CHARACTERIZATION OF CAVE SEDIMENTS FROM BEROME MOORE, PERRY COUNTY, MISSOURI

Sediments from four hydraulically distinct locations within Berome Moore Cave (Perry County, Missouri) were collected monthly, from February 2006 to June 2006. The bulk density, porosity, mass wetness, moisture content, percent saturation, and percent organic carbon of the samples were measured to assess possible spatial and temporal relationships. The four locations are the edge of a plunge pool of a perennial waterfall, a clay and gravel point bar within the main stream, a stagnant conduit, and a clay bank in a conduit with evidence of “pipe-full” conditions. The average monthly data suggest little to no temporal variation of the properties. However, further monitoring is needed to verify the temporal stability since the flow regime varied little during the sampling period. Bulk density, porosity, mass wetness, and moisture content are similar at all locations at 1.7 g/cm³, 0.5, 0.4, and 0.5 respectively except for the point bar where these properties are 1.9 g/cm³, 0.4, 0.2, and 0.4 respectively. The percent saturation is over 90% at all locations. However, the main stream has a standard deviation of 7.71% compared to <2.4% at other locations. The difference probably represents a larger variability in flow. The percent organic carbon is spatially variable and either represents the ability of the karst water to redistribute the sediment or the deposition of large volumes of plant debris. The point bar has the lowest organic carbon at 1.52% which is in agreement with previous work on cave sediments that say that the organic carbon content is around 1%. The stagnant conduit, waterfall, and “pipe-full” conduit have organic carbon contents of 2.73%, 3.51%, and 4.71% respectively. The data show that sediment properties are spatially variable in the cave environment but may be temporally stable. Further sediment work is needed in other cave systems to determine if any properties can be globally applied and which must be taken on a case by case basis. This work suggests, in comparison to other work, that the percent organic carbon may have to be taken on a case by case basis. The variability is probably due to differences in flow regime and/or differences in the amount of plant debris carried into the cave.