On the origin of fiber calcite crystals in moonmilk deposits.
In this study, we show that moonmilk subaerial speleothems in Altamira Cave (Spain) consist of a network of fiber calcite crystals and active microbial structures. In Altamira moonmilks, the study of the typology and distribution of fiber crystals, extracellular polymeric substances, and microorganisms allowed us to define the initial stages of fiber crystal formation in recent samples as well as the variations in the microstructural arrangement in more evolved stages. Thus, we have been able to show the existence of a relationship among the different types of fiber crystals and their origins. This allowed us to outline a model that illustrates the different stages of formation of the moonmilk, developed on different substrata, concluding that microbes influence physicochemical precipitation, resulting in a variety of fiber crystal morphologies and sizes.
Cañaveras
Juan Carlos
JC
Unidad Asociada CSIC-UA, Laboratorio de Petrologia Aplicada, Departamento de Ciencias de la Tierra, Universidad de Alicante, Alicante, Spain.
Cuezva
Soledad
S
Sanchez-Moral
Sergio
S
Lario
Javier
J
Laiz
Leonila
L
Gonzalez
Juan Miguel
JM
Saiz-Jimenez
Cesareo
C
D001419:Bacteria / Q000648:ultrastructure; D018407:Bacterial Physiological Phenomena; D002119:Calcium Carbonate / Q000737:chemistry*; D005844:Geology / Q000379:methods; D019110:Meteoroids; D008903:Minerals / Q000032:analysis; D013030:Spain
D008903:Minerals; D002119:Calcium Carbonate