii Cave, hydroxylapatite was also identified in black crusts deposited on fossil rib fragments within the limestones.

Mineralogy of Cave No. 4 from Runcului Hill (Metaliferi Mts., Romania)

Theoretical and Applied Karstology, 2003

The Cave No. 4 from Runcului Hill, discovered in 2002, is the largest cave in the Trestia-Băiţa karst area, a metallogenic region located in the central part of the Metaliferi Mountains (South Eastern Apuseni Mts.), characterized by a complex geological setting. The cave connects with a 13 m long mine gallery with a collapsed entrance, which ends at a hydrothermal vein. Aside from calcite, aragonite and gypsum, an interesting range of minerals was discovered both in the cave and in the mine gallery. These minerals are sulfates (barite, serpierite), sulfides (galena, pyrite), carbonates (cerusite, smithsonite), quartz and goethite. Some silicates such as kaolinite, montmorillonite and muscovite form a consistent clay layer covering the floor and partially the walls of the cave. Some of the minerals studied are hydrothermal in origin, or resulted from the alteration of primary hydrothermal minerals. Of these, cerusite has not been previously reported from a Romanian cave, whereas for serpierite this is the first known occurrence in Romania.

Mineralogy of Iza Cave (Rodnei Mountains, N. Romania)

International Journal of …, 2011

The δ 18O record of a Holocene stalagmite from V11 Cave, NW Romania

geocities.ws

Stable isotope analyses on a Holocene stalagmite from V11 Cave yield a paleoclimate record for the last 9200 years. The stalagmite chronology is based on seven high precision U-Th ages obtained by thermal ionization mass spectrometry (TIMS).