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on studies in Scotland, northern China and Alpine
settings for example, are typical for humid temperate
environments (Fairchild et al. 2001; Frisia et al.
2005; Tan et al. 2006; Borsato et al. 2007; Baker
et al. 2008). In these environments, there is a signifi-
cant seasonality both of external temperature, which
strongly influences cave circulation, and of infiltrat-
ing precipitation. This fluid transfer constitutes an
important aspect of what can be termed the physi-
ology of cave environments, and we examine how
this
on three years monitoring. The result was the formu-
lation of a new model for d
13
C variations in which:
(a) enhanced winter circulation leads to low PCO
2
;
(b) dripwaters develop high d
13
C values by degas-
sing isotopically light CO
2
; and (c) supersaturations
for calcite are increased. The expectation would be
that, during the winter, stalagmites should grow
faster and display higher d
13
C values. Another
parameter which might be expected to respond
to changes in air circulation is sulphate since
Busenberg & Plummer (1985) identified solution
pH as an important control on its incorporation
and dripwater pH is limited by the PCO
2
of cave
air, which varies seasonally as stated above. In a
synchrotron study of stalagmite calcite from
Ernesto cave, Frisia et al. (2005) interpreted annual-
scale variations of sulphate in this way, correspond-
ing to an example of a crystal-dominated trace
element pattern as introduced above. In this paper
we test these ideas using data of d
13
C and sulphate
variation within the annual scale.
A second mode of chemical variation within the
Obir stalagmites is also present, coinciding with the
presence of optically visible laminae. Smith et al.
(2009), in introducing a new statistical model for
testing for annual variation of trace element proper-
ties, used
14
C evidence to demonstrate that such
laminae in stalagmite Obi84 from the chamber
S¨ulenhalle were annual. They also showed that
the laminae in this and two other similar stalagmites
(Obi12 and Obi55) coincided with depletions in Sr
and enrichments in several other trace elements. In
this paper, we extend the range of determinands
and note similarities in the type of elemental enrich-
ments with annual laminae at Ernesto cave
described by Borsato et al. (2007). These authors
proposed that the enrichments, associated with the
development of non-equilibrium crystal faces,
were the result of element transport in association
with soil-derived humic substances by high rates
of water infiltration during the autumn period
when vegetation is dying back. This is a water-
dominated pattern, requiring a time-limited high
flux of water to the stalagmite top, or a higher con-
centration of trace elements in the dripwater, or
both, to explain the pattern. We look critically at
the application of this model to Obir cave, making
use of quantitative comparisons of dripwater and
speleothem chemistry.
physiology
impacts
on
the
formation
of
stalagmites.
When comparing the behaviour of the cave
systems with that of the resulting speleothems, it is
necessary to be aware of the processes that fraction-
ate isotopes and partition elements between solution
and crystal. Specifically for trace elements, Fairchild
et al. (2006a) and Fairchild & Treble (2009) con-
sidered three types of pattern. The first of these, the
temperature-controlled pattern, does not concern us
here as the cave under discussion does not display
significant temperature variation on the annual
scale. The fluid-dominated pattern refers to stalag-
mite patterns of change that directly reflect analo-
gous changes in trace element composition
(absolute abundance, flux, or ratio to calcium or
carbonate) in the fluid. The crystal-dominated
pattern refers to compositional changes dictated by
crystallographic properties. Such properties could
be functions of growth rate (and hence solution
supersaturation), or more specifically pH, and so
there can still be a link to the cave physiology.
Here, we describe and discuss the petrography
and geochemistry of stalagmites from Obir cave in
Austria (Sp¨tl et al. 2005). Obir lies beneath an
alpine forest at 1100 m altitude and the climatic
context and ecological setting are comparable to
that of the more extensively described Grotta di
Ernesto in NE Italy (Fairchild et al. 2000, 2001;
Frisia et al. 2000, 2003, 2005; Huang et al. 2001;
Borsato et al. 2007; Wynn et al. 2010; Miorandi
et al. in press) which lies 220 km to the WSW.
Both caves contain stalagmites with distinct
annual laminae as viewed in thin section.
However, whereas Ernesto consists of a simple
tube mostly 15 - 30 m below the sloping ground
surface with which it intersects, the Obir cave
system is much more extensive, including a
number of chambers, and our study site is 70 m
below the surface. The caves display similar seaso-
nal patterns of variation in PCO
2
(Frisia et al. 2000;
Sp¨tl et al. 2005) although the magnitude of air
movement required to maintain steady values (that
is by exchanging more CO
2
-rich internal air with
outside air) is much lower at Ernesto because of
its near-surface position.
Sp¨tl et al. (2005) detailed the distinctive pattern
of seasonal variation of air circulation at Obir based
Methods
Thin sections for petrography and ion microprobe
analysis for stalagmite samples Obi12, 55 and 84
were polished and c. 150 mm thick. Lamina thick-
ness measurement was carried out on a polarizing
microscope using a graticule in which the smallest
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