Geologic time rock dating methods

Rated 4.84/5 based on 670 customer reviews

As a result, rocks that record its earliest history have not been found and probably no longer exist.

Nevertheless, there is substantial evidence that the Earth and the other bodies of the Solar System are 4.5-4.6 billion years old, and that the Milky Way Galaxy and the Universe are older still.

However, it was not until this century that nuclear age technology was developed that uses measurements of radioactivity in certain types of rocks to give us ages in numbers of years.Concealed within the rocks that make up the Earth’s crust lies evidence of over 4.5 billion years of time.The written record of human history, measured in decades and centuries, is but a blink of an eye when compared with this vast span of time.Long before scientists had developed the technology necessary to assign ages in terms of number of years before the present, they were able to develop a 'relative' geologic time scale.They had no way of knowing the ages of individual rock layers in years (radiometric dates), but they could often tell the correct sequence of their formation by using relative dating principles and fossils.

Leave a Reply