Biotic and inorganic control on travertine deposition at Bullicame 3 spring (Viterbo, Italy): A multidisciplinary approach

Arsenic uptake in bacterial calcite

“…Biogenic calcites with higher amounts of As (LCC-Mg and LCC) clearly exhibit increased c-lattice constants, which is consistent with previous observations of the elongation of the c-axis due to the substitution of either pyramidal As(III) or tetrahedral As(V) for a planar carbonate ion (Cheng et al, 1999;Román-Ross et al, 2006;Di Benedetto et al, 2011), although we point out that Winkel et al (2013) reported no changes in the crystal lattice in As-bearing calcite in travertine rocks. For relatively high As concentrations (samples LCC-Mg and LCC) such effect is significant with an increase of the c-axis length in Asbearing calcite by $0.03 Å with respect to As-free calcite.…”

“…S1), usually referred to as the ''Bullicame" thermal field . The physical and chemical properties of the water at Bullicame, as well as the mineralogical and chemical characteristics of the travertines precipitated by the thermal waters, have been described with some detail by Angelone et al (2009) and Di Benedetto et al (2011). At the spring, water had a temperature of 57°C, a pH of 6.5 and a conductivity of 2.75 mS.…”

Investigating fossil hydrothermal systems by means of fluid inclusions and stable isotopes in banded travertine: an example from Castelnuovo dell’Abate (southern Tuscany, Italy)

“…Since fluorite shows prograde solubility in the temperature/salinity range suggested by fluid inclusions (Richardson and Holland 1979), fluorite likely followed calcite deposition at Castelnuovo dell'Abate, being related to cooling of the hydrothermal fluid (Renaut et al 2013) and/or a drop in salinity, following fluid mixing. High levels of F (several mg L −1 ) are also documented in modern thermal springs of Tuscany and Latium (Minissale et al 2002;Frondini et al 2008), and travertine-depositing waters are often oversaturated in fluorite (Di Benedetto et al 2011). The elevated concentrations of F and Sr in fossil and current travertine deposits suggest deep circulation of waters inside the Tuscan rock pile (Minissale et al 2002).…”

“…Arsenic, however, is an important component in travertine deposits of Western Turkey (Dogan and Dogan 2007), Greece (Winkel et al 2013) and Italy (Dessau 1968;Di Benedetto et al 2006;Costagliola et al 2013). The association between travertine and As in southern Tuscany and northern Latium is well documented, and up to hundreds mg kg −1 of As is found in fossil travertine and calcareous tufa deposits (Costagliola et al 2010(Costagliola et al , 2013Di Benedetto et al 2011). At Castelnuovo dell'Abate, As is mainly associated with primary pyrite (and pseudomorph Fe-(hydr)oxides after pyrite), which possibly scavenged the metalloid from the hydrothermal fluids.…”

Stable C & N isotopes in 2100 Year-B.P. human bone collagen indicate rare dietary dominance of C4 plants in NE-Italy

“…A second alternative explanation is a freshwater tropic web with an anomalous enriched 13 C source of carbon (DIC) from dissolution or thermic decomposition of carbonates. This geochemical scenario is present in some areas of Italy34 in which natural water becomes enriched in CO 2 . This archaeological site was near to the Adige River that runs through Verona.…”