Geochemical data of altered volcanic ash

Geochemical data are provided for bentonites hosted in calcareous mudstones from the Eagle Ford formation in west Texas from a roadcut along old Highway 90 (29.826030,-101.623631). Geochemical data were collected using in situ laser ablation ICP-MS on bentonite billets. Data are reported as cation fraction because this method can only measure non-volatile components. Samples have variable amounts of carbonate component.