Kamal Ghorui
Scientists working in a Canadian mine discovered something that has revolutionised the experts’ view of life underground and our planet’s history. The researchers found water trapped within fractures in ancient rocks at a depth of nearly 1.5 miles beneath the surface. According to chemical analysis, some of the water might be older than 1.5 billion years, and perhaps 2 billion years.This makes some of the water as old as multicellular life forms, forests, and many other things we know today. The finding was made at the Kidd Creek Mine, Ontario, Canada, which is among the deepest base-metal mines in the world. According to a 2013 paper published in Nature, the scientists focused their attention on analysing fluids flowing in the cracks of ancient rocks, instead of finding fossils or frozen ice crystals.Why it shocked the scientific communityWhen one thinks about ancient water, it evokes an image of glacier ice or enclosed lakes buried underground for millennia. However, the Kidd Creek case involved water that stayed in its liquid state under chemical stress conditions underground. It was located using mine tunnels dug deep into the crust. The water itself was found in cracks of ancient crystalline rock underground underneath the Canadian Shield. The underground environments are extremely stable. While surface systems get replenished constantly due to precipitation and river flows, fluid in fractures is able to stay in isolation for millions of years.The researchers noted in the Nature study that rather than being simple old water, it is water that has been isolated from the atmosphere for geological timescales.How scientists determined the age of the waterThe estimates did not involve any dating techniques but relied solely on geochemistry. Noble gases dissolved in the underground fluids were examined. Such noble gases include helium, neon, argon, and xenon. Based on the chemical fingerprints, the water was estimated to have stayed sealed underground for up to hundreds of millions to even billions of years. In another study conducted at the University of Toronto, it was found that some fluid may be more than 2 billion years old, which would mean they would be some of the oldest waters that have been taken from the earth.Meanwhile, one more study supported by NASA found this discovery exciting as it can help scientists learn more about survival on other planets such as Mars.
Researchers found liquid water nearly 2 billion years old deep below Canada. Image credit – Wikimedia
Why this water did not get used upAccording to scientists, the key lies within the geology of the Canadian Shield. This is because the water is stored in fractures in ancient rocks whose circulations are very slow. The fluids do not get mixed with surface groundwaters but remain sealed underground while undergoing reactions with minerals around them.This leads to interesting chemistry in the waters, which turn out to be salty along with gases formed due to the reactions occurring at great depths. Scientists believe that this discovery helps understand the longevity of underground water sources over time.Implications of the discovery at Kidd Creek It has completely altered the nature of debates around what is known as the “deep biosphere,” or the term used by scientists to describe microbial ecosystems residing in depths underneath Earth’s crust.Where there is an opportunity for water to remain below the surface for billions of years, it is believed that microbes can also reside in isolated areas underground without depending on solar energy as an energy source. This discovery can be extremely significant for both astrobiology and planetary sciences.NASA scientists researching Mars and other terrestrial planets have been searching for underground areas where ancient water bodies would remain safe from harsh surface climates. This discovery gives a concrete example of such an area. According to the NASA scientists, chemical energy may be generated in such regions through interactions between water and rocks, thus making microbial life possible.Earth’s ancient water trapped in its depthsResearch is still going on regarding the Kidd Creek fluids due to uncertainties in the age and origins of the fluids. Different samples may consist of water from various eras in Earth’s history. Nevertheless, the scientific community agrees that these fluids are some of the oldest liquids to have ever been found.It is intriguing for scientists due to the unexpected nature of their discovery. Rather than finding fossils of ancient life forms trapped in rocks, scientists found traces of water flowing through cracks in rocks, dating back billions of years.This is what makes Kidd Creek unique, according to many experts. The discovery showed that some parts of the Earth’s crust could be hiding an underground system that functions even when surface conditions change entirely.
