CLAYS IN CAVES OF THE GUADALUPE MOUNTAINS, NEW MEXICO

The origins of clay minerals in the caves of the Guadalupe Mountains, New Mexico are categorized as (1) detrital, (2) inherited from the weathering of dolostone and siltstone, and (3) authigenic. Clay minerals found in these caves include hydrated halloysite, kaolinite, dickite, illite, montmorillonite, illite-smectite mixed-layers, palygorskite, and trioctahedral smectite. The detrital clay minerals are montmorillonite, illite, dickite and kaolinite. The clay minerals inherited from the bedrock by condensation-induced weathering (in wall residues) are illite and dickite. Cave-authigenic clay minerals include hydrated halloysite (endellilte), trioctahedral smectite, montmorillonite, and probably palygorskite. Hydrated halloysite formed by the alteration of illite, montmorillonite, illite-smectite mixed-layers, kaolinite, or dickite during sulfuric acid-related speleogenesis. Trioctahedral smectite precipitated with Mg-carbonate minerals in dolomite crusts and huntite moonmilk. Montmorillonite formed in saturated ledge deposits of redistributed wall residues. Less clear is the origin of palygorskite in laminated silt and clay deposits in Carlsbad Cavern