Top 10 Commonly Confused Words in Petrology

Top 10 Commonly Confused Words in Petrology 1. Intrusive vs. Extrusive One of the first concepts in petrology is understanding the difference between intrusive and extrusive rocks. Intrusive rocks, like granite, form beneath the Earth's surface, while extrusive rocks, such as basalt, are formed through volcanic activity. Remember, 'in' for intrusive, 'ex' for extrusive. 2. Lava vs. Magma Lava and magma are often used interchangeably, but they have distinct meanings. Magma is molten rock beneath the Earth's surface, while lava is the same material when it reaches the surface. So, magma is underground, and lava is on the ground. 3. Weathering vs. Erosion Weathering and erosion are processes that shape the Earth's surface. Weathering refers to the breakdown of rocks, while erosion involves the movement of these broken pieces. In simple terms, weathering is the 'breaking,' and erosion is the 'moving.' 4. Cleavage vs. Fracture When it comes to the texture of rocks, cleavage and fracture are two important terms. Cleavage refers to the tendency of a mineral to break along preferred planes, resulting in smooth surfaces. Fracture, on the other hand, is the irregular breakage of a mineral, resulting in rough surfaces. 5. Felsic vs. Mafic