Read the passage. The Oldest and Youngest Places on Earth

What is the oldest place on the earth? While the earth itself is estimated to be approximately five billion years old, most landforms are not nearly that old. Scientists debate what the oldest landform truly is, but it might be on Baffin Island. On this large northern Canadian island, which falls inside the Arctic Circle, rocks have been found that are believed to be over 4.5 billion years old. If these rocks truly are that old, then they have been around longer than the earth’s crust!

It is hard to believe that any rocks could be older than the outer surface of the earth, but their discovery in 2016 has given scientists some interesting insights about how the earth was created. As melted mantle rose to the surface and the earth’s denser elements sunk towards its center to form its core, most of the first rocks were absorbed into the earth’s inner layers. But not the rock on Baffin Island.

While there is still debate about whether Baffin Island is the oldest place on the earth, there is little question of where one of the youngest is. In December of 2014, an underwater volcano near the Pacific islands of Tonga erupted violently and continued to spurt lava and ash for over a month. When the volcano quieted, there was a new island in its place. Hunga Tonga-Hunga Ha'apai, as the island was named, was about one square mile in area and covered in black gravel.

It’s not unusual for small islands to be created by volcanoes, which erupt when the magma of the earth’s mantle breaks through the crust in the form of lava and ash. What is unusual is for those islands to remain longer than five years after they have been created. Hunga Tonga-Hunga Ha'apai was expected to dissolve back into the Pacific Ocean shortly after it was formed. But in 2020, the island was not only still around, but had developed a thriving ecosystem. From above, much of the dark gray island is now lush and green, and birds, such as owls and seagulls, make it their home. It is unknown whether the earth’s youngest island will last for long, but it has already exceeded expectations.
What do the earth’s oldest and youngest places have in common? Both were created from volcanic rock. The same type of rock that hardened and remained above ground in Baffin Island also hardened to form Hunga Tonga-Hunga Ha'apai more than four billion years later.

What is the tone of this sentence from “The Oldest and Youngest Places on Earth”?

If these rocks truly are that old, then they have been around longer than the earth’s crust!

informative
enthusiastic
humorous
formal