We have seen that younger rocks are usually formed on top of older rocks . But ,as the the tectonic plates move and bump into one another , old rocks can be brought to the surface . Erosion can also wear away rocks , exposing older ones underneath them .

This means that we can sometimes find very old rocks at the surface.

4 comments

Comments (4)

Priya Sarath

Aug 06

5. Ans. The geological time scale (GTS) is a system of chronological dating that relates geological strata to time. It is used by geologists, paleontologists, and other Earth scientists to describe the timing and relationships of events that have occurred during Earth's history. Here's how the GTS correlates with other time scales:

1. Astronomical Time Scale: This is based on the movements and cycles of celestial bodies. The GTS can be correlated with astronomical time scales through processes such as orbital forcing, where variations in Earth's orbit influence climate patterns and sediment deposition.

2. Radiometric Time Scale: This involves dating rocks and minerals using the decay of radioactive isotopes. Radiometric dating provides absolute ages that can be used to calibrate the relative ages determined from the GTS.

3. Archaeological Time Scale: This time scale focuses on human history and prehistory. The archaeological time scale often overlaps with the most recent part of the GTS, particularly the Quaternary period, which includes the Pleistocene (the age of human evolution) and the Holocene (the current epoch).

4. Historical Time Scale: This scale records human events over the past few thousand years. The historical time scale is much shorter and more precise compared to the GTS. However, significant geological events like volcanic eruptions or major earthquakes can sometimes be correlated with historical records.

5. Biological/Evolutionary Time Scale: This scale tracks the evolution of life on Earth. The GTS is heavily influenced by major biological events, such as mass extinctions and the appearance of significant life forms. These events help define the boundaries between different periods, epochs, and eras in the GTS.

By integrating data from these different time scales, scientists can create a more comprehensive and accurate picture of Earth's history.

Karthikeyan A

Aug 06

Replying to

Priya Sarath

Aug 03

1. What is the most important in geological time scale?

2. How have major events in Earth's history shaped the geological time scale?

3. What criteria are used to differentiate between different eons, eras, periods, epochs and ages?

4. How does the geological time scale help us understand Earth's evolutionary history?

5. How does the geological time scale correlate with other time scales (Eg: human history, climatic records)?

Edited

Karthikeyan A

Aug 05

Replying to

Most of the boundaries on the geological time scale correspond to the origination or extinction of particular kinds of fossils.
How is the Geological Time Scale organized? The GTS is organized into hierarchical divisions of time called eons, eras, periods, epochs, and ages. These divisions are based on significant geological and biological changes that occurred during Earth's history.
Flexi Says: Eons, eras, periods, and epochs are units of geological time distinguished by their duration and the significant geological or life events that occurred during them.
The geologic time scale divides up the history of the earth based on life-forms that have existed during specific times since the creation of the planet.
Idk i also search it at google but their was no answer

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