Answer: Sedimentary rocks make up 75 percent of the rocks at the earth's surface but only 5 percent of the outer 10 miles of the earth. Sediment, as distinguished from sedimentary rock, is a collective name for loose, solid particles and is generally derived from weathering and erosion of preexisting rock.
The outermost 10 kilometers of rock according to geographers has about 5% of sedimentary rocks.
The continental area of the Earth represents the Earth surface and the total land area of all continents is about 148,647,000 square kilometres.
Geographers also discovered that sedimentary rocks make up 75% of the rocks at the entire earth's surface not focusing on the outermost 10 kilometers of the Earth surface.
The reserves of oil and natural gas are formed and found in the sedimentary and igneous rocks mostly in the porous rocks as they have pores that allow for the water in small quantities to pass through them.
As the naturally occurring oil is drilled and mined from the ground in the oceans and lakes and mapping of their location is called as hydrocarbon kitchens