Answer:
On their mode of formation
Explanation:
The classification of rocks into three major categories is strictly based on their mode of formation.
Rocks are naturally formed aggregates of minerals. Based on mode of formation, they can be classified into;
- Igneous rocks: these rocks are formed by the cooling and solidification of molten magma.
- Sedimentary rocks are formed by the compaction and lithification of sediment.
- Metamorphic rocks: these are changed rocks that have been formed by subjecting rocks to pressure and temperature conditions which causes an alteration of their minerology.
In most cases, as altitude increases, the air in the troposphere cools. Vertical mixing occurs as a result of warm air rising. However, a layer of cool air may form beneath a layer of warm air on occasion. Temperature/thermal inversion refers to this deviation from normal temperature.
When an inversion occurs, polluted areas (such as London and Donora PA) experience unhealthy air and an increase in smog because pollutants are trapped at ground level rather than circulating away.
20% of italian immigrants settled in California and one third of Italian immigrants settled in new york city
