AMCS Bulletin 19 / SMES Boletín 7 — 2006

171

Lava Tubes of the Naolinco Lava Flow, El Volcancillo, Veracruz, México
Guillermo Gassós1 and Ramón Espinasa-Pereña2
2 1 Club de Exploraciones de México, Sección Veracruz, A.C. Sociedad Mexicana de Exploraciones Subterráneas A.C., ramone@cablevision.net.mx

Six caves up to nearly a kilometer long have been discovered on the Naolinco lava flow, which was emmited by El Volcancillo 870 years ago and reached a length of about 50 kilometers. All of the caves seem to be remains of a master tube which probably fed most of the lavas that form the flow. Of particular interest is the fact that at least two of the caves capture and carry surface streams of considerable size. The water

Abstract …ver más…

The whole of the Río Naolinco lavas were fed through lava tubes, as evidenced by numerous primary inflation structures such as tumuli, pressure ridges, inflation
Figure 2. Map of Cueva del Arco.

Naolinco lava flow

AMCS Bulletin 19 / SMES Boletín 7 — 2006

173

Figure 4. Plan map of Cueva del Volcancillo.

clefts and ropy textures throughout. After 15 kilometers and a steep fall near the town of Tlacolulan, the lavas entered the deep valley of the Naolinco River and followed it for nearly 35 kilometers. The lava flow ends at a narrow canyon west of the town of Chicuasen at an altitude of 360 meters, immediately beyond the popular Descabezadero Cascades, the birthplace of the Actopan River, which comes out at the contact of the lava flow with underlying conglomerates. With over 50 kilometers in length, it is one of the longest lava flows recognized in México. To date, 6 different caves have been discovered on this lava flow, but not all have been surveyed properly, or even completely explored. They are possibly all part of what must have been a large master tube which probably fed most of the lava. Undoubtedly, many more caves probably exist and await discovery, exploration and mapping. The known caves will be described downflow: Cueva de El Volcancillo: This cave is located right at the north side of the west crater. It is a tube segment 685