STUDY OF CAVE POOLS IN CARLSBAD CAVERN, NEW MEXICO: CONTROLS ON BIOTHEM DISTRIBUTION

Biothems are cave features or speleothems that exhibit evidence of microbial life. The main objective of this undergraduate research project is to categorize geologic relationships associated with biothems in the fossil cave pools in Carlsbad Cavern near Carlsbad, New Mexico. These relationships could then be used to better understand biothems and the conditions in which they form.

Data was collected in the field through the use of standardized field notes and then cataloged in a database. The data recorded consisted of cave pool depth, surface area, estimated throughput or flow, depth of biothem occurrences, and detailed documentation of the cave pool’s setting in hand drawn field maps. The database includes 83 cave pools; 50 with biothems, 33 without biothems. Basic statistical methods were then used to determine the relevance of geological relationships, such as biothem depth, cave pool depth, cave pool flow, and cave pool surface area.

Depth is an important environmental constraint on the formation of biothems. 96% of biothems are found within the upper 50 cm of the pool and 85% are found within the upper 25 cm. The overall cave pool depth does not significantly impede or promote the occurrence of biothems. Cave pool flow and surface area do not show as strong a trend as depth, but the trends are notable. Cave pools suspected to have high flow had a higher rate of biothem occurrence than those with lower flow values. 52% of the cave pools containing biothems were assigned a high flow value. Cave pools with a surface area less that 5 square meters had a higher rate of biothem occurrence than pools with greater surface area. 56% of cave pools with biothems have a surface area less than 5 square meters. Statistical T-testing did not show these trends to be statistically significant with the current number of cave pools.