An Investigation of Meromixis in Cave Pools, Lechuguilla Cave, New Mexico.

Abstract

Chemical characteristics of permanent stratification in cave pools (meromixis) may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically 0.9 m), and are probably the result of localized and transient atmospheric CO2(g) concentrations. At LOBG, an EC increase of 93 µS cm-1 at the 0.9-m depth suggests meromictic conditions which are ectogenic, possibly due to surface inflow of fresh water as drips or seepage into a pre-existing layer of higher salinity.

Keywords

• chemocline
• geochemistry
• meromixis
• mixing
• stratification
• United States
• Carlsbad Caverns National Park