No abstract

The growth rate and composition of cave calcite deposits (speleothems) are often used as proxies for past environmental change. There is, however, the potential for bias in the speleothem record due to seasonal fluctuations in calcite growth and dripwater chemistry. It has been proposed that the growth rate of speleothem calcite in Texas caves varies seasonally in response to density-driven fluctuations in cave-air CO 2 , with lower growth rates in the warmer months when cave-air CO 2 is highest. We monitored CO 2 in three undeveloped caves and three tourist caves spread over 130 km in central Texas to determine whether seasonal CO 2 fluctuations are confined to tourist caves, which have been modified from their natural states, and the extent to which cave-air CO 2 is controlled by variations in cave geometry, host rocks, cave volume, and soils. Nearly 150 lateral transects into six caves over three years show that CO 2 concentrations vary seasonally in five of the caves monitored, with peak concentrations in the warmer months and lower concentrations in the cooler months. The caves occur in six stratigraphic units of lower Cretaceous marine platform carbonate rocks and vary in volume (from 100 to .100,000 m 3 ) and geometry. Seasonal CO 2 fluctuations are regional in extent and unlikely due to human activity. Seasonal fluctuations are independent of cave geometry, volume, depth, soil thickness, and the hosting stratigraphic unit. Our findings indicate that seasonal variations in calcite deposition may introduce bias in the speleothem record, and should be considered when reconstructing paleoclimate using speleothem proxies.

No abstract

Cave drips are useful for characterizing recharge and transport through soils, particularly in upland karst settings. Estimation of upland recharge is important for the Barton Springs Segment (BSS) of the Edwards Aquifer, but discrepancies between previous and recent studies indicate how little is known about it in the BSS. We outline a methodology for using cave drips to characterize upland recharge and present initial findings from a study of drips in four BSS caves.

In the ever evolving NHS change is the one consistent factor. For some change is exciting, for others it’s threatening. No community likes to ‘lose’ its hospital, but what if change could bring a better local service? Brian Cowan reflects on the development of ACADs as a complimentary alternative to the traditional hospital site: a service and buildings redesigned around the patients. Chris Levison reflects on the practical implications the change could have on chaplaincy including: multidisciplinary team-working, spiritual needs, and closer community contacts. These papers were presented at the Chaplaincy Conference at Crieff in May 2000.