Exploring Earth's Crust and Rock Types

The Earth's crust is composed of continental and oceanic crust, which differ in thickness and density.

Mafic rocks, common in oceanic crust, are generally defined by their high silica and potassium content.

The lithosphere is composed solely of the Earth's crust.

Earthquakes primarily initiate at the boundary between the asthenosphere and the mesosphere due to high friction.

Sedimentary rocks are formed from the accumulation and cementation of sediments at the Earth's surface.

Metamorphism is a process that always involves the complete melting of pre-existing rocks.

Igneous rocks are classified exclusively by their color, which indicates their age.

The presence of vesicles in an extrusive igneous rock indicates it cooled slowly deep within the Earth.

Foliation in metamorphic rocks results from the random alignment of minerals without a preferred orientation.

Chemical weathering involves the physical breakdown of rocks into smaller pieces without changing their chemical composition.

Mechanical weathering enhances chemical weathering by increasing the surface area of rock exposed to chemical agents.

The rate of weathering is uniform across all rock types, irrespective of their mineral composition and environmental conditions.

Erosion is the process by which weathered material is transported away from its source by agents such as wind, water, or ice.

Deposition occurs when the energy of a transporting agent decreases, causing sediments to settle out of the transporting medium.

The principle of superposition states that in an undisturbed sequence of rocks, the oldest rocks are found at the top.

Index fossils are useful for correlating rock layers because they are widespread and existed for long geological periods.

Radiometric dating uses the decay of stable isotopes to determine the absolute age of rocks.

The half-life of a radioactive isotope is the time it takes for half of the parent isotope to decay into the daughter product.

Unconformities represent periods of continuous deposition without any erosion or non-deposition.

Plate tectonics solely influences geological phenomena and has no discernible impact on biological evolution or climate patterns.