Geologic Time

Geologic Time refers to the vast time scale used by geologists and paleontologists to describe the timing and relationships of events in Earth's history.

Half-life is the time required for half of the radioactive atoms in a sample to decay into a different element or isotope.

Stromatolites are layered structures created by the activity of microorganisms, particularly cyanobacteria, and are among the oldest evidence of life on Earth.

The appearance of fossilized organisms with hard body structures, such as shells and bones, marks the end of the Precambrian era.

The presence of iridium in rock layers dating to 66.4 million years ago, which is also found in meteorites, supports the meteorite impact theory.

In an undisturbed geological cross-section, the oldest rock layers are at the bottom, and the youngest are at the top.

The Cenozoic Era is the most recent geological era, beginning 66 million years ago, characterized by the dominance of mammals and birds.

The Mesozoic Era, often called the Age of Reptiles, is known for the dominance of dinosaurs and the emergence of mammals and birds.

The four main divisions are Eons, Eras, Periods, and Epochs.

Relative dating is a method used to determine the age of rocks and fossils in relation to one another, without determining their exact age.