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Origin and modern microbial ecology of secondary mineral deposits in Lehman Caves, Great Basin National Park, NV, USA.
- Source :
-
Geobiology [Geobiology] 2024 May-Jun; Vol. 22 (3), pp. e12594. - Publication Year :
- 2024
-
Abstract
- Lehman Caves is an extensively decorated high desert cave that represents one of the main tourist attractions in Great Basin National Park, Nevada. Although traditionally considered a water table cave, recent studies identified abundant speleogenetic features consistent with a hypogenic and, potentially, sulfuric acid origin. Here, we characterized white mineral deposits in the Gypsum Annex (GA) passage to determine whether these secondary deposits represent biogenic minerals formed during sulfuric acid corrosion and explored microbial communities associated with these and other mineral deposits throughout the cave. Powder X-ray diffraction (pXRD), scanning electron microscopy with electron dispersive spectroscopy (SEM-EDS), and electron microprobe analyses (EPMA) showed that, while most white mineral deposits from the GA contain gypsum, they also contain abundant calcite, silica, and other phases. Gypsum and carbonate-associated sulfate isotopic values of these deposits are variable, with δ <superscript>34</superscript> S <subscript>V-CDT</subscript> between +9.7‰ and +26.1‰, and do not reflect depleted values typically associated with replacement gypsum formed during sulfuric acid speleogenesis. Petrographic observations show that the sulfates likely co-precipitated with carbonate and SiO <subscript>2</subscript> phases. Taken together, these data suggest that the deposits resulted from later-stage meteoric events and not during an initial episode of sulfuric acid speleogenesis. Most sedimentary and mineral deposits in Lehman Caves have very low microbial biomass, with the exception of select areas along the main tour route that have been impacted by tourist traffic. High-throughput 16S rRNA gene amplicon sequencing showed that microbial communities in GA sediments are distinct from those in other parts of the cave. The microbial communities that inhabit these oligotrophic secondary mineral deposits include OTUs related to known ammonia-oxidizing Nitrosococcales and Thaumarchaeota, as well as common soil taxa such as Acidobacteriota and Proteobacteria. This study reveals microbial and mineralogical diversity in a previously understudied cave and expands our understanding of the geomicrobiology of desert hypogene cave systems.<br /> (© 2024 John Wiley & Sons Ltd.)
- Subjects :
- Nevada
Archaea metabolism
Geologic Sediments microbiology
Geologic Sediments chemistry
Parks, Recreational
RNA, Ribosomal, 16S genetics
Sulfuric Acids
Phylogeny
Microbiota
Calcium Sulfate chemistry
Microscopy, Electron, Scanning
Caves microbiology
Minerals analysis
Bacteria classification
Bacteria metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1472-4669
- Volume :
- 22
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Geobiology
- Publication Type :
- Academic Journal
- Accession number :
- 38700397
- Full Text :
- https://doi.org/10.1111/gbi.12594