The variable x is equal to 3
For this case we have the following inequality:

The first thing we must do is to graph the linear function:

Then, we must evaluate ordered pairs in the following way:
(x, y)
The ordered pairs that meet the inequality, will be included as part of the graph.
Therefore, the shaded region contains all the ordered pairs that meet the inequality.
Answer: See attached image.
I'd say this high concentration is due to geological processes
Geological processes are things such as erosion, tectonic plate shifts, e.t.c.