The most appropriate answer would be magma. Lava is a magma that reaches the Earth's surface, which is technically it is also a magma, and magma is located below the Earth's surface.
Lava at Earth's surface or magma below Earth's surface cools and harden to form mineral crystals.
An analysis was conducted to determine the Worst Cities for Respiratory Infections to promote awareness to people concerning respiratory infections. And according to the surveys conducted, not only did the West region have the least cities on the list of the “The 50 Worst Cities for Respiratory Infections”, but the American West is ranked eight out of the top ten cities wherein physicians noted and recorded the fewest respiratory antibiotic prescriptions for each individual in that area.
Less dense then water its self
Factors increasing erosion
Coastal erosion: the strength of the waves breaking along the coastline. Bigger, stronger waves have more erosive power.
Abrasion - rocks carried along by the river wear down the river bed and banks.
Attrition - rocks being carried by the river smash together and break into smaller, smoother and rounder particles.
