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What effects does Rocks and Rubble produced during crushing and mining have on the environment?
Rocks and rubble produced during crushing and mining
Are continental rocks or oceanic rocks older?
Continental Rocks are older
What is true about the igneous rocks produced in association with subduction zone volcanic activity?
Igneous rocks produced in association with subduction zone volcanic activity are typically andesitic in composition, reflecting the melting of both the subducting oceanic crust and the overlying mantle wedge. These rocks often exhibit a range of textures, including porphyritic and vesicular, due to the varying rates of cooling and gas release during volcanic eruptions. Additionally, subduction-related volcanic rocks are often rich in water and other volatiles, which contribute to their explosive eruption styles. The presence of these rocks is commonly associated with volcanic arcs that form parallel to oceanic trenches.
Are metamorphic rocks produced by volcanoes?
No. Igneous rocks can be produced by volcanism. Metamorphic rocks are produced by changes to existing rocks.
How much older are the oceanic rocks than the continental rocks?
Oceanic rocks are generally younger than continental rocks, with oceanic crust averaging about 200 million years old and continental crust averaging about 2.5 billion years old. This is due to the process of seafloor spreading at mid-ocean ridges, where new oceanic crust is constantly being formed and pushing older crust away.
What is the relationship between distance from the ridges and age of the crust?
At the oceanic ridges the age of igneous basalt rocks is approximately zero (as that is where they formed) and the rocks get older the farther away. The ages of sedimentary and metamorphic rocks does not correlate reliably with distance from the oceanic ridges like the ages of igneous rocks, because they can form anywhere not mainly at oceanic ridges. Igneous granite rocks are generally formed around continental volcanos not oceanic ridges.
Does continental lithosphere contain more mafic rocks than oceanic lithosphere?
No, oceanic lithosphere contains more mafic rocks compared to continental lithosphere. Oceanic lithosphere is mainly composed of basalt, which is a mafic rock, whereas continental lithosphere is composed of a variety of rock types, including granitic rocks which are more felsic in composition.
Why are oceanic plates made up of newer rocks?
Oceanic plates are made up of newer rocks primarily because they are formed at mid-ocean ridges through volcanic activity. As magma rises from the mantle and solidifies, it creates new oceanic crust. This process continuously recycles the oceanic plates; they eventually subduct into the mantle at ocean trenches, leading to the formation of new crust and ensuring that oceanic rocks are generally younger than continental rocks. Consequently, most oceanic crust is less than 200 million years old, while continental crust can be billions of years old.
What are the characteristic of the oceanic crust?
The rocks that makes up the oceanic crusts, are very dark, relatively thin and highly dense.
What was obsidian before it was obsidian?
It was liquid rock (magma) which solidified after an extrusion or eruption. Crustal rocks can re-dissolve into magma during subduction of oceanic crust.
Oceanic crust returns to the mantle at deep ocean trenches which are?
rocks
What type of earth plate is more dense?
Oceanic plates are typically more dense than continental plates. This higher density is due to the composition of oceanic plates, which contain basaltic rocks that are denser than the granitic rocks found in continental plates.
