Instead , erosion ate away at it , in the form of acid leaching , and broke down much of its pumice content .
Inside Calabozos , the ash resisted welding and contains more phenocrysts .
Erosion ate away at Calabozos , in the form of acid leaching , and broke down much of Calabozos ' pumice content .
Inside Calabozos , the ash resisted welding and contains more phenocrysts .