Why are some units of the geologic time scale longer, and some are shorter?

dam your mom lookin' so fine

Explanation:

The geologic time scale is divided into several different units. There are eon, era, period, epoch. They all have different lengths, and some are very long, while some are much shorter. The eon is the longest of them all spending for over half a billion years, or even more than a billion. The era stretches for few hundreds of millions of years. The period lasts for tens of millions of years, while the epoch is stretching for several millions of years. The reason why they are with different lengths is that they are marked by certain important events in the past. Some are marked by significant changes in the climate, some by extinction of species, some by big disasters, some by changes on the surface of the Earth, some by the changes of the atmosphere.

it will be bbb bbb bbb bbb bbb bbb bbb bbb

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 !