Discover the Andes

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by Martin Mergili

General information

Guido is an old railway station in the valley of the Río Mendoza, which is deeply incised between the Precordillera in the northeast and the Cordillera Frontal in the southwest. The bright granitic rocks are remarkable in this area. They are, in some places, sharply separated from the surrounding volcanic rocks in which the granitic magma once intruded. Granite, in principle, is considered quite resistant towards weathering. The granite in Guido, however, is intensely faulted and jointed, and surfically weathered to grit. Rock falls and debris flows occur from time to time, particularly in case of earthquakes or heavy rainfall. This is a major issue for the trans-Andean road traffic in the valley. In former times, it was also a problem for the railway traffic. A walk along the abandoned railway line provides deep insights into the field of tension between traffic, geology, and natural hazards in mountain areas.

Click into the title image to change between views of the Mendoza Valley near Guido in upstream and downstream direction.

On the rails into the past

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Head for discoveries along the old railway track!

An old railway bridge spans the Río Mendoza some kilometres upstream of Guido. It can be crossed by foot. But be careful: the swells are made of resistant quebracho wood, but can be rotten due to lacking maintenance of the abandoned bridge. Furthermore, the Río Mendoza flowing rapidly 10 m beneath represents a challenge for the sense of equilibrium because the bridge neither has a continuous bottom, nor does it have handrails. At least, one can be sure that no train will come along.

References and links

Moreiras, S.M. (2004): Landslide incidence zonation in the Rio Mendoza valley, Mendoza province, Argentina. Earth Surface Processes and Landforms 29(2): 255-266 [Access source]

Moreiras, S.M. (2005): Landslide susceptibility zonation in the Rio Mendoza valley, Argentina. Geomorphology 66(1-4): 345-357 [Access source]

Moreiras, S.M. (2005): Climatic effect of ENSO associated with landslide occurrence in the Central Andes, Mendoza province, Argentina. Landslides 2(1): 53-59 [Access source]

Moreiras, S.M. (2006): Frequency of debris flows and rockfall along the Mendoza river valley (Central Andes), Argentina: Associated risk and future scenario. Quaternary International 158(1): 110-121 [Access source]

Wikipedia article on the Transandine Railway [Access source]