Why are time. On the geological time still not even in length they are based on the thickness of the Earth's Rock layers they are based on the type of fossils found in the Rock layers of Earth
Geological time divisions are not based solely on the thickness of rock layers or the type of fossils found in them. The division of geological time is a complex process that takes into account various factors, including but not limited to:
1. Rock layers: The thickness of rock layers can provide valuable information about the time period they represent. However, it is not the sole determinant of geological time divisions.
2. Fossils: Fossils found in rock layers help in identifying and correlating the time periods. Different organisms appeared and became extinct at different times, and the presence of specific fossils can indicate the relative age of rocks.
3. Radiometric dating: The development and advancement of radiometric dating techniques have provided a more precise understanding of the absolute ages of rocks. This method uses the decay of radioactive isotopes in minerals to determine their age.
4. Stratigraphy: The study of rock layers and their relationships is known as stratigraphy. By analyzing the sequential order and the arrangement of rock layers, scientists can develop a relative timeline of events.
5. Index fossils: Certain fossils, known as index fossils, are found only in specific time periods. These fossils are widespread and easily recognizable, allowing scientists to correlate similar-aged rocks in different regions.
6. Global events: Significant geological events, such as mass extinctions or major changes in Earth's climate, can act as markers for defining geological epochs or eras.
It is important to remember that the geological time scale is constantly refined and updated as new evidence emerges. Scientists use a combination of all these factors to create a comprehensive and accurate understanding of Earth's history and the time divisions within it.