After our explorations of the Los Perros Glacier, its moraine, and the bedrock it has scraped so deliciously clean, we headed on up the trail, towards the highest point on Torres del Paine's Grand Circuit: Paso John Gardner. Here's a look back at the valley we've been hiking up from Refugio Dickson... Note the Los Perros moraine and the edge of the lake:


First graded bed of the day. I photographed this one for the lovely scours into the underlying muddy (dark) layer:


Another turbidite clast. Is that a clastic dike on the left?


I thought this was really cool, too. It's a vein: a fracture filled in with a mineral deposit. I really like here how you can see little shreddy flakes of the mudrock (dark) peeling back and flexing in the fracture's void space (prior to being locked in place by mineral deposits):

I interpret this to indicate that the fracture opened in a transtensional fashion, with the top to the right.

A ravine revealed this blind thrust:


Can't see it? Here's an annotated version. The thrust fault below morphs into a fold further up:


A sand-dominated series of graded beds:


Annotated below. Some of the turbidites I saw were a meter thick!

...and what's up with those rotty-appearing rusty spheres? (like the one left of my boot) I saw them several places... hematite concretions? (???)

Brace yourself. Here is possibly the most spectacular boulder I've ever seen:


Annotated version below. This boulder shows a series of graded beds (sand = light colored; mud = dark colored). The direction of gradation shows us that the boulder is upside-down relative to original depositional orientation. A couple of small flame structures reinforce this interpretation. It has been gently folded into a broad anticline (remember, it's upside-down!) and there appear to be some small "parasitic folds" superimposed on the broader fold (at boulder-bottom; depositional-top). Additionally, the turbidites are cross-cut by a small fault which has offset the layers. If I could choose just one boulder to be airlifted from Patagonia to the front of the Science Building at NOVA, this would be the one I would choose.


We keep hiking. We cross several snowfields and other bouldery alluvial aprons, interspersed with fingers of forest reaching up towards the hills. Looking up at the peaks, we can see turbidite layers intensely folded. Check out the straight-limbed anticline (left) and syncline (center) on this mountainside:


Looking up ahead -- there at the left center (between the two peaks) is John Gardner Pass:


We cross through a few more stretches of forest. This one really struck me: "Creep much?"

Besides the freeze-thaw soil-shoving action of creep, I think another factor for the J-shaped (or even L-shaped) tree trunks in this forest is the thick blanket of snow they get each winter: this tamps down the whole forest in a downhill direction.

Look! On the left! Another glacier!


...Shift the perspective a bit, and something else pops out. Once the hammy glacier is off-screen, you can see the wallflower in the background: A mountain composed of pink granite rather than black turbidites.


We keep climbing. Higher up, another opportunity for gazing down the valley we have climbed. The Los Perros Glacier moraine and lake are readily distinguishable even from this distance:


Up in the snow, we trudge higher and higher, and eventually reach the Pass. But for that, and for what we saw on the other side... I'm going to make you wait for Part III.

Labels: chile, glaciation, mass wasting, patagonia, primary structures, south america, structure, travel