Steptoe Butte explanatory sign
400 million years of geography explained, for that is the age of the quartzite comprising Steptoe Butte. By contrast, the oldest rocks on Earth are more than 4 billion years old. If 4 billion years makes 400 million year old quartzite seem young, then remember that the Pangaea supercontinent only formed 300 million years ago, and that North America only began to look similar as it does now 200 million years ago.
Steptoe Butte explanatory sign
400 million years of geography explained, for that is the age of the quartzite comprising Steptoe Butte. By contrast, the oldest rocks on Earth are more than 4 billion years old. If 4 billion years makes 400 million year old quartzite seem young, then remember that the Pangaea supercontinent only formed 300 million years ago, and that North America only began to look similar as it does now 200 million years ago.