Intricate tunnels in garnets from soils and river sediments in Thailand - Possible endolithic microborings.
Magnus IvarssonHenrik SkogbyBongkot PhichaikamjornwutStefan BengtsonSandra SiljeströmPrayote OunchanumApichet BoonsoongMingkhwan KruachantaFederica MaroneVeneta BelivanovaSara HolmströmPublished in: PloS one (2018)
Garnets from disparate geographical environments and origins such as oxidized soils and river sediments in Thailand host intricate systems of microsized tunnels that significantly decrease the quality and value of the garnets as gems. The origin of such tunneling has previously been attributed to abiotic processes. Here we present physical and chemical remains of endolithic microorganisms within the tunnels and discuss a probable biological origin of the tunnels. Extensive investigations with synchrotron-radiation X-ray tomographic microscopy (SRXTM) reveal morphological indications of biogenicity that further support a euendolithic interpretation. We suggest that the production of the tunnels was initiated by a combination of abiotic and biological processes, and that at later stages biological processes came to dominate. In environments such as river sediments and oxidized soils garnets are among the few remaining sources of bio-available Fe2+, thus it is likely that microbially mediated boring of the garnets has trophic reasons. Whatever the reason for garnet boring, the tunnel system represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack.
Keyphrases
- heavy metals
- risk assessment
- organic matter
- water quality
- high resolution
- human health
- climate change
- mental health
- polycyclic aromatic hydrocarbons
- radiation therapy
- single molecule
- gene expression
- optical coherence tomography
- drinking water
- radiation induced
- genome wide
- magnetic resonance
- transcription factor
- cone beam