Geologic time is divided into units based upon types

Organisms

Explanation:

When we speak of geological time, we refer to a time scale that is usually measured in millions or even billions of years, such as the classification of geological ages and their respective periods. Geological time is a scale obtained from the relative dating of the rocks, either by observing the marks of the events recorded in them, either by the order of superposition of the sedimentary layers or by the fossils they contain, or even by the absolute dating of the rocks, through calculating the rate of disintegration of a radioactive isotope. Radiometric dating of rocks from the Moon and meteorites gave an approximate age of the planet Earth in 4.5 billion years.  In addition, geological time is divided into units based on the types of organisms.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

answer: accepted answer: aquatic animals use the oxygen dissolved in water to carry out respiration. since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore the rate of breathing in aquatic animals is much faster than it is in terrestrial animals.

explanation: