Browsing by Author "Fadel Cury, Leonardo"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Microbial and Geochemical Diversity of Laguna Timone, an Extreme Hypersaline Crater Lake in Patagonia (52° S)
    (2025) Henríquez, Carolina; Pérez-Donoso, José M.; Bruna, Nicolás; Calderón, Mauricio; Fadel Cury, Leonardo; Quezada, Paulo; Athayde, Gustavo; Oyarzún, Poldie; Bahniuk, Anelize
    Extreme environments, such as hypersaline habitats, hot springs, deep-sea hydrothermal vents, glaciers, and permafrost, provide diverse ecological niches for studying microbial evolution. However, knowledge of microbial communities in extreme environments at high southern latitudes remains limited, aside from Antarctica. Laguna Timone is a hypersaline crater lake located in a Pleistocene maar of the Pali Aike Volcanic Field, southern Patagonia; the lake was formed during basaltic eruptions in a periglacial setting. Here, we report the first integrative characterization of microbial communities from biofilms and microbial mats in this lake using high-throughput 16S rRNA and ITS gene sequencing, along with mineralogical and hydrochemical analyses of water, sediments, and carbonates. Bacterial communities were dominated by the genera Enterobacterales ASV1, Pseudomonas, Oscillatoria, Nodularia, and Belliella, with site-specific assemblages. Fungal communities included Laetinaevia, Ilyonectria, Thelebolus, Plectosphaerella, and Acrostalagmus, each showing distinct distribution patterns. These baseline data contribute to understanding microbial dynamics in hypersaline maar environments and support future investigations. This integrative approach highlights key microbe–mineral relationships and underscores the potential of Laguna Timone as a natural laboratory for exploring biosignature formation and microbial adaptation in chemically extreme environments, both on early Earth and potentially beyond.
  • Thumbnail Image
    Item
    The role of physicochemical and biochemical processes on carbonate precipitation within the Laguna Timone maar in the Pali Aike Volcanic Field, southernmost extra-Andean Patagonia
    (2022) Henríquez, Carolina; Calderón, Mauricio; Fadel Cury, Leonardo; Athayde, Gustavo; Carvajal, Sergio; Oyarzún, Poldie; Bahniuk, Anelize
    in the regional environmental register. The Laguna Timone is situated within a maar of the Pali Aike Volcanic Field, a Quaternary volcano-tectonic complex in southernmost South America and represents one of hundreds of “pools” of brines developed after explosive volcanic eruptions in a periglacial environment. The lake constitutes an endorheic hydrological system where processes leading to carbonate precipitation took place under extreme physicochemical conditions and biological influences that can be explored. Laguna Timone is recharged by groundwater and sporadic episodes of precipitation (ca. 200 mm/year) and high evaporation rates are controlled by regimes of strong wind (westerlies) and seasonal solar radiation. Carbonate precipitation was studied in microbialite fragments of tufa deposits and carbonate crust located in the edge of the lake, and the mineralogy of all samples is calcite. The clay fraction of the sediment underlying the carbonates was characterized and HRTEM analysis shows that authigenic smectites have influence on calcite crystal precipitation. The positive δ18O values (2.28 ‰) in thin crust layers are associated with evaporation processes. In contrast, the negative δ18O values (−6.52 ‰) in the microbialites show meteoric and/or groundwater influences. The δ13C (−0.43 ‰ to 2.50 ‰) values indicate physico-chemical and biochemical processes controlling the precipitation. The carbonate precipitation involves the interrelations of hydrogeological properties, climate and biological influences. Laguna Timone provides a natural laboratory for understanding mineral precipitation processes that register continuous climatic and environmental archives.

Implementado por OpenGeek Services