Abstract
The ability to distinguish the features of a chemical sedimentary rock that can only be attributed to biology is a challenge relevant to both geobiology and astrobiology. This study aimed to test criteria for recognizing petrographically the biogenicity of microbially influenced fabrics and fossil microbes in complex Quaternary stalactitic carbonate rocks from Caerwys, UK. We found that the presence of carbonaceous microfossils, fabrics produced by the calcification of microbial filaments, and the asymmetrical development of tufa fabrics due to the more rapid growth of microbially influenced laminations could be recognized as biogenic features. Petrographic evidence also indicated that the development of ”speleothem-like” laminae was related to episodes of growth interrupted by intervals of non-deposition and erosion. The lack of any biogenic characteristics in these laminae is consistent with their development as a result of variation in the physico-chemical parameters that drive calcite precipitation from meteoric waters in such environmental settings.
Original language | English |
---|---|
Pages (from-to) | 883-900 |
Number of pages | 19 |
Journal | Astrobiology |
Volume | 15 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 2015 |
Keywords
- microfossil
- stromalite
- biogenicity
- carbonate
- tufa
- speleothem
Fingerprint Dive into the research topics of 'A Test of the Biogenicity Criteria Established for Microfossils and Stromatolites on Quaternary Tufa and Speleothem Materials Formed in the “Twilight Zone” at Caerwys, UK'. Together they form a unique fingerprint.
Profiles
-
Alexander Brasier
- School of Geosciences, Geology and Geophysics - Senior Lecturer
- Earth Systems and Environmental Sciences
Person: Academic