The Eruption of Nevado Del Ruiz Volcano Colombia, South America, November 13, 1985 (1991) / Chapter Skim
Currently Skimming:
Appendix A Geologic Setting and Prehistoric Volcanic Activities
Appendix A Geologic Setting and Prehistoric Volcanic Activities
Pages 91-96
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 91... ...
This province forms a 45-km-wide band from the city of Manizales in the west to the foothills of the eastern front of the Central Cordillera and includes Nevado del Ruiz volcano. The second geologic province consists of a thick series of Cenozoic sedimentary rocks of the Magdalena River valley that extends east from the Mulatos fault to the Magdalena River and includes the 20-km-wide floodplain of the Magdalena River.
|
From page 92... ...
Magdalena River Valley Province The Magdalena River Valley, west of the river, includes a relatively flat plain 20-25 km wide between the Mulatos fault along the eastern foothills of Nevado del Ruiz and the north-bound river. The surficial deposits of this region are Quaternary floodplain deposits of stratified sand, silt, and gravel.
|
From page 93... ...
The main fault systems in the Nevado del Ruiz area can be summarized as follows: Caribbean Plate \ 8cm Cocos Plate //// ~ 'I ~/~ Nazca Plate ////// 5cm 1 by,: ~ RIJIZ / South America Plate FIGURE A.1 Diagrammatic map showing the tectonic setting of Nev ado del Ruiz. Bold lines are fault zones; barbed lines are subduction zones of underthrusting (barbs are on plate above thrust)
|
From page 94... ...
Over time, the violent, episodic eruptions partially destroyed the north and northeast slopes of the Nevado del Ruiz summit. A large depression at the upper Azufrado and Guali river valleys was caused by a lateral explosion corresponding to the intense eruptive activity that took place around 3100 B.P.
|
From page 95... ...
However, farther up the roadcut, three additional lahar units similar to those shown are exposed. (Photo by R
|
From page 96... ...
, who reported that the lahar deposits extend from snow line down to an elevation of 3,200 m. Older lahar deposits in the foothills near the floodplain of the Magdalena River valley were also observed by the study team.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.