Once you’ve seen the magnificent peaks of Chile’s premier national park, you will always recognize them in photos. In this post, I provide photos and descriptions of hikes, and explain a little of the geologic history that is responsible for these remarkable landscapes.
After returning to Punta Arenas from Antarctica, we took a bus to Puerto Natales, gateway to Torres del Paine. Because we only had 4 full days, we decided to do day trips from Puerto Natales—two were to Torres del Paine.
This view of Torres del Paine is looking to the northwest as we approached the park entrance. The prominent dark mountain in the foreground obscures some of the granite massif (light-colored rock) behind it, but the iconic parts are clearly visible. To the left are Los Cuernos (the horns) del Paine and to the right are Las Torres (the towers) del Paine. The dark mountain on the left side of the photo is another thick pile of sedimentary rock called Paine Grande. I’ll explain more about these two rock types—sedimentary and igneous—below.The most popular hike is the “W” circuit (light blue line) that extends along the west, south and east sides of the massif (white area with snow). The Francés Valley (center leg of the “W”) separates Paine Grande from Los Cuernos. Jay and I did the “W” circuit when we were in Patagonia in 2006. A longer circuit is the “O”, which includes the “W” circuit and connects the two ends of the “W” around the north side of the massif. This map is from Las Torres Patagonia company that will make accommodation and other arrangements for tourists: https://lastorres.com/en/.
From Puerto Natales we entered the park from the east. On our first day we entered through the Lago Sarmiento Park Entrance and drove west to Cuernos Mirador, which is located on the south side of the lake right across from the refugio labeled Cuernos. On the second day we entered through the Laguna Amargo Park Entrance and drove to the Welcome Center where we parked and then walked west, along the north side of the lake, from Hotel Las Torres.
Mirador Cuernos
A view of Los Cuernos along the path toward Mirador Cuernos (for location, see map at top of the page).Here is our hiking team at Mirador Cuernos, located right across the lake from Los Cuernos. The peaks were named “cuernos” because the black sediments on the top look like horns on the granite. The day was rainy and cloudy, but clouds parted enough to give us fleeting views. After we returned from Antarctica, our San Francisco friends Anita and Ralf continued with us to hike in Patagonia.
Las Torres
See photo at top of page for position of Las Torres, shown in this photo. The towers are a favorite for climbers. At 51° south latitude, it is the world’s southernmost climbing area outside of Antarctica. Las Torres are not capped by black sediment like Los Cuernos, but a large pile of sediments surround the granite spires—notice how the sediments wrap around the granite on the right side of the photo. I’ll explain this relationship below.
The geologic processes that created the landscape of Torres del Paine
Deep-marine basin. During the Jurassic Period about 150 million years ago, as Pangea began to break apart, an oceanic rift basin formed in what is now southern Patagonia. The continually-subsiding basin accumulated a 3-km (1.8-mile) thick sequence of mud-rich sediments.
Here is a closer view of the stack of sedimentary mudstone. The layers are accumulations of mud that settled from suspension and thin layers of fine sandstone that resulted from turbidity flows generated by submarine landslides. The sediments are small because they were deposited in a low-energy environment far from land.
Change from extension to compression. During the Cretaceous Period, around 100 million years ago, plate interactions caused a gradual change from extension to compression. In other words, plates evolved from moving away from each other (creating extension) to moving toward each other (creating compression). Eventually the area evolved from a basin to an uplifted mountain range but in the meantime there was another important event.
This is a southward view along our second day of hiking in Torres del Paine when we walked west from Hotel Las Torres (see map above). The sedimentary rocks on the south side of the lake are tilted into folds—the most prominent fold is a bowl shape with layers tilting in toward the center of the fold that is called a syncline. There are many folds and faults throughout the park that formed because of compression. These are the structures that lifted the land up out of the sea.
