Primary sublimates at Parícutin volcano

The first lava flow of Parícutin Volcano, which began within two days of the birth of the Volcano, was particularly rich in fumaroles. With each succeeding flow the fumaroles decreased in abundance, the later flows showing very few. The fumaroles of the first flow were concentrated about the periphery of the lava and persisted for more than a year, when they were covered by later lava flows. From the odor of their gases and the character of the salts about their orifices, it was obvious that they were of two different types.