No, that is not an image from a 1960s era science fiction movie…
The Naica Mine in Chihuahua, Mexico is an active lead, zinc and silver mine. In the year 2000, while tunnelling under a mountain for lead, the mining company discovered a huge cavern 300m beneath the surface– a cave a football field in size, two stories high and filled with huge selenite crystals. The crystals in the cave are truly massive. Although related to the grade school crystal growing projects many of us have done, there is a distinct difference of scale. Some of the crystals in the cave are as long as telephone poles and weigh over 45 tonnes! It was a 500 000-year submersion in scalding mineral-rich water that allowed the crystals in the Crystal Cave to grow this way. Other caves in the region, such as the Queen’s Eye cave and the Cave of Sails show smaller crystal structures, because they were not submerged as long, or because submergence has been intermittent. For now, the caverns and the mines are kept clear of water by the mining company which keeps pumps running 24 hours a day, removing over 60 000 litres per minute.
In 2006, The Naica Project was initiated to preserve, explore and document the caves as well as to raise public awareness. In 2008 explorers in the cave found a small passage that indicated that there might be more interconnecting chambers. The possibility of this was confirmed in 2009, when the mining company bored a 600m ventilation shaft down into the earth. The shaft, called the Robin Hole, was filmed with a camera mounted on the drill bit. The image seemed to reveal more large crystals at about the 150 m deep level. Was this part of a possible Great Crystal Cave complex?
In 2009, National Geographic sponsored an expedition to the Cueva de Los Cristales. This was possibly the last expedition before the mining company turned the pumps off, allowing the caves to flood once more. There were two teams – the first was to do research within the Crystal Cave and to explore the possibility of entering more chambers. The second team was going to descend the ventilation shaft to find out if another cave had been revealed.
The research team consisted of astro-biologists and virologists that wanted to extract water and mineral samples from the cave to see if they could discover any organisms that could survive in the harsh conditions of the caves. Almost any task in the 45° – 50° C heat and 90 percent humidity was not only dangerous to the people; it played havoc with any equipment. The Naica Project had developed specialized cooling suits and respirators, but they were bulky and they still only provided for a 45-minute window to explore the cave before the conditions became deadly. Electronics would fail or became extremely unreliable. A cooling tent, called “The Ice Cube” was set-up as a refuge deeper within the cave, but even it had difficulty keeping temperatures moderate enough to cool the human body. Time spent in the cave had to be strictly monitored so as not to endanger lives. In bulky suits and respirators, it was no easy task to collect samples while still paying strict attention to proper technique to avoid contamination.
What was the team expecting to find in the water samples? In the extreme, volcanic heat of this subterranean world, the biologists were looking for clues of bacteria and viruses that could survive in these conditions. These forms of life are called ‘extremophiles’, microbes that could provide clues on the formation of life on earth. For astro-biologists like Dr Penelope Boston they could indicate where and how to begin to look for life when exploring extra-terrestrial locations. For virologist Dr Curtis Suttle, and his team from UBC, the goal is to find clues of ancient viruses, locked in the crystals and the rocks of this half-million year-old cave.
On the surface of the desert, the second team was taking a different approach. Mark Beverly and his team rigged up equipment that would allow them to descend safely into the 600 m ventilation shaft. The cave to be examined is 150 m down. Once more, the danger level is high. Mark descends to discover that there is indeed a cave, but it is small and the crystals are not so imposing. Some are hair like, while others are like cauliflower or coral-like in appearance. In the far end of the cave, there is a narrow tunnel from which comes a continuous blast of heat. They explore further, but they must eventually retreat due to the heat and return to the cool ventilation shaft. They have failed to determine if this new cave links to the Crystal Cave.
And the team in the Crystal Cave? You will have to see the documentary to learn what they discovered. With this expedition complete, the mines may be returned to their former state, with the pumps turned off and the scalding water allowed to re-enter the mountain. The crystals may continue growing, and perhaps the wonder of the Crystal caverns might be seen again by a future generation.
I enjoyed this production, linking the adventure of exploration with science and discovery. At times, the danger level is exaggerated, for instance, when Mark Beverly is descending the ventilation shaft and the commentator explains that if the winch fails, Mark will fall 600m to his death. Of course, any one touted as a climbing expert will have a second safety rope attached (which seems to be visible in the video), so this is not necessarily a possibility. The commentator also says, when once more emphasising the danger, that there is…“…no way of knowing if he is trapped or even killed”. Of course there is a way, even several ways to determine this, so why make these overly dramatic statements? I think it is important that NGC create narrative for their documentaries that are not unnecessarily sensationalistic. The facts are fascinating enough.
Into the Lost Crystal Cave is premiering this Sunday , October 6 at 6 PM (MT) on National Geographic Channel(Check your local listings)
For more on how the crystals reach such an amazing size, see:
Juan Manuel García-Ruiz, Roberto Villasuso, Carlos Ayora, Angels Canals, and Fermín Otálora. Formation of natural gypsum megacrystals in Naica, Mexico. Geology, April, 2007, v. 35, p. 327-330, doi:10.1130/G23393A.1
(Image courtesy of National Geographic, © Speleoresearch & Films / Oscar Necoechea)