TY - JOUR
T1 - Guano-related phosphate-rich minerals in European caves
AU - Madonia, Giuliana
AU - Scopelliti, Giovanna
AU - Vattano, Marco
AU - Chroňáková, Alica
AU - Nobécourt, Jean-Claude
AU - Carbone, Cristina
AU - Bigot, Jean-Yves
AU - Sanz-Arranz, Aurelio
AU - Temovski, Marjan
AU - Cailhol, Didier
AU - D’Angeli, Ilenia M.
AU - D’Angeli, Ilenia M.
AU - De Waele, Jo
AU - Bentaleb, Ilham
AU - Bentaleb, Ilham
AU - Vanara, Nathalie
AU - Krištůfek, Václav
AU - Bentaleb, Ilham
AU - Rull, Fernando
AU - Audra, Philippe
AU - Galli, Ermanno
AU - Bigot, Jean-Yves
PY - 2019
Y1 - 2019
N2 - 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.
AB - 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.
UR - http://hdl.handle.net/10447/359184
M3 - Article
VL - 48
SP - 75
EP - 105
JO - International Journal of Speleology
JF - International Journal of Speleology
SN - 0392-6672
ER -