Discovery of calcium carbonate formation induced by plateau freshwater algae

Rock communities along water area often serve as habitats for animals and plants. In the present investigation of Fuxian Lake in Yunnan Province, China, we observe for the first time an intriguing phenomenon in rock communities along the lakeshore and algae attached to their surfaces: as algal life process progresses, mineral deposition coatings resembling coral have formed on the rock surfaces. To explore the correlation between mineral deposition coatings on rock surfaces and algal vital activities in the unique plateau environment, we design genetic identification, X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), carbon-nitrogen isotope analysis, and other techniques to trace algal metabolic processes, while quantifying the physical properties of their products via point load tests. The results not only confirm that algal vital activities induce calcite-type calcium carbonate precipitation on the original rock surface but also prove potential insights for the development of new technologies in geotechnical engineering and medical fields.