Intrusion of granite. During the Miocene Epoch about 12 million years ago, subduction-related small granite plutons intruded into the sedimentary rocks. These intrusions were not large plutons like the Sierra Nevada in California, but small plutons called laccoliths because of their mushroom-like shape with a flat bottom and domed top.
This west–east profile across the Torres del Paine massif shows how the granitic laccolith intrusion formed. See map and top photo for orientation. Lago Grey on the west side of the map is a valley because of a fault that lifted the sedimentary rocks of Cerro Paine upward relative to the sediments on the east side of the fault. The granitic magma (liquid rock—dotted pattern highlighted in orange on profile) used the fault to flow upward. It then found a zone of weakness within the sedimentary layers and forced its way sideways.
Los Cuernos have horns because there are bits of sedimentary rock on top of the granite towers. In contrast, all of the sedimentary rock on top of Las Torres has been eroded away. The granite did not extend farther east from the towers, as shown in the figure above and in the photo of Las Torres. Figure is from an article in the Chilean Journal of Geology: https://www.scielo.cl/scielo.php?pid=S0716-02082003000100005&script=sci_arttext&tlng=pt.
Glacial erosion. Since Earth entered an Ice Age several million years ago, glaciers have been advancing and retreating during glacial and interglacial periods. Since we are currently in an interglacial period, glaciers are smaller than they were 18,000 years ago when our planet was at the zenith of a glacial period. The effects of the last glaciation are easy to see at Torres del Paine.
These photos are closeups of Las Torres taken when Jay and I did the hike up the east side of the “W” circuit in 2006. Left-side photo: The lake is in a cirque basin, which is a depression formerly occupied by a glacier. The towers themselves form an arête—a narrow knife-edge ridge of rock that forms between two valleys as a result of glacial erosion. The rock face between the cirque lake and the arête ridge is a result of glacial ice sliding over the rock and eroding it into a smooth surface. The large boulders in the foreground are part of the moraine, a pile of rocks eroded from the mountains, carried downslope by the glacier, and dumped as a sediment ridge when the ice retreats.
Right-side photo: View across the terminal moraine that connects with the moraine in the left-side photo. Note person for scale. Ice is the only substance sufficiently viscous to carry boulders this large. Because the rocks are carried in the ice they do not get sorted into different sizes or rounded as they do when carried in liquid water.
I hope you can see many features in the photos above that were formed by glacial erosion. Erosion affects different rock types differently. The sedimentary mudstone is soft and weak relative to the granite that is hard and strong. This is why the granite forms the highest peaks and the sedimentary rocks are found mostly in the valleys. The dark sedimentary rocks that form the “horns” of Los Cuernos are remnants that have not yet been completely eroded away.
Other photos in the region
I took this photo along our route as we were heading northwest toward the park entrance. The view is toward the south. The vivid rainbow was one benefit of the rain and clouds we experienced that day.Herds of guanacos are common sights in the region. Guanacos are one of four species of camelids found in South America. The other three species are llamas, alpacas, and vicuñas. Although llamas and alpacas have been domesticated, guanacos and vicuñas remain wild.
My next post will be about Puerto Natales, gateway to Parque Nacional Torres del Paine.
Fabulous. Send more pics and descriptions of the geology. I’m headed there in November and am reading in preparation. But photos tell best story.
Kathleen
So good to hear from you Ali! I was thinking of you during our days in Torres del Paine and remembering meeting you at a refugio! I also thought of you when we were in Santiago. So glad we’ve stayed in touch over the past 20 years!
Fabulous. Send more pics and descriptions of the geology. I’m headed there in November and am reading in preparation. But photos tell best story.
Kathleen
That’s awesome Kathleen! I’ll send you an email with more info.
It’s always good to read about Torres del Paine, the place where we met 20 years ago! Thanks for the geological explanation!
So good to hear from you Ali! I was thinking of you during our days in Torres del Paine and remembering meeting you at a refugio! I also thought of you when we were in Santiago. So glad we’ve stayed in touch over the past 20 years!