Zelda Breath of the Wild Geology Tour: Death Mountain

The summit of Death Mountain is an unbearably hot place, a place even Calamity Ganon himself will avoid if possible. Good thing we stocked up on Fireproof Elixirs, now let’s approach the crater. Reaching the summit is no easy task due to the steep, tall walls of the volcano and the explosive eruptions which cause ash and thick lava to flow downward from the summit. Notice the lumps and crags of black, bubbly rock? Past lava flows that have solidified have now formed extrusive igneous rocks such as basalt. But the symmetrical cone shaped crater is now within reach. All our observations on the way up to the crater are clear pieces of evidence that this volcano we have summited is an example of a stratovolcano. Go ahead and peer down the other side of the volcano, but be careful, not even Daruk’s Protection can save you if you fall there. That steeper flank you are looking at drops down into a deep trench. This is where the subducting oceanic plate moves towards and meets one of Hyrule’s continental plates. This subduction zone is characteristic of volcano-forming events. As the oceanic plate slides under the continental plate, rock melts in the mantle and rises to the surface creating lava flows and eruptions. Repeated eruptions from Death Mountain have created its iconic cone shape and steep rising slopes of andesitic and basaltic rock as the magma cools to form new parts of the stratovolcano.

You can trust a Goron when he says, “Don’t play chicken with a volcano.” Surprisingly, many Hylians have done just that when they build structures near volcanoes or venture too close expecting the volcano to be tame and dormant. Igneous rock from volcanoes are prized for their function as durable building material or tool use as well as for their beauty, especially intrusive igneous rocks formed deep beneath Death Mountain that uplift to the surface from the slow movement of tectonic plates. Volcanoes give very few warnings before they erupt and extreme eruptions from volcanoes like Death Mountain can create deadly pyroclastic flows that can travel down the mountain of speeds up to 80 km/hour. This is evidenced by ancient ruined building structures near the mountain slope or rough terrain all along the slope. Of course, the eruptions from Death Mountain can be slow and gradual as seen in the images with dark, lumpy extrusive igneous rock flows that cooled halfway down the mountain. The movement of tectonic plates and the countdown until a volcano erupts can be unfathomably slow. For that reason, Goron and Hylian alike can take it for granted. But the destructive power of the moving plates can be clearly seen all around if you know what you are looking for.

As time marches on, tectonic plates and erosional processes continue to shape the land near Death Mountain. Despite the dry heat from Death Mountain, the Akkala Highlands and the Eldin Mountains near the stratovolcano receive a large amount of cool rainfall annually. This rain water seeps down into the ground and is stored in porous rock and soil. Volcanic activity and tectonic processes help to heat the water and push it to the surface as heat from nearby, underground magma chambers moves upwards towards the surface. These processes combine to form hot springs. There are a number of these hot springs near the volcano throughout the Akkala region. We Gorons swear by the healing properties of these hot springs, you will see many of us soaking in them! Even the great Daruk himself would soak his rock-hard bunions in the springs, claiming the silica and sulfur minerals from the earth mixed with the water to create healing effects, though not all scientists are in accord with this claim.

Underground magma chambers can also create some interesting features on the surface such as exposed dikes. A dike forms as magma from a magma chamber leaks outward and intrudes into the surrounding rock layers. Over time, these igneous dikes can become uplifted or exposed due to weathering and erosion of nearby softer rock. These dikes can be seen shooting up into the sky as jagged black pillars and pyramids. Other large igneous rock bodies that can become exposed onto the surface are laccoliths and batholiths. Anytime you run into a large igneous rock that looks out of place, it could be from underground volcanic activity!

Now turn around and grab your binoculars. See that deep continental trench out there? This part of Hyrule sits upon two divergent tectonic plates, or two slabs of continental crust moving away from each other. As one plate moves towards this subducting plate (and thus forming the stratovolcano we now stand upon), the other plate is moving away, and forming this continental rift zone. This whole process of plates moving towards and away from each other is driven by a fluid-like mantle layer that is in constant, circular motion deep under the crust. When plates move away from each other like this, a rift valley forms. These particular plates have been moving away from each other for a very long time, that is why the rift valley is so massive. These rift valleys are often found near volcanoes because that indicates very active tectonic plates in the area.

This rift valley, ‘The Great Rift Valley of Hyrule’, has been a major point of interest for Rito scientists who fly down into the valley to explore. Because the rift has been forming for millions of years, it is a great place to study the ancient life of Hyrule. Rito scientists have discovered a fully intact fossil of the extinct behemoth species known as “the Leviathan.” Scientists have also collected a set of bones that might lead to a common ancestor species related to the modern Lynel, except this ancestor had 3 sets of legs (instead of 2) and was much larger. The Rito researchers also believe that The Great Rift Valley of Hyrule could be used as an energy source. By tapping into the immense geothermal energy located deep inside the valley and building steam wells to harness that energy, the Rito hypothesize that this could be an extremely effective renewable energy source. The electrical energy produced could be enough energy to satisfy the needs of all citizens of Hyrule!