Why the oldest rocks on Earth are way older than the Earth
Discovery of Erg Chech 002
A single meteor crash landed in the Sahara in 2020 and got fragmented into tiny pieces. Erg Chech 002 is an ancient volcanic meteorite that was discovered in the Erg Chech region of the Sahara desert in Algeria. Fragments of Erg chech 002 were discovered by meteor hunters in the Sahara in 2020. Scientists believe that it was formed in the first million years of our solar system making it the most ancient thing on earth. These 4.6 billion old rocks are the oldest magmatic rocks ever discovered. With the earth being 4.54 billion years old, the rocks are way older than the big blue marble. The fascination behind these visually appealing rocks that has perhaps witnessed the creation of our planet makes them extremely rare and expensive.
The composition of the rocks
Erg Chech 002 formed just two million years after the formation of our solar system. It is an asteroidal achondrite. Achondrites are silicate rich mafic and ultra mafic igneous rocks that are not too dissimilar from those forming on earth but with slightly different chemistry and isotopic compositions. They exhibit features that would be expected if their parent bodies experienced melting. The amazement of finding the accurate age of something this old always bewilders great minds but it is possible to find the accurate times and can always be found via proven scientific techniques. The age of meteors can be found by using the isochron method i.e. radioactive age dating. The absolute age of when the surface of magmatic rocks were formed (i.e when the lava crystallized and turned solid) can be found by such methods. The earth is 4.54 billion years old and yet we cannot study rocks that were formed before 3.5 billion years. This is because plate tectonics have destroyed the earth’s crust.
Achondrites are typically 4.5 billion years old and unlike the earth their parent bodies did not experience tectonic plate movements. These rocks can give clues on how the earth was formed. Most asteroidal achondrites are basalts. Basalts are very rich in magnesium and iron, which are very similar to the rocks found on moon and Mars and had led scientists to believe that the earth’s crust was basaltic. But many recent discoveries of space rocks are not basaltic it is andesitic which is a very different composition because andesites are rich in silicon, potassium and sodium. This has given scientists reasons to believe that that the earliest of the earth’s crust was perhaps andesitic. EC 002 was studied by Jean-Alix Barrat and his colleagues at the University de Bretagne in France. Barrat and his colleagues analyzed Eerg Chech 002 using a variety of geochemical techniques and found that Eerg Chech 002 is very different than any other andesitic achondrite and that it was formed at higher temperatures. It is older than any other andesitic achondrite ever discovered making it the oldest magmatic rock ever analyzed. Erg Chech 002 belonged to a planet that was destroyed by evolution.
Where did Erg Chech come from?
Researches believed that Erg Chech 002 belonged to the crust of an ancient protoplanet that was rocky and magmatic and eventually broke up. The magma from which EC 002 was formed would have been at least 1220 degrees Celsius and would have taken at least a hundred thousand years to cool. Evidence suggests that the timing between melting and crystallization were significant due to the viscosity of the magma. It was once molten and then solidified 4.6 billion years ago. It is from an extinct chondritic (consisting of melted rocks) protoplanet. Such a planet existed during the earliest years of our solar system. This protoplanet may have become part of another larger planet or may have been smashed into dust. It definitely provides clues on how the crusts of planets were formed.
How was it discovered?
It was discovered by professional meteor hunters who brave the searing heat of the Sahara to scour the land for bounties fallen from the sky. These celestial treasure hunters sell meteorites, that are usually more valuable than gold, to an international market.
Rocks coming from Mars are usually very expensive sometimes as much as 10,000 dirhams or approximately 2700 USD per gram. And yes, Elon Musk is a collector along with many other wealthy collectors. Equipped with very strong magnets and magnifying glass, many of these hunters have gotten very lucky. Although meteorites are usually found in Morocco, Erg Chech 002 was found in the interiors of the Sahara in Algeria. Demand from meteorite dealers and specialist brokers keep all the meteorite hunters inspired and many of them are still hoping to find more fragments of Erg Chech 002.
Where are the rocks now?
Due to the scientific importance of EC 002 the largest fragment of the rock, weighing approximately 10 pounds is kept in the Maine Mineral and Gem museum. The museum in Maine contains many other ancient igneous rocks from the solar system.
Although there are 43 officially documented fragments of Erg Chech 002 many other fragments probably still exist in the ground and are unaccounted for. Some researchers think that Erg Chech 002’s protoplanet is exactly the kind of protoplanets that have provided the raw materials for growth and life in our planet. This reminded me of a quote from an iconic scene in Gattaca when Ethan Hawke was finally leaving Earth, “Of course, they say every atom in our bodies was once part of a star. Maybe I am not leaving, maybe I am going home.” So perhaps it is possible that there is a bit of Erg Chech 002 inside all of us.
