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https://doi.org/10.5194/egusphere-2024-2973
https://doi.org/10.5194/egusphere-2024-2973
08 Oct 2024
 | 08 Oct 2024

Bacteria as paleoenvironmental proxies: the study of a cave Pleistocene profile

Catalina Haidău, Ionuț Cornel Mirea, Silviu Constantin, and Oana Teodora Moldovan

Abstract. Caves are well-known archives that preserve valuable information about the past, relevant for reconstructing past climates and environments. We sampled sediments from a 480 cm deep profile. 16S rRNA gene-based metabarcoding analyses were undertaken that complemented lithological logging, sedimentology, and Optically Stimulated Luminescence (OSL) dating. These analyses revealed different sedimentation conditions along the profile with various water inputs. The OSL age of the sediments places the profile between 74.7 ± 12.3 to 56 ± 8 ka (base to top). However, more recent reworking processes (during LGM – Last Glacial Maximum paleofloods) in the upper and lower passages of the cave might have occurred. Bacterial compositions changed with depth, from soil bacteria (present in the upper part of the sediment profile) to thermophilic/sulfurous bacteria (abundant in the deeper samples of the profile). Considering the thermophilic bacteria, we could only assume their origin from a surface of hot sulfurous, old thermal springs, or sapropel sediments.

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Journal article(s) based on this preprint

05 Mar 2025
Bacteria as paleoenvironmental proxies: the study of a cave Pleistocene profile
Cătălina Haidău, Ionuţ Cornel Mirea, Silviu Constantin, and Oana Teodora Moldovan
Biogeosciences, 22, 1163–1182, https://doi.org/10.5194/bg-22-1163-2025,https://doi.org/10.5194/bg-22-1163-2025, 2025
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
Caves help us understand old climates and environments. Bacterial DNA, sediment composition, and...
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