World’s Oldest Rocks.
Recently, my husband and I were attempting to calculate how old the world’s oldest rock would be according to the earth’s development timeline. Of course, we were handling our inquiry in the best non-scientific manner (sheer guesswork), and came up with a time period relatively close to what Wikipedia has to say on the matter. Wiki dates the oldest rocks in the world to the Hadean Eon (Hadean comes from the Greek root “hades” to indicate the “hellish” conditions of earth during this time period). The Hadean Eon is listed as lasting from 4540 million years ago to 4000 million years ago, and scientists believe the age of the rocks themselves is 2.5 and 3.8 billion years (doesn’t seem to line up exactly, does it). These rocks can be found in very few places anymore, but some remaining deposits have been found in Australia, Africa, and the far north of North America.
Now, the general scientific consensus is that the age of the earth is 4.54 billion years old. Whew! So how old are these newly discovered, ancient crystals? They are 4.4 billion years old! How can this be? Even with the release of these findings, some people are still skeptical. The scientific community pretty much agrees that at that age, the earth was a big massive heaving fiery ball of heat and magma. Supposedly, this is even before the earth’s own core was created! So how did these crystals form? Hopefully, scientists will be able to give us more answers as the studies continue.
In the meantime, here’s what we know. The ancient crystals are of zircon. They are so small that you cannot see them with the naked eye. They were found in a field in Western Australia, within a rock that was part of a beach three billion years ago. Yes, the scientists were studying a three billion year old rock, and found within 4.4 billion year old zircon crystals! I’m still amazed.
Some skeptics tried to say the study was false because lead atoms – how these particular scientists were measuring the age of rocks – move around too much to give an accurate picture of age. However, the scientific team went one further, creating a new test that would track the lead atoms more specifically to get an even more precise picture of the zircon’s age… and what did they come up with? They came up with 4.374 billion years, plus or minus 6 million years. Wow!
But don’t take our word for it. Read the article about the world’s oldest rock for yourself here. It’s got a great timeline in the left margin, check it out!.