Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/10277
Authors: Cangemi, M.* 
Censi, P.* 
Reimer, A.* 
D'Alessandro, W.* 
Hause-Reitner, D.* 
Madonia, P.* 
Oliveri, Y.* 
Pecoraino, G.* 
Reitner, J.* 
Title: Carbonate precipitation in the alkaline lake Specchio di Venere (Pantelleria Island, Italy) and the possible role of microbial mats
Journal: Applied geochemistry 
Series/Report no.: /67 (2016)
metadata.dc.publisher.name: Elsevier Science Limited
Issue Date: Apr-2016
DOI: 10.1016/j.apgeochem.2016.02.012
Keywords: alkaline lake
carbonate precipitation
hydrochemistry
Pantelleria
Subject Classification03. Hydrosphere::03.01. General::03.01.07. Physical and biogeochemical interactions 
Abstract: Alkaline lakes like the hydrothermally affected lake Specchio di Venere (Pantelleria Island, Central Mediterranean) are typical geological settings harbouring calcified microbial mats. The present work is focused on the discrimination between biotic and abiotic processes driving carbonate precipitation in this lake, using hydrochemical, mineralogical and isotopic data. Hydrochemical analyses demonstrate that the lake is nearly 10 fold supersaturated with regard to aragonite and seasonally reaches hydromagnesite supersaturation. Microscopic observations depict organosedimentary laminated structures consisting of microbial communities and aragonitic precipitates, which are rather disseminated in pores than directly linked to microorganisms. Oxygen isotopic data indicate that authigenic carbonate crystallisation from evaporating water is the dominant precipitation process, further suggested by the absence of textural evidence of diagenetic processes. Conversely, the observed d13C values reflect an influence of extracellular polymeric substances (EPS) on carbon fractionation during the precipitation process, due to the selective sequestration of 12C in the biomass. The above considerations suggest that at lake Specchio di Venere the carbonate precipitation is mainly of inorganic nature, but a minor role played by biologically influenced processes in microbial mats is not excluded.
Appears in Collections:Article published / in press

Files in This Item:
File Description SizeFormat Existing users please Login
Cangemi et al., 2016.pdfmain article1.65 MBAdobe PDF
Show full item record

Page view(s) 20

216
Last Week
0
Last month
0
checked on Mar 30, 2020

Download(s) 50

59
checked on Mar 30, 2020

Google ScholarTM

Check

Altmetric