Stability of cave phosphates: Case study from Liliecilor Cave (Trasc?u Mountains, Romania)

Pušcaš, C. M.; Kristály, Ferenc; Stremtan, Ciprian; Onac, Bogdan P.; Effenberger, H.

doi:10.1127/0077-7757/2014/0254

Cited by 4 publications

(10 citation statements)

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“…The special underground environmental conditions that prevailed over the centuries, temperature, high relative humidity, CO 2 concentration, lack of outside influences, limited percolating water, permitted not only the precipitation of a variety of minerals, but also their evolution to more stable mineral species under these conditions. On the contrary, this environmental scenario would have prevented the widespread preservation of other guano-related minerals like gypsum because of their high solubility (Onac & Vereş, 2003;Onac et al, 2005;Puşcaş et al, 2014), occurring only in small quantities at Galeria d'En Pau.…”

Section: Discussionmentioning

confidence: 99%

“…Guano related morphologies and the resulting mineral assemblages have been described by many authors from caves worldwide that at present have open entrances and contain current or ancient bat guano deposits: Tarhule-Lips & Ford (1998), Onac & Veres (2003), Marincea et al (2004), Onac et al (2005Onac et al ( , 2009), Bird et al (2007), Lundberg & McFarlane (2008, Wurster et al (2010Wurster et al ( , 2015, Serra-Cobo et al (2011, Giurgiu &Tămaş (2013), Pogson et al (2014), Puşcaş et al (2014), Audra et al (2016Audra et al ( , 2017Audra et al ( , 2019, McFarlane & Lundberg (2018), Dandurand et al (2019), etc. Nevertheless, Cova des Pas de Vallgornera represents a peculiar and uncommon site, it hosted bat colonies for an uncertain period of time, leaving their imprints and guano deposits until the entrances collapsed around 2.4 My ago.…”

Section: Introductionmentioning

confidence: 99%

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Morphological and mineralogical evidence for ancient bat presence in Cova des Pas de Vallgornera (Llucmajor, Mallorca, Western Mediterranean)

Merino¹,

Fornós²,

Mulet³

et al. 2019

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Cova des Pas de Vallgornera is a unique karst cave located at the Llucmajor coastal platform that stands out not only because of its length, more than 78 km, but also for its particular morphological suite, richness and variety of speleothems and mineral infillings. Although the mineralogy of speleothems and minerals related to hypogene morphologies has been studied and described, the existence of minerals derived from guano deposits was still poorly investigated. The cave hosted bat colonies until the collapse of its natural entrances, circa 2.4 My ago, since then until its discovery in 1968, the cave remained sealed. These particular environmental conditions, kept along millennia, helped the interaction of guano-related leachates with the bedrock and clay deposits provoking dissolution and mineral precipitation. Moreover, thanks to the discovery of guano-associated cave minerals, it has also been possible to determine the presence of morphologies related to ancient guano deposits. In this paper, we report on features caused by bat's biomechanical erosion, bat claws and bat thumb marks and the influence of geobiological modifications caused by guano deposits on stalagmites and fallen boulders, haystack-shaped stalagmites, stalagmites covered in niches and crypto-corrosion features on fallen boulders. In addition, an array of guanorelated minerals is reported, being phosphates the most abundant mineral group identified, underlining the broad presence of fluorapatite from all the studied sites. Among the oxides and hydroxides, nordstrandite, gibbsite and todorokite are especially common. Finally, connections between microclimatic conditions in the cave and the location of bat roosting and breeding sites are discussed. littoral karstic cave,

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Morphological and mineralogical evidence for ancient bat presence in Cova des Pas de Vallgornera (Llucmajor, Mallorca, Western Mediterranean)

Merino¹,

Fornós²,

Mulet³

et al. 2019

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“…Since gypsum and brushite are isostructural, ardealite originating from an additional sulfate-ion exchange is frequently associated with these two minerals (Onac, 2012). This sulfate-calcium phosphate corresponds to the early stage of guano breakdown from the reaction of sulfuric and phosphoric acids with limestone (Hill & Forti, 1997;Puşcaş et al, 2014). It is stable in slightly dry conditions and in an acidic environment, at pH of 5.7 to 6.6 (Puşcaş et al, 2014), or even less than 5.5, providing sulfur is available (Marincea et al, 2004a).…”

Section: Phosphate Mineralsmentioning

confidence: 99%

“…This sulfate-calcium phosphate corresponds to the early stage of guano breakdown from the reaction of sulfuric and phosphoric acids with limestone (Hill & Forti, 1997;Puşcaş et al, 2014). It is stable in slightly dry conditions and in an acidic environment, at pH of 5.7 to 6.6 (Puşcaş et al, 2014), or even less than 5.5, providing sulfur is available (Marincea et al, 2004a). Ardealite may form during successive stages involving hydroxylapatite ⇒ brushite ⇒ ardealite ⇒ gypsum, this last mineral depositing on the surface (Onac & Vereş, 2003;Marincea et al, 2004a;Onac et al, 2005a;Pogson et al, 2011).…”

Section: Phosphate Mineralsmentioning

confidence: 99%

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Guano-related phosphate-rich minerals in European caves

Audra¹,

Waele²,

Chroňáková³

et al. 2019

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Guano is a typical deposit found in caves derived from the excretions of bats and in minor cases of birds. These organic deposits decompose and form a series of acid fluids and gases that can interact with the minerals, sediments, and rocks present in the cave. Over sixty phosphates are known and described from caves, but guano decay also often leads to the formation of nitrates and sulfates. In this study twenty-two European caves were investigated for their guano-related secondary minerals. Using various analytical techniques, seventeen phosphates, along with one sulfate (gypsum), were recognized as secondary products of guano decay. Among those minerals, some are very rare and result from the interaction of guano leachates with clays, fluvial deposits, or pyrite. Some of these minerals are even found only in the studied caves (spheniscidite, robertsite). The most common minerals belong to the apatite group. The common mineral association present in fresh decaying guano is brushiteardealite-gypsum, minerals that usually are not present in older deposits because of their higher solubility. Most minerals are in hydrated form because of the wet cave environment; however, some specific dry conditions may favor the presence of dehydrated minerals, such as berlinite, formed during guano combustion. Investigation on the acidity of guano piles shows pH values as low as 3.5 with an increase of acidity with age and depth. Finally, cave guano deposits should be better studied in the future because of their role in paleoenvironmental and paleoclimatic reconstructions and because it is important to better understand the origin of guano-related minerals, especially the phosphates and sulfates. Among all of the caves studied, Corona 'e sa Craba (Italy) and Domica-Baradla Cave (Slovakia-Hungary) are considered to be outstanding sites with respect to their phosphate mineralogy. secondary cave minerals, phosphates, minerogenesis, limestone caves, bat guano

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