Cave atmosphere controls on stalagmite growth rate and palaeoclimate records - Tufas and Speleothems: Unravelling the Microbial and Physical Controls - page 283

Fig. 2. Measured P CO 2 ranges from a selection of caves with available time series measurements, across a variety
of temperatures (Ek et al. 1968; Ek 1979; Troester & White 1984; Ek & Gewelt 1985; Baker & Genty 1998; Bourges
et al. 2001; Huang et al. 2001; Sp¨ tl et al. 2005; Banner et al. 2007; Baldini et al. 2008; Mattey et al. 2008). The
approximate mean annual temperature of the cave is shown along the right hand side of the figure, but this 'y-axis' is not
to scale. The dashed line indicates current outside air mean P CO 2 of approximately 0.0038%. The grey filled circles are
P CO 2 estimates derived by using Equation 1. To estimate the ventilation factor bthe minimum P CO 2 values measured at
each site were used in Equation 2.