Question

Question 3. a) Write the geological times with its colours and symbols
b) What are the meanings of geological times, give some examples, and explain
why it is important to know geological times.

Answer 1

1)

2) The geological time (GTS) divides and chronicles earth’s evolutionary history into various periods from the starting to the present time based on definite events that made a major change in earth’s physical, chemical and biological features. For example:

a) Ordovician period : It Spans from 485 million years to 440 million years ago. Many species still prevalent today such as primitive fish, corals, etc. The most common forms of life, however, were trilobites, snails and shellfish. By the end of the Ordovician, Gondwana portion had moved from the equator to the South Pole result in glaciation . This glaciation caused a snowball Earth, leading to the Ordovician-Silurian extinction (First Mass Extinction)

b) Silurian Period : It ranges from 440 million years to 415 million years ago.It saw warming from Snowball Earth. This period saw the mass evolution of fish. Fully terrestrial life evolved, which included fungi, and centipedes.

c) Cambrian Period: It Spans from 541 to 485 million years ago. The period marked a rapid expansion in an event known as the Cambrian Explosion during which the greatest number of creatures evolved in a single period in the Earth's history. Plants like algae evolved, and arthropods dominated the fauna and almost all marine phyla evolved in this period.

Importance- The geologic time scale is an important tool used to understand the history of the Earth. This scale provides a standard timeline to describe the age of rocks and fossils, the associated fauna among other  and the events that formed them.Time is a very important variable in geology, because the exact timing of spatially separated events allows us to reconstruct the surface and surface conditions of the ancient earth.It opens the doorway to align the geologic phenomenon in a well structured way and it helps in unfolding the present mystery using the past events and to understand the responsible activities for this continual change in earth.