Having a wavelength shorter than that of the violet end of the visible spectrum but longer than that of the x rays
C. Please hand me the big,blue notebook
Answer;
The Huronian Supergroup <span>is </span>particularly<span> exciting and </span>interesting<span> because, by chance, these </span>rocks<span> were laid down at a period when the atmosphere underwent a transition from containing no free oxygen to containing at least some free oxygen.”
</span> Explanation;
The Huronian
Supergroup, a massive
formation of rock laid down
gradually between about
2.5 billion and 2.2 billion
years ago, precisely the
period when oxygen
began to accumulate in the
atmosphere. The Huronian Supergroup is 10 or 11
kilometers (six or seven
miles) thick and extends well below ground
