Colombia is a tapestry of snow-capped mountain ranges, peaks soaring to 5700m, volcanoes (15 of them active), tropical jungle with the myriad life-forms it supports, cascading rivers, and lazy rivers that in the east meander across the broad Orinoco and the northern edge of Amazonia. The tapestry has a few rents and many tears wrought by insurgence and drug wars, but Colombians it seems are a pretty resilient bunch and the prospect of peace is edging nearer.
Visitors at Rio Calderas
Ancient rivers through older rocks
The Andean mountains in Colombia are a continuation of the chain that extends from Patagonia. A broad view of their formation, in a plate tectonic context is included in an earlier post.
These large drainage systems are very old. Geological studies indicate that the ancestral Magdalena Valley may be as old as 26 million years, corresponding to the period when the Cordillera Oriental began to rise (this is also about the time that the Amazon drainage system, as we know it now, began to form). Geologists don’t know the age of our three rivers, but their ancestral drainage could also date back several million years. Testaments to this are the deep and steep-sided valleys through which they flow. The drainage basins, ancient as they are, can be related back to the plate tectonic events and processes that gave rise to the oceans and South American continent
Boulder cascades
The geological backbone of Cordillera Central consists of very old metamorphic rocks (200 million years and more) and younger granite-like rocks. The three rivers on this journey run mostly over and through granite, a rock commonly consisting of large quartz and feldspar crystals; hence its white to pinkish colour. Quartz crystals are usually clear and glassy whereas feldspar
The final two days were dedicated to Rio Samana that by now has gathered water from Calderas, Verde, and many smaller tributaries. It has Class 4/4+ (depending on water levels) that take you through cascades and standing waves. The take-out, after a 40km run from Rio Verde, is near the small village of Narisse, that as the image below suggests is definitely worth the visit.
Postscript
Colombia, from all accounts is a beautiful country – people, scenery, culture. At the time this item was posted, the peace process was thankfully still alive.
Jules now runs a raft-guiding and kayaking company out of Medellin. Check it out if you are heading in that direction.
Also, check out Sam’s SeaToSkyWhitewater image gallery.
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