Gravel areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over of gravel roads. Both sand and small gravel are also important for the manufacture of concrete. Large gravel deposits are a common geological feature, being formed as a result of the weathering and erosion of rocks. The action of rivers and waves tends to pile up gravel in large accumulations. This can sometimes result in gravel becoming compacted and lithified into the sedimentary rock called conglomerate. Where natural gravel deposits are insufficient for human purposes, gravel is
Granular dogfish Granular dogfish The granular dogfish, "Centroscyllium granulatum", is a little-known, very small dogfish shark of the family Etmopteridae, endemic to the Falkland Islands. The granular dogfish has no anal fin, two dorsal spines with the second one much larger than the first, a large second dorsal fin, a long abdomen, small pectoral and pelvic fins, a large eye, prominent nostrils and spiracles, and brownish-black coloration. It is very small, growing to only 28 cm. They have only been found around the Falkland Islands in the South Atlantic. Almost nothing is known about this shark. It has been caught at around