Trace element fixation in sediments rich in organic matter from a saline lake in tropical latitude with hydrothermal inputs (Sochagota Lake, Colombia): The role of bacterial communities

Low Temperature Illitization through Illite-Dioctahedral Vermiculite Mixed Layers in a Tropical Saline Lake Rich in Hydrothermal Fluids (Sochagota Lake, Colombia)

“…Cifuentes et al [28] documented an important variation in the geochemical distribution of sediments in the Sochagota Lake. Sediments near the south entrance have high contents of some elements commonly considered as detrital (Zr, Si, Al, Ti, and Na) and show low organic-matter contents (Total Organic Carbon, TOC < 0.7 wt.%).…”

“…This volcanic building is characterized by the presence of a collapsed caldera that includes hydrothermal vents associated to deep faults discharging SO4-Na-K-rich thermal waters and Fe-rich cold waters [27]. These hydrothermal saline waters mixed with rain waters flow from N to S through the Salitre River to feed the Sochagota Lake [24,27,28]. The small map represents the regional context of the global area, i.e., situation of the Paipa province (Boyaca region) in Colombia.…”

“…The Waters and Sediments of the Lake Natural hydrothermal saline waters feed the Sochagota Lake at the south entrance from El Salitre River [27]. These hydrothermal waters are mixed at the lake with rain surface waters, causing waters to be rich in SO4 2− (around 2150 mg/L), Na + (around 1500 mg/L), and K + (around 280 mg/L) [27,28]. The waters of the lake are alkaline (pH around 9.3) and show very high electric conductivity (around 2500 µS/cm).…”

“…The waters of the lake are alkaline (pH around 9.3) and show very high electric conductivity (around 2500 µS/cm). Cifuentes et al [27,28] suggested that the mean values of δ 34 S (6.4‰) and δ 18 O (8.1‰) reveal an isotopic composition of the water analogous to other hydrothermal waters (see e.g., [29,30]). Considering these data and that evaporitic rocks are absent in the geological framework, Cifuentes et al [27] argued that hydrothermal inputs are responsible of the S-enrichment of the waters and its high salinity.…”

“…Sediments near the south entrance have high contents of some elements commonly considered as detrital (Zr, Si, Al, Ti, and Na) and show low organic-matter contents (Total Organic Carbon, TOC < 0.7 wt.%). Cifuentes et al [27,28] indicated that the deposit of this type of materials is related to the prevalence of transport conditions over the deposit of particles due to the higher hydraulic energy of the waters at this segment of the lake. The deposit of clay-rich sediments with high contents of organic matter (values of TOC around 11 wt.%) is characteristic of the deepest sections of the lake (located at the center and north parts).…”