Final answer:
The oldest known rocks and minerals on Earth, like the Jack Hills zircons from Australia, date back nearly 4.4 billion years.
Step-by-step explanation:
The oldest rocks on Earth have been found in various locations around the world, including Greenland, Australia, and Swaziland. However, as of 2014, the Jack Hills zircons from Australia hold the title for the oldest known minerals, dated at nearly 4.4 billion years old using uranium-lead dating. This pushes the minimum age of the Earth a bit further back as the planet is older than any rocks found within its crust.
The Acasta Gneiss in the Northwest Territory, Canada is another example of ancient Earth rocks, at about 3.96 billion years old. Earth scientists have used various forms of radiometric dating, such as potassium-argon (K-40 decays to Ar-40) and rubidium-strontium (Rb-87 decays to Sr-87), to determine the age of rocks and estimate the lower limit for the Earth's age.
Since the Earth cannot be older than the solar system, the oldest possible age of the Earth is 4.57 billion years old, which is the age of the solar system.
The study of the geologic time scale provides insight into Earth's history, highlighting when both geologic and biological events occurred, such as the appearance of stromatolites, indicating that life had developed by 3.5 billion years ago. Notably, many of the early rocks have not survived due to geological activity, and it is challenging to uncover rocks that formed during the earliest periods of Earth's history.