Monday, October 25, 2010

a brief geologic history of time (or really of kayaking in the Andes)

(Typical Basalt formations that we encounter on the Rivers here in Ecuador. This particular formation is just below El Torro Rapid in the El Chaco Section of the Rio Quijos)

So, rather than letting this blog just continue down the path of eye candy and kayaking porn, I've decided to infuse a little substance into it this season (sorry, I know some of you won't like that, but it's got to be done for your sake and mine)!

The 2010 and 2011 Kayaking Season in Ecuador is also going to be the Season of the History of Ecuador from a Kayaker's Perspective (uh, really it’s just from my perspective).

Seeing as I have a masters degree in history and all I thought I'd at least try to use it a little bit!

I know history can sometimes get boring, so I'll try to keep it to interesting-as-possible topics; and hopefully things that are at least somewhat relevant to kayakers.

Don't worry, there will still be trip reports and plenty of kayaking photos (Tarquino just bought a nice camera so we might actually have quality photos this year) but there will also be little interesting tid-bits about Ecuador's history throughout each blog.

To start, I thought I'd look for a topic which all kayakers could appreciate--The Andean Event--AKA the history of the rivers we paddle in Ecuador! This basically involves some plates colliding into each other with a massive force, pushing a lot of material upwards and creating some serious topographical relief.

(Dude! If this is not serious topographical relief, I don't know what is)

To be more specific, this all took place during the late Miocene and early Pliocene ages (about 5 to 7 million years ago depending on how you do the math). Obviously, there was tons of geological formation happening well before this; but the landscape we kayak in today was more or less formed during this era.

The "Andean Event," as described by Kennerley (a geologist dude who wrote on Ecuador for the purpose of oil exploration), "caused a differential vertical movement in the Sierra and folding and thrusting of the Sub Andean Zone in the Oriente."

So what? You might ask.

This uplift and folding and thrusting created what we now call the Cordieralla Real."
And it is in this Cordieralla Real that we find real good kayaking!

Our lodge, near the town of Borja sits in the region between the Cordieralla Real and the Oriente Basin. We are right in the zone of massive “faulting and folding” which I’m pretty sure in kayaker-speak means we are right in the zone of amazing kayaking because was have perfect gradient, tons of different valleys (and therefore rivers), and rugged, incredible topography as a back drop to all this marvelous whitewater.

Because most of the geological investigations were carried out by oil companies, and because they weren’t too interested in oil in Borja (they were very interested in areas near Borja, but, fortunately for us, they didn’t think that Quijos Valley had much petroleum potential), very little studies have been done about the actual rocks we kayak through—I can tell you firsthand, though, that basalt abounds, which makes sense since volcanoes were an integral part of geological formation in the Andes.

(Volcano Antisana, one of the creators of the Basalt, AND headwaters of the Rio Quijos)

Before the volcanic activity, geologists believe that many “red beds” were laid down creating shales, sandstones, limestones and conglomerates. So, our deeper layers are sedimentary rocks, while the upper layers seem to be Extrusive Igneous Rocks mainly (Basalt)—take this all with a grain of salt since I’m just an arm chair geologist. But, anyhow, these red beds are important to the oil people because R.B’s usually contain reservoirs of petroleum which is what attracted oil people/geologists to this area in the first place.

(when you don't have Basalt, you mostly have Granite--which is really good for boofing)

After a few comings and goings of the ocean—laying down more sedimentary rock, all of this was later capped by lavas during various volcanic events—and now we are left with some pretty amazing river canyons. Our rivers have only scratched the surface though in their journey to cut through these layers. In most of our rivers, Igneous rocks of various kinds (basalt and granite mainly) still dominate. We haven’t even begun to cut down to the underlying layers except for a few special spots.

(Here is one of the those special spots! Here, the Rio Quijos has cut through the Basalt down to the limestone layers--but this "tunnel" is super rare, cool, and special--join our Rios Escondidos trip Feb. 5th to see this spot)!

Ok, that’s it for today’s Intro to Andean Geologic History Lesson. Obviously there’s a lot I’ve left out, but I don’t want to overload us on the 1st try!


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