The eternal flame at Yanartaş
The Earth naturally generates a number of components that burn when they reach the oxygen-rich atmosphere of the surface, creating eternal flames that have been recorded burning for all recorded human history. Obviously, these sites have a rich mythology, in addition to interesting geologic stories. Many eternal flames are associated with buried hydrocarbon deposits; the same rocks we use for oil and natural gas can burn if they leak upwards. However, this site in Turkey, known as Yanartaş or Mount Chimaera, is a different geologic tale. The site today is found in Olympos National Park. The term Yanartaş translates to “flaming rocks” as naturally occurring flames pop out of the ground across an area of about ½ a hectare. The flames can be seen from the surrounding terrain and they’ve been used as a navigation tool at night in historical times.
This site sits atop an ophiolite, a special geologic site where rocks that normally are found in the oceanic crust get pushed up onto continents by thrust faults. A fully in-tact ophiolite sequence would include oceanic sediments, basalts like those of the ocean floor, gabbroic rocks that formed from the magma chambers beneath mid-ocean ridges, and olivine-rich mantle rocks below them. Most of the time, ophiolites are broken up and only parts of this sequence actually are seen, because the process of bringing the ocean floor up onto a continent is a rough, violent ride for the rocks.
Many ophiolites are found at sites where 2 continents have collided; in these locations little bits of the ocean that was once in-between the continents gets stuck in the middle. Turkey is the site of continent collisions like these; there are a complicated series of thrust and strike slip faults running throughout the country as a result of the collision of Africa, Arabia, and India with the large Eurasian plate to the north.
Olivine-rich rocks like those of the mantle have a peculiar chemistry. Mantle rocks are very unstable when put at low temperatures and surrounded by water and available oxygen. They rapidly break down into minerals called serpentines and in the process give of a whole lot of energy. If there is water around, that energy can be used to cause the formation of hydrogen; if there is water and CO2, the energy can cause the formation of methane. Both of these gases will burn when they reach the planet’s surface.
The fires of Yanartaş are triggered by this chemistry. An ophiolite trapped here during the collision of these massive continents is exposed to water, weathers, and gives off methane. That methane migrates up to the surface as seeps, where it has ignited into permanently burning flames. As the seasons change and water flow rates change, the fires can change in size and vigor, but they have been here throughout human history.
Scientists have studied the process that triggers these flames in the search for the chemistry that can cause the origin of life. There is life existing today that can process hydrogen and methane into energy. Weathering of these minerals would have taken place even on the earliest earth, over 4 billion years ago. Methane and hydrogen would have been given off, possibly creating conditions where subsequent chemical reactions could eventually have created the building blocks of the first life. Similar chemistry – olivine rich rocks exposed to water – has probably occurred throughout our solar system, including on Mars, Europa, Titan, and even deep beneath the ice of Pluto. That this simple chemistry can trigger the formation of reactive gases like hydrogen and methane is an argument that life could have evolved in a number of places around the universe over time.
The ancient Greeks recorded a number of stories about these flames. This site, Mount Chimaera, was used as the inspiration for the Chimera, a 3-headed, fire-breathing dragon that was slain at this site by Bellerophon; this tale appears in Homer’s epic The Iliad. The burning tongue of the dragon continued to feed the flames at this location even after its demise.
-JBB
Image credit: http://bit.ly/2GRG4cv
References: http://wxch.nl/2oIsosR http://bit.ly/2oIsSiF https://link.springer.com/chapter/10.1007/978-3-319-14601-0_9 https://www.sciencedirect.com/science/article/pii/S0012821X11004560 https://geochemicaltransactions.springeropen.com/articles/10.1186/1467-4866-12-6 http://onlinelibrary.wiley.com/doi/10.1111/gfl.12106/full