These scripts and the included datafiles were used to produce the figures of the following research article:
Endres, L., Jacquin, C., González-Lemos, S., Rodríguez-Rodríguez, L., Sliwinski, J., Kaushal, N., . . . Stoll, H. (2023). Climatic and cave settings influence on drip water fluorescent organic matter with implications for fluorescent laminations in stalagmites. Quaternary Research, 1-21. doi:10.1017/qua.2023.41
Note that only the code is given for figures produced in R. Code has been transferred to Rmarkdown and slightly adapted for better documentation, you can open these files and look at the code e.g. with Rstudio. Data and code are released under a CC BY 4.0 license, which requires attribution (please use the citation above) but permits unrestricted re-use, distribution and reproduction.
For drip water chemical data, please also cite:
Kost, O., González-Lemos, S., Rodríguez-Rodríguez, L., Sliwinski, J., Endres, L., Haghipour, N., Stoll, H., 2023. Relationship of seasonal variations in drip water δ 13 C DIC , δ 18 O, and trace elements with surface and physical cave conditions of La Vallina cave, NW Spain. Hydrol. Earth Syst. Sci. 27, 2227–2255. doi:10.5194/hess-27-2227-2023
Please feel free to reach out, when you spot errors in the code & need additional data/ information (endres@erdw.ethz.ch).
Authors: Laura Sibylla Endres, Céline Jacquin, Saúl González-Lemos, Laura Rodríquez-Rodríquez, Jakub Sliwinski, Nikita Kaushal, Oliver Kost and Heather Marie Stoll.
Abstract: Speleothem fluorescence can provide insights into past vegetation dynamics and stalagmite chronology. However, its origin and especially the formation of fluorescent laminations in stalagmites are poorly understood. We conducted a year-long monthly monitoring of drip water fluorescence in La Vallina cave (northern Iberian Peninsula) and compared the results to drip water chemistry and active speleothems from the same sites. Drip waters were analyzed using fluorescence spectroscopy and parallel factor analysis (PARAFAC), and the resulting five-component model indicates contributions from vegetation, microbial activity, and bedrock. Intra-site fluorescence variability is mainly influenced by changes in overlying vegetation, water reservoir time, and respiration rates. Contrary to prevailing views, we find no systematic increase in drip water fluorescence during rainy conditions across drip sites and seasonal variations in drip water fluorescence are absent at a location where present-day speleothem layers form. Our findings challenge the notion of a higher abundance of humic-like fluorescence during the rainy season as the primary cause for layer formation and suggest additional controls on drip water fluorescence, such as bedrock interaction and microbial reprocessing. We also propose that growth rate may control the dilation of the fluorescence signal in stalagmites, indicating other potential mechanisms for fluorescent layer formation.
Keywords: Banding, Speleothem, Monitoring, Karst aquifer, Climate reconstruction, Proxy development, PARAFAC, Spectrofluorometer, Absorbance, EEM