Microbial fabrics of geyserites around hot spring pools in Daggyai, Tibet, China

Abstract

The Daggyai geyserites serve as hosts for cesium deposits; however, their origin, whether by chemical deposition or biological formation, is a topic of debate. To decipher the origin of geyserites, the petrographic features of the geyserite samples were examined. The geyserites exhibited columnar laminated, planar laminated and spicular morphologies. Furthermore, they contained morphological and confocal microscopic evidence of the coccoid, bacilliform and filamentous microbes that formed them. Minor calcite and quartz crystals were found locally in the columnar laminated and spicular geyserites. Cyanobacteria tentatively assigned to the genus Calothrix dominated in the planar and columnar laminated geyserites, but were rare in the spicular geyserites. The results demonstrated that the microbes contributed to the Daggyai geyserite formation.

Cs enrichment controlled by microbial community: Evidence from sinters along a temperature gradient of the Daggyai Major Geyser, Tibet

“…In terms of microfabric components, the stromatolite‐like sinters (DDC‐1, Figure 3a) from the pool margin of the Major Geyser are similar to sample TGJ#1 found around other Daggyai geyser (Li et al, 2020, their figure 8). Both samples, deposited on the margins of pools with waters temperatures >80 °C, are characterized by filamentous mats formed of small‐diameter filaments (~1 μm; Figure 3b–g).…”

“…For the sinter fabrics associated with cyanobacteria, the columnar laminated fabrics evident in samples collected from the discharge apron (TGJ#2, Li et al, 2020) have higher Cs concentrations (10,881 ppm) than the planar laminated fabric (5,094 ppm), the stromatolite‐like fabric (DDC‐1, 3,184 ppm), and the spicular fabric (TGJ #1, 6,756 ppm), indicating that the microbial abundance may also control the Cs enrichment. The strong fluorescence emissions for the columnar laminated sinter (Figure 6b,c) probably reflect the large quantities of organic matters related to the microbial abundance.…”

“…Samples TGJ #1, #3 to #5 came from pool margin, whereas TGJ #2 came from discharge apron. The fabrics for samples TGJ #1 and TGJ #2 were studied by Li et al (2020). to 43°C at the end of the discharge channel (Table 1).…”

“…(b) Google satellite map showing location of the Daggyai major geyser situated on the west of the Changmaqu River and sampling locations in the Daggyai geothermal field. TGJ#1 and TGJ#2 represent the sites of sinter samples studied by Li et al (2020). (c) General view of the Daggyai major geyser located on a sinter terrace showing the vent pool and overflow (indicated by arrows) downslope to the river.…”

Distribution of Hydrogen-Producing Bacteria in Tibetan Hot Springs, China

“…The lithology of the reservoir host rocks in the DG area is basically granite, while the QZM area consists of marine carbonate minerals. Such lithology difference makes the hydrochemical type in the DG and QZM belong to Na-HCO 3 -Cl and Ca-Na-SO 4 -Cl, respectively ( Guo et al, 2014 , 2019 ; Liu et al, 2019 ; Li et al, 2020 ). Therefore, it is reasonable that the geological processes affect both environmental difference and the observed spatial variables causing the HPB differences in the studied Tibetan hot springs.…”