Calcium oxalates in biofilms on limestone walls of Maya buildings in Chichén Itzá, Mexico
| Autor: | W. S. González-Gómez, Patricia Quintana, S. C. De la Rosa-García, S. Gómez-Cornelio, C. García-Solis, Otto Ortega-Morales, Aránzazu Sierra-Fernández |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Cyanobacteria Biomineralization Stone heritage Algae Geochemistry Soil Science Lichen 010501 environmental sciences engineering.material 01 natural sciences 03 medical and health sciences Rock fragment Environmental Chemistry Quartz 0105 earth and related environmental sciences Earth-Surface Processes Water Science and Technology Global and Planetary Change biology Chemistry Whewellite Fungi Geology biology.organism_classification Pollution 030104 developmental biology engineering Weddellite |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Microbial biofilms frequently cause the esthetic and biological deterioration of stone monuments. Chichén Itzá, designated as a UNESCO World Heritage Site and as one of the seven new wonders of the world, is one Maya archeological site affected by biofilms. In the present study, we analyzed the biofilms at three different building complexes of Chichén Itzá: the Lower Temple of the Jaguars, the Temple of the Warriors, and Tzompantli. Samples of biofilms and detached rocks were taken from walls with abundant white-, green-, black-, and orange-colored biofilms. The morphology of rock fragments and dust was analyzed by electron and optical microscopy and was structurally characterized by X-ray diffraction. An HCl treatment (5% v/v) was subsequently applied to eliminate carbonates. The morphological analysis evidenced the presence of cyanobacteria, algae, and lichens. Some algae formed small nodules on orange- or black-colored rocks. Lichens were associated with a distinct mineral content on the inner surface of rocks versus on the outer surface. The presence of calcium oxalates such as weddellite (C2CaO4·2H2O) and whewellite (C2CaO4·H2O) and other minerals, including quartz and feldspars, was confirmed by X-ray diffraction. The lichens collected from the Lower Temple of the Jaguars and Tzompantli were therefore confirmed to disintegrate rock surfaces through biomineralization and the formation of oxalate crystals. At sites with greater solar radiation, a higher quantity of weddellite and a lower quantity of whewellite were observed. In conclusion, the establishment of microorganisms on the stone surfaces of Chichén Itzá causes esthetic damage and also leads to the biomineralization of these rock surfaces. |
| Databáze: | OpenAIRE |
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