Embedded Files
Geologic time refers to the billions of years since the Earth's formation. Geologists are scientists who study the structure and history of the Earth. Geology is the name of their field of study. Geologists examine rocks and fossils, which are the remains of living organisms preserved in the earth. It spans Earth's entire history and is divided into four major parts. The geologic timescale is split into eons, eras, periods, epochs, and ages, with eons being the longest and ages being the shortest time divisions. Formal geologic time begins with the Archean Eon (4.0 billion to 2.5 billion years ago) and extends to the present.
The Earth is about 4.5 billion years old, a number too large for people to conceptualize. If we were to shrink the Earth down to the size of a basketball and compress those 4.5 billion years into a few hours we would be able to observe radical changes. Continents would race around the globe, sink beneath the sea, rise up again, smash into other continents, build mountains, and erode back into the sea. Volcanoes would continually erupt and then quickly be weathered away. An astounding array of life would evolve and most of it would pass into extinction seconds later. Asteroids would occasionally slam into Earth. Indeed, the Earth would look like an extraordinarily dynamic little sphere before us.
From our reference point, change of this magnitude is hard to appreciate. Yet if we begin to grasp the immensity of geologic time, we can begin to recognize the changing nature of Earth.
Page updated
Google Sites
Report abuse