What percentage of the US total coal production comes from here?

According to the U.S. Energy Information Administration (EIA), in 2015 Wyoming, West Virginia, Kentucky, Illinois, and Pennsylvania produced about 639 million short tons (580 million metric tons) representing 71% of total U.S. coal production in the United States.

Explanation:

639 million short tons (580 million metric tons) representing 71% of total U.S. coal production in the United States.

Explanation:

In 2018, about 756 million short tons of coal were produced in 23 U.S. states. Surface mines were the source of 63% of total U.S. coal production and accounted for 63% of the total number of mines.

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 